JP7134166B2 - Curable resin composition, dry film, cured product, electronic component and printed wiring board - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act On May 24, 2017, press releases were distributed to media companies using the distribution service provided by PR TIMES Co., Ltd. On May 24, 2017, Kagaku Co., Ltd. Sent an email with the press release attached to Kogyo Nippo and Nikkei Inc. Posted on website on May 25, 2017 [Website address] http://www. taiyo-hd. co. jp/_cms/wp-content/uploads/2017/05/20170525_01. pdf

The present invention relates to a curable resin composition, dry film, cured product and electronic component. The present invention also relates to a curable resin composition, a cured product and a printed wiring board.

Electronic components include wiring boards, and active and passive components fixed to the wiring boards. Some wiring boards connect and fix active and passive components by applying conductor wiring to an insulating base material. An insulating base material is sometimes used, and it is an important electronic component in electronic equipment. Wiring boards are also used in semiconductor packages, and curable resin compositions and dry films for wiring boards are used as wiring boards and outer layers after semiconductor packaging. Active components and passive components include transistors, diodes, resistors, coils, capacitors and the like.

In recent years, with the miniaturization of electronic devices, the required characteristics of electronic components have become stricter. There has been a demand for higher wiring density in wiring boards, and low thermal expansion is required for wiring board materials in order to ensure the reliability of wiring and component connections. Active components and passive components are also required to be miniaturized and highly integrated, and similarly low thermal expansion is required to ensure reliability.

As a method of achieving low thermal expansion, for example, Patent Document 1 proposes a method of filling resin with an inorganic filler to obtain a low coefficient of thermal expansion.

In addition, as means for achieving low thermal expansion of such materials, for example, a method of reinforcing with cellulose fibers to form a fiber-reinforced composite material has been proposed (see Patent Document 2).

Furthermore, in recent years, with the miniaturization of electronic devices, electronic components are required to have low dielectric properties in order to efficiently transmit high frequencies. As a method of achieving low dielectric properties, for example, Non-Patent Document 1 proposes a method of using an epoxy resin having a dicyclopentadiene skeleton to lower the dielectric constant and dielectric loss tangent.

Furthermore, in recent years, as the performance of electronic equipment has improved, higher frequencies than before have been handled, and electronic components are required to efficiently transmit high frequencies. A characteristic of high frequencies is the skin effect. For example, Non-Patent Document 2 explains that as the frequency increases, the current passes only near the surface of the conductor.

Further, in recent years, printed wiring boards have been made lighter, thinner, and smaller in order to cope with the miniaturization and higher functionality of devices equipped with printed wiring boards. Therefore, conductor circuits on printed wiring boards are required to be further thinned and have a reduced mounting area.
On the other hand, in the method of manufacturing a printed wiring board, a resin filler is filled in recesses and through holes such as via holes and through holes provided in the wiring board, and after curing and polishing to make a smooth surface, the resin filler is added. A method of building up an insulating layer and a conductor layer on via holes or through holes filled with
Resin fillers used in such construction methods are required to be excellent in various properties such as fillability in recesses and through holes, polishing properties of cured products, and heat resistance. A flexible resin composition has been proposed.

On the other hand, in order to further increase the density, recently, a method of mounting components by providing wiring such as conductor pads and via holes on recesses and through holes such as via holes and through holes filled with a resin filler has been adopted. ing.

JP-A-2001-72834 JP 2011-001559 A JP 2015-10146 A

"Network Polymer" Vol. 17, No. 2 (1996) pp69 "Physics Education" Vol.61 No.1 (2013) pp.18-20

However, in the material described in Patent Document 1, a large amount of inorganic filler must be filled in order to obtain a desired low coefficient of thermal expansion, and there is a problem that the physical properties of the cured product such as toughness are inferior.
Furthermore, the inventors of the present invention have found that the material described in Patent Document 1 has a large coefficient of thermal expansion in a temperature range exceeding 200°C during component mounting, and is not effective for ensuring reliability. I noticed a new problem.
Therefore, the first object of the present invention is to provide a curable resin composition that can maintain a low coefficient of thermal expansion even in a high temperature range during component mounting and that can provide a cured product excellent in various properties such as toughness. be.
A first and other object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Moreover, in the material described in Patent Document 2, fibers having an average fiber diameter of 4 to 200 nm are dispersed in the matrix material, so that a composite material with low thermal expansion can be obtained.
However, in the method described in Patent Document 2, cellulose fibers are selected in order to further improve low thermal expansion properties, but on the other hand, for the purpose of miniaturization, high density, and high integration, electronic devices with a laminated structure The inventors have found that when used as a component, there is a new problem that the insulation reliability between layers deteriorates.
Therefore, the second object of the present invention is a cured product that has low thermal expansion and excellent interlayer insulation reliability even when it is used as an electronic component with a laminated structure for the purpose of miniaturization, high density, and high integration. It is to provide a curable resin composition that can obtain.
A second other object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Furthermore, in the use of high-frequency electronic components, it is important not only to have low dielectric properties, but also to be able to form high-definition circuits. In this regard, the present inventors have found that the insulating layer described in Non-Patent Document 1 can provide low dielectric properties, but does not provide adhesion strength to a high-definition circuit (plated copper).
Therefore, a third object of the present invention is to provide a curable resin composition which has low dielectric properties and which can give a cured product with good adhesion between the cured product and plated copper.
A third and other object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Furthermore, the skin effect also occurs in the wiring of electronic components, meaning that high frequencies pass through only the very surface of the wiring. Therefore, in order to efficiently transmit high frequencies, it is conceivable to smooth the interface between the wiring of the electronic component and the insulating material.
However, when such smoothing is performed, there is a problem that the adhesiveness (peel strength) between the insulating material and the plated copper forming the wiring is lowered.
On the other hand, in order to improve the adhesion of the plated copper that makes up the wiring, it is possible to roughen the surface of the insulating material at the same time as removing the smear that occurs at the bottom when the insulating material is drilled with a laser (desmear). commonly practiced.
However, such roughening causes a problem that high frequencies cannot be transmitted efficiently.
Therefore, the fourth main object of the present invention is to provide a cured product that can remove smear by laser processing in the desmear process, has a small surface roughness that is advantageous for high-frequency transmission, and has excellent peel strength. An object of the present invention is to provide a curable resin composition that can be obtained.
A fourth object of the present invention is to provide a dry film, a cured product and an electronic part using the curable resin composition.

Furthermore, certainly, according to the material described in Patent Document 2, since fibers having an average fiber diameter of 4 to 200 nm are dispersed in the matrix material, a low thermal expansion composite material can be obtained.
However, the inventors of the present invention have noticed that, in the above-described composite material, if the plated copper is formed in a solid state on the material, the plated copper will blister due to the heat history of component mounting, etc., which is a new problem. .
Therefore, the fifth main object of the present invention is to provide copper plating for the purpose of producing wiring on a cured product of a composition having low thermal expansion, and plating for the purpose of electromagnetic wave shielding in addition to wiring patterns. To provide a curable resin composition which does not cause blistering of plated copper due to heat history even when copper is formed in a solid state, and which can provide a cured product excellent in high temperature resistance.
A fifth other object of the present invention is to provide a dry film, a cured product and an electronic component using the curable resin composition.

Furthermore, in the material described in Patent Document 1, a large amount of inorganic filler must be filled in order to obtain a desired low coefficient of thermal expansion, and there is a problem that the physical properties of the cured product such as toughness are inferior.
Furthermore, the inventors of the present invention have found that the material described in Patent Document 1 has a large coefficient of thermal expansion in a temperature range exceeding 200°C during component mounting, and is not effective for ensuring reliability. I noticed a new problem.

Therefore, the sixth object of the present invention is to provide a curable resin composition that can maintain a low coefficient of thermal expansion even in a high-temperature region during component mounting, and that can provide a cured product having excellent properties such as toughness and heat resistance. to do.
A sixth object of the present invention is to provide a dry film, a cured product and an electronic part using the curable resin composition.

Furthermore, when a thermosetting resin composition such as that of Patent Document 3 is used as a resin filler for the above method used in the method for manufacturing a printed wiring board, recesses such as via holes and through holes filled with the resin filler However, there is a problem that conductor pads on through-holes and metal wiring such as via holes swell in a high-temperature heating process during component mounting, and such swell affects reliability.
In addition, the thermosetting resin composition filled in the recesses and through holes (hereinafter also simply referred to as "holes, etc.") melts and hardens when the resin component is heated. There was a problem. Since such exuded resin composition has a thin filler component, it cannot be completely removed by polishing in the next step due to its stickiness and remains, causing defects in plating.
Furthermore, in the polishing step after curing of the thermosetting resin composition filled in the recesses and through holes, it is necessary to completely remove the protruding resin filler around the holes. Another problem is that excessive polishing causes dents and does not provide a perfectly smooth surface.

Therefore, the seventh main object of the present invention is to provide a curable resin composition that can solve the above-mentioned problems. There is no bulging in recesses such as via holes and through holes, wiring such as conductor pads and via holes on through holes, and there is no exudation of the resin composition with a thin filler component during curing, and polishing after curing. An object of the present invention is to provide a curable resin composition which does not cause dents such as holes due to excessive polishing for smoothing in the process.
A seventh object of the present invention is to provide a cured product of a curable resin composition that can solve the above-mentioned problems, and a printed wiring board in which holes and the like are filled with this cured product.

As a result of intensive studies by the present inventors, fillers such as silica, calcium carbonate, barium sulfate, talc, and titanium oxide, which have been conventionally used as fillers for electronic component materials such as solder resists, interlayer insulating materials, and hole-filling materials, On the other hand, it was found that the above-mentioned problems can be unexpectedly solved by combining fine powder having at least one dimension smaller than 100 nm (hereinafter also simply referred to as "fine powder"), and the present invention is solved. came to.

That is, the curable resin composition of the first aspect of the present invention is characterized by comprising a curable resin, a fine powder having at least one dimension smaller than 100 nm, and a filler other than the fine powder. It is.

In the present invention, fine cellulose powder (hereinafter also simply referred to as "CNF") or cellulose nanocrystal particles (hereinafter simply referred to as "CNC") is preferably used as the fine powder. In addition, the blending ratio of the fine powder and the filler other than the fine powder in the total filler is preferably (filler other than the fine powder: fine powder) = 100: (0.04 to 30).

In the present invention, the curable resin comprises a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton, or a cyclic ether compound having a dicyclopentadiene skeleton and a phenolic resin having a dicyclopentadiene skeleton. or a phenoxy resin, or at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton. .

The dry film of the present invention is characterized by having a resin layer obtained by applying the curable resin composition on a film and drying the composition.

The cured product of the present invention is obtained by curing the curable resin composition or the resin layer of the dry film.

An electronic component of the present invention is characterized by comprising the cured product.

Here, in the present invention, cellulose nanocrystal particles are obtained by hydrolyzing a cellulose raw material with a high-concentration mineral acid (hydrochloric acid, sulfuric acid, hydrobromic acid, etc.) to remove the non-crystalline portion and isolate only the crystalline portion. It is. Specifically, non-crystal obtained by hydrolyzing with a strong acid of 7 wt% or more, preferably 9 wt% or more, more preferably a strong acid such as sulfuric acid that can be easily concentrated at a concentration of 60 wt% or more. It is a crystal that contains no moieties.

In addition, as a result of intensive studies aimed at solving the above problems, the present inventors found that as a filling material for recesses and through holes such as via holes and through holes in printed wiring boards, fine powder with at least one dimension smaller than 100 nm and thermosetting The present inventors have newly found that the above problems can be solved by using a curable resin composition in which the components are dispersed, and have completed the present invention.

A curable resin composition according to a second aspect of the present invention is a curable resin composition for filling at least one of recesses and through holes of a printed wiring board, comprising: (A) at least one dimension smaller than 100 nm; It is characterized by containing fine powder and (B) a thermosetting component.

The curable resin composition of the present invention preferably contains a cyclic ether compound having an amine as a precursor as (B) a thermosetting component, and also contains a bisphenol A type epoxy resin and a bisphenol F type epoxy resin. is preferred.

The curable resin composition of the present invention preferably contains (C) a borate ester compound.

The curable composition of the present invention preferably contains (D) a filler other than the (A) fine powder.

The cured product of the present invention is obtained by curing the curable resin composition.

The printed wiring board of the present invention is characterized in that at least one of the concave portion and the through hole of the printed wiring board is filled with the curable resin composition.

Here, in the present invention, the fine powder is not particularly limited in shape, and may be fibrous, scaly, granular, or the like. It means smaller than 100 nm in any one, two or three dimensions. For example, in the case of fibrous fine powder, the two dimensions are smaller than 100 nm, and the remaining one dimension is spread, and in the case of scale-like fine powder, one side is smaller than 100 nm and remains. Examples thereof include those having a two-dimensional spread, and in the case of granular fine powders, examples thereof include those smaller than 100 nm in all three dimensions.
Further, in the present invention, the one-dimensional, two-dimensional and three-dimensional sizes of the fine powder are determined by examining the fine powder by SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), or It can be observed and measured with an AFM (Atomic Force Microscope) or the like.
For example, in the case of scale-like fine powder, the average value of the thickness, which is the smallest one dimension, is measured and this average thickness is made smaller than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, and 12 fine powders in the vicinity of the line and whose thickness can be measured are randomly extracted, and the thickest fine powder and the thinnest fine powder are selected. After removal, the thickness of the remaining 10 points is measured and the average value is less than 100 nm.
In the case of a fibrous fine powder, the average value of the smallest two-dimensional fiber diameter (hereinafter also simply referred to as "average fiber diameter") is measured, and this average fiber diameter is set to be smaller than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, 12 points of fine powder in the vicinity are randomly extracted, and after removing the fine powder with the thickest and thinnest fiber diameters, the remaining 10 Measure the fiber diameter of the points and average the value to be less than 100 nm.
In the case of granular fine powders, the average particle size is measured and this average particle size is less than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, 12 points of fine powder in the vicinity are randomly extracted, and after removing the fine powder with the largest and smallest particle sizes, the remaining 10 The particle size of the dots is measured and the average value is less than 100 nm.
For fine powders with extension in other dimensions such as fibrous or scaly, the extension is for example less than 1000 nm, preferably less than 650 nm, more preferably less than 450 nm. If the spread is less than 1000 nm, it is possible to effectively obtain the reinforcing effect due to the interaction between the fine powders.
In the present invention, the definition of the fine cellulose powder is the same as that of the fine powder.

First, according to the present invention, it is possible to provide a curable resin composition that can maintain a low coefficient of thermal expansion even in a high-temperature region during component mounting and can provide a cured product that is excellent in various properties such as toughness. can.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product, and an electronic component using the curable resin composition.

Secondly, according to the present invention, a cured product that has low thermal expansion and excellent insulation reliability between layers even when it is used as an electronic component with a laminated structure for the purpose of miniaturization, high density, and high integration. It is possible to provide a curable resin composition that can be obtained.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product, and an electronic component using the curable resin composition.

Thirdly, according to the present invention, it is possible to provide a curable resin composition that has low dielectric properties and can give a cured product with good adhesion between the cured product and plated copper.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product, and an electronic component using the curable resin composition.

Fourthly, according to the present invention, smear can be removed by laser processing in the desmear process, and a cured product having a small surface roughness advantageous for high-frequency transmission and excellent peel strength can be obtained. It is possible to provide a curable resin composition that can be.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product, and an electronic component using the curable resin composition.

Fifthly, according to the present invention, the composition has low thermal expansion and is plated with copper for the purpose of producing wiring on the cured product of the composition. It is possible to provide a curable resin composition that does not cause blistering of plated copper due to heat history even when it is formed in a solid state, and that can provide a cured product that is excellent in high temperature resistance.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product and an electronic component using this curable resin composition.

Sixthly, according to the present invention, it is possible to obtain a cured product excellent in various properties such as toughness and heat resistance while maintaining a low coefficient of thermal expansion even in a high temperature range during component mounting, and curing excellent in pot life. It is possible to provide a flexible resin composition.
Moreover, according to the present invention, it is possible to provide a dry film, a cured product, and an electronic component using the curable resin composition.

Seventhly, according to the present invention, in a printed wiring board having at least one of a concave portion and a through hole, even in a high-temperature heating process during component mounting, over the concave portion and the through hole such as via holes and through holes filled with a resin filler, Wiring such as conductor pads and via holes does not swell, and there is no exudation of the resin composition with a dilute filler component during curing, and in the polishing process after curing, holes due to excessive polishing for smoothing It is possible to provide a curable resin composition that does not cause dents such as parts.
Further, according to the present invention, it is possible to provide a cured product of a curable resin composition that can solve the above-described problems, and a printed wiring board in which holes and the like are filled with this cured product.

It is a graph which shows the relationship between the compounding quantity of a silica and fine cellulose powder, and a coefficient of thermal expansion. It is a graph which shows the effect of thermal expansion coefficient reduction by combined use of fine cellulose powder. It is a graph which shows the effect of thermal expansion coefficient reduction by combined use of fine cellulose powder. It is a graph which shows the effect of elongation improvement by combined use of fine cellulose powder. It is an explanatory view showing a test board used in an example. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of an electronic component of the present invention; FIG. It is an explanatory view showing a test board used in an example. It is another explanatory view showing the test substrate used in the example. FIG. 10 is still another explanatory diagram showing a test substrate used in Examples. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of an electronic component of the present invention; FIG. It is an explanatory view showing a test board used in an example. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of an electronic component of the present invention; FIG. It is an explanatory view showing a test board used in an example. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of an electronic component of the present invention; FIG. It is an explanatory view showing a test board used in an example. 4 is a graph showing the relationship between the compounding amounts of silica and cellulose nanocrystal particles and the coefficient of thermal expansion. 4 is a graph showing the effect of reducing the coefficient of thermal expansion by the combined use of cellulose nanocrystal particles. 4 is a graph showing the effect of reducing the coefficient of thermal expansion by the combined use of cellulose nanocrystal particles. 4 is a graph showing the effect of improving elongation rate by combined use of cellulose nanocrystal particles. It is an explanatory view showing a test board used in an example. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of the manufacturing method of the printed wiring board using the curable resin composition of this invention. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of the printed wiring board of the present invention; FIG. 1 is a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of the printed wiring board of the present invention; FIG. It is a schematic sectional drawing explaining the dents, such as a hole part which arises in a grinding|polishing process.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

<<First aspect of the present invention>>
The curable resin composition of the first aspect of the present invention is most characterized in that it uses both a fine powder and a filler other than the fine powder as a filler.
With such a configuration, in relation to the first object, a cured product that can maintain a low coefficient of thermal expansion even in a temperature range exceeding 200° C. during component mounting and has excellent properties such as toughness. can provide.

[Fine powder]
The fine powder used in the present invention is a powder having at least one dimension smaller than 100 nm. and a sheet-like (scale-like) having a thickness of less than 100 nm. Such fine powders have a much larger surface area per unit mass than powders with all three dimensions of 100 nm or more, and the proportion of atoms exposed to the surface is increased. Therefore, it is considered that the fine powder interacts with each other to exert a reinforcing effect and reduce the thermal expansibility.

The fine powder may be a particle with at least one dimension smaller than 100 nm, and the material is not particularly limited, and two or more kinds may be used in combination. Examples of fine powders include carbon-based materials such as graphite, graphene, fullerene, single-walled carbon nanotubes, multi-walled carbon nanotubes, silver, gold, iron, nickel, titanium oxide, cerium oxide, zinc oxide, silica, and aluminum hydroxide. minerals such as clay, smectite, bentonite, etc., cellulose nanocrystal particles obtained by isolating only the crystal part from fine cellulose powder and cellulose raw materials, crustaceans, etc. Examples include fine chitin obtained by opening chitin, fine chitosan obtained by further treating these fine chitins with an alkali, and the like. These may be processed into nanotubes, nanowires, and nanosheets, and two or more of them may be used in combination. You may Among these, the hydrophilic fine powder includes metal oxide fine particles such as titanium oxide, metal hydroxide fine particles such as aluminum hydroxide, mineral fine particles such as clay, fine cellulose fibers, and fine chitin. . Among such fine powders, fine cellulose powder is particularly desirable from the viewpoints of reinforcing effect and ease of handling, and also from the viewpoint of the effect of improving adhesion to plated copper and ease of handling. Cellulose nanocrystal particles are also preferred.

The inventors focused on fine cellulose powder as a powder having at least one dimension smaller than 100 nm, and extensively studied the relationship between the compounding amount and the coefficient of thermal expansion in comparison with silica. It was newly discovered that a small amount of compounding can significantly reduce the coefficient of thermal expansion (see Fig. 1-1).
Furthermore, the inventors focused on the fact that a sufficient effect of reducing the coefficient of thermal expansion can be obtained by blending fine cellulose powder even in a small amount. The present inventors have found that by blending a filler such as silica for ensuring the required properties, and blending the fine cellulose powder together, the above-mentioned effects peculiar to the present invention can be obtained. (See Figures 1-2 and 1-3).

When hydrophilic fine powder is used as the fine powder described above, it is preferable to subject the particles to hydrophobic treatment or surface treatment using a coupling agent. For such treatment, known and commonly used methods suitable for fine powders can be used.

The amount of the fine powder to be blended in the present invention is preferably 0.04 to 64% by mass, more preferably 0.08 to 30% by mass, more preferably 0.08 to 30% by mass, based on the total amount of the composition excluding the solvent, It is 0.1 to 10% by mass. When the content of the fine powder is 0.04% by mass or more, the effect of reducing the coefficient of linear expansion can be favorably obtained, and the effect of improving the adhesion to plated copper can be favorably obtained. On the other hand, when it is 64% by mass or less, the film formability is improved.

Among the fine powders according to the present invention, the fine cellulose powder can be obtained in the following manner, but is not limited to these.

(fine cellulose powder)
Raw materials for fine cellulose powder include pulp obtained from natural plant fiber raw materials such as wood, hemp, bamboo, cotton, jute, kenaf, beet, agricultural waste, cloth, and regenerated cellulose fibers such as rayon and cellophane. Among them, pulp is particularly suitable. The pulp includes chemical pulp such as kraft pulp and sulfite pulp obtained by chemically or mechanically pulping plant raw materials, or a combination of both, semi-chemical pulp, chemi-grand pulp, chemi-mechanical pulp, Thermomechanical pulp, chemithermomechanical pulp, refiner mechanical pulp, groundwood pulp, deinked waste paper pulp, magazine waste paper pulp, corrugated waste paper pulp, etc. containing these plant fibers as the main component can be used. Among them, various softwood-derived kraft pulps having high fiber strength, such as softwood unbleached kraft pulp, softwood oxygen-exposed unbleached kraft pulp, and softwood bleached kraft pulp, are particularly suitable.

The raw material is mainly composed of cellulose, hemicellulose and lignin, and the content of lignin is usually about 0 to 40% by mass, particularly about 0 to 10% by mass. As for these raw materials, if necessary, lignin can be removed or bleached to adjust the amount of lignin. In addition, the measurement of lignin content can be performed by the Klason method.

In the cell walls of plants, cellulose molecules are not single molecules but are regularly aggregated to form crystalline microfibrils (fine cellulose fibers), which are the basic skeletal substances of plants. ing. Therefore, in order to produce fine cellulose powder from the above raw material, the above raw material is subjected to beating or pulverization treatment, high-temperature and high-pressure steam treatment, treatment with phosphate, etc., and oxidation of cellulose fibers using an N-oxyl compound as an oxidation catalyst. A method of unraveling the fibers to a nano size can be used by applying a treatment or the like to the fibers.

