WO2016072224A1 - Wiring board material and wiring board using same - Google Patents

Abstract

The purpose of the present invention is to provide a wiring board material having low water absorbency while maintaining low thermal expansion and a high breaking elongation rate, and a wiring board that uses the wiring board material. The wiring board material is characterized by including a binder component, sheet-shaped cellulose nanofibers, and an inorganic filler having low water absorbency. This wiring board material is capable of being favorably used as an interlayer insulator in a multilayer wiring board, and as a solder resist or a cover lay. The present invention also provides a wiring board that uses this wiring board material.

Description

Wiring board material and wiring board using the same

The present invention relates to a wiring board material having low water absorption while maintaining low thermal expansion and high breaking elongation, and a wiring board using the same.

As a wiring board for an electronic device, a prepreg (semi-cured resin insulating layer) obtained by impregnating a substrate made of glass fiber or aramid fiber with a resin such as epoxy is generally applied to a metal foil such as copper. A circuit was formed by copper plating or the like after forming an insulating layer by applying an insulating resin composition or laminating a sheet-like insulating resin composition, or by forming a circuit by etching and bonding the insulating resin composition. Things are used. The wiring board is provided with a solder resist in order to prevent the solder from flowing out during component mounting.

With the increase in the density of wiring boards, wiring board materials are required to have low thermal expansion equivalent to copper foil (copper wiring) or silicon chip components. This is because if there is a large difference in thermal expansion (thermal expansion coefficient) between the copper foil and the wiring board material, the wiring board warps due to thermal stress during component mounting, resulting in poor bonding of the components. Because. Further, the wiring board material needs to have a high elongation at break. This is because if the elongation at break of the wiring board material is low, the wiring board material cannot follow the copper foil and cracks are generated due to temperature changes in a heat cycle test or the like of the wiring board. In addition, it is essential for the wiring board material to have low water absorption. This is because when the water absorption is high, a metal component migrates into the wiring board material in a HAST test or the like of the wiring board, causing a problem of migration and occurrence of insulation failure.
Therefore, the wiring board material is required to have low thermal expansibility, high elongation at break, and low water absorption.

As a conventional technique, for example, there is a method of using cellulose nanofibers made of cellulose fibers for a wiring board (see Patent Documents 1 and 2). However, when it is contained in a large amount, there is a problem that water absorption is increased due to cellulose fibers.

JP 2011-001559 A JP 2012-119470 A

An object of the present invention is to provide a wiring board material having low water absorption while maintaining low thermal expansion and a high elongation at break, and a wiring board using the same.

As a result of intensive studies to solve the above problems, the present inventors have found the following.
In other words, cellulose nanofibers exhibit low thermal expansion by being present in a wiring board material produced by mixing with a resin or the like. When sheet-like cellulose nanofibers are used, entanglement between fibers and mutual It exhibits low thermal expansion due to its action. However, when a large amount of cellulose nanofibers are present in the wiring board material, the water absorption is increased.
As described above, it is important for the wiring board material to have low thermal expansion, high elongation at break, and low water absorption.

As a result of the above studies, the present inventors have found that the following configuration can be used as a wiring board material while balancing thermal expansion, elongation at break, and water absorption.
That is, the wiring board material of the present invention is characterized by including a binder component, a sheet-like cellulose nanofiber, and a low water-absorbing inorganic filler. Here, “low water absorption” means that the inorganic filler alone is a moisture absorption rate of 3% or less.
In the wiring board material of the present invention, the binder component preferably contains a thermosetting resin, the low water-absorbing inorganic filler is preferably silica, and the volume content of the low water-absorbing inorganic filler is The volume content of the sheet-like cellulose nanofiber is preferably larger.
The wiring board material of the present invention can be suitably used for interlayer insulating materials for multilayer wiring boards and for forming a permanent insulating film such as a solder resist or a coverlay.
Furthermore, the wiring board of the present invention is characterized by having the wiring board material of the present invention.

According to the present invention, it is possible to obtain a wiring board material having low water absorption while maintaining low thermal expansion and high elongation at break. That is, in the present invention, by including a sheet-like cellulose nanofiber and a low water-absorbing inorganic filler, a wiring board material having low thermal expansion and high breaking elongation and low water absorption is obtained. The condition of the material for finding was found. This is because wiring board materials for interlayer insulating materials and solder resists for multilayer wiring boards need to have the above-mentioned characteristics. For example, if a large amount of cellulose nanofiber is used, water absorption is increased. However, according to the present invention, the problem of water absorption can be solved while maintaining low thermal expansion and high elongation at break.

It is a fragmentary sectional view which shows one structural example of the multilayer wiring board of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The wiring board material of the present invention is characterized in that it includes a binder component, a sheet-like cellulose nanofiber, and a low water-absorbing inorganic filler.
Such a sheet-like cellulose nanofiber can be obtained as follows.

(Sheet-like cellulose nanofiber)
The fine cellulose fiber that is a component of the sheet-like cellulose nanofiber is usually obtained by defibrating a cellulose fiber raw material, and the number average fiber diameter is preferably 400 nm or less. The number average fiber diameter of the fine cellulose fibers is preferably as small as possible. However, in order to reduce the linear expansion, it is important to maintain the crystallinity of cellulose, and the fiber diameter of the cellulose crystal unit is usually 4 nm or more. It is.

In addition, the fiber diameter of the fine cellulose fiber can be obtained by measuring the cellulose nonwoven fabric obtained by drying and removing the dispersion medium in the fine cellulose fiber dispersion described in detail below by observing with SEM, TEM, or the like. it can. Specifically, it is usually observed with SEM, TEM, etc., a line is drawn on the diagonal line of the photograph, 12 points of fibers in the vicinity are randomly extracted, and 10 points obtained by removing the thickest fiber and the thinnest fiber are extracted. The number average fiber diameter is measured and averaged.
The cellulose fiber raw material is normally defibrated in a cellulose fiber raw material dispersion (cellulose fiber raw material dispersion). In the dispersion, a cellulose fiber raw material dispersion having a solid content concentration of, for example, 0.1% by mass or more, preferably 0.2% by mass or more, and 10% by mass or less, preferably 6% by mass or less is used. A liquid is preferred.
When the solid content concentration in the cellulose fiber raw material dispersion to be subjected to this defibrating step is 0.1% by mass or more, the amount of liquid is moderate with respect to the amount of cellulose to be processed, and the efficiency of the defibrating process is good. On the other hand, when the solid content concentration is 10% by mass or less, the fluidity is good.

As the dispersion medium, an organic solvent, water, or a mixed solution of an organic solvent and water can be used. Organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, n-butanol, ethylene glycol and ethylene glycol mono-t-butyl ether, ketones such as acetone and methyl ethyl ketone, and other water-soluble organic compounds. One kind or two or more kinds of solvents can be used. The dispersion medium is preferably a mixed liquid of an organic solvent and water or water, and particularly preferably water.
There are no particular restrictions on the method of defibrating the cellulose fiber raw material, but for example, ceramic beads having a diameter of about 1 mm are placed in the cellulose fiber raw material dispersion, and vibration is applied using a paint shaker or bead mill. Cellulosic fiber raw material is defibrated, blended with a blender-type disperser or a high-speed rotating slit, and a method of defibration by applying shear force through the cellulose fiber raw material dispersion (high-speed rotating homogenizer method) A method of using a counter