Among the above, the beating or pulverization treatment is a method of mechanically beating or pulverizing raw materials such as pulp by directly applying force to loosen fibers to obtain fine cellulose powder. More specifically, for example, pulp or the like is mechanically treated with a high-pressure homogenizer or the like to loosen cellulose fibers to a fiber diameter of about 0.1 to 10 μm, and an aqueous suspension of about 0.1 to 3% by mass is prepared. Furthermore, by repeatedly grinding or crushing this with a grinder or the like, fine cellulose powder having a fiber diameter of about 10 to 100 nm can be obtained.

The grinding or crushing treatment can be performed using, for example, a grinder "Pure Fine Mill" manufactured by Kurita Machinery Co., Ltd., or the like. This grinder is a stone grinder that pulverizes the raw material into ultrafine particles by impact, centrifugal force, and shearing force generated when the raw material passes through the gap between the upper and lower grinders. , dispersing, emulsifying and fibrillating simultaneously. The grinding or melting treatment can also be performed using an ultra-fine grinder "Super Mascolloider" manufactured by Masuko Sangyo Co., Ltd. The Super Mascolloider is a grinder that goes beyond mere pulverization and enables ultra-atomization to the extent that it feels like melting. The Super Mascolloider is a millstone-type ultra-fine grinder composed of two non-porous grindstones whose spacing can be freely adjusted. The upper grindstone is fixed and the lower grindstone rotates at high speed. The raw material put into the hopper is sent into the gap between the upper and lower grinding wheels by centrifugal force, and the raw material is gradually ground into ultrafine particles by the strong compression, shearing and rolling frictional forces generated there.

The high-temperature and high-pressure steam treatment is a method for obtaining fine cellulose powder by exposing raw materials such as pulp to high-temperature and high-pressure steam to loosen fibers.

Furthermore, the treatment with the phosphate or the like is performed by phosphate-esterifying the surface of the raw material such as the pulp to weaken the binding force between the cellulose fibers, and then performing a refiner treatment to unravel the fibers and make them fine. This is a processing method for obtaining cellulose powder. For example, the raw material such as the pulp is immersed in a solution containing 50% by mass of urea and 32% by mass of phosphoric acid, and the solution is sufficiently impregnated between cellulose fibers at 60 ° C., and then heated at 180 ° C. After proceeding with phosphorylation and washing with water, it is hydrolyzed in a 3% by mass hydrochloric acid aqueous solution at 60° C. for 2 hours, washed again with water, and then in a 3% by mass aqueous sodium carbonate solution. Phosphorylation is completed by treating at room temperature for about 20 minutes, and fine cellulose powder can be obtained by fibrillating the treated material with a refiner.

The treatment of oxidizing cellulose fibers using the N-oxyl compound as an oxidation catalyst is a method of obtaining fine cellulose powder by oxidizing raw materials such as pulp and then pulverizing them.

First, an aqueous dispersion is prepared by dispersing natural cellulose fibers in water of about 10 to 1000 times the amount (mass basis) on the absolute dry basis using a mixer or the like. Examples of natural cellulose fibers used as raw materials for the fine cellulose fibers include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as straw pulp and bagasse pulp, cotton pulp such as cotton lint and cotton linter, Bacterial cellulose etc. can be mentioned. These may be used individually by 1 type, or may be used in combination of 2 or more types as appropriate. In addition, these natural cellulose fibers may be preliminarily subjected to a treatment such as beating in order to increase the surface area.

Next, an N-oxyl compound is used as an oxidation catalyst in the aqueous dispersion to oxidize the natural cellulose fibers. Such N-oxyl compounds include, for example, TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), 4-carboxy-TEMPO, 4-acetamido-TEMPO, 4-amino-TEMPO, 4 -dimethylamino-TEMPO, 4-phosphonooxy-TEMPO, 4-hydroxy TEMPO, 4-oxy TEMPO, 4-methoxy TEMPO, 4-(2-bromoacetamido)-TEMPO, 2-azaadamantane N-oxyl, etc. A TEMPO derivative or the like having various functional groups at the C4 position can be used. The amount of these N-oxyl compounds to be added is sufficient in the catalytic amount, and can usually be in the range of 0.1 to 10% by mass on the absolute dry basis relative to the natural cellulose fiber.

In the oxidation treatment of the natural cellulose fibers, an oxidizing agent and a co-oxidizing agent are used in combination. Examples of the oxidizing agent include halogenous acid, hypohalous acid and perhalogenous acid and salts thereof, hydrogen peroxide, and perorganic acid, and among them sodium hypochlorite and hypobromous acid. Alkali metal hypohalites such as sodium are preferred. Moreover, as a co-oxidant, for example, an alkali metal bromide such as sodium bromide can be used. The amount of the oxidizing agent used is usually in the range of about 1 to 100% by mass on an absolute dry basis relative to the natural cellulose fiber, and the amount of the co-oxidizing agent is usually used relative to the natural cellulose fiber on an absolute dry basis. is in the range of about 1 to 30% by mass.

During the oxidation treatment of the natural cellulose fibers, it is preferable to maintain the pH of the aqueous dispersion in the range of 9 to 12 from the viewpoint of efficiently proceeding with the oxidation reaction. Moreover, the temperature of the aqueous dispersion during the oxidation treatment can be arbitrarily set within the range of 1 to 50° C., and the reaction can be performed even at room temperature without temperature control. The reaction time can range from 1 to 240 minutes. A penetrating agent may be added to the aqueous dispersion in order to allow the agent to permeate into the interior of the natural cellulose fibers and introduce more carboxyl groups to the fiber surfaces. Penetrants include anionic surfactants such as carboxylates, sulfates, sulfonates, and phosphates, and nonionic surfactants such as polyethylene glycol type and polyhydric alcohol type. .

After the oxidation treatment of the natural cellulose fibers, it is preferable to carry out a purification treatment for removing impurities such as unreacted oxidizing agents and various by-products contained in the aqueous dispersion prior to micronization. Specifically, for example, a method of repeatedly washing and filtering oxidized natural cellulose fibers can be used. The natural cellulose fibers obtained after the refining treatment are usually impregnated with an appropriate amount of water and subjected to a fine treatment, but if necessary, they may be dried to form fibers or powder.

Next, refinement|miniaturization of a natural cellulose process is performed in the state disperse|distributing the natural cellulose fiber refined according to necessity in solvent, such as water. The solvent as the dispersion medium used in the micronization treatment is usually preferably water, but if desired, alcohols (methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, ethylene glycol, glycerin, etc.), ethers (ethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, etc.), etc. water-soluble organic solvents may be used, and mixtures thereof may also be used. The solid content concentration of the natural cellulose fibers in the dispersion of these solvents is preferably 50% by mass or less. If the solid content concentration of the natural cellulose fiber exceeds 50% by mass, it is not preferable because extremely high energy is required for dispersion. Refinement of natural cellulose processing is achieved by low-pressure homogenizers, high-pressure homogenizers, grinders, cutter mills, ball mills, jet mills, beaters, disintegrators, short-screw extruders, twin-screw extruders, ultrasonic agitators, household juicer mixers, etc. It can be done using a dispersing device.

The fine cellulose powder obtained by the pulverization treatment can be in the form of a suspension with an adjusted solid content concentration, or in the form of a dried powder, as desired. Here, when making a suspension, only water may be used as a dispersion medium, and water and other organic solvents such as alcohols such as ethanol, surfactants, acids, bases, etc. Mixed solvents may also be used.

By the oxidation treatment and refining treatment of the natural cellulose fiber, the hydroxyl group at the C6 position of the structural unit of the cellulose molecule is selectively oxidized to the carboxyl group via the aldehyde group, and the content of the carboxyl group is reduced to 0.1. It is possible to obtain a highly crystalline fine cellulose powder having the predetermined number average fiber diameter, which consists of cellulose molecules of ˜3 mmol/g. This highly crystalline fine cellulose powder has a cellulose type I crystal structure. This means that such a fine cellulose powder is obtained by surface-oxidizing naturally occurring cellulose molecules having a type I crystal structure and making them fine. In other words, in natural cellulose fibers, fine fibers called microfibrils produced in the biosynthetic process are bundled into multiple bundles to build a higher-order solid structure, and there is a strong cohesive force between the microfibrils (surface-to-surface ) is weakened by introducing an aldehyde group or a carboxyl group by an oxidation treatment, and a fine cellulose powder is obtained by further undergoing a refining treatment. By adjusting the oxidation treatment conditions, the content of carboxyl groups can be increased or decreased to change the polarity. , average aspect ratio, etc. can be controlled.

The fact that the natural cellulose fiber has the I-type crystal structure is typical at two positions near 2θ = 14 to 17° and 2θ = 22 to 23° in the diffraction profile obtained by measuring the wide-angle X-ray diffraction image. It can be identified by having a specific peak. In addition, the fact that carboxyl groups have been introduced into the cellulose molecules of the fine cellulose powder is due to absorption (1608 cm ^{− 1} ) exists. In the case of carboxyl groups (COOH) there is an absorption at 1730 cm ⁻¹ in the above measurements.

Since halogen atoms are attached to or bonded to the natural cellulose fibers after the oxidation treatment, a dehalogenation treatment may be performed for the purpose of removing such residual halogen atoms. The dehalogenation treatment can be performed by immersing the natural cellulose fibers after the oxidation treatment in a hydrogen peroxide solution or an ozone solution.

Specifically, for example, natural cellulose fibers after oxidation treatment are added to a hydrogen peroxide solution having a concentration of 0.1 to 100 g/L at a bath ratio of about 1:5 to 1:100, preferably 1:10 to 1. : Immersed under the condition of about 60 (mass ratio). The concentration of the hydrogen peroxide solution in this case is preferably 1-50 g/L, more preferably 5-20 g/L. Also, the pH of the hydrogen peroxide solution is preferably 8-11, more preferably 9.5-10.7.

The amount [mmol/g] of carboxyl groups in cellulose with respect to the mass of the fine cellulose powder contained in the aqueous dispersion can be evaluated by the following method. That is, 60 ml of a 0.5 to 1% by mass aqueous dispersion of a fine cellulose powder sample whose dry mass was accurately weighed in advance was prepared, and after adjusting the pH to about 2.5 with a 0.1 M hydrochloric acid aqueous solution, 0.05 M was added. is added dropwise until the pH reaches about 11, and the electrical conductivity is measured. From the amount of sodium hydroxide (V) consumed in the neutralization step of the weak acid, whose electrical conductivity changes slowly, the amount of functional groups can be determined using the following formula. This amount of functional groups indicates the amount of carboxyl groups.
Functional group amount [mmol/g] = V [ml] x 0.05/fine cellulose powder sample [g]

Further, the fine cellulose powder used in the present invention may be chemically and/or physically modified to enhance functionality. Here, as chemical modification, functional groups are added by acetalization, acetylation, cyanoethylation, etherification, isocyanate, etc., inorganic substances such as silicates and titanates are combined by chemical reactions, sol-gel methods, etc., Alternatively, it can be carried out by a method such as coating. As a method of chemical modification, for example, a method of immersing a sheet-shaped fine cellulose powder in acetic anhydride and heating it can be mentioned. In addition, fine cellulose powder obtained by oxidizing cellulose fibers using an N-oxyl compound as an oxidation catalyst modifies the carboxyl groups in the molecule with amine compounds, quaternary ammonium compounds, etc. with ionic bonds or amide bonds. There is a method to make
Physical modification methods include, for example, metal and ceramic raw materials, vacuum deposition, ion plating, sputtering and other physical vapor deposition methods (PVD methods), chemical vapor deposition methods (CVD methods), electroless plating and electrolytic plating. method, etc., for coating. These modifications may be made before or after the treatment.

When the fine cellulose powder used in the present invention is fibrous, it is desirable that the average fiber diameter is 3 nm or more and less than 100 nm. Since the minimum diameter of a fine cellulose fiber single fiber is 3 nm, it is practically impossible to produce a cellulose fiber with a diameter of less than 3 nm. Also, if it is less than 100 nm, the desired effects of the present invention can be obtained without excessive addition, and the film formability will be good. The average fiber diameter of the fine cellulose powder can be measured according to the method for measuring the size of the fine powder described above.

(cellulose nanocrystal particles)
The inventors of the present invention further focused on the crystal form of fine cellulose powder and conducted intensive studies. It has also been found that it is possible to provide a curable resin composition having excellent pot life while solving the above problems.
As a filler, by using cellulose nanocrystal particles obtained by isolating only the crystalline portion from a cellulose raw material together with a filler other than the cellulose nanocrystal particles, the thermal expansion is low even in a temperature range exceeding 200 ° C. during component mounting. It is possible to provide a curable resin composition excellent in pot life, which can obtain a cured product excellent in various properties such as toughness and heat resistance while maintaining the rate.

The inventors focused on cellulose nanocrystal particles obtained by isolating only the crystalline portion from a cellulose raw material, and extensively studied the relationship between the compounding amount and the coefficient of thermal expansion in comparison with silica, and found that the cellulose nanocrystal particles According to the inventors, it was found that a small amount of compounding can achieve a remarkable effect of reducing the coefficient of thermal expansion (see FIG. 6-1).
In addition, the inventors have found that the cellulose nanocrystal particles are combined with a filler such as silica to ensure various properties required for insulating materials for electronic parts, such as toughness and heat resistance. , it has been found that the above-described effects peculiar to the present invention can be obtained (see FIGS. 6-2 and 6-3).
Furthermore, the inventors have found that cellulose nanocrystal particles consisting only of a crystalline portion can provide a curable resin composition having an excellent pot life. I have found that it works.

In the present invention, the cellulose nanocrystal particles are obtained by hydrolyzing a cellulose raw material with a high-concentration mineral acid (hydrochloric acid, sulfuric acid, hydrobromic acid, etc.) to remove the non-crystalline portion and isolate only the crystalline portion. Any particles can be used. The size of the particles is preferably 3 to 70 nm in average crystal width and 100 to 500 nm in average crystal length, more preferably 3 to 50 nm in average crystal width and 100 to 400 nm in average crystal length, still more preferably. has an average crystal width of 3 to 10 nm and an average crystal length of 100 to 300 nm. Here, the crystal width refers to the length of the short side of the grain, and the crystal length refers to the length of the long side of the grain. Such cellulose nanocrystal particles have a much larger surface area per unit mass and a greater proportion of atoms exposed on the surface than those with greater widths and lengths. Therefore, it is considered that the cellulose nanocrystal particles interact with each other to exert a reinforcing effect and reduce the thermal expansibility.

Here, the size of the cellulose nanocrystal particles (average crystal width, average crystal length) can be measured by SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope) or AFM (Atomic Force Microscope). ; atomic force microscope) can be observed and measured.
Specifically, a line is drawn on the diagonal line of the micrograph, 12 particles in the vicinity of the line and whose size can be measured are randomly extracted, and after removing the largest and smallest particles, the remaining The average crystal width and average crystal length of the cellulose nanocrystal particles are obtained by measuring the sizes (crystal width and crystal length) at 10 points and averaging the respective values.

As the cellulose nanocrystal particles, two or more kinds of different cellulose raw materials may be used in combination.

Such cellulose nanocrystal particles are preferably subjected to hydrophobic treatment, surface treatment using a coupling agent, or the like. For such treatment, a known and commonly used method suitable for cellulose nanocrystal particles can be used.

The amount of cellulose nanocrystal particles in the present invention is preferably 0.04 to 30% by mass, more preferably 0.08 to 20% by mass, more preferably 0.08 to 20% by mass, relative to the total amount of the composition excluding the solvent. , 0.1 to 10% by mass. When the blending amount of the cellulose nanocrystal particles is 0.04% by mass or more, the effect of reducing the coefficient of thermal expansion can be favorably obtained. On the other hand, when it is 30% by mass or less, the film formability is improved.

The cellulose nanocrystal particles according to the present invention are obtained by hydrolyzing a cellulose raw material with a mineral acid of high concentration (hydrochloric acid, sulfuric acid, hydrobromic acid, etc.) to remove the amorphous portion and isolate only the crystalline portion. can be done.
Examples of the cellulose raw material include paper pulp, cotton pulp such as cotton linter and cotton lint, non-wood pulp such as hemp, straw, and bagasse, and cellulose isolated from sea squirts, seaweed, and the like. It is not particularly limited. Among these, pulp for papermaking is preferable from the point of view of availability, and cotton and sea squirt are preferable from the point of being able to manufacture a CNC having excellent heat resistance.
Examples of papermaking pulp include hardwood kraft pulp and softwood kraft pulp.
Hardwood kraft pulps include bleached kraft pulp (LBKP), unbleached kraft pulp (LUKP), oxygen-bleached kraft pulp (LOKP), and the like.
Softwood kraft pulps include bleached kraft pulp (NBKP), unbleached kraft pulp (NUKP), oxygen-bleached kraft pulp (NOKP), and the like.
Other examples include chemical pulp, semi-chemical pulp, mechanical pulp, non-wood pulp, and deinked pulp made from waste paper. Chemical pulp includes sulfite pulp (SP), soda pulp (AP), and the like. Semi-chemical pulp includes semi-chemical pulp (SCP), chemigroundwood pulp (CGP), and the like. Mechanical pulp includes ground wood pulp (GP), thermomechanical pulp (TMP, BCTMP), and the like. Non-wood pulps include those made from paper mulberry, mitsumata, hemp, kenaf, and the like.
Such cellulose raw materials may be used singly or in combination of two or more. In addition, cellulose nanofibers (hereinafter also simply referred to as “CNF”) produced by a mechanical fibrillation method, a phosphoric acid esterification method, a TEMPO oxidation method, or the like may be used as the cellulose raw material.

Next, the hydrolysis of the cellulose raw material as described above can be carried out, for example, by treating an aqueous suspension or slurry containing the cellulose raw material with sulfuric acid, hydrochloric acid, hydrobromic acid, etc., or by treating the cellulose raw material as it is with sulfuric acid, hydrochloric acid, odorant, etc. It can be carried out by suspending it in an aqueous solution such as hydrochloride acid. In particular, when pulp is used as the cellulose raw material, it is preferable to hydrolyze the fibrous fiber using a cutter mill, pin mill, or the like, since it can be hydrolyzed uniformly.
In such hydrolysis treatment, the temperature conditions are not particularly limited, but can be, for example, 25 to 90°C. The conditions for the hydrolysis treatment time are also not particularly limited, but can be, for example, 10 to 120 minutes.
The cellulose nanocrystal particles obtained by hydrolyzing the cellulose raw material in this manner can be neutralized using an alkali such as sodium hydroxide.

The cellulose nanocrystal particles thus obtained can be subjected to micronization treatment if necessary. In this atomization treatment, the treatment apparatus and treatment method are not particularly limited.
Examples of atomization equipment include grinders (stone mill type grinders), high pressure homogenizers, ultra-high pressure homogenizers, high pressure impact grinders, ball mills, bead mills, disk refiners, conical refiners, twin-screw kneaders, vibration mills, high-speed A homomixer under rotation, an ultrasonic disperser, a beater, etc. can be used.

At the time of the atomization treatment, it is preferable to dilute the cellulose nanocrystal particles with water and an organic solvent alone or in combination to form a slurry, but there is no particular limitation. Preferred organic solvents include alcohols, ketones, ethers, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like. One type of dispersion medium may be used, or two or more types may be used. In addition, the dispersion medium may contain solids other than the cellulose nanocrystal particles, such as urea having hydrogen bonding properties.

Moreover, the cellulose nanocrystal particles used in the present invention may be chemically and/or physically modified to enhance functionality. Here, as chemical modification, functional groups are added by acetalization, acetylation, cyanoethylation, etherification, isocyanate, etc., inorganic substances such as silicates and titanates are combined by chemical reactions, sol-gel methods, etc., Alternatively, it can be carried out by a method such as coating. Physical modification can be performed by plating or vapor deposition.

[Filler other than fine powder]
The resin composition of the present invention further contains a filler other than the fine powder described above. Such fillers include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride. and inorganic fillers such as titanium oxide. Further, when the fine powder is cellulose nanocrystal particles, an organic filler may be used, and cellulose nanofibers may be used as the organic filler. Silica is preferred among the fillers.
The average particle diameter of this filler is preferably 3 μm or less, more preferably 1 μm or less. The average particle size of the filler can be determined using a laser diffraction particle size distribution analyzer.

The blending amount of this filler is 1 to 90% by mass, preferably 2 to 80% by mass, more preferably 5 to 75% by mass of the total amount of the composition excluding the solvent. By setting the blending amount of the filler within the above range, it is possible to ensure good coating performance of the cured product after curing.

The blending ratio of the filler other than the fine powder and the fine powder in the total filler is (filler other than the fine powder: fine powder) = 100: (0.04 to 30), preferably 100: ( 0.1 to 20), more preferably 100:(0.2 to 10). By using the filler in such a compounding ratio, various properties such as toughness and heat resistance required for insulating materials for electronic parts can be achieved while maintaining a low coefficient of thermal expansion.
In addition, the total amount of the filler to be blended in the curable resin composition is appropriately used according to the properties required of the insulating material such as the application of the curable resin composition, such as an interlayer insulating material for electronic parts. Quantity is preferred.

<Fine powders for the first and sixth purposes and other compounding ingredients excluding fillers other than fine powders>
In the first aspect of the present invention, the fine powders and other compounding components other than the fillers other than the fine powders related to the first and sixth objects are as follows.

[Curable resin]
In the present invention, the curable resin is not particularly limited, and a well-known one can be used. For example, it may be a material containing either one of a thermosetting component and a photocurable component, Materials containing thermosetting components are preferred.
The thermosetting component may be any resin that cures by heating and exhibits electrical insulation properties. , Amino resins such as benzoguanamine derivatives, polyisocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, episulfide resins, bismaleimide, carbodiimide resins, polyimide resins, polyamideimide resins, polyphenylene ether resins, known thermosetting resins such as polyphenylene sulfide resins Resin can be used. Thermosetting resins having at least one of a plurality of cyclic ether groups and cyclic thioether groups (hereinafter abbreviated as cyclic (thio)ether groups) in the molecule are particularly preferred. Among them, epoxy compounds and oxetane compounds are preferable, and epoxy resins, which are epoxy compounds, are more preferable.

Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol Z type epoxy resin, and the like. Bisphenol type epoxy resin, bisphenol A novolak type epoxy resin, phenol novolac type epoxy resin, cresol novolak epoxy resin, and other novolac type epoxy resins, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, arylalkylene type epoxy resin, tetraphenylolethane type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin, glycidyl methacrylate copolymer type epoxy resin, Copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-di Glycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, sorbitol polyglycidyl ether, tris(2,3-epoxypropyl)isocyanurate, triglycidyltris(2-hydroxyethyl)isocyanate Examples include nurate and phenoxy resin.
Among them, at least one of a solid epoxy resin that is solid at 40°C and a semi-solid epoxy resin that is solid at 20°C and liquid at 40°C is used in combination with a liquid epoxy resin that is liquid at 20°C. Use is preferable from the viewpoint of excellent crack resistance during thermal cycles while maintaining the effects of the present invention. Examples of solid epoxy resins, semi-solid epoxy resins, and liquid epoxy resins include those described in JP-A-2015-10232.

The above thermosetting component is used together with a curing agent as needed. Curing agents include phenolic resins, polycarboxylic acids and their acid anhydrides, cyanate ester resins, active ester resins in which hydroxyl groups are capped by acetylation, etc., and cycloolefin polymers having carboxyl groups, hydroxyl groups, and active ester structures in side chains. and a curing agent having a substituent that reacts with a hydroxyl group, a carboxyl group, or a cyclic ether group having an active ester structure as part of the above-described curable resin, and can be used alone or in combination of two or more.

Examples of the phenol resin include phenol novolak resin, alkylphenol borak resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene-modified phenol resin, cresol/naphthol resin, polyvinylphenols, phenol/naphthol resin. , an α-naphthol skeleton-containing phenolic resin, a triazine-containing cresol novolac resin, and the like can be used.

The polycarboxylic acids and acid anhydrides thereof are compounds and acid anhydrides thereof having two or more carboxyl groups in one molecule, such as (meth)acrylic acid copolymers and maleic anhydride copolymers. , dibasic acid condensates, and resins having carboxylic acid terminals such as carboxylic acid-terminated imide resins.

The cyanate ester resin is a compound having two or more cyanate ester groups (--OCN) in one molecule. Any conventionally known cyanate ester resin can be used. Examples of cyanate ester resins include phenol novolac type cyanate ester resins, alkylphenol novolac type cyanate ester resins, dicyclopentadiene type cyanate ester resins, bisphenol A type cyanate ester resins, bisphenol F type cyanate ester resins, and bisphenol S type cyanate ester resins. is mentioned. Also, a prepolymer partially triazined may be used.

The active ester resin is not particularly limited, and a resin having two or more active ester groups in one molecule is preferable. Active ester resins can generally be obtained by a condensation reaction between one or more of carboxylic acid compounds and thiocarboxylic acid compounds and one or more of hydroxy compounds and thiol compounds. Examples of active ester resins include dicyclopentadienyl diphenol ester compounds, bisphenol A diacetate, diphenyl phthalate, diphenyl terephthalate, bis[4-(methoxycarbonyl)phenyl] terephthalate, and the like.
This active ester resin is suitable for obtaining an electronic component having low dielectric properties by lowering the dielectric constant and dielectric loss tangent.

Such thermosetting components, curing agents, and the like are appropriately used according to the application of the thermosetting resin composition containing them as a component, for example, the required properties of insulating materials such as interlayer insulating materials for electronic parts. It is preferable to blend with a known composition.

In the present invention, the thermosetting resin composition containing the thermosetting component includes, in addition to the above components, thermoplastic resins, elastomers, polymer resins such as rubber particles, imidazole compounds, amine compounds, hydrazine compounds, and phosphorus compounds. , a curing accelerator such as an S-triazine derivative, a flame retardant, a coloring agent, a diluent such as an organic solvent, and other additives.

Next, the photocurable component may be a resin that exhibits electrical insulation properties when cured by light irradiation. Examples include alkyl (meth)acrylates such as 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate. hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and other alkylene oxide derivatives mono- or di(meth ) acrylates; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, trishydroxyethyl isocyanurate, or polyhydric (meth)acrylates of these ethylene oxide or propylene oxide adducts; (Meth)acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth)acrylate and polyethoxydi(meth)acrylate of bisphenol A; glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc. and (meth)acrylates of glycidyl ether of; and melamine (meth)acrylate.

The above photocurable component is used together with a photoreaction initiator that generates any one of radicals, bases and acids, if necessary. Examples of the photoreaction initiator include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2 ,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis- (2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6 -trimethylbenzoyl)-phenylphosphine oxide (manufactured by BASF Japan Ltd., IRGACURE819) and other bisacylphosphine oxides; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF Japan ( Co., Ltd., DAROCUR TPO) and other monoacylphosphine oxides; 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane -1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2- Hydroxyacetophenones such as methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl] Acetophenones such as 2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, N,N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone , 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone , 2-tert-butyl anthraquinone, 1-chloroanthraquinone, 2-amyl anthraquinone, 2-aminoanthraquinone and other anthraquinones; acetophenone dimethyl ketal, benzyl dimethyl ketal and other ketals; ethyl-4-dimethylaminobenzoate, 2-( Benzoic acid esters such as dimethylamino)ethyl benzoate and p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1 -Oxime esters such as [9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime); bis(η5-2,4-cyclopentadiene- 1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-( 1-Pyr-1-yl)ethyl)phenyl]titanium; phenyl disulfide 2-nitrofluorene, butyroin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. Any one of the above photoreaction initiators may be used alone, or two or more thereof may be used in combination.

Such photocurable components, photoreaction initiators, and the like are appropriately used according to the application of the photocurable resin composition containing them as a component, for example, the required properties of insulating materials such as interlayer insulating materials for electronic parts. It is preferable to mix with a known composition.

In the present invention, the photocurable resin composition containing the photocurable component includes, in addition to the above components, thermoplastic resins, elastomers, polymer resins such as rubber particles, sensitizers, flame retardants, colorants, organic A diluent such as a solvent and other additives may also be included.

Further, when the curable resin composition of the present invention is used as an alkali developable photosolder resist composition that can be developed with an alkaline aqueous solution, in addition to the thermosetting component and the photocurable component described above, a carboxyl group-containing resin is preferably used.

(Carboxyl group-containing resin)
As the carboxyl group-containing resin, both a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond and a carboxyl group-containing resin having no photosensitive unsaturated double bond can be used. and is not limited to a specific one. As the carboxyl group-containing resin, particularly the resins listed below can be preferably used.
(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid and a compound having an unsaturated double bond, and a carboxyl group-containing resin obtained by modifying it to adjust the molecular weight and acid value.
(2) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth)acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.
(3) reacting an unsaturated monocarboxylic acid with a copolymer of a compound having one epoxy group and an unsaturated double bond in one molecule and a compound having an unsaturated double bond, and produced by this reaction A photosensitive carboxyl group-containing resin obtained by reacting a saturated or unsaturated polybasic acid anhydride with a secondary hydroxyl group.
(4) After reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride, a compound having one epoxy group and an unsaturated double bond in each molecule is added to the carboxylic acid produced by this reaction. A photosensitive hydroxyl group- and carboxyl group-containing resin obtained by a reaction.
(5) A photosensitive carboxyl group obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting some or all of the secondary hydroxyl groups generated by this reaction with a polybasic acid anhydride. Contained resin.
(6) reacting a polyfunctional epoxy compound, a compound having two or more hydroxyl groups in one molecule and one reactive group other than a hydroxyl group that reacts with the epoxy group, and an unsaturated group-containing monocarboxylic acid to obtain A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.
(7) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product of a resin having a phenolic hydroxyl group and an alkylene oxide or a cyclic carbonate, and reacting the resulting reaction product with a polybasic acid anhydride. Carboxyl group-containing photosensitive resin.
(8) a reaction product obtained by reacting a polyfunctional epoxy compound, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and an unsaturated group-containing monocarboxylic acid; A carboxyl group-containing photosensitive resin obtained by reacting an anhydride group of a polybasic acid anhydride with an alcoholic hydroxyl group of the above.

This carboxyl group-containing resin is preferably blended in a known composition commonly used in alkali-developable curable resin compositions such as solder resist compositions containing this resin as a constituent component.

The curable resin composition of the present invention as described above can further contain other conventional compounding components as appropriate depending on its use. Other conventional compounding components include, for example, thermoplastic resins, elastomers, polymer resins such as rubber particles, curing accelerators, sensitizers, flame retardants, colorants, and diluents such as organic solvents, as described above. , and other additives, specifically known and commonly used additives such as antifoaming agents/leveling agents, thixotropy-imparting agents/thickening agents, coupling agents, dispersing agents, and the like.

In particular, as the colorant, commonly known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and pigments can be used. However, it is preferable not to contain halogen from the viewpoint of environmental load reduction and influence on the human body.

Red colorant:
Examples of red colorants include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone colorants.

Blue Colorant, Green Colorant:
Examples of blue colorants and green colorants include phthalocyanine-based and anthraquinone-based colorants, and pigment-based compounds classified as pigments. Colorists (published by The Society of Dyers and Colorists) numbered ones can be mentioned. In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone colorants.

In addition, coloring agents such as purple, orange, brown and black may be added for the purpose of adjusting the color tone.

A specific mixing ratio of the coloring agent can be appropriately adjusted depending on the type of coloring agent used and the type of other additives.

Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and diethylene glycol. Glycol ethers such as monoethyl ether, dipropylene glycol monoethyl ether and triethylene glycol monoethyl ether; Esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and esters of the above glycol ethers; Alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha.

The curable resin composition of the present invention containing the components as described above may be used in the form of a dry film, or may be used as it is in the form of a liquid. In addition, when it is used as a liquid, it may be a one-liquid type or a two-liquid or more liquid type.
The curable resin composition of the present invention can also be used as a so-called prepreg, which is obtained by coating or impregnating a sheet-like fibrous base material such as glass cloth, glass or aramid nonwoven fabric and semi-curing it.

The dry film of the present invention has a resin layer obtained by coating and drying the curable resin composition of the present invention on a film (supporting film).
Here, when forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate value, and then a comma coater, blade coater, lip coater, and rod coater are used. , a squeeze coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like, so as to obtain a uniform thickness on the film. After that, the applied composition is usually dried at a temperature of 40 to 130° C. for 1 to 30 minutes to form a resin layer. The coating thickness is not particularly limited, but is generally selected appropriately within the range of 3 to 150 μm, preferably 5 to 60 μm, in terms of film thickness after drying.

As the film (supporting film), a resin film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of this film is not particularly limited, but is generally selected appropriately within the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

In order to prevent dust from adhering to the surface of the resin layer on the film on which the resin layer composed of the curable resin composition of the present invention is thus formed, a peelable film ( It is preferable to further laminate a protective film).
As the peelable film, any film may be used as long as the adhesive force to the resin layer when peeled is smaller than the adhesive force to the resin layer and the support film. Examples include polyethylene film, polytetrafluoroethylene film, and polypropylene film. , surface-treated paper, or the like can be used.

The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the dry film of the present invention. Such a cured product of the present invention can be suitably used as electronic component materials such as solder resists, interlayer insulating materials, and hole-filling materials that require insulation reliability.

The electronic component of the present invention comprises the cured product of the present invention, and specific examples thereof include printed wiring boards. In particular, a multilayer printed wiring board using the curable resin composition of the present invention as an interlayer insulating material can have good interlayer insulation reliability.

<Other compounding ingredients excluding fine powders and fillers other than fine powders for the second to fifth purposes>
In the first aspect of the present invention, the fine powders and other compounding components other than the fillers other than the fine powders related to the second to fifth objects are as follows.

Regarding the second object of the present invention, the curable resin composition of the present invention preferably contains a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton as the curable resin.
Thus, by using a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton, in the case of an electronic component having a laminated structure, it is possible to suppress interlayer migration, thereby achieving good interlayer insulation. Reliability can be obtained. In particular, since migration tends to occur on the surface of the insulating layer roughened by the desmear treatment, the present invention is useful in that it is easy to ensure interlayer insulation reliability even in such a case.
In addition, the effect of lowering the thermal expansibility by blending the fine powder is remarkably exhibited by the hydrophilic fine powder among the fine powders. Since such fine powders have a large quantum effect on optical, electrical, and magnetic properties, physical properties such as reactivity and electrical properties change, and unexpected changes can occur. This is considered to be the reason why the reliability of insulation between layers is inferior in the case of an electronic component having a laminated structure as in this case. When the fine powder is, for example, hydrophilic particles such as fine cellulose fibers, migration between layers is particularly bad. This point can be solved by using a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton.

[Cyclic ether compound having at least one of naphthalene skeleton and anthracene skeleton]
A cyclic ether compound having a naphthalene skeleton is a compound having a naphthalene skeleton or a structure derived from a naphthalene skeleton and having a cyclic ether. Cyclic ether compounds having a naphthalene skeleton are not particularly limited, but those having two or more cyclic ethers in one molecule are preferred. The cyclic ether may be a cyclic thioether.
Commercially available products include Epiclon HP-4032, HP-4032D, HP-4700, HP-4770, HP-5000 (all manufactured by DIC Corporation), NC-7000L, NC-7300L, NC-7700L (all Japanese Kayaku Co., Ltd.), ZX-1355, ESN-155, ESN-185V, ESN-175, ESN-355, ESN-375, ESN-475V, ESN-485 (all manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) etc.

A cyclic ether compound having an anthracene skeleton is a compound having an anthracene skeleton or a structure derived from an anthracene skeleton and having a cyclic ether. Cyclic ether compounds having an anthracene skeleton are not particularly limited, but those having two or more cyclic ethers in one molecule are preferred. The cyclic ether may be a cyclic thioether.
Commercially available products include YX-8800 (manufactured by Mitsubishi Chemical Corporation).

The amount of the cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass, based on the total amount of the composition excluding the solvent. % or more and 40 mass % or less, more preferably 1.5 mass % or more and 30 mass % or less. When the blending amount of the cyclic ether compound is 0.5% by mass or more, it is possible to prevent deterioration in insulation reliability between layers due to fine cellulose fibers. On the other hand, when it is 80% by mass or less, curability is improved.

In the present invention, the cyclic ether compound having at least one of the naphthalene skeleton and the anthracene skeleton functions as a curable resin, and includes a cyclic ether compound having a naphthalene skeleton and a cyclic ether compound having an anthracene skeleton. may be used alone or in combination.

In the present invention, if desired, a curable resin such as a thermosetting resin or a photocurable resin other than the cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton can be used in combination.

Regarding the third object of the present invention, in the curable resin composition of the present invention, at least It is preferred that one species is included.
Thus, by using at least one selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenolic resin having a dicyclopentadiene skeleton, the dielectric constant and the dielectric loss tangent are lowered, resulting in a low dielectric constant. An electronic component having properties can be obtained. On the other hand, by using the fine powder, it is possible to ensure the adhesion between the cured product and the plated copper, and to enable the formation of high-definition circuits.
In addition, the fine powder used in the present invention is blended with a curable resin having a dicyclopentadiene skeleton with low adhesion to plated copper, so that the cured product of the composition containing such a curable resin is very high. Adhesion with plated copper can be obtained. Moreover, this effect can be obtained without deteriorating the dielectric properties derived from the dicyclopentadiene skeleton.

[Cyclic Ether Compound Having Dicyclopentadiene Skeleton and Phenolic Resin Having Dicyclopentadiene Skeleton]
A cyclic ether compound having a dicyclopentadiene skeleton is a compound having a dicyclopentadiene skeleton or a structure derived from a dicyclopentadiene skeleton and having a cyclic ether. Although the cyclic ether compound having a dicyclopentadiene skeleton is not particularly limited, those having two or more cyclic ethers in one molecule are preferred. The cyclic ether may be a cyclic thioether.
Commercially available products include Epiclon HP-7200, HP-7200H, HP-7200L (all manufactured by DIC Corporation), XD-1000-1L, XD-1000-2L (all manufactured by Nippon Kayaku Co., Ltd.), Tactix558, Tactix756 (both manufactured by Huntsman Advanced Materials) and the like.

A phenolic resin having a dicyclopentadiene skeleton is a compound having a dicyclopentadiene skeleton or a structure derived from a dicyclopentadiene skeleton and having a phenolic hydroxyl group. Phenolic resins having a dicyclopentadiene skeleton are not particularly limited, but those having two or more phenolic hydroxyl groups in one molecule are preferred. Commercially available products include Resitop GDP-6085, Resitop GDP-6095LR, Resitop GDP-6095HR, Resitop GDP-6115L, Resitop GDP-6115H, Resitop GDP-6140 (all manufactured by Gunei Chemical Industry Co., Ltd.), J-DPP-95. , and J-DPP-115 (both manufactured by JFE Chemical Co., Ltd.).

The amount of at least one compound selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenolic resin having a dicyclopentadiene skeleton is preferably 0.5 mass with respect to the total amount of the composition excluding the solvent. % or more and 80 mass % or less, more preferably 1 mass % or more and 40 mass % or less, and still more preferably 1.5 mass % or more and 30 mass % or less. When the amount of at least one selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenolic resin having a dicyclopentadiene skeleton is 0.5% by mass or more, good low dielectric properties can be obtained. can. On the other hand, when it is 80% by mass or less, curability is improved.

In the present invention, at least one selected from the group consisting of the cyclic ether compound having a dicyclopentadiene skeleton and the phenolic resin having a dicyclopentadiene skeleton functions as a curable resin and has a dicyclopentadiene skeleton. A cyclic ether compound having a dicyclopentadiene skeleton and a phenol resin having a dicyclopentadiene skeleton may be used alone or in combination.

In the present invention, if desired, a thermosetting resin or a photocurable resin other than at least one selected from the group consisting of a cyclic ether compound having a dicyclopentadiene skeleton and a phenolic resin having a dicyclopentadiene skeleton A curable resin such as can be used in combination.

Regarding the fourth object of the present invention, the curable resin composition of the present invention preferably contains a phenoxy resin as the curable resin.
In this way, by using the phenoxy resin and the fine powder, it is possible to remove smears in a short time in the desmear process, and the surface roughness of the cured product can be kept small, so high frequencies can be efficiently transmitted. It becomes possible to On the other hand, even if the surface roughness is small, the adhesiveness between the cured product and the plated copper can be ensured, so it is possible to form a high-definition circuit.
In addition, by using the fine powder according to the present invention, it is possible to easily remove smear from a cured product of a composition containing such fine powder, and the surface roughness of the cured product can be suppressed to a low level. Adhesion to plated copper can also be ensured. This effect is exhibited by a combination with a phenoxy resin, which will be described later. In addition, this effect is remarkably exhibited even among fine powders that are hydrophilic.

[phenoxy resin]
Phenoxy resins are generally synthesized from bisphenols and epichlorohydrin. The bisphenols to be used include bisphenol A type, bisphenol F type, bisphenol S type, biphenyl type, bisphenolacetophenone type, fluorene type, trimethylcyclohexane type, terpene type, and the like, and also copolymers of two or more of these types. be. Although the phenoxy resin is not particularly limited, when it is used as a photocurable composition, a terminal epoxy type is desirable. Commercially available products include 1256, 4250, 4275, YX8100, YX6954, YL7213, YL7290, YL7482 (all manufactured by Mitsubishi Chemical Corporation), FX280, FX293, YP50, YP50S, YP55, YP70, YPB-43C (all new Nippon Steel & Sumikin Chemical Co., Ltd.), PKHB, PKHC, PKHH, PKHJ, PKFE, PKHP-200, PKCP-80 (all manufactured by InChem) and the like.

The amount of the phenoxy resin is preferably 0.1% by mass or more and 50% by mass or less, more preferably 0.3% by mass or more and 30% by mass or less, still more preferably 0.1% by mass or more and 50% by mass or less, based on the total amount of the composition excluding the solvent. It is 5 mass % or more and 10 mass % or less. When the amount of the phenoxy resin is 0.1% by mass or more, the removability of smear caused by fine powder and the adhesion of the conductor are improved. On the other hand, when the content is 50 parts by mass or less, curability is improved.

In the present invention, curable resins such as thermosetting resins and photocurable resins other than phenoxy resins can be used in combination as desired.

Regarding the fifth object of the present invention, the curable resin composition of the present invention contains, as a curable resin, at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton. is preferred.
Thus, by using at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton, when the plated copper is solidly formed on the cured product, the parts can be mounted. It is possible to suppress the occurrence of swelling in the plated copper due to thermal history such as.
In addition, the effect of lowering the thermal expansibility by blending the fine powder is remarkably exhibited by the hydrophilic fine powder among the fine powders. On the other hand, when the fine powder is, for example, hydrophilic particles such as fine cellulose fibers, it is considered that the solid plated copper described above is particularly likely to swell at high temperatures. Application is useful.

[At least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton]
A cyclic ether compound having a biphenyl skeleton is a compound having a biphenyl skeleton or a structure derived from a biphenyl skeleton and having a cyclic ether. Cyclic ether compounds having a biphenyl skeleton are not particularly limited, but those having two or more cyclic ethers in one molecule are preferred. The cyclic ether may be a cyclic thioether.
Commercially available products include NC-3000H, NC-3000L, NC-3100 (all manufactured by Nippon Kayaku Co., Ltd.), YX-4000, YX4000H, YL-6121 (all manufactured by Mitsubishi Chemical Corporation), and Denacol EX. -412 (manufactured by Nagase ChemteX Corporation) and the like.

The amount of the cyclic ether compound having a biphenyl skeleton is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 40% by mass or less, based on the total amount of the composition excluding the solvent. is 1.5% by mass or more and 30% by mass or less. When the compounding amount of the above compound is 0.5% by mass or more, it is possible to prevent blistering of plated copper caused by fine particles. On the other hand, when it is 80% by mass or less, curability is improved.

A phenolic resin having a biphenyl skeleton is a compound having a biphenyl skeleton or a structure derived from a biphenyl skeleton and having a phenolic hydroxyl group. Phenolic resins having a biphenyl skeleton are not particularly limited, but those having two or more phenolic hydroxyl groups in one molecule are preferred. Commercially available products include GPH-65, GPH-103 (manufactured by Nippon Kayaku Co., Ltd.), MEH-7851SS, MEH-7851M, MEH-7851-4H, MEH-7851-3H (manufactured by Meiwa Kasei Co., Ltd.), HE200 (manufactured by Air Water Inc.) and the like can be mentioned.

The amount of the phenol resin having a biphenyl skeleton is preferably 0.5% by mass or more and 60% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and still more preferably It is 1.5 mass % or more and 20 mass % or less. When the compounding amount of the above compound is 0.5% by mass or more, it is possible to prevent blistering of plated copper caused by fine particles. On the other hand, when it is 60% by mass or less, the curability is improved.

In the present invention, at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton functions as a curable resin, and a cyclic ether compound having a biphenyl skeleton; A phenol resin having a biphenyl skeleton may be used alone or in combination.

In the present invention, if desired, a thermosetting resin other than at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton, a photocurable resin, etc. A resin can be used in combination.

(Thermosetting resin)
As the thermosetting resin, any resin can be used as long as it is cured by heating and exhibits electrical insulating properties. For example, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol E epoxy resin, bisphenol Bisphenol type epoxy resins such as M type epoxy resin, bisphenol P type epoxy resin, bisphenol Z type epoxy resin, bisphenol A novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. Novolak type epoxy resin, biphenyl type epoxy Resins, biphenylaralkyl type epoxy resins, arylalkylene type epoxy resins, tetraphenylolethane type epoxy resins, phenoxy type epoxy resins, dicyclopentadiene type epoxy resins, norbornene type epoxy resins, adamantane type epoxy resins, fluorene type epoxy resins, glycidyl methacrylate copolymer epoxy resin, copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, Biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, sorbitol polyglycidyl ether, tris(2,3-epoxypropyl) isocyanurate, triglycidyl Tris(2-hydroxyethyl)isocyanurate, novolac-type phenolic resins such as phenolic novolac resin, cresol novolac resin, bisphenol A novolak resin, unmodified resol phenolic resin, oil-modified resole modified with tung oil, linseed oil, walnut oil, etc. Phenolic resins such as resol-type phenolic resins such as phenolic resins, phenoxy resins, urea (urea) resins, triazine ring-containing resins such as melamine resins, unsaturated polyester resins, bismaleimide resins, diallyl phthalate resins, silicone resins, benzoxazine rings resin, norbornene resin, cyanate resin, isocyanate resin, urethane resin, benzocyclobutene resin, maleimide resin, bismaleimide triazine resin, polyazomethine resin, thermosetting polyimide, dicyclopentadiene resin Examples include active ester compounds such as enyldiphenol ester compounds, bisphenol A diacetate, diphenyl phthalate, diphenyl terephthalate, and bis[4-(methoxycarbonyl)phenyl] terephthalate. Among them, the use of an active ester compound is preferable because it can reduce the thermal expansion in a high-temperature region and satisfactorily ensure a low coefficient of thermal expansion.

(Photosetting resin (radical polymerization))
As such a photo-curing resin, any resin may be used as long as it is cured by active energy ray irradiation and exhibits electrical insulating properties. In particular, a compound having one or more ethylenically unsaturated bonds in the molecule is preferably used. As the compound having an ethylenically unsaturated bond, a known and commonly used photopolymerizable oligomer, photopolymerizable vinyl monomer, and the like are used.

Examples of photopolymerizable oligomers include unsaturated polyester-based oligomers and (meth)acrylate-based oligomers. (Meth)acrylate oligomers include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolak epoxy (meth)acrylate, bisphenol type epoxy (meth)acrylate, urethane (meth)acrylate, epoxyurethane (meth)acrylate, ) acrylates, polyester (meth)acrylates, polyether (meth)acrylates, polybutadiene-modified (meth)acrylates, and the like. In this specification, (meth)acrylate is a generic term for acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions.

Examples of photopolymerizable vinyl monomers include known and commonly used monomers, for example, styrene derivatives such as styrene, chlorostyrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate and vinyl benzoate; vinyl isobutyl ether, vinyl- Vinyl ethers such as n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinylcyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, (Meth)acrylamides such as methacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; triallyl isocyanurate, diallyl phthalate, Allyl compounds such as diallyl isophthalate; 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc. Esters of (meth)acrylic acid; hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and pentaerythritol tri(meth)acrylate; methoxyethyl (meth)acrylate, ethoxyethyl Alkoxyalkylene glycol mono (meth) acrylates such as (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylates, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di ( Alkylene polyol poly(meth)acrylates such as meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol Polyoxyalkylene glycol poly(meth)acrylates such as di(meth)acrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane tri(meth)acrylate, etc. meth)acrylates; poly(meth)acrylates such as hydroxybivalic acid neopentylglycol ester di(meth)acrylate; isocyanurate type poly(meth)acrylates such as tris[(meth)acryloxyethyl]isocyanurate, etc. are mentioned.

(Photosetting resin (cationic polymerization))
Alicyclic epoxy compounds, oxetane compounds, vinyl ether compounds, and the like can be suitably used as such photocurable resins. Among these, alicyclic epoxy compounds include 3,4,3′,4′-diepoxybicyclohexyl, 2,2-bis(3,4-epoxycyclohexyl)propane, 2,2-bis(3,4-epoxy cyclohexyl)-1,3-hexafluoropropane, bis(3,4-epoxycyclohexyl)methane, 1-[1,1-bis(3,4-epoxycyclohexyl)]ethylbenzene, bis(3,4-epoxycyclohexyl) Adipate, 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate, (3,4-epoxy-6-methylcyclohexyl)methyl-3′,4′-epoxy-6-methylcyclohexanecarboxylate, ethylene - Alicyclic epoxy compounds having an epoxy group such as 1,2-bis(3,4-epoxycyclohexanecarboxylic acid) ester, cyclohexene oxide, 3,4-epoxycyclohexylmethyl alcohol, and 3,4-epoxycyclohexylethyltrimethoxysilane etc. Commercially available products include, for example, Celoxide 2000, Celoxide 2021, Celoxide 3000 and EHPE3150 manufactured by Daicel Chemical Industries, Ltd.; Epomic VG-3101 manufactured by Mitsui Chemicals, Inc.; E-1031S manufactured by Yuka Shell Epoxy Co., Ltd. TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd.; EPB-13 and EPB-27 manufactured by Nippon Soda Co., Ltd.;

The oxetane compounds include bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, 1,4-bis[(3-methyl-3- Oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, (3-ethyl-3-oxetanyl)methyl acrylate , (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and their oligomers or copolymers, as well as polyfunctional oxetanes such as oxetane alcohols and novolak resins, poly(p -hydroxystyrene), cardo-type bisphenols, calixarenes, calixresorcinarenes, or etherified products with resins having a hydroxyl group such as silsesquioxane, unsaturated monomers having an oxetane ring and alkyl (meth)acrylates Examples include oxetane compounds such as copolymers. Commercially available products include, for example, ethanecol OXBP, OXMA, OXBP, EHO manufactured by Ube Industries, Ltd., xylylene bisoxetane, and Aron oxetane OXT-101, OXT-201, OXT-211 and OXT manufactured by Toagosei Co., Ltd. -221, OXT-212, OXT-610, PNOX-1009 and the like.

Examples of vinyl ether compounds include cyclic ether-type vinyl ethers such as isosorbite divinyl ether and oxanorbornene divinyl ether (vinyl ethers having a cyclic ether group such as an oxirane ring, an oxetane ring, and an oxolane ring); aryl vinyl ethers such as phenyl vinyl ether; n-butyl vinyl ether. , octyl vinyl ether; cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; polyfunctional vinyl ethers such as hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexanedivinyl ether, cyclohexanedimethanol divinyl ether; includes vinyl ether compounds having substituents such as alkyl groups and allyl groups. Examples of commercially available products include 2-hydroxyethyl vinyl ether (HEVE), diethylene glycol monovinyl ether (DEGV), 2-hydroxybutyl vinyl ether (HBVE) and triethylene glycol divinyl ether manufactured by Maruzen Petrochemical Co., Ltd.

When the curable resin composition of the present invention is used as an alkali-developable photosolder resist that can be developed with an aqueous alkali solution, it is also preferable to use a carboxyl group-containing resin.

(Carboxyl group-containing resin)
As the carboxyl group-containing resin, both a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond and a carboxyl group-containing resin having no photosensitive unsaturated double bond can be used. and is not limited to a specific one. As the carboxyl group-containing resin, particularly the resins listed below can be preferably used.
(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid and a compound having an unsaturated double bond, and a carboxyl group-containing resin obtained by modifying it to adjust the molecular weight and acid value.
(2) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth)acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.
(3) reacting an unsaturated monocarboxylic acid with a copolymer of a compound having one epoxy group and an unsaturated double bond in one molecule and a compound having an unsaturated double bond, and produced by this reaction A photosensitive carboxyl group-containing resin obtained by reacting a saturated or unsaturated polybasic acid anhydride with a secondary hydroxyl group.
(4) After reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride, a compound having one epoxy group and an unsaturated double bond in each molecule is added to the carboxylic acid produced by this reaction. A photosensitive hydroxyl group- and carboxyl group-containing resin obtained by a reaction.
(5) A photosensitive carboxyl group obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting some or all of the secondary hydroxyl groups generated by this reaction with a polybasic acid anhydride. Contained resin.
(6) reacting a polyfunctional epoxy compound, a compound having two or more hydroxyl groups in one molecule and one reactive group other than a hydroxyl group that reacts with the epoxy group, and an unsaturated group-containing monocarboxylic acid to obtain A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.
(7) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product of a resin having a phenolic hydroxyl group and an alkylene oxide or a cyclic carbonate, and reacting the resulting reaction product with a polybasic acid anhydride. Carboxyl group-containing photosensitive resin.
(8) a reaction product obtained by reacting a polyfunctional epoxy compound, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and an unsaturated group-containing monocarboxylic acid; A carboxyl group-containing photosensitive resin obtained by reacting an anhydride group of a polybasic acid anhydride with an alcoholic hydroxyl group of the above.

[Filler]
The curable resin composition of the present invention preferably further contains a filler other than the fine powder. Examples of fillers include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, and aluminum nitride. be done. Among these fillers, silica, especially spherical silica, is preferred because it has a small specific gravity, can be blended in a composition at a high proportion, and is excellent in low thermal expansion properties. The average particle size of the filler is preferably 3 μm or less, more preferably 1 μm or less. The average particle size of the filler can be determined using a laser diffraction particle size distribution analyzer.

The amount of filler compounded is 1 to 90% by mass, preferably 2 to 80% by mass, more preferably 5 to 75% by mass of the total amount of the composition excluding the solvent. By setting the blending amount of the filler within the above range, it is possible to ensure good coating performance of the cured product after curing.

The curable resin composition of the present invention may further contain other conventional compounding components as appropriate, depending on its use. Other conventional compounding components include, for example, curing catalysts, photopolymerization initiators, colorants, organic solvents, and the like.

As a curing catalyst, phenolic compounds; Imidazole derivatives such as (2-cyanoethyl)-2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzyl amines, amine compounds such as 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, commercially available products include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Shikoku Chemical Industry Co., Ltd.), U-CAT3503N, U-CAT3502T, DBU, DBN, U-CATSA102, U- CAT5002 (manufactured by San-Apro Co., Ltd.), etc., may be used alone or in combination of two or more. Similarly, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6 S-triazine derivatives such as -diamino-S-triazine/isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine/isocyanuric acid adduct can also be used.

In the present invention, among others, phenol compounds are preferably used. Examples of phenolic compounds include phenol novolak resins, alkylphenol novolak resins, triazine structure-containing novolak resins, bisphenol A novolak resins, dicyclopentadiene type phenol resins, Zyloc type phenol resins, copna resins, terpene-modified phenol resins, polyvinyl phenols, and the like. phenol compounds, naphthalene-based curing agents, fluorene-based curing agents, and the like can be used alone or in combination of two or more. Examples of the phenol compounds include HE-610C and 620C manufactured by Air Water Inc., TD-2131, TD-2106, TD-2093, TD-2091, TD-2090 and VH-4150 manufactured by DIC Corporation, VH-4170, KH-6021, KA-1160, KA-1163, KA-1165, TD-2093-60M, TD-2090-60M, LF-6161, LF-4871, LA-7052, LA-7054, LA- 7751, LA-1356, LA-3018-50P, EXB-9854, Nippon Steel & Sumikin Chemical Co., Ltd. SN-170, SN180, SN190, SN475, SN485, SN495, SN375, SN395, JX Nippon Oil & Energy Corporation DPP manufactured by Meiwa Kasei Co., Ltd. HF-1M, HF-3M, HF-4M, H-4, DL-92, MEH-7500, MEH-7600-4H, MEH-7800, MEH-7851, MEH -7851-4H, MEH-8000H, MEH-8005, XL, XLC, RN, RS, RX manufactured by Mitsui Chemicals, Inc., but not limited thereto. These phenol compounds can be used alone or in combination of two or more.

The amount of the curing catalyst used in the present invention is sufficient at a ratio normally used. 100 parts by mass, more preferably 10 to 50 parts by mass, and in the case of other curing catalysts, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass Department.

The photopolymerization initiator is for curing the photocurable resin among the curable resins, and may be a photoradical polymerization initiator or a photocationic polymerization initiator.
Examples of photoradical polymerization initiators include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy -Acetophenones such as 2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino -1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone aminoalkylphenones such as; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and other anthraquinones; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chloro Thioxanthones such as thioxanthone and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl)-2,4,4- pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, etc. Phosphine oxides; various peroxides, titanocene-based initiators, and the like. These include photosensitizers such as N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine and other tertiary amines. It may be used in combination with a drug or the like.

Examples of photocationic polymerization initiators include onium salts such as diazonium salts, iodonium salts, bromonium salts, chloronium salts, sulfonium salts, selenonium salts, pyrylium salts, thiapyrylium salts, and pyridinium salts; tris(trihalomethyl)-s-triazine; 2-nitrobenzyl ester of sulfonic acid; iminosulfonate; 1-oxo-2-diazonaphthoquinone-4-sulfonate derivative; N-hydroxyimide=sulfonate; tri(methanesulfonyloxy)benzene derivatives; bissulfonyldiazomethanes; sulfonylcarbonylalkanes; sulfonylcarbonyldiazomethanes; disulfone compounds and the like.
These photopolymerization initiators can be used alone or in combination of two or more.

The amount of the photopolymerization initiator compounded is, for example, 0.05 to 10 parts by mass, preferably 0.1 to 8 parts by mass, more preferably 0.1 to 8 parts by mass, based on 100 parts by mass of the photocurable resin, in terms of solid content. 3 to 6 parts by mass. By blending the photopolymerization initiator within this range, the photocurability on copper is sufficient, the curability of the coating film is improved, and the coating film properties such as chemical resistance are improved. also improve.

As the coloring agent, commonly known coloring agents such as red, blue, green and yellow can be used, and any of pigments, dyes and pigments can be used. However, it is preferable not to contain halogen from the viewpoint of environmental load reduction and influence on the human body.

Blue colorant:
Blue colorants include phthalocyanines and anthraquinones, and pigments are compounds classified as pigments. (published by The Society of Dyers and Colourists), which may be numbered: Pigment Blue 15, Pigment Blue 15:1, Pigment Blue 15:2, Pigment Blue 15:3, Pigment Blue 15:4 , Pigment Blue 15:6, Pigment Blue 16, Pigment Blue 60.
染料系としては、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ３５、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ６３、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ６８、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ７０、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ８３、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ８７、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ９４、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ９７、Ｓｏｌｖｅｎｔ Ｂｌｕｅ １２２、Ｓｏｌｖｅｎｔ Ｂｌｕｅ １３６、Ｓｏｌｖｅｎｔ Ｂｌｕｅ ６７、Ｓｏｌｖｅｎｔ Blue 70 or the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Green colorant:
The green colorants also include phthalocyanine-based and anthraquinone-based coloring agents, and specifically Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, etc. can be used. . In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone colorants, and specific examples thereof include the following.
Anthraquinone series: Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202.
Isoindolinone series: Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185.
Condensed azo series: Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180.
Benzimidazolone series: Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181.
Monoazo series: Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116 , 167, 168, 169, 182, 183.
Disazo series: Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

Red colorant:
Examples of red colorants include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone colorants. be done.
Monoazo type: Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151 , 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.
Disazo series: Pigment Red 37, 38, 41.
Monoazo lake system: Pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:1, 52:2, 53:1, 53:2, 57 : 1, 58: 4, 63: 1, 63: 2, 64: 1, 68.
Benzimidazolone series: Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208.
Perylene series: Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 190, Pigment Red 194, Pigment Red 224.
Diketopyrrolopyrrole series: Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, Pigment Red 272.
Condensed azo systems: Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221, Pigment Red 242.
Anthraquinone series: Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207.
Quinacridones: Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209.

In addition, coloring agents such as purple, orange, brown and black may be added for the purpose of adjusting the color tone.
Specific examples include Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, C.I. I. Pigment Orange 1, C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 14, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 17, C.I. I. Pigment Orange 24, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 40, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 46, C.I. I. Pigment Orange 49, C.I. I. Pigment Orange 51, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 63, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 71, C.I. I. Pigment Orange 73, C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, C.I. I. Pigment Black 1, C.I. I. Pigment Black 7, etc.

A specific mixing ratio of the coloring agent can be appropriately adjusted depending on the type of coloring agent used and the type of other additives.

Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and diethylene glycol. Glycol ethers such as monoethyl ether, dipropylene glycol monoethyl ether and triethylene glycol monoethyl ether; Esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and esters of the above glycol ethers; Alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha.

In addition, known and commonly used additives such as antifoaming agents/leveling agents, thixotropy-imparting agents/thickening agents, coupling agents, dispersants, and flame retardants can be added as necessary.

The curable resin composition of the present invention may be used as a dry film, or may be used as a liquid. The curable resin composition of the present invention can also be used as a prepreg, which is obtained by coating or impregnating a sheet-like fibrous base material such as glass cloth, glass or aramid non-woven fabric and semi-curing it. When used as a liquid, it may be one-liquid or two-liquid or more. Examples of the two-liquid composition include fine cellulose fibers, at least one selected from the group consisting of cyclic ether compounds having a naphthalene skeleton and cyclic ether compounds having an anthracene skeleton, and a cyclic ether compound having a dicyclopentadiene skeleton. and at least one selected from the group consisting of a phenol resin having a dicyclopentadiene skeleton, a phenoxy resin, or at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenol resin having a biphenyl skeleton may be separate compositions.

The dry film of the present invention has a resin layer obtained by coating and drying the curable resin composition of the present invention on a carrier film. When forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate value, and then a comma coater, blade coater, lip coater, rod coater, and squeeze coater are used. , a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like to a uniform thickness on the carrier film. After that, the applied composition is usually dried at a temperature of 40 to 130° C. for 1 to 30 minutes to form a resin layer. The coating thickness is not particularly limited, but is generally selected as appropriate in the range of 3 to 150 μm, preferably 5 to 60 μm, in terms of thickness after drying.

As the carrier film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, but is generally selected appropriately within the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming the resin layer composed of the curable resin composition of the present invention on the carrier film, for the purpose of preventing dust from adhering to the surface of the resin layer, a peelable cover is further placed on the surface of the resin layer. It is preferred to laminate the films. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. Any cover film may be used as long as the adhesive force between the cover film and the resin layer is smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the curable resin composition of the present invention may be coated on the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface of the resin layer. That is, either a carrier film or a cover film may be used as the film to which the curable resin composition of the present invention is applied when producing the dry film in the present invention.

The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the dry film of the present invention.

The electronic component of the present invention comprises the cured product of the present invention, and specific examples thereof include printed wiring boards. The cured product of the present invention can be suitably used in electronic parts that require insulation reliability between layers. In particular, a multilayer printed wiring board using the curable resin composition of the present invention as an interlayer insulating material can have good interlayer insulation reliability.

FIG. 2-1 (FIGS. 3-1, 4-1, and 5-1) shows a partial cross-sectional view showing one configuration example of a multilayer printed wiring board according to one example of the electronic component of the present invention. The illustrated multilayer printed wiring board can be manufactured, for example, as follows. First, a through hole is formed in the core substrate 2 on which the conductor pattern 1 is formed. Formation of the through-holes can be performed by appropriate means such as drilling, die punching, and laser light. After that, a roughening treatment is performed using a roughening agent. In general, the roughening treatment is carried out by swelling with an organic solvent such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, methoxypropanol, or an alkaline aqueous solution such as caustic soda, caustic potash, etc., followed by dichromate, permanganate. It is carried out using an oxidizing agent such as salt, ozone, hydrogen peroxide/sulfuric acid, nitric acid.

Next, the conductor pattern 3 is formed by a combination of electroless plating and electrolytic plating. The step of forming a conductor layer by electroless plating is a step of immersing the substrate in an aqueous solution containing a plating catalyst to adsorb the catalyst and then immersing the substrate in a plating solution to deposit plating. A predetermined circuit pattern is formed on the conductor layer on the surface of the core substrate 2 according to a conventional method (subtractive method, semi-additive method, etc.), and as shown in the figure, conductor patterns 3 are formed on both sides. At this time, a plated layer is also formed in the through hole, and as a result, the connection portion 4 of the conductor pattern 3 of the multilayer printed wiring board and the connection portion 1a of the conductor pattern 1 are electrically connected. , through holes 5 are formed.

Next, an appropriate method such as screen printing, spray coating, or curtain coating is used to apply, for example, a thermosetting composition, followed by heat curing to form the interlayer insulating layer 6 . When a dry film or prepreg is used, the interlayer insulating layer 6 is formed by lamination or hot plate pressing and heat curing. Next, vias 7 for electrically connecting connection portions of each conductor layer are formed by suitable means such as laser light, and conductor patterns 8 are formed in the same manner as the conductor patterns 3 described above. Furthermore, an interlayer insulating layer 9, vias 10 and conductor patterns 11 are formed in a similar manner. After that, a multilayer printed wiring board is manufactured by forming a solder resist layer 12 as the outermost layer. In the above, an example in which an interlayer insulating layer and a conductor layer are formed on a laminated substrate has been described, but a single-sided substrate or a double-sided substrate may be used instead of the laminated substrate.

<<Second aspect of the present invention>>
The curable resin composition of the second aspect of the present invention is characterized by containing (A) fine powder having at least one dimension smaller than 100 nm, and (B) a thermosetting component.
According to such a characteristic configuration of the second aspect of the present invention, in the printed wiring board having at least one of the concave portion and the through hole, the via hole or through hole filled with the resin filler is filled with the resin filler even when the component is mounted at a high temperature. Therefore, it is possible to exhibit the effect peculiar to the present invention that there is no bulge in recesses such as the above, conductor pads on through holes, and wiring such as via holes.
Although the detailed mechanism of the swelling of the wiring due to high temperature heating is not clear, it is caused by the large difference in thermal expansion coefficient between the via holes and through holes made of copper and the resin filler at high temperatures. It is considered to be
In general, a method is known in which a large amount of inorganic filler is blended in order to reduce the thermal expansion coefficient of an organic substance such as resin to a coefficient close to that of metal. According to this method, it is certainly possible to make the coefficient of thermal expansion close to that of metal near room temperature, but when heating to high temperatures such as when mounting parts, the coefficient of thermal expansion remains low even if a large amount of filler is contained. Much larger than metal. For this reason, it is considered that the resin filler expands, for example, in the vertical direction of the through-hole when heated to a high temperature. Moreover, pressure is applied to the walls of the through holes and the bottoms of the via holes, which suppress the expansion, so that reliability deterioration such as disconnection occurs.
In this regard, according to the present invention, since fine powder such as fine cellulose fibers is dispersed in the resin filler, the fine powder interacts with each other such that the fine powder attracts each other, thereby exerting a reinforcing effect. An increase in the coefficient of thermal expansion can be suppressed even when heated to a high temperature, and as a result, it is thought that the unique effect of not causing swelling of the wiring due to high-temperature heating can be obtained.

Further, according to the characteristic configuration of the second aspect of the present invention, in the method for manufacturing a printed wiring board having at least one of a recess and a through hole, the curable resin composition filled in the recess and the through hole It is possible to exhibit the effect peculiar to the present invention that the resin composition having a dilute filler component does not bleed out during curing.
Although the detailed mechanism of the blurring of the resin component, which is a thin filler component during curing, is not clear, it is believed to be caused by the fact that a liquid resin component is always used to adjust the viscosity. Conceivable. It is desirable that the resin filler that fills recesses and through holes such as via holes and through holes does not use solvents, which are volatile components, as much as possible. It is thought that the viscosity decreases before the curing reaction occurs, and the resin component exudes along the profile of the copper foil due to capillary action.
In this regard, according to the second aspect of the present invention, since fine powder such as fine cellulose fibers is dispersed in the resin filler, the above-described interaction between the fine powders produces a reinforcing effect, Since the viscosity at rest is maintained even after being heated to a high temperature, it is thought that a unique effect can be obtained in which curing proceeds before the resin component oozes out into the copper foil.

Further, according to such a characteristic configuration of the present invention, in the printed wiring board having at least one of the concave portion and the through hole, in the polishing step after curing of the curable resin composition filled in the concave portion and the through hole, smoothness is obtained. Therefore, it is possible to exhibit the effect peculiar to the present invention that dents such as holes due to excessive polishing for hardening do not occur.
Although the detailed mechanism of the dents in the recesses and through holes in this polishing process is not clear, the resin filler is used so as to completely fill the recesses and through holes such as via holes and through holes. For example, the filler is filled around the through hole and above the through hole so as to protrude (FIG. 7-4(a)), and after thermal curing, unnecessary portions are scraped off with a buff roll or the like in a polishing process. However, since such a thermoset resin filler is deformed when pressure is applied, it is easy to leave uncut portions (FIG. 7-4(b)). At this time, if the polishing conditions are strict so that there is no uncut portion, the resin filler may be excessively polished, resulting in dents in the through-hole portion (FIG. 7-4(c)).
In this regard, according to the second aspect of the present invention, since fine powder such as fine cellulose fibers is dispersed in the resin filler, the interaction between the fine powders described above produces a reinforcing effect, and the resin Since the strength of the steel increases, deformation under pressure is reduced, and it is thought that a unique effect of enabling uniform polishing can be obtained.
Hereinafter, embodiments of the second aspect of the present invention will be described in detail.

[(A) fine powder]
As the fine powder used in the second aspect of the present invention, the same fine powder as explained in the first aspect can be used. By using such fine powders, when a curable resin composition containing such fine powders is used as a resin filler for filling holes, etc., the fine powders interact with each other such that they attract each other. By exerting a reinforcing effect, as described above, swelling after high temperature heating and exudation of the resin component are less likely to occur, and it is possible to form a cured product that is less likely to dent the filler filled in the hole etc. even in the polishing process. become. In addition, this effect is remarkably exhibited even among fine powders that are hydrophilic.

[(B) thermosetting component]
The thermosetting component is not particularly limited, but compounds having two or more cyclic ethers in one molecule are preferred. The cyclic ether may be a cyclic thioether. A cyclic ether compound may be used individually by 1 type, and may use 2 or more types together. Among such cyclic ether compounds, epoxy resins and oxetane resins are preferred, and epoxy resins are particularly preferred.

A known epoxy resin can be used as the epoxy resin. For example, the thermosetting resin may be a resin that cures by heating and exhibits electrical insulation properties. Examples include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and bisphenol E epoxy resin. , Biphenyl type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, biphenylaralkyl type epoxy resin, arylalkylene type epoxy resin, tetraphenylolethane type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin , adamantane-type epoxy resin, fluorene-type epoxy resin, glycidyl methacrylate copolymer epoxy resin, copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, epoxy-modified polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4′-diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, sorbitol polyglycidyl ether, tris ( 2,3-epoxypropyl)isocyanurate, triglycidyltris(2-hydroxyethyl)isocyanurate and the like.

In the curable resin composition of the present invention, the dispersibility of fine powder such as fine cellulose fibers can be improved by mixing an epoxy resin having an amine as a precursor. Specifically, when a dispersion of fine powder is produced, the fluidity increases and the viscosity can be lowered, so that the workability improves and the viscosity of the composition decreases, so that the fine powder can be easily prepared without a solvent. Bodies can be mixed or blended.

Examples of epoxy resins using amines as precursors include positional isomers of tetraglycidyldiaminodiphenylmethane, glycidyl compounds of xylenediamine, triglycidylaminophenol, and glycidylaniline, and substituted products with alkyl groups and halogens. Commercial products of tetraglycidyldiaminodiphenylmethane include, for example, Sumepoxy ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), Araldite MY720, MY721, MY9512, MY9612, MY9634, MY9663 (manufactured by Huntsman Advanced Materials), JER604 (Mitsubishi (manufactured by Kagaku Co., Ltd.). Examples of commercially available products of triglycidylaminophenol include JER630 (manufactured by Mitsubishi Chemical Corporation), Araldite MY0500 and MY0510 (manufactured by Huntsman Advanced Materials), and ELM100 (manufactured by Sumitomo Chemical Co., Ltd.). Examples of commercially available glycidylanilines include GAN and GOT (manufactured by Nippon Kayaku Co., Ltd.).

In addition, when the curable resin composition of the present invention is made to have a low viscosity by mixing or blending fine powder such as fine cellulose fibers, the heat resistance is lowered. Blending these components tends to increase the viscosity, but this problem can be solved by blending the bisphenol A type epoxy resin and the bisphenol F type epoxy resin together.

Also, since alkyl glycidyl ethers such as 1,6-hexanediol diglycidyl ether have low viscosities, they are preferably used as diluents and viscosity modifiers when the viscosity of the composition is high.

In the present invention, thermosetting resins other than the cyclic ether compound may be used as the (B) thermosetting component, if desired. The thermosetting resin other than the cyclic ether compound may be any resin that is cured by heating. Phenolic resins such as resol-type phenolic resins such as oil-modified resol phenolic resins modified with tung oil, linseed oil, walnut oil, etc., triazine ring-containing resins such as phenoxy resins, urea (urea) resins, melamine resins, unsaturated polyester resins, Bismaleimide resin, diallyl phthalate resin, silicone resin, resin having benzoxazine ring, norbornene resin, cyanate resin, isocyanate resin, urethane resin, benzocyclobutene resin, maleimide resin, bismaleimide triazine resin, polyazomethine resin, heat curing active ester compounds such as polyimides, dicyclopentadienyl diphenol ester compounds, bisphenol A diacetate, diphenyl phthalate, diphenyl terephthalate, and bis[4-(methoxycarbonyl)phenyl] terephthalate.

The amount of thermosetting component (B) to be blended is preferably 10 to 70% by mass relative to the total amount of the composition. When it is 10% by mass or more, workability such as printing is excellent. When it is 70% by mass or less, the thermal expansion is further reduced. More preferably 20 to 60% by mass.

[Curing agent]
A curing agent is preferably used in the curable resin composition of the present invention, if desired.
As the curing agent of the present invention, for example, an imidazole compound can be used. Examples of imidazole compounds include 2-methylimidazole, 4-methyl-2-ethylimidazole, 2-phenylimidazole, 4-methyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-ethylimidazole, 2 -isopropylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole and other imidazole derivatives.

Moreover, the imidazole compound includes an imidazole compound containing a triazine structure. Examples of imidazole compounds containing a triazine structure include 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-S-triazine, 2,4-diamino-6-[2'-methylimidazolyl -(1′)]-ethyl-S-triazine, 2,4-diamino-6-[2′-undecylimidazolyl-(1′)]-ethyl-S-triazine, 2,4-diamino-6-[ 2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-S-triazine and the like can be mentioned. Examples of these commercially available products include 2MZ-A, 2MZ-AP, 2MZA-PW, C11Z-A and 2E4MZ-A (manufactured by Shikoku Kasei Co., Ltd.).

Among imidazole compounds, 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-S-triazine, 2,4-diamino-6-[2′-ethyl-4′-methyl Imidazolyl-(1′)]-ethyl-S-triazine is preferred. As a result, the curable resin composition has excellent storage stability and can be cured in a short time without causing cracks.

As a curing agent, compounds other than imidazole compounds may be used, for example, dicyandiamide and its derivatives, melamine and its derivatives, diaminomaleonitrile and its derivatives, diethylenetriamine, triethylenetetramine, tetramethylenepentamine, bis(hexamethylene). triamine, triethanolamine, diaminodiphenylmethane, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzyl Amines such as amines, organic acid hydrazides such as adipic acid dihydrazide and sebacic acid dihydrazide, 1,8-diazabicyclo[5.4.0]undecene-7,3,9-bis(3-aminopropyl)-2,4 ,8,10-tetraoxaspiro[5.5]undecane, organic phosphine compounds such as triphenylphosphine, tricyclohexylphosphine, tributylphosphine and methyldiphenylphosphine, and phenol compounds may also be used. In addition, commercially available products include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Shikoku Chemical Industry Co., Ltd.), ATU (manufactured by Ajinomoto Co., Inc.), U-CAT3503N, U-CAT3502T, and DBU. , DBN, U-CATSA102, U-CAT5002 (manufactured by San-Apro Co., Ltd.) and the like. Dicyandiamide, melamine, acetoguanamine, benzoguanamine, 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl]-2,4,8,10-tetraoxaspiro[ 5.5] Guanamine such as undecane, derivatives thereof, organic acid salts thereof, epoxy adducts, and the like are known to have adhesiveness to copper and antirust properties, and act as curing agents for epoxy resins. In addition, it can contribute to prevention of discoloration of copper on the printed wiring board.

Examples of the phenol compound include phenol novolak resin, alkylphenol novolak resin, triazine structure-containing novolak resin, bisphenol A novolak resin, dicyclopentadiene-type phenol resin, Zyloc-type phenol resin, copna resin, terpene-modified phenol resin, and polyvinylphenols. A phenolic compound such as , a naphthalene-based curing agent, a fluorene-based curing agent, or the like can be used alone or in combination of two or more. Examples of the phenol compounds include HE-610C and 620C manufactured by Air Water Inc., TD-2131, TD-2106, TD-2093, TD-2091, TD-2090 and VH-4150 manufactured by DIC Corporation, VH-4170, KH-6021, KA-1160, KA-1163, KA-1165, TD-2093-60M, TD-2090-60M, LF-6161, LF-4871, LA-7052, LA-7054, LA- 7751, LA-1356, LA-3018-50P, EXB-9854, Nippon Steel & Sumikin Chemical Co., Ltd. SN-170, SN180, SN190, SN475, SN485, SN495, SN375, SN395, JX Nippon Oil & Energy Corporation DPP manufactured by Meiwa Kasei Co., Ltd. HF-1M, HF-3M, HF-4M, H-4, DL-92, MEH-7500, MEH-7600-4H, MEH-7800, MEH-7851, MEH -7851-4H, MEH-8000H, MEH-8005, XL, XLC, RN, RS, RX manufactured by Mitsui Chemicals, Inc., but not limited thereto.

Curing agents may be used singly or in combination of two or more. The amount of the curing agent may be a known and commonly used amount for the thermosetting component, and is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. However, when the curing agent is a phenol compound, it is preferably 1 to 150 parts by mass with respect to 100 parts by mass of the epoxy resin.

[(C) boric acid ester compound]
The curable resin composition of the present invention can contain a borate ester compound. A borate ester compound is preferably used because it has the effect of further improving the storage stability of the resin composition. It is believed that the borate ester compound exerts such action by reacting with the surface of the latent curing accelerator to modify and encapsulate the surface of the latent curing agent. Boric acid ester compounds include trimethylborate, triethylborate, tri-n-propylborate, triisopropylborate, tri-n-butylborate, tripentylborate, triallylborate, trihexylborate, tricyclohexylborate, and trioctylborate. , trinonylborate, tridecylborate, tridodecylborate, trihexadecylborate, trioctadecylborate, tris(2-ethylhexyloxy)borane, bis(1,4,7,10-tetraoxaundecyl)(1, 4,7,10,13-pentoxatetradecyl)(1,4,7-trioxaundecyl)borane, tribenzylborate, triphenylborate, tri-o-tolylborate, tri-m-tolylborate, tri Ethanolamine borate etc. can be mentioned. These can be purchased as reagents. Commercially available products include Cure Duct L-07N and L-07E (manufactured by Shikoku Kasei Kogyo Co., Ltd.), which are blends of epoxy resin and phenol novolac resin.

The boric acid ester compounds may be used singly or in combination of two or more. The amount of the boric acid ester compound to be blended is preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the thermosetting component. If it is 0.01 part by mass or more, the storage stability will be good. If it is 3 parts by mass or less, the curability will be good.

[(D) Filler]
The curable resin composition of the present invention may further contain a filler other than the (A) fine powder. As the (A) filler other than the fine powder, both organic fillers and inorganic fillers can be used, as long as they are appropriately and commonly used and known according to the required properties of the curable resin composition of the present invention. However, it is more preferable to use an inorganic filler.
Inorganic fillers include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica powder, Neuburg silica, Examples include silicon nitride and aluminum nitride. Among inorganic fillers, calcium carbonate is preferred.

The shape of the filler may be spherical, needle-like, plate-like, scale-like, hollow, amorphous, hexagonal, cubic, flake-like, etc., but spherical is preferred from the viewpoint of high filling.

A filler may be used individually by 1 type, and may be used in combination of 2 or more type. The amount of the filler compounded is preferably 10-70% by mass, more preferably 20-60% by mass, relative to the total amount of the composition. When it is 10% by mass or more, workability such as printing is excellent. When it is 70% by mass or less, the thermal expansion becomes lower.

[Other ingredients]
In the curable resin composition of the present invention, it is not always necessary to use an organic solvent, but for the purpose of adjusting the viscosity of the composition, etc., an organic solvent may be added to the extent that voids do not occur.

Further, the curable resin composition of the present invention may optionally contain known and commonly used colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black and naphthalene black. , known and commonly used thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, tert-butyl catechol, pyrogallol, phenothiazine, clay, kaolin, organic bentonite, montmorillonite, etc., to impart storage stability during storage. Viscosity agent or thixotropic agent, antifoaming agent and/or leveling agent such as silicone type, fluorine type, polymer type, adhesion imparting agent such as imidazole type, thiazole type, triazole type, silane coupling agent, photopolymerization initiator , dispersants, and flame retardants.

The curable resin composition of the present invention may be one-component or two-component or more.

The curable resin composition of the present invention obtained as described above can be applied to via holes and through holes of printed wiring boards using conventionally used methods such as screen printing, roll coating, and die coating. It is possible to easily fill holes such as

Therefore, the viscosity of the curable resin composition of the present invention is preferably in the range of 100 to 1000 dPa·s, more preferably 200 to 900 dPa·s, particularly 300 to 800 dPa·s at 25±1°C. With such a range, the holes can be easily filled, and the concave portions and the through holes can be satisfactorily filled without the generation of voids or the like.

Further, the glass transition temperature (Tg) of the curable resin composition of the present invention is preferably 150°C or higher, more preferably 160°C or higher. When Tg is 150° C. or higher, the occurrence of delamination can be suppressed.

The cured product of the present invention is obtained by curing the curable resin composition of the second aspect of the present invention.

In the printed wiring board of the present invention, at least one of the concave portion and the through hole is filled with the cured product of the curable resin composition of the second aspect of the present invention.

Hereinafter, an example of a method for producing a printed wiring board, in which recesses and through holes such as via holes and through holes provided in a wiring board are filled with the curable resin composition of the present invention, and pads and wiring are formed thereon, is shown in FIG. Description will be made with reference to 7-1.

(1) Hole filling First, as shown in FIG. When a plate is used, recesses such as via holes as well as through holes are filled with the curable resin composition of the present invention as shown in FIG. 7-1(b). For example, a mask having openings in through-hole portions is placed on the substrate, and the through-holes are filled by a printing method, a dot printing method, or the like.
Here, as the wiring board 101, a glass epoxy base material laminated with a copper foil, a resin base material such as a polyimide resin base material, a bismaleimide-triazine resin base material, a fluororesin base material, a ceramic base material, or a metal base material can be used. A through hole is drilled in a base material 102 such as the above, and the wall surface of the through hole and the copper foil surface are subjected to electroless plating or further electrolytic plating to form a through hole 103 and a conductive circuit layer 104. can be done. Copper plating is generally used as the plating.

(2) Polishing Next, the filled curable resin composition is precured by heating at about 90 to 130° C. for about 30 to 90 minutes. Since the hardness of the cured product 105 precured in this way is relatively low, the unnecessary portion protruding from the substrate surface can be easily removed by physical polishing, and the surface can be flattened. After that, it is heated again at about 140 to 180° C. for about 30 to 90 minutes for final hardening (finish hardening).
The term "precured" or "precured product" as used herein generally refers to a state in which the reaction rate of epoxy is 80% to 97%. Further, the hardness of the pre-cured product can be controlled by changing the heating time and heating temperature for pre-curing. After that, as shown in FIG. 7-1(c), unnecessary portions of the hardened product 105 protruding from the through-holes are removed by polishing and flattened. Polishing can be performed by a belt sander, buffing, or the like.

(3) Formation of Conductor Circuit Layer A plated film is formed on the surface of the substrate on which the through holes have been filled, as shown in FIG. 7-1(d). After that, an etching resist is formed, and the resist non-formed portion is etched (not shown). Next, by removing the etching resist, the conductive circuit layer 106 is formed as shown in FIG. 7-1(e).

As described above, the curable resin composition of the present invention can be used as a resin filler for through holes provided in a printed wiring board as shown in FIG. Although it can be suitably used as a resin filler for through holes and via holes provided in multilayer printed wiring boards as shown in 3, it is not limited to these uses, and can also be used, for example, as a sealing material. can be used.

The present invention will now be described in more detail using examples.
<First embodiment>
[Preparation of fibrous fine cellulose powder]
Production Example 1 (CNF1)
After sufficiently stirring softwood bleached kraft pulp fiber (650 ml of Machenzie CSF manufactured by Fletcher Challenge Canada) with 9900 g of ion-exchanged water, TEMPO (2,2,6,6-tetramethyl Piperidine 1-oxyl free radical) 1.25% by weight, sodium bromide 12.5% by weight and sodium hypochlorite 28.4% by weight were added in this order. Using a pH stud, the pH was maintained at 10.5 by dropwise addition of 0.5M sodium hydroxide. After the reaction was carried out for 120 minutes (20° C.), the dropwise addition of sodium hydroxide was stopped to obtain oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion-exchanged water and then dehydrated. After that, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water were subjected to refining treatment twice at 245 MPa using a high-pressure homogenizer (Starburst Lab HJP-2 5005, manufactured by Sugino Machine Co., Ltd.) to obtain a carboxyl group-containing fine cellulose powder. A dispersion liquid (solid content concentration: 1.3% by weight) of the solid content was obtained.

Next, 4088.75 g of the dispersion of the obtained carboxyl group-containing fine cellulose powder was placed in a beaker, and 4085 g of ion-exchanged water was added to make a 0.5% by mass aqueous solution. Stirred for 30 minutes. Subsequently, 245 g of 1M hydrochloric acid aqueous solution was charged and reacted at room temperature for 1 hour. After completion of the reaction, the precipitate was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added and filtered to obtain a dispersion of acetone-containing acid-form cellulose powder (solid concentration: 5.0% by mass) in which the carboxyl group-containing fine cellulose powder was swollen in acetone. After completion of the reaction, it was filtered and then washed with ion-exchanged water to remove hydrochloric acid and salts. After the solvent was replaced with acetone, the solvent was replaced with DMF to obtain a dispersion of DMF-containing acid-type cellulose powder in which the carboxyl group-containing fine cellulose powder was swollen (average fiber diameter: 3.3 nm, solid content concentration: 5.0 mass. %) was obtained.

Production Example 2 (CNF2)
40 g of the DMF-containing acid-form cellulose powder dispersion obtained in Production Example 1 and 0.3 g of hexylamine were placed in a beaker equipped with a magnetic stirrer and stirrer, and dissolved in 300 g of ethanol. The reaction solution was allowed to react at room temperature (25° C.) for 6 hours. After completion of the reaction, the mixture was filtered, washed with DMF, and the solvent was replaced to obtain a dispersion of fine cellulose powder (solid concentration: 5.0% by mass) in which amine was linked to fine cellulose powder through ionic bonding. .
The CNF2 produced by the method of Production Example 2 has particularly good dispersibility, and can be dispersed by a general method without using a special dispersing machine such as a high-pressure homogenizer.

Production Example 3 (CNF3)
10% by mass of fibrous fine cellulose powder (BiNFi-s manufactured by Sugino Machine, average fiber diameter 80 nm) is dehydrated and filtered, 10 times the amount of carbitol acetate is added to the filtered material, stirred for 30 minutes, and filtered. did. This substitution operation was repeated three times, and carbitol acetate was added in an amount 20 times the amount of the filter material to prepare a fine cellulose powder dispersion (solid content concentration: 5.0% by mass).

[Preparation of cellulose nanocrystal particles]
Production example 4 (CNC1)
A paper sheet of dried softwood bleached kraft pulp was processed with a cutter mill and a pin mill to obtain cotton-like fibers. 100 g of this cotton-like fiber was taken in absolute dry mass, suspended in 2 L of a 64% sulfuric acid aqueous solution, and hydrolyzed at 45° C. for 45 minutes.

After the resulting suspension was filtered, 10 L of ion-exchanged water was poured into the suspension and stirred to uniformly disperse the suspension to obtain a dispersion. Then, the step of filtering and dehydrating the dispersion was repeated three times to obtain a dehydrated sheet. Next, the obtained dehydrated sheet was diluted with 10 L of ion-exchanged water, and 1N sodium hydroxide aqueous solution was added little by little while stirring to adjust the pH to about 12. Thereafter, this suspension was filtered and dehydrated, and the process of adding 10 L of ion-exchanged water, stirring, and filtering and dehydrating was repeated twice.

Then, deionized water was added to the obtained dehydrated sheet to prepare a 2% suspension. This suspension was passed through a wet atomization device ("Ultimizer" manufactured by Sugino Machine Co., Ltd.) 10 times at a pressure of 245 MPa to obtain an aqueous dispersion of cellulose nanocrystal particles.

Thereafter, the solvent was replaced with acetone and then with DMF to obtain a DMF dispersion (solid concentration: 5.0% by mass) in which the cellulose nanocrystal particles were swollen. As a result of observing and measuring the cellulose nanocrystal particles in the obtained dispersion by AFM, the average crystal width was 10 nm and the average crystal length was 200 nm.

Production example 5 (CNC2)
A DMF dispersion of swollen cellulose nanocrystal particles (solid content concentration: 5.0% by mass) was obtained in the same manner as in Production Example 4, except that absorbent cotton (manufactured by Hakujuji Co., Ltd.) was used as the cellulose raw material. rice field. As a result of observing and measuring the cellulose nanocrystal particles in the obtained dispersion by AFM, the average crystal width was 7 nm and the average crystal length was 150 nm.

(Examples 1-1 to 1-6, Reference Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-8)
According to the description in Tables 1 to 3 below, each component was blended and stirred, and then dispersed repeatedly six times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo Co., Ltd. to prepare each composition. The numerical values in Tables 1 to 3 indicate parts by mass.
The thermal expansion coefficient, solder heat resistance, insulation properties, and toughness (elongation rate) of each composition obtained in Examples, Reference Examples, and Comparative Examples were evaluated. Evaluation methods are as follows.

[Thermal expansion coefficient]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 120 μm, and dried at 90° C. for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Thereafter, a resin layer of each composition was laminated by pressure bonding with a vacuum laminator at 60° C. and a pressure of 0.5 MPa for 60 seconds to a copper foil having a thickness of 18 μm, and the PET film was peeled off. Then, it was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven, and then peeled off from the copper foil to obtain a film sample composed of a cured product of each composition. The obtained film sample was cut into a 3 mm width×30 mm length to obtain a test piece for thermal expansion coefficient measurement. For this test piece, TMA (Thermomechanical Analysis) Q400 manufactured by TA Instruments Co., Ltd. was used in tension mode with a chuck distance of 16 mm, a load of 30 mN, and a nitrogen atmosphere from 20 to 250 ° C. at 5 ° C./min. The temperature was then lowered to 250 to 20° C. at a rate of 5° C./min, and the coefficients of thermal expansion α1 and α2 (ppm/K) were measured. These measurement results are also shown in Tables 1 to 3.

[Solder heat resistance]
An FR-4 copper-clad laminate having a size of 150 mm×95 mm and a thickness of 1.6 mm was coated with each composition on the entire surface by 80-mesh Tetron bias plate screen printing, and dried at 80° C. for 30 minutes in a hot air circulation drying oven. Then, the composition was cured by heating at 180° C. for 30 minutes to obtain a test substrate on which a resin layer composed of a cured product of each composition was formed. A rosin-based flux was applied to the surface of the resin layer of this test substrate, flowed to a solder layer at 260° C. for 60 seconds, and washed with propylene glycol monomethyl ether acetate and then ethanol. Soldering heat resistance was evaluated by visually observing swelling and peeling of the resin layer and changes in the surface condition of the test substrate after washing. The evaluation criteria were as follows: x when abnormalities such as swelling or peeling of the resin layer, dissolution or softening of the surface were observed, and ◯ when no abnormality was observed. The evaluation results are also shown in Tables 1-3.

[Insulation]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 120 μm, and dried at 90° C. for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIGS. 1-4). A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured and evaluated.
As the evaluation criteria, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The evaluation results are also shown in Tables 1-3.

[Toughness]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 200 μm, and dried in a hot air circulation drying oven at 90° C. for 20 minutes to obtain a dry film having a resin layer of each composition. Next, a 18 μm-thick electrolytic copper foil with the glossy side facing upward was fixed with a tape onto a 1.6 mm-thick FR-4 copper-clad laminate, and the dry film was dried at 60° C. in a vacuum laminator. A resin layer of each composition was laminated on the electrolytic copper foil by crimping for 60 seconds at a pressure of 0.5 MPa, then the PET film was peeled off, and heated at 180 ° C. for 30 minutes in a hot air circulation drying oven. The resin layer was cured. Then, the fixed tape was peeled off, and the electrolytic copper foil was further peeled off to obtain a film sample composed of a resin layer. Next, according to JIS K7127, the film sample was cut into a predetermined size to prepare a test piece for evaluation. The test piece was measured for stress [MPa] and strain [%] at a tensile speed of 10 mm/min using a compact tabletop tester EZ-SX manufactured by Shimadzu Corporation. The strain [%] at this time is the elongation rate when the test piece breaks, and since the larger the strain, the higher the toughness can be evaluated, the toughness was evaluated from this strain [%].
As the evaluation criteria, a strain [%] of less than 2.0% was rated as x, and a strain of 2.0% or more was rated as ◯. The evaluation results are also shown in Tables 1-3.

*1-1) Thermosetting resin 1-1: Epiclon HP-4032, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a naphthalene skeleton)
*1-2) Thermosetting resin 1-2: NC-7300L Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a naphthalene skeleton)
*1-3) Thermosetting resin 1-3: YX-8800 Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having an anthracene skeleton)
*1-4) Thermosetting resin 1-4: Epiclon HP-7200 Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a dicyclopentadiene skeleton)
*1-5) Thermosetting resin 1-5: NC-3000H Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound with a biphenyl skeleton)
*1-6) Thermosetting resin 1-6: YX-4000 Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a biphenyl skeleton)
*1-7) Thermosetting resin 1-7: Epiclon N-740, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass *1-8) Thermosetting resin 1-8: Epiclon 830, manufactured by DIC Corporation *1-9) Thermosetting resin 1-9: JER827 manufactured by Mitsubishi Chemical Corporation *1-10) Phenoxy resin 1-1: YX6954 manufactured by Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 30% by mass *1-11 ) Curing agent 1-1: HF-1 Meiwa Kasei Co., Ltd. Solid content 60% by mass cyclohexanone varnish * 1-12) Curing agent 1-2: Bisphenol A diacetate Tokyo Chemical Industry Co., Ltd. (active ester)
*1-13) Curing catalyst 1-1: 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd. *1-14) Filler 1-1: Admafine SO-C2 Admatechs Co., Ltd. (silica)
* 1-15) Organic solvent 1-1: dimethylformamide * 1-16) Antifoaming agent 1-1: BYK-352 BYK-Chemie Japan Co., Ltd.

* 1-17) Filler 1-2: B-30 Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. * 1-18) Filler 1-3: DAW-07 Alumina manufactured by Denka Co., Ltd. * 1-19) Dispersant 1- 1: DISPERBYK-111 manufactured by BYK-Chemie

As is clear from the results shown in Tables 1 to 3, by using fine cellulose powder together with a filler other than fine cellulose powder, a low coefficient of thermal expansion can be maintained not only at room temperature but also at high temperatures during component mounting. It was also confirmed that a cured product excellent in various properties such as toughness can be obtained. Moreover, it was confirmed from the evaluation results of solder heat resistance that the compositions of Examples and Reference Examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards. Furthermore, it was confirmed that the dielectric constant and the dielectric loss tangent were lowered by using an active ester as a curing agent.

<Second embodiment>
As the fine cellulose fibers CNF1 to CNF3 and the cellulose nanocrystal particles CNC1 and CNC2, those of Production Examples 1 to 5 similar to those of the first example were used.

Synthesis example 1 (varnish 1)
A 2-liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet was charged with 900 g of diethylene glycol dimethyl ether as a solvent and t-butylperoxy 2-ethylhexanoate as a polymerization initiator. (manufactured by NOF Corporation, trade name: Perbutyl O) 21.4 g was added and heated to 90°C. After heating, 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (manufactured by Daicel Co., Ltd., trade name: Plaxel FM1) were added with a polymerization initiator. 21.4 g of certain bis(4-t-butylcyclohexyl)peroxydicarbonate (manufactured by NOF Corporation, trade name: Perroyl TCP) was added dropwise over 3 hours. Furthermore, by aging this for 6 hours, a carboxyl group-containing copolymer resin was obtained. These reactions were carried out under a nitrogen atmosphere.

Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (manufactured by Daicel Co., Ltd., trade name: Cychromer A200) and 3.3 g of dimethylbenzylamine as a ring-opening catalyst were added to the obtained carboxyl group-containing copolymer resin. 6 g and 1.80 g of hydroquinone monomethyl ether as a polymerization inhibitor were added, heated to 100° C., and stirred to conduct ring-opening addition reaction of epoxy. After 16 hours, a solution containing 53.8% by mass (nonvolatile matter) of a carboxyl group-containing resin having a solid acid value of 108.9 mgKOH/g and a mass average molecular weight of 25,000 was obtained.

Synthesis example 2 (varnish 2)
A flask equipped with a thermometer, stirrer, dropping funnel and reflux condenser was charged with diethylene glycol monoethyl ether acetate as a solvent and azobisisobutyronitrile as a catalyst and heated to 80°C under a nitrogen atmosphere. Then, a monomer obtained by mixing methacrylic acid and methyl methacrylate at a molar ratio of 0.40:0.60 was added dropwise over about 2 hours. Further, after stirring this for 1 hour, the temperature was raised to 115° C. for deactivation to obtain a resin solution.

After cooling this resin solution, tetrabutylammonium bromide was used as a catalyst, and butyl glycidyl ether was added at a molar ratio of 0.40 under conditions of 95 to 105° C. for 30 hours to remove the carboxyl groups of the resulting resin. Add an equal amount and cool.
Further, tetrahydrophthalic anhydride was added to the OH groups of the resin obtained above at a temperature of 95 to 105° C. for 8 hours at a molar ratio of 0.26. This was taken out after cooling to obtain a solution containing 50% by mass (nonvolatile matter) of a carboxyl group-containing resin having a solid content of acid value of 78.1 mgKOH/g and a mass average molecular weight of 35,000.

Synthesis Example 3 (Varnish 3)
A flask equipped with a thermometer, stirrer, dropping funnel and reflux condenser was charged with 210 g of a cresol novolac type epoxy resin (manufactured by DIC Corporation, Epiclon N-680, epoxy equivalent = 210) and carbitol acetate 96 as a solvent. .4 g was added and dissolved by heating. Subsequently, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of triphenylphosphine as a reaction catalyst were added to this. This mixture was heated to 95 to 105° C., 72 g of acrylic acid was gradually added dropwise, and the mixture was reacted for about 16 hours until the acid value became 3.0 mgKOH/g or less. After cooling the reaction product to 80 to 90° C., 76.1 g of tetrahydrophthalic anhydride was added, and the temperature was maintained for about 6 hours until the absorption peak (1780 cm ⁻¹ ) of the acid anhydride disappeared by infrared absorption analysis. reacted. 96.4 g of aromatic solvent Ipsol #150 (manufactured by Idemitsu Kosan Co., Ltd.) was added to this reaction solution, diluted, and taken out. The carboxyl group-containing photosensitive polymer solution thus obtained had a nonvolatile content of 65% by mass and an acid value of 78 mgKOH/g of the solid content.

According to the description in Tables 4 to 12 below, each component was blended and stirred, and then dispersed repeatedly six times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo Co., Ltd. to prepare each composition. The numerical values in Tables 4 to 12 indicate parts by mass.

[Interlayer insulation reliability]
(Thermosetting composition)
Each composition shown in Tables 4 to 6 was applied to a PET film with a thickness of 38 μm with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate (the part indicated by the arrow in FIG. 2-2: the comb pattern at the bottom of the figure on the right side) with a vacuum laminator at 60 ° C. and a pressure of 0.5 MPa for 60 seconds to laminate the resin layer of each composition, peel off the PET film, and heat at 180 ° C. for 30 minutes in a hot air circulation drying oven. Cured by heating. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Then, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. Then, an acid-resistant tape formed into a circle with a diameter of 1 cm is attached on the copper plating so that it is in the center of the A coupon, and copper plating is performed on the resin cured product other than the acid-resistant tape portion with an aqueous solution of 40% by weight ferric chloride at 40 ° C. was removed by etching. At this time, the test substrate was an A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 on which a cured product of each composition was formed as a coating film, and a circular copper plating with a diameter of 1 cm was formed thereon. Yes (see Figure 2-3). Next, a wire was attached to the circular copper plating with wire solder and a soldering iron, and a wire was also attached to the wiring of the IPC MULTI-PURPOSE TEST BOARD in the same way. A test was conducted for 200 hours under an environment of 130° C. and 85% by applying a voltage. Ten test pieces were produced for each composition. At this time, the insulation resistance was constantly measured, and when it became 1×10 ⁶ Ω or less, it was regarded as NG. Those with no NG until the end of the test were evaluated as ⊚, those with 1 to 4 NG were evaluated as ◯, those with 5 to 9 NG were evaluated as Δ, and those with all NG were evaluated as ×. The evaluation results are shown in Tables 4-6.

(Photocurable thermosetting composition)
Each composition shown in Tables 7 to 12 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition is laminated, the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. was used for 60 seconds in a developing machine. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Then, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. Then, an acid-resistant tape formed into a circle with a diameter of 1 cm is attached on the copper plating so that it is in the center of the A coupon, and copper plating is performed on the resin cured product other than the acid-resistant tape portion with an aqueous solution of 40% by weight ferric chloride at 40 ° C. was removed by etching. Next, a wire is attached to the circular copper plating with thread solder and a soldering iron, and a wire is also attached to the wiring of the IPC MULTI-PURPOSE TEST BOARD in the same way, with the circle being the anode and the wire being the cathode, and the voltage of 3.3 V. A test was conducted for 200 hours under an environment of 130° C. and 85% by applying a voltage. Ten test pieces were produced for each composition. At this time, the insulation resistance was constantly measured, and when it became 1×10 ⁶ Ω or less, it was regarded as NG. Those with no NG until the end of the test were evaluated as ⊚, those with 1 to 4 NG were evaluated as ◯, those with 5 to 9 NG were evaluated as Δ, and those with all NG were evaluated as ×. The evaluation results are shown in Tables 7-12.

[Comb-shaped electrode insulation reliability]
(Thermosetting composition)
Each composition shown in Tables 4 to 6 was applied to a PET film with a thickness of 38 μm with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIG. 2-4). Then, a voltage of 50 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and a test was conducted for 200 hours in an environment of 130° C. and 85%. Ten test pieces were produced for each composition. At this time, the insulation resistance was constantly measured, and when it became 1×10 ⁶ Ω or less, it was regarded as NG. Those with no NG until the end of the test were evaluated as ⊚, those with 1 to 4 NG were evaluated as ◯, those with 5 to 9 NG were evaluated as Δ, and those with all NG were evaluated as ×. The evaluation results are shown in Tables 4-6.

(Photocurable thermosetting composition)
Each composition shown in Tables 7 to 12 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition is laminated, and the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. was used for 60 seconds in a developing machine. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut off to form an electrically independent terminal. Then, a voltage of 50 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and a test was conducted for 200 hours in an environment of 130° C. and 85%. Ten test pieces were produced for each composition. At this time, the insulation resistance was constantly measured, and when it became 1×10 ⁶ Ω or less, it was regarded as NG. Those with no NG until the end of the test were evaluated as ⊚, those with 1 to 4 NG were evaluated as ◯, those with 5 to 9 NG were evaluated as Δ, and those with all NG were evaluated as ×. The evaluation results are shown in Tables 7-12.

[Solder heat resistance]
(Thermosetting composition)
On an FR-4 copper-clad laminate having a size of 150 mm x 95 mm and a thickness of 1.6 mm, a solid pattern was formed on the entire surface of each composition by 80-mesh Tetron bias plate screen printing, and dried in a hot air circulation drying oven at 80°C for 30 minutes. It was dried and then cured by heating at 180° C. for 30 minutes to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. The test piece was visually observed for swelling and peeling of the coating film and changes in the surface condition. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. The evaluation results are shown in Tables 4-6.

(Photocurable thermosetting composition)
On an FR-4 copper-clad laminate having a size of 150 mm x 95 mm and a thickness of 1.6 mm, a solid pattern was formed on the entire surface of each composition by 80-mesh Tetron bias plate screen printing, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After drying, the entire surface was exposed at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards, and developed with a developer of 1 wt % Na ₂ CO ₃ at 30° C. for 60 seconds with a developing machine. Then, it was heated and cured at 150° C. for 60 minutes in a hot air circulating drying oven to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. Blistering and peeling of the coating film and changes in the surface condition of the test piece were observed visually. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. The evaluation results are shown in Tables 7-12.

[Preparation of sample for thermal expansion measurement]
(Thermosetting resin composition)
Each composition shown in Tables 4 to 6 was applied to a PET film with a thickness of 38 μm with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. Thereafter, the resin layer of each composition was laminated by pressure bonding with a vacuum laminator at 60° C. and a pressure of 0.5 MPa for 60 seconds to a copper foil having a thickness of 18 μm, and the PET film was peeled off. Then, the film was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven, and the copper foil was peeled off to obtain a cured film sample.

(Photocurable thermosetting resin composition)
A copper foil with a thickness of 18 μm was attached to an FR-4 copper clad laminate with a thickness of 1.6 mm, each composition shown in Tables 7 to 12 was applied with an applicator with a gap of 120 μm, and dried in a hot air circulation drying oven at 90 ° C. Allow to dry for 10 minutes. After that, a negative mask with a pattern of 3 mm width×30 mm length was brought into close contact, and exposed at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards. Then, using a developer of 1 wt % Na ₂ CO ₃ at 30° C., it was developed with a developing machine for 60 seconds. Then, the film was cured by heating in a hot air circulating drying oven at 150° C. for 60 minutes, and the copper foil was peeled off to obtain a cured film sample.

[Measurement of thermal expansion coefficient]
(Thermosetting resin composition)
The prepared sample for thermal expansion measurement was cut into 3 mm width×30 mm length. This test piece is subjected to tension mode using TMA (Thermomechanical Analysis) Q400 manufactured by TA Instruments Co., Ltd., a chuck distance of 16 mm, a load of 30 mN, under a nitrogen atmosphere, from 20 to 250 ° C. at 5 ° C./min. It was warmed and then cooled to 250-20°C at a rate of 5°C/min and measured. An average coefficient of thermal expansion α1 from 30° C. to 100° C. and an average coefficient of thermal expansion α2 from 200° C. to 230° C. during temperature drop were obtained. The results are shown in Tables 4-6.

(Photocurable thermosetting resin composition)
The same method as for the thermosetting resin composition was used, except that the prepared sample was used as it was. The results are shown in Tables 7-12.

*2-1) Thermosetting resin 2-1: Epiclon HP-4032, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a naphthalene skeleton)
*2-2) Thermosetting resin 2-2: NC-7300L Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a naphthalene skeleton)
*2-3) Thermosetting resin 2-3: YX-8800 Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having an anthracene skeleton)
*2-4) Thermosetting resin 2-4: Epiclon N-740, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass *2-5) Thermosetting resin 2-5: Epiclon 830, manufactured by DIC Corporation * 2-6) Thermosetting resin 2-6: JER827 Mitsubishi Chemical Co., Ltd. * 2-7) Thermosetting resin 2-7: HF-1 Meiwa Kasei Co., Ltd. solid content 60% by mass cyclohexanone varnish * 2-8) Curing catalyst 2-1: 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd. *2-9) Filler 2-1: Admafine SO-C2 Admatechs Co., Ltd. ( silica)
*2-10) Organic solvent 2-1: dimethylformamide *2-11) Antifoaming agent 2-1: BYK-352 manufactured by BYK-Chemie Japan Co., Ltd.

*2-18) Filler 2-2: B-30 Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. *2-19) Filler 2-3: DAW-07 Alumina manufactured by Denka Co., Ltd. *2-20) Dispersant 2- 1: DISPERBYK-111 manufactured by BYK-Chemie

* 2-12) Curing catalyst 2-2: Finely ground melamine manufactured by Nissan Chemical Industries, Ltd. * 2-13) Curing catalyst 2-3: Dicyandiamide * 2-14) Photopolymerization initiator 2-1: Irgacure 907 BASF Corporation ) manufactured by * 2-15) Photocurable resin 2-1: Dipentaerythritol tetraacrylate * 2-16) Thermosetting resin 2-8: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd. *2-17) Coloring agent 2-1: phthalocyanine blue

As is clear from the results shown in Tables 4 to 12, by including fine powder such as fine cellulose fibers and a cyclic ether compound having at least one of naphthalene skeleton and anthracene skeleton, interlayers and electrodes It was confirmed that a curable resin composition having excellent interlayer insulation reliability, particularly interlayer insulation reliability, and a low coefficient of thermal expansion can be obtained. Moreover, it was confirmed from the evaluation results of solder heat resistance that the compositions of Examples and Reference Examples are excellent in heat resistance and chemical resistance and can be used as compositions for wiring boards.

<Third embodiment>
As fine cellulose fibers CNF1 to CNF3 and cellulose nanocrystal particles CNC1 and CNC2, those of Production Examples 1 to 5 similar to those in Example 1 were used, and Varnish 1 to Varnish 3 were synthesized in the same manner as in Example 2. Those of Examples 1-3 were used.

According to the description in Tables 13 to 21 below, each component was blended and stirred, and then dispersed repeatedly 6 times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo to prepare each composition. The numerical values in Tables 13 to 21 indicate parts by mass.

[Peel strength of plated copper]
(Thermosetting composition)
Each composition shown in Tables 13 to 15 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm at 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. The resin layer was laminated, the PET film was peeled off, and the resin layer was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Next, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. A test substrate was cut out to a width of 1 cm and a length of 7 cm or more, and the peel strength at an angle of 90 degrees was determined using a small desktop tester EZ-SX manufactured by Shimadzu Corporation and a 90-degree print peeling jig. The evaluation was evaluated as ◯ when 4.5 N/m or more, Δ when 2.5 N/m or more and less than 4.5 N/m, and x when less than 2.5 N/m. The results are shown in Tables 13-15. If the peel strength is 4.5 N/m or more, it is considered that there is no problem of peeling even in a high-definition circuit. This criterion is a fairly strict evaluation condition.

(Photocurable thermosetting composition)
Each composition shown in Tables 16 to 21 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. After laminating the resin layer of , the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and developed using a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. Machine developed for 60 seconds. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Next, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. A test substrate was cut out to a width of 1 cm and a length of 7 cm or more, and the peel strength at an angle of 90 degrees was determined using a small desktop tester EZ-SX manufactured by Shimadzu Corporation and a 90-degree print peeling jig. The evaluation was evaluated as ◯ when 4.5 N/m or more, Δ when 2.5 N/m or more and less than 4.5 N/m, and x when less than 2.5 N/m. The results are shown in Tables 16-21.

[Solder heat resistance]
(Thermosetting composition)
Each composition shown in Tables 13 to 15 was applied to an FR-4 copper clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by screen printing with an 80-mesh Tetron bias plate to form a solid pattern on the entire surface, followed by a hot air circulation drying oven. was dried at 80°C for 30 minutes, and then cured by heating at 180°C for 30 minutes to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. The test piece was visually observed for swelling and peeling of the coating film and changes in the surface condition. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. The evaluation results are shown in Tables 13-15.

(Photocurable thermosetting composition)
Each composition shown in Tables 16 to 21 was applied to an FR-4 copper-clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by 80-mesh Tetron bias plate screen printing to form a solid pattern on the entire surface, followed by a hot air circulation drying furnace. and dried for 30 minutes at 80° C., exposed to the entire surface at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards, and used a developer of 1 wt % Na ₂ CO ₃ at 30° C. for 60 seconds with a developing machine. Developed. Then, it was heated and cured at 150° C. for 60 minutes in a hot air circulating drying oven to obtain a test piece. A rosin-based flux was applied to the cured composition side of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. Blistering and peeling of the coating film and changes in the surface condition of the test piece were observed visually. When abnormalities due to blistering, peeling, surface dissolution, softening, etc. were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. The evaluation results are shown in Tables 16-21.

[Insulation]
(Thermosetting composition)
Each composition shown in Tables 13 to 15 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIG. 3-2). A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 13-15.

(Photocurable thermosetting composition)
Each composition shown in Tables 16 to 21 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition is laminated, and the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. was used for 60 seconds in a developing machine. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut off to form an electrically independent terminal. A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 16-21.

[Dielectric constant, dielectric loss tangent]
(Thermosetting composition)
Each composition shown in Tables 13 to 15 is applied to a 38 μm thick PET film with an applicator with a gap of 200 μm, dried in a hot air circulating drying oven at 90 ° C. for 20 minutes, and a dry having a resin layer of each composition. got the film. After that, an electrolytic copper foil with a thickness of 18 μm was fixed with tape to a FR-4 copper clad laminate with a thickness of 1.6 mm with the glossy side facing upwards. The resin layer of each composition was laminated by pressure bonding under the conditions for 60 seconds, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Then, the fixed tape was peeled off, the electrolytic copper foil was peeled off, and a size of 1.7 mm×100 mm was cut out to obtain a sample for evaluation. The measurement was performed with a network analyzer E-507 manufactured by Keysight Technologies using a cavity resonator (5 GHz) manufactured by Kanto Denshi Applied Development Co., Ltd. For the evaluation of the relative dielectric constant, the average value of less than 2.8 measured three times was evaluated as ◯, the average value of 2.8 or more and less than 3.0 was evaluated as Δ, and the average value of 3.0 or more was evaluated as ×. For the evaluation of the dielectric loss tangent, an average value of less than 0.02 measured three times was evaluated as ○, and an average value of 0.02 or more was evaluated as ×. The respective results are shown in Tables 13-15.

(Photocurable thermosetting composition)
Each composition shown in Tables 16 to 21 is applied to a 38 μm thick PET film with an applicator with a gap of 200 μm, dried in a hot air circulation drying oven at 80 ° C. for 30 minutes, and a dry having a resin layer of each composition. got the film. After that, an electrolytic copper foil with a thickness of 18 μm was fixed with tape to a FR-4 copper clad laminate with a thickness of 1.6 mm with the glossy side facing upwards. The resin layer of each composition is laminated by pressure bonding for 60 seconds under the conditions, and using a 1.7 mm × 100 mm opening mask, exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, and then PET The film was peeled off and developed in a developer for 60 seconds using a developer of 1 wt % Na ₂ CO ₃ at 30°C. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Then, the fixed tape was peeled off, and the electrolytic copper foil was peeled off to obtain a sample for evaluation. The measurement was performed with a network analyzer E-507 manufactured by Keysight Technologies using a cavity resonator (5 GHz) manufactured by Kanto Denshi Applied Development Co., Ltd. For the evaluation of the relative permittivity, the average value of less than 3.0 measured three times was evaluated as ◯, the average value of 3.0 or more and less than 3.2 was evaluated as Δ, and the average value of 3.2 or more was evaluated as ×. For the evaluation of the dielectric loss tangent, an average value of less than 0.02 measured three times was evaluated as ○, and an average value of 0.02 or more was evaluated as ×. The respective results are shown in Tables 16-21.

*3-1) Thermosetting resin 3-1: Epiclon HP-7200 Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a dicyclopentadiene skeleton)
*3-2) Thermosetting resin 3-2: Tactix756 Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a dicyclopentadiene skeleton)
*3-3) Thermosetting resin 3-3: Epiclon N-740, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass *3-4) Thermosetting resin 3-4: Epiclon 830, manufactured by DIC Corporation *3-5) Thermosetting resin 3-5: JER827 manufactured by Mitsubishi Chemical Corporation *3-6) Thermosetting resin 3-6: Resitop GDP-6085 solid content 60% by mass cyclohexanone varnish (dicyclopentadiene skeleton phenolic resin)
* 3-7) Thermosetting resin 3-7: HF-1 Meiwa Kasei Co., Ltd. solid content 60% by mass cyclohexanone varnish * 3-8) Curing catalyst 3-1: 2E4MZ (2-ethyl-4-methylimidazole ) Shikoku Kasei Kogyo Co., Ltd. * 3-9) Filler 3-1: Admafine SO-C2 Co., Ltd. Admatechs (silica)
* 3-10) Organic solvent 3-1: dimethylformamide * 3-11) Antifoaming agent 3-1: BYK-352 BYK-Chemie Japan Co., Ltd.

*3-18) Filler 3-2: B-30 Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. *3-19) Filler 3-3: DAW-07 Alumina manufactured by Denka Co., Ltd. *3-20) Dispersant 3- 1: DISPERBYK-111 manufactured by BYK-Chemie

* 3-12) Curing catalyst 3-2: finely ground melamine manufactured by Nissan Chemical Industries, Ltd. * 3-13) Curing catalyst 3-3: Dicyandiamide * 3-14) Photopolymerization initiator 3-1: Irgacure 907 BASF Corporation ) manufactured by * 3-15) Photocurable resin 3-1: dipentaerythritol tetraacrylate * 3-16) Thermosetting resin 3-8: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd. *3-17) Coloring agent 3-1: phthalocyanine blue

As is clear from the results described in Tables 13 to 21, it is selected from the group consisting of fine powder such as fine cellulose fibers, a cyclic ether compound having a dicyclopentadiene skeleton, and a phenolic resin having a dicyclopentadiene skeleton. By containing at least one of them, it was confirmed that a curable resin composition having excellent insulation reliability, low dielectric properties, and good adhesion between the cured product and the plated copper can be obtained. Moreover, it was confirmed from the results of evaluation of solder heat resistance that each composition of Reference Examples was excellent in heat resistance and chemical resistance and could be used as a composition for wiring boards.

<Fourth embodiment>
As fine cellulose fibers CNF1 to CNF3 and cellulose nanocrystal particles CNC1 and CNC2, those of Production Examples 1 to 5 similar to those in Example 1 were used, and Varnish 1 to Varnish 3 were synthesized in the same manner as in Example 2. Those of Examples 1-3 were used.

According to the description in Tables 22 to 30 below, each component was blended and stirred, and then dispersed repeatedly 6 times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo to prepare each composition. The numerical values in Tables 22 to 30 indicate parts by mass.

[Solder heat resistance]
(Thermosetting composition)
Each composition shown in Tables 22 to 25 was applied to an FR-4 copper clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by screen printing with an 80-mesh Tetron bias plate to form a solid pattern on the entire surface. was dried at 80°C for 30 minutes, and then cured by heating at 180°C for 30 minutes to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. The test piece was visually observed for swelling and peeling of the coating film and changes in the surface condition. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. Evaluation results are shown in Tables 22-25.

(Photocurable thermosetting composition)
Each composition shown in Tables 26 to 30 was applied to an FR-4 copper-clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by 80-mesh Tetron bias plate screen printing to form a solid pattern on the entire surface, followed by a hot air circulation drying oven. and dried for 30 minutes at 80° C., exposed to the entire surface at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards, and used a developer of 1 wt % Na ₂ CO ₃ at 30° C. for 60 seconds with a developing machine. Developed. Then, it was heated and cured at 150° C. for 60 minutes in a hot air circulating drying oven to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. Blistering and peeling of the coating film and changes in the surface condition of the test piece were observed visually. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. Evaluation results are shown in Tables 26-30.

[Insulation]
(Thermosetting composition)
Each composition shown in Tables 22 to 25 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIG. 4-2). A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 22-25.

(Photocurable thermosetting composition)
Each composition shown in Tables 26 to 30 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition is laminated, and the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. was used for 60 seconds in a developing machine. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut off to form an electrically independent terminal. A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 26-30.

[Removability of smear]
(Thermosetting resin composition)
Each composition shown in Tables 22 to 25 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. was laminated, the PET film was peeled off, and cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven to obtain a test piece.
A hole was drilled in the test piece with a beam diameter of 100 μm using a carbon dioxide laser drilling machine LC-2K212 (manufactured by Hitachi Via Mechanics Co., Ltd.). Next, permanganate desmear (manufactured by ATOTECH) was performed. The standard process for desmearing is the swelling process (60°C for 5 minutes), the permanganate etching process (80°C for 20 minutes), and the neutralization process (40°C for 5 minutes) in that order. , 15 minutes, and 20 minutes.
Then, the drilled portion was observed with a scanning electron microscope JSM-6610LV (manufactured by JEOL Ltd.) at a magnification of 3500 to confirm the presence or absence of smear on the copper surface. The evaluation was evaluated as ◯ when smear disappeared after 10 minutes of permanganic acid etching, Δ when smear disappeared after 15 minutes, and x when smear finally disappeared after 20 minutes. The results are shown in Tables 22-25.

(Photocurable thermosetting resin composition)
Each composition shown in Tables 26 to 30 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. After laminating the resin layer of , the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and developed using a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. Machine developed for 60 seconds. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. It was cured to obtain a test piece.
A hole was drilled in the test piece with a beam diameter of 100 μm using a carbon dioxide laser drilling machine LC-2K212 (manufactured by Hitachi Via Mechanics Co., Ltd.). Next, using a permanganate desmear (manufactured by ATOTECH), the permanganate etching process was divided into three stages of 10 minutes, 15 minutes, and 20 minutes, and tests were performed.
Then, the drilled portion was observed with a scanning electron microscope JSM-6610LV (manufactured by JEOL Ltd.) at a magnification of 3500 to confirm the presence or absence of smear on the copper surface. The evaluation was evaluated as ◯ when smear disappeared after 10 minutes of permanganic acid etching, Δ when smear disappeared after 15 minutes, and x when smear finally disappeared after 20 minutes. The results are shown in Tables 26-30.

[Measurement of peel strength and Ra]
(Thermosetting resin composition)
Each composition shown in Tables 22 to 25 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulation drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. The resin layer was laminated, the PET film was peeled off, and the resin layer was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, using a permanganate desmear (manufactured by ATOTECH), samples were prepared in which the permanganate etching process time was 10 minutes only for the reference example and 10 minutes and 20 minutes for the comparative examples. Ra (arithmetic mean roughness) was measured using an optical interference microscope Contour GT (manufactured by BRUKER) to measure the surface roughness of the sample. Ra indicates arithmetic average roughness, and is a value obtained by drawing a line at the center of the cross-sectional curve and dividing the total area on the curve obtained by the center line by the length. The smaller the value, the higher the smoothness. Incidentally, Ra is specified in JIS B0031:2003. The results are shown in Tables 22-25.

Next, the test piece that had been desmeared was subjected to electroless copper plating (Thrucup PEA, manufactured by Uyemura & Co., Ltd.) and electrolytic copper plating, in that order, to give a copper thickness of 25 μm. Then, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. A test substrate was cut out to a width of 1 cm and a length of 7 cm or more, and the peel strength at an angle of 90 degrees was determined using a small desktop tester EZ-SX manufactured by Shimadzu Corporation and a 90-degree print peeling jig. The evaluation was evaluated as ◯ when 4.5 N/m or more, Δ when 2.5 N/m or more and less than 4.5 N/m, and x when less than 2.5 N/m. The results are shown in Tables 22-25.

(Photocurable thermosetting resin composition)
Each composition shown in Tables 26 to 30 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. After laminating the resin layer of , the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and developed using a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. Machine developed for 60 seconds. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, using a permanganate desmear (manufactured by ATOTECH), samples were prepared in which the permanganate etching process time was 10 minutes only for the reference example and 10 minutes and 20 minutes for the comparative examples. Ra was measured using an optical interference microscope Contour GT (manufactured by BRUKER) to measure the surface roughness of the sample. The results are shown in Tables 26-30.

Next, the test piece that had been desmeared was subjected to electroless copper plating (Thrucup PEA, manufactured by Uyemura & Co., Ltd.) and electrolytic copper plating, in that order, to give a copper thickness of 25 μm. Then, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. A test substrate was cut out to a width of 1 cm and a length of 7 cm or more, and the peel strength at an angle of 90 degrees was determined using a small desktop tester EZ-SX manufactured by Shimadzu Corporation and a 90-degree print peeling jig. The evaluation was evaluated as ◯ when 4.5 N/m or more, Δ when 2.5 N/m or more and less than 4.5 N/m, and x when less than 2.5 N/m. The results are shown in Tables 26-30.

*4-1) Phenoxy resin 4-1: YX6954 Mitsubishi Chemical Co., Ltd. cyclohexanone varnish with a solid content of 30% by mass *4-2) Phenoxy resin 4-2: 1256 Mitsubishi Chemical Co., Ltd. Solid content of 30% by mass Cyclohexanone varnish * 4-3) Phenoxy resin 4-3: 4250 Mitsubishi Chemical Co., Ltd. Cyclohexanone varnish with a solid content of 30% by mass * 4-4) Thermosetting resin 4-1: Epiclon N-740 DIC Corporation Cyclohexanone varnish with a solid content of 50% by mass * 4-5) Thermosetting resin 4-2: Epiclon 830, manufactured by DIC Corporation * 4-6) Thermosetting resin 4-3: JER827, manufactured by Mitsubishi Chemical Corporation * 4 -7) Thermosetting resin 4-4: HF-1 Meiwa Kasei Co., Ltd. Solid content 60% by mass cyclohexanone varnish * 4-8) Curing catalyst 4-1: 2E4MZ (2-ethyl-4-methylimidazole) Shikoku Kasei Kogyo Co., Ltd. * 4-9) Filler 4-1: ADMAFINE SO-C2 Admatechs Co., Ltd. (silica)
* 4-10) Organic solvent 4-1: dimethylformamide * 4-11) Antifoaming agent 4-1: BYK-352 BYK-Chemie Japan Co., Ltd.

* 4-18) Filler 4-2: B-30 Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. * 4-19) Filler 4-3: DAW-07 Alumina manufactured by Denka Co., Ltd. * 4-20) Dispersant 4- 1: DISPERBYK-111 manufactured by BYK-Chemie

* 4-12) Curing catalyst 4-2: Finely ground melamine manufactured by Nissan Chemical Industries, Ltd. * 4-13) Curing catalyst 4-3: Dicyandiamide * 4-14) Photopolymerization initiator 4-1: Irgacure 907 BASF Corporation ) manufactured by * 4-15) Photocurable resin 4-1: Dipentaerythritol tetraacrylate * 4-16) Thermosetting resin 4-5: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd. *4-17) Coloring agent 4-1: phthalocyanine blue

As is clear from the results described in Tables 22 to 30, by containing fine powder such as fine cellulose fibers and phenoxy resin, smear can be removed by laser processing in the desmear process, and high frequency It was confirmed that a curable resin composition having excellent peel strength while having a small surface roughness advantageous for transmission can be obtained. Moreover, it was confirmed from the results of evaluation of solder heat resistance that each composition of Reference Examples was excellent in heat resistance and chemical resistance and could be used as a composition for wiring boards.

<Fifth embodiment>
As fine cellulose fibers CNF1 to CNF3 and cellulose nanocrystal particles CNC1 and CNC2, those of Production Examples 1 to 5 similar to those in Example 1 were used, and Varnish 1 to Varnish 3 were synthesized in the same manner as in Example 2. Those of Examples 1-3 were used.

According to the description in Tables 31 to 39 below, each component was blended and stirred, and then dispersed repeatedly 6 times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo to prepare each composition. The numerical values in Tables 31 to 39 indicate parts by mass.

[Bulging of plated copper]
(Thermosetting composition)
Each composition shown in Tables 31 to 33 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. The resin layer was laminated, the PET film was peeled off, and the resin layer was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Next, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. Then, after passing through a reflow furnace with a peak temperature of 265° C. three times, swelling of the plated copper was visually evaluated. ○ indicates that there was no swelling among the 10 test substrates; did. The results are shown in Tables 31-33.

(Photocurable thermosetting composition)
Each composition shown in Tables 34 to 39 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, each composition was press-bonded to an FR-4 copper-clad laminate (copper thickness: 18 μm) having a size of 150 mm×100 mm and a thickness of 1.6 mm under conditions of 60° C. and a pressure of 0.5 MPa for 60 seconds using a vacuum laminator. After laminating the resin layer of , the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and developed using a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. Machine developed for 60 seconds. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, permanganate desmear (manufactured by ATOTECH), electroless copper plating (Thrucup PEA, manufactured by Uemura & Co., Ltd.), and electrolytic copper plating were performed in this order to form copper plating with a copper thickness of 25 μm. Next, the substrate was annealed at 190° C. for 60 minutes in a hot air circulating drying oven to obtain a copper-plated test substrate. Then, after passing through a reflow furnace with a peak temperature of 265° C. three times, swelling of the plated copper was visually evaluated. ○ indicates that there was no swelling among the 10 test substrates; did. The results are shown in Tables 34-39.

[Solder heat resistance]
(Thermosetting composition)
Each composition shown in Tables 31 to 33 was applied to an FR-4 copper-clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by 80-mesh Tetron bias plate screen printing to form a solid pattern on the entire surface, followed by a hot air circulation drying furnace. was dried at 80°C for 30 minutes, and then cured by heating at 180°C for 30 minutes to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. The test piece was visually observed for swelling and peeling of the coating film and changes in the surface condition. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. Evaluation results are shown in Tables 31-33.

(Photocurable thermosetting composition)
Each composition shown in Tables 34 to 39 was applied to an FR-4 copper clad laminate having a size of 150 mm × 95 mm and a thickness of 1.6 mm by screen printing with an 80-mesh Tetron bias plate to form a solid pattern on the entire surface, followed by a hot air circulation drying furnace. and dried for 30 minutes at 80° C., exposed to the entire surface at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards, and used a developer of 1 wt % Na ₂ CO ₃ at 30° C. for 60 seconds with a developing machine. Developed. Then, it was heated and cured at 150° C. for 60 minutes in a hot air circulating drying oven to obtain a test piece. A rosin-based flux was applied to the side of the cured composition of this test piece, flowed to a solder layer at 260° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. Blistering and peeling of the coating film and changes in the surface condition of the test piece were observed visually. When abnormalities such as blistering, peeling, surface dissolution or softening were observed in the coating film, it was evaluated as x, and when it was not observed, it was evaluated as ○. Evaluation results are shown in Tables 34-39.

[Insulation]
(Thermosetting composition)
Each composition shown in Tables 31 to 33 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIG. 5-2). A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 31-33.

(Photocurable thermosetting composition)
Each composition shown in Tables 34 to 39 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition is laminated, and the entire surface is exposed at 700 mJ / cm ² with a metal halide lamp exposure machine for printed wiring boards, the PET film is peeled off, and a developer of 1 wt% Na ₂ CO ₃ at 30 ° C. was used for 60 seconds in a developing machine. After that, it was cured by heating at 150° C. for 60 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut off to form an electrically independent terminal. A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured. In the evaluation, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 34-39.

[Preparation of sample for thermal expansion measurement]
(Thermosetting resin composition)
Each composition shown in Tables 31 to 33 is applied to a 38 μm thick PET film with an applicator with a gap of 120 μm, dried in a hot air circulating drying oven at 90 ° C. for 10 minutes, and a dry having a resin layer of each composition. got the film. Thereafter, the resin layer of each composition was laminated by pressure bonding with a vacuum laminator at 60° C. and a pressure of 0.5 MPa for 60 seconds to a copper foil having a thickness of 18 μm, and the PET film was peeled off. Then, the film was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven, and the copper foil was peeled off to obtain a cured film sample.

(Photocurable thermosetting resin composition)
A copper foil with a thickness of 18 μm was attached to an FR-4 copper clad laminate with a thickness of 1.6 mm, each composition shown in Tables 34 to 39 was applied with an applicator with a gap of 120 μm, and dried in a hot air circulation drying oven at 90 ° C. Allow to dry for 10 minutes. After that, a negative mask with a pattern of 3 mm width×30 mm length was brought into close contact, and exposed at 700 mJ/cm ² with a metal halide lamp exposure machine for printed wiring boards. Then, using a developer of 1 wt % Na ₂ CO ₃ at 30° C., it was developed with a developing machine for 60 seconds. Then, the film was cured by heating in a hot air circulating drying oven at 150° C. for 60 minutes, and the copper foil was peeled off to obtain a cured film sample.

[Measurement of thermal expansion coefficient]
(Thermosetting resin composition)
The prepared sample for thermal expansion measurement was cut into 3 mm width×30 mm length. This test piece is subjected to tension mode using TMA (Thermomechanical Analysis) Q400 manufactured by TA Instruments Co., Ltd., a chuck distance of 16 mm, a load of 30 mN, under a nitrogen atmosphere, from 20 to 250 ° C. at 5 ° C./min. It was warmed and then cooled to 250-20°C at a rate of 5°C/min and measured. An average coefficient of thermal expansion α1 from 30° C. to 100° C. and an average coefficient of thermal expansion α2 from 200° C. to 230° C. during temperature drop were obtained. Moreover, evaluation was performed from the value. α1 was evaluated as ∘ when less than 25 ppm, Δ when less than 35 ppm, and x when 35 ppm or more. α2 was evaluated as ∘ when less than 75 ppm, Δ when less than 95 ppm, and x when 95 ppm or more. The results are shown in Tables 31-33.

(Photocurable thermosetting resin composition)
The same method as for the thermosetting resin composition was used, except that the prepared sample was used as it was. The results are shown in Tables 34-39.

*5-1) Thermosetting resin 5-1: NC-3000H Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound with a biphenyl skeleton)
*5-2) Thermosetting resin 5-2: YX-4000 Mitsubishi Chemical Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound having a biphenyl skeleton)
*5-3) Thermosetting resin 5-3: Epiclon N-740, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass *5-4) Thermosetting resin 5-4: Epiclon 830, manufactured by DIC Corporation * 5-5) Thermosetting resin 5-5: JER827 Mitsubishi Chemical Co., Ltd. * 5-6) Thermosetting resin 5-6: GPH-103 Nippon Kayaku Co., Ltd. solid content 60% by mass cyclohexanone varnish (Phenolic resin with biphenyl skeleton)
* 5-7) Thermosetting resin 5-7: HF-1 Meiwa Kasei Co., Ltd. solid content 60% by mass cyclohexanone varnish * 5-8) Curing catalyst 5-1: 2E4MZ (2-ethyl-4-methylimidazole ) Shikoku Kasei Kogyo Co., Ltd. * 5-9) Filler 5-1: ADMAFINE SO-C2 Admatechs Co., Ltd. (silica)
* 5-10) Organic solvent 5-1: dimethylformamide * 5-11) Antifoaming agent 5-1: BYK-352 BYK-Chemie Japan Co., Ltd.

＊５－１８）熱硬化性樹脂５－８：ビスフェノールＡジアセテート 東京化成工業（株）製 （活性エステル化合物）

* 5-18) Thermosetting resin 5-8: Bisphenol A diacetate Tokyo Chemical Industry Co., Ltd. (active ester compound)

* 5-19) Filler 5-2: B-30 Barium sulfate manufactured by Sakai Chemical Industry Co., Ltd. * 5-20) Filler 5-3: DAW-07 Alumina manufactured by Denka Co., Ltd. * 5-21) Dispersant 5- 1: DISPERBYK-111 manufactured by BYK-Chemie

* 5-12) Curing catalyst 5-2: Finely ground melamine manufactured by Nissan Chemical Industries, Ltd. * 5-13) Curing catalyst 5-3: Dicyandiamide * 5-14) Photopolymerization initiator 5-1: Irgacure 907 BASF Corporation ) manufactured by * 5-15) Photocurable resin 5-1: Dipentaerythritol tetraacrylate * 5-16) Thermosetting resin 5-9: TEPIC-H (triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd. *5-17) Colorant 5-1: Phthalocyanine blue

As is clear from the results described in Tables 31 to 39, fine powder such as fine cellulose fibers, and at least one selected from the group consisting of a cyclic ether compound having a biphenyl skeleton and a phenolic resin having a biphenyl skeleton. By containing, it is possible to obtain a cured product that has low thermal expansion and does not cause blistering of the plated copper due to heat history even when the plated copper is formed solidly on the cured product of the composition. It was confirmed that a curable resin composition was obtained. Moreover, it was confirmed from the results of evaluation of solder heat resistance that each composition of Reference Examples was excellent in heat resistance and chemical resistance and could be used as a composition for wiring boards.

<Sixth embodiment>
As the cellulose nanocrystal particles CNC1 and CNC2, those of Production Examples 4 and 5 similar to those of the first example were used.

According to the description in Tables 40 and 41 below, each component was blended and stirred, and then dispersed repeatedly six times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo Co., Ltd. to prepare each composition. Numerical values in Tables 40 and 41 indicate parts by mass.
The thermal expansion coefficient, heat resistance, insulating properties, toughness (elongation rate), and pot life of each composition obtained in Reference Examples and Comparative Examples were evaluated. Evaluation methods are as follows.

[Thermal expansion coefficient]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 120 μm, and dried at 90° C. for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Thereafter, the resin layer of each composition was laminated by pressure bonding with a vacuum laminator at 60° C. and a pressure of 0.5 MPa for 60 seconds to a copper foil having a thickness of 18 μm, and the PET film was peeled off. Then, it was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven, and then peeled off from the copper foil to obtain a film sample composed of a cured product of each composition. The obtained film sample was cut into a 3 mm width×30 mm length to obtain a test piece for thermal expansion coefficient measurement. For this test piece, TMA (Thermomechanical Analysis) Q400 manufactured by TA Instruments Co., Ltd. was used in tension mode, with a chuck distance of 16 mm, a load of 30 mN, and a nitrogen atmosphere. The temperature was then lowered to 250 to 20° C. at a rate of 5° C./min, and the coefficients of thermal expansion α1 and α2 (ppm/K) were measured. These measurement results are shown in Tables 40 and 41 together.

[Heat-resistant]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 120 μm, and dried at 90° C. for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. Thereafter, the resin layer of each composition was laminated by pressure bonding with a vacuum laminator at 60° C. and a pressure of 0.5 MPa for 60 seconds to a copper foil having a thickness of 18 μm, and the PET film was peeled off. Then, it was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven, and then peeled off from the copper foil to obtain a film sample composed of a cured product of each composition. The resulting film sample was pulverized in an agate mortar, and then measured in accordance with JIS-K-7120 at a heating rate of 10° C./min under a nitrogen stream. The temperature was checked and evaluated. The evaluation criteria were as follows: x when the 3% by weight weight loss temperature on heating is less than 300°C;

[Insulation]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 120 μm, and dried at 90° C. for 10 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. After that, it was crimped for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed with a copper thickness of 35 μm on a 1.6 mm thick FR-4 substrate at 60° C. and a pressure of 0.5 MPa with a vacuum laminator. Then, the resin layer of each composition was laminated, the PET film was peeled off, and the laminate was cured by heating at 180° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut to form an electrically independent terminal (cut along the dotted line in FIG. 6-4). A bias of DC 500 V was applied so that the upper portion of the A coupon became the cathode and the lower portion became the anode, and the insulation resistance value was measured and evaluated.
As the evaluation criteria, the insulation resistance value of 100 GΩ or more was evaluated as ◯, and the insulation resistance value of less than 100 GΩ was evaluated as x. The evaluation results are also shown in Tables 40 and 41.

[Toughness]
Each composition was applied to a PET film having a thickness of 38 μm using an applicator with a gap of 200 μm, and dried in a hot air circulation drying oven at 90° C. for 20 minutes to obtain a dry film having a resin layer of each composition. Next, a 18 μm-thick electrolytic copper foil with the glossy side facing upward was fixed with a tape onto a 1.6 mm-thick FR-4 copper-clad laminate, and the dry film was dried at 60° C. in a vacuum laminator. A resin layer of each composition was laminated on the electrolytic copper foil by crimping for 60 seconds at a pressure of 0.5 MPa, then the PET film was peeled off, and heated at 180 ° C. for 30 minutes in a hot air circulation drying oven. The resin layer was cured. Then, the fixed tape was peeled off, and the electrolytic copper foil was further peeled off to obtain a film sample composed of a resin layer. Next, according to JIS K7127, the film sample was cut into a predetermined size to prepare a test piece for evaluation. The test piece was measured for stress [MPa] and strain [%] at a tensile speed of 10 mm/min using a compact tabletop tester EZ-SX manufactured by Shimadzu Corporation. The strain [%] at this time is the elongation rate when the test piece breaks, and since the larger the strain, the higher the toughness can be evaluated, the toughness was evaluated from this strain [%].
As the evaluation criteria, a strain [%] of less than 2.0% was rated as x, and a strain of 2.0% or more was rated as ◯. The evaluation results are also shown in Tables 40 and 41.

[Pot life]
The viscosity of each composition after dispersion was measured using a cone plate type viscometer TPE-100-H manufactured by Toki Sangyo Co., Ltd. and taken as the initial viscosity. After that, it was placed in a container that can be closed and left at a temperature of 23° C., and the viscosity was measured and evaluated after 48 hours and 96 hours. The evaluation criteria are: ○ if the increase rate of viscosity after 96 hours is within 30%, △ if the increase rate after 48 hours is within 30%, and × if the increase rate after 48 hours is 30% or more. and Items marked with an X have a short usable life, so if one-liquid or film-like items are stored at room temperature from a low-temperature storage, problems may occur unless the next process is carried out early. Since it can be used for a long time, it is easy to handle in either one-liquid form or film form.

*6-1) Thermosetting resin 6-1: Epiclon HP-4032, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a naphthalene skeleton)
*6-2) Thermosetting resin 6-2: NC-7300L Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound with a naphthalene skeleton)
*6-3) Thermosetting resin 6-3: YX-8800 Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having an anthracene skeleton)
*6-4) Thermosetting resin 6-4: Epiclon HP-7200 Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a dicyclopentadiene skeleton)
* 6-5) Thermosetting resin 6-5: NC-3000H Nippon Kayaku Co., Ltd. Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound with a biphenyl skeleton)
*6-6) Thermosetting resin 6-6: YX-4000 Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 50% by mass (a cyclic ether compound having a biphenyl skeleton)
*6-7) Thermosetting resin 6-7: Epiclon N-740, manufactured by DIC Corporation, cyclohexanone varnish with a solid content of 50% by mass *6-8) Thermosetting resin 6-8: Epiclon 830, manufactured by DIC Corporation *6-9) Thermosetting resin 6-9: JER827 manufactured by Mitsubishi Chemical Corporation *6-10) Phenoxy resin 6-1: YX6954 manufactured by Mitsubishi Chemical Corporation Cyclohexanone varnish with a solid content of 30% by mass *6-11 ) Curing agent 6-1: HF-1 Meiwa Kasei Co., Ltd. Solid content 60% by mass cyclohexanone varnish * 6-12) Curing agent 6-2: Bisphenol A diacetate Tokyo Chemical Industry Co., Ltd. (active ester)
* 6-13) Curing catalyst 6-1: 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd. * 6-14) Filler 6-1: Admafine SO-C2 Admatechs Co., Ltd. (silica)
*6-15) Organic solvent 6-1: dimethylformamide *6-16) Antifoaming agent 6-1: BYK-352 BYK-Chemie Japan *6-17) Cellulose powder: NP fiber W-06MG (average Particle size 6 μm) made by Nippon Paper Industries

As is clear from the results shown in Tables 40 and 41, the combined use of cellulose nanocrystal particles and fillers other than cellulose nanocrystal particles maintains a low coefficient of thermal expansion not only at room temperature but also at high temperatures during component mounting. It was confirmed that a cured product excellent in various properties such as toughness and heat resistance can be obtained while maintaining the heat resistance, and a curable resin composition excellent in pot life can be obtained. Although not shown in Tables 40 and 41, it was confirmed that the use of an active ester as a curing agent lowered the dielectric constant and the dielectric loss tangent.

<Seventh embodiment>
[Preparation of fine cellulose fibers]
Production Example 6 (CNF dispersion 1)
After sufficiently stirring softwood bleached kraft pulp fiber (650 ml of Machenzie CSF manufactured by Fletcher Challenge Canada) with 9900 g of ion-exchanged water, TEMPO (2,2,6,6-tetramethyl Piperidine 1-oxyl free radical) 1.25% by weight, sodium bromide 12.5% by weight and sodium hypochlorite 28.4% by weight were added in this order. Using a pH stud, the pH was maintained at 10.5 by dropwise addition of 0.5M sodium hydroxide. After the reaction was carried out for 120 minutes (20° C.), the dropwise addition of sodium hydroxide was stopped to obtain oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion-exchanged water and then dehydrated. After that, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water were subjected to refining treatment twice at 245 MPa using a high-pressure homogenizer (Starburst Lab HJP 25005, manufactured by Sugino Machine Co., Ltd.) to disperse fine cellulose fibers containing carboxyl groups. A liquid (solid concentration: 1.3% by mass) was obtained.

Next, 4088.75 g of the resulting carboxyl group-containing fine cellulose fiber dispersion liquid was placed in a beaker, 4085 g of ion-exchanged water was added to make a 0.5% by mass aqueous solution, and the mixture was stirred with a mechanical stirrer at room temperature (25°C) for 30 minutes. Stirred. Subsequently, 245 g of 1M hydrochloric acid aqueous solution was charged and reacted at room temperature for 1 hour. After completion of the reaction, the precipitate was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added and filtered to obtain an acetone-containing acid-type cellulose fiber dispersion (solid concentration: 5.0% by mass) in which the carboxyl group-containing fine cellulose fibers were swollen in acetone. After completion of the reaction, it was filtered and then washed with ion-exchanged water to remove hydrochloric acid and salts. Then, the solvent was replaced with acetone to obtain a dispersion having a solid content of 5.0% by mass. Next, Epiclon 830 DIC Corporation (bisphenol F type epoxy resin) 250 g, JER827 Mitsubishi Chemical Corporation (bisphenol A type epoxy resin) 100 g and ELM100 Sumitomo Chemical Co., Ltd. (amines as precursors Epoxy resin: triglycidylaminophenol) 250 g and 1000 g of the dispersion adjusted to a solid content of 5.0% by mass by replacing the solvent with acetone were blended, and after stirring, acetone was removed with an evaporator to contain the epoxy resin. An acid-type cellulose fiber dispersion (average fiber diameter 3.3 nm, CNF concentration 7.7% by mass) was obtained.

Production Example 7 (CNF dispersion 2)
After sufficiently stirring softwood bleached kraft pulp fiber (650 ml of Machenzie CSF manufactured by Fletcher Challenge Canada) with 9900 g of ion-exchanged water, TEMPO (2,2,6,6-tetramethyl Piperidine 1-oxyl free radical) 1.25% by weight, sodium bromide 12.5% by weight and sodium hypochlorite 28.4% by weight were added in this order. Using a pH stud, the pH was maintained at 10.5 by dropwise addition of 0.5M sodium hydroxide. After the reaction was carried out for 120 minutes (20° C.), the dropwise addition of sodium hydroxide was stopped to obtain oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion-exchanged water and then dehydrated. After that, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water were subjected to refining treatment twice at 245 MPa using a high-pressure homogenizer (Starburst Lab HJP 25005, manufactured by Sugino Machine Co., Ltd.) to disperse fine cellulose fibers containing carboxyl groups. A liquid (solid concentration: 1.3% by mass) was obtained.

Next, 4088.75 g of the resulting carboxyl group-containing fine cellulose fiber dispersion liquid was placed in a beaker, 4085 g of ion-exchanged water was added to make a 0.5% by mass aqueous solution, and the mixture was stirred with a mechanical stirrer at room temperature (25°C) for 30 minutes. Stirred. Subsequently, 245 g of 1M hydrochloric acid aqueous solution was charged and reacted at room temperature for 1 hour. After completion of the reaction, the precipitate was reprecipitated with acetone, filtered, and then washed with acetone/ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added and filtered to obtain an acetone-containing acid-type cellulose fiber dispersion (solid concentration: 5.0% by mass) in which the carboxyl group-containing fine cellulose fibers were swollen in acetone. After completion of the reaction, it was filtered and then washed with ion-exchanged water to remove hydrochloric acid and salts. After replacing the solvent with acetone, the solvent was replaced with DMF, and a DMF-containing acid-type cellulose fiber dispersion (average fiber diameter 3.3 nm, solid content concentration 5.0% by mass) in which the carboxyl group-containing fine cellulose fibers were swollen was prepared. Obtained.

400 g of the obtained DMF-containing acid-form cellulose fiber dispersion and 3 g of hexylamine were placed in a beaker equipped with a magnetic stirrer and stirrer, and dissolved in 3000 g of ethanol. The reaction solution was reacted at room temperature (25° C.) for 6 hours. After completion of the reaction, the mixture was filtered, washed with DMF, and the solvent was replaced to obtain a fine cellulose fiber composite (solid concentration: 5.0% by mass) in which amines were linked to the fine cellulose fibers via ionic bonds. Next, Epiclon 830 DIC Corporation (bisphenol F type epoxy resin) 25 g, JER827 Mitsubishi Chemical Corporation (bisphenol A type epoxy resin) 10 g and ELM100 Sumitomo Chemical Co., Ltd. (amines as precursors Epoxy resin: triglycidyl aminophenol) 25 g and 200 g of a fine cellulose fiber composite in which an amine is linked to the fine cellulose fibers through an ionic bond are blended, and after stirring, DMF is removed with an evaporator to contain the epoxy resin. A fine cellulose fiber composite (CNF concentration: 15.4% by mass) was obtained in which amines were linked to fine cellulose fibers through ionic bonds.
The CNF produced by the method of Production Example 7 has particularly good dispersibility, and can be dispersed by a general method without using a special dispersing machine such as a high-pressure homogenizer.

Production Example 8 (CNF dispersion 3)
10% by mass of fine cellulose fibers (BiNFi-s manufactured by Sugino Machine, average fiber diameter 80 nm) was dehydrated and filtered, 10 times the amount of acetone was added to the filtered material, and the mixture was stirred for 30 minutes and then filtered. This replacement operation was repeated three times, and acetone was added in an amount 20 times the amount of the filter material to prepare a fine cellulose fiber dispersion (solid concentration: 5.0% by mass). Next, Epiclon 830 DIC Corporation (bisphenol F type epoxy resin) 250 g, JER827 Mitsubishi Chemical Corporation (bisphenol A type epoxy resin) 100 g and ELM100 Sumitomo Chemical Co., Ltd. (amines as precursors Epoxy resin: triglycidyl aminophenol) 250 g and 1000 g of the fine cellulose fiber dispersion were blended, and after stirring, acetone was removed with an evaporator to obtain a cellulose fiber dispersion containing an epoxy resin (CNF concentration 7.7% by mass ).

Production Example 9 (CNC dispersion 1)
A paper sheet of dried softwood bleached kraft pulp was processed with a cutter mill and a pin mill to obtain cotton-like fibers. 100 g of this cotton-like fiber was taken in absolute dry mass, suspended in 2 L of a 64% sulfuric acid aqueous solution, and hydrolyzed at 45° C. for 45 minutes.

After the resulting suspension was filtered, 10 L of ion-exchanged water was poured into the suspension and stirred to uniformly disperse the suspension to obtain a dispersion. Then, the step of filtering and dehydrating the dispersion was repeated three times to obtain a dehydrated sheet. Next, the obtained dehydrated sheet was diluted with 10 L of ion-exchanged water, and 1N sodium hydroxide aqueous solution was added little by little while stirring to adjust the pH to about 12. Thereafter, this suspension was filtered and dehydrated, and the process of adding 10 L of ion-exchanged water, stirring, and filtering and dehydrating was repeated twice.

Then, deionized water was added to the obtained dehydrated sheet to prepare a 2% suspension. This suspension was passed through a wet atomization device ("Ultimizer" manufactured by Sugino Machine Co., Ltd.) 10 times at a pressure of 245 MPa to obtain an aqueous dispersion of cellulose nanocrystal particles.

After that, the solvent was replaced with acetone to obtain an acetone dispersion (solid concentration: 5.0% by mass) in which the cellulose nanocrystal particles were swollen. As a result of observing and measuring the cellulose nanocrystal particles in the obtained dispersion by AFM, the average crystal width was 10 nm and the average crystal length was 200 nm.

Next, Epiclon 830 DIC Corporation (bisphenol F type epoxy resin) 50 g, JER827 Mitsubishi Chemical Corporation (bisphenol A type epoxy resin) 20 g and ELM100 Sumitomo Chemical Co., Ltd. (amines as precursors Epoxy resin: triglycidylaminophenol) 50 g and 200 g of the acetone dispersion were blended, and after stirring, the acetone was removed by an evaporator to obtain an epoxy resin-containing acid-type cellulose fiber dispersion.

Production Example 10 (CNC dispersion 2)
100 g of absorbent cotton (manufactured by Hakujuji Co., Ltd.) in terms of absolute dry mass was suspended in 2 L of a 64% sulfuric acid aqueous solution and hydrolyzed at 45° C. for 45 minutes.

After the resulting suspension was filtered, 10 L of ion-exchanged water was poured into the suspension and stirred to uniformly disperse the suspension to obtain a dispersion. Then, the step of filtering and dehydrating the dispersion was repeated three times to obtain a dehydrated sheet. Next, the obtained dehydrated sheet was diluted with 10 L of ion-exchanged water, and 1N sodium hydroxide aqueous solution was added little by little while stirring to adjust the pH to about 12. Thereafter, this suspension was filtered and dehydrated, and the process of adding 10 L of ion-exchanged water, stirring, and filtering and dehydrating was repeated twice.

Then, deionized water was added to the obtained dehydrated sheet to prepare a 2% suspension. This suspension was passed through a wet atomization device ("Ultimizer" manufactured by Sugino Machine Co., Ltd.) 10 times at a pressure of 245 MPa to obtain an aqueous dispersion of cellulose nanocrystal particles.

After that, the solvent was replaced with acetone to obtain an acetone dispersion (solid concentration: 5.0% by mass) in which the cellulose nanocrystal particles were swollen. As a result of observing and measuring the cellulose nanocrystal particles in the obtained dispersion by AFM, the average crystal width was 7 nm and the average crystal length was 150 nm.

Next, Epiclon 830 DIC Corporation (bisphenol F type epoxy resin) 50 g, JER827 Mitsubishi Chemical Corporation (bisphenol A type epoxy resin) 20 g and ELM100 Sumitomo Chemical Co., Ltd. (amines as precursors Epoxy resin: triglycidylaminophenol) 50 g and 200 g of the acetone dispersion were blended, and after stirring, the acetone was removed by an evaporator to obtain an epoxy resin-containing acid-type cellulose fiber dispersion.

According to the description in Tables 42 and 43 below, each component was blended and stirred, and then dispersed repeatedly six times using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Co., Ltd. to prepare each composition. Numerical values in Tables 42 and 43 indicate parts by mass.

[Bleeding around through holes]
An FR-4 copper-clad laminate (copper thickness: 18 μm) with a size of 150 mm×100 mm and a thickness of 1.6 mm was drilled with a 0.8 mm diameter drill at 30 locations in 3 columns and 10 rows at intervals of 10 mm. , electroless copper plating, and electrolytic copper plating were performed in this order, and a test substrate was prepared by subjecting the surface of the copper clad laminate to copper plating to a thickness of 25 μm. After buffing the test substrate, each composition was filled in the through-holes by screen printing using a plate with circular openings with a diameter of 0.9 mm in the hole portions. It was placed in a circulating drying oven and precured at 120° C. for 1 hour to obtain a test piece. The test piece was observed with a magnifying glass to evaluate the bleeding state of the cured product. The evaluation criteria were as follows: ◯ when no bleeding was observed, △ when there was no bleeding but spread beyond the size of the plate, and bleed-like bleeding where only the resin bleed along the polishing marks of the buff occurred. X was evaluated for those that did. The results are shown in Tables 42 and 43.

[Abrasiveness]
Abrasivity was evaluated by buffing (#320) for the test piece for which bleeding around the through hole was evaluated. Observation using a magnifying glass indicated that the cured product could be completely removed by 1 time, and that it required 2 or more times to be x. The results are shown in Tables 42 and 43.

[Expansion mark on through hole]
The test pieces for which polishability was evaluated were subjected to electroless copper plating (Thrucup PEA, manufactured by Uyemura & Co., Ltd.) and electrolytic copper plating (copper thickness: 10 µm) in that order. Next, after passing through a reflow furnace with a peak temperature of 265° C. three times, the portion above the hole was visually evaluated. ∘ indicates no expansion marks on 15 through-holes, △ indicates expansion marks on 1 to 5 through-holes, and 6 or more through-holes have expansion marks. x. The results are shown in Tables 42 and 43.

Since Examples 7-1 to 7-4 contain thermosetting resins 7-1 to 7-3 in the CNF dispersion, the resin content is almost the same for both Examples and Comparative Examples.
* 7-1) Thermosetting resin 7-1: Epiclon 830 manufactured by DIC Corporation (bisphenol F type epoxy resin)
* 7-2) Thermosetting resin 7-2: jER827 manufactured by Mitsubishi Chemical Corporation (bisphenol A type epoxy resin)
* 7-3) Thermosetting resin 7-3: Sumiepoxy ELM100 manufactured by Sumitomo Chemical Co., Ltd. (epoxy resin with amines as precursor: triglycidylaminophenol)
* 7-4) Thermosetting resin 7-4: Denacol EX-212 Nagase ChemteX Co., Ltd. (1,6 hexanediol diglycidyl ether)
* 7-5) Curing agent 7-1: 2MZA-PW manufactured by Shikoku Kasei Co., Ltd. (2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-S-triazine)
* 7-6) Storage stabilizer 7-1: Cure Duct L-07N, manufactured by Shikoku Kasei Co., Ltd. (compound of 5% by mass of borate ester, epoxy resin, and novolac resin)
* 7-7) Inorganic filler 7-1: Softon 1800 manufactured by Bihoku Funka Kogyo Co., Ltd. (calcium carbonate)
* 7-8) Defoamer 7-1: KS-66 manufactured by Shin-Etsu Chemical Co., Ltd.

As is clear from the results shown in Tables 42 and 43, by using a curable resin composition in which a fine powder such as fine cellulose fibers is dispersed in a resin filler, holes can be filled even during heating during component mounting. It was confirmed that a hole-filling material that does not cause bulges on the holes, does not cause bleeding of the resin component, and does not cause depressions in the holes even in the polishing process can be obtained.

1, 3, 8, 11 conductor pattern 2 core substrate 1a, 4 connection portion 5 through holes 6, 9 interlayer insulation layers 7, 10 via 12 solder resist layer 101 wiring board 102 base material 103 plated through hole 104 conductor circuit layer 105 curing Pre-cured product or main cured product of the flexible resin composition 106 Conductor circuit layer 107 Multilayer printed wiring board 108 in which the buildup layer is laminated on the core substrate Buildup layer 109 Conductor circuit layer 110 In forming the buildup layer, above the hole A multilayer printed wiring board 111 filled with a cured product of a curable resin composition. A via hole 112 filled with a cured product of a curable resin composition. Dent in hole

Claims (11)

A curable resin, a fine powder having at least one dimension smaller than 100 nm, and a filler other than the fine powder ,
The fine powder is a fine cellulose powder having a carboxyl group in the molecule and chemically modified with an amine compound or a quaternary ammonium compound,
The curable resin includes a cyclic ether compound having at least one of a naphthalene skeleton and an anthracene skeleton,
A curable resin composition, wherein the amount of the cyclic ether compound is 0.5% by mass or more and 80% by mass or less with respect to the total amount of the composition excluding the solvent . The mixing ratio of the fine powder and the filler other than the fine powder in the total filler is (filler other than the fine powder: fine powder) = 100: (0.04 to 30) in terms of mass ratio. 2. The curable resin composition according to 1. A dry film comprising a resin layer formed by coating and drying the curable resin composition according to claim 1 on a film. A cured product obtained by curing the curable resin composition according to claim 1 or the resin layer of the dry film according to claim 3 . An electronic component comprising the cured product according to claim 4 . A curable resin composition for filling at least one of recesses and through holes of a printed wiring board,
(A) a fine powder with at least one dimension smaller than 100 nm;
(B) a thermosetting component;
(D) a filler other than the (A) fine powder;
including
The (A) fine powder is fine cellulose powder or cellulose nanocrystal particles,
The thermosetting component (B) contains an alkyl glycidyl ether,
The (D) filler is calcium carbonate,
A curable resin composition, wherein the amount of calcium carbonate is 10 to 70% by mass relative to the total amount of the composition. 7. The curable resin composition according to claim 6 , wherein the thermosetting component (B) contains a cyclic ether compound having an amine as a precursor. 7. The curable resin composition according to claim 6 , comprising a bisphenol A type epoxy resin and a bisphenol F type epoxy resin as the thermosetting component (B). 7. The curable resin composition according to claim 6 , comprising (C) a boric acid ester compound. A cured product obtained by curing the curable resin composition according to claim 6 . A printed wiring board, wherein at least one of the concave portion and the through hole of the printed wiring board is filled with the cured product according to claim 10 .

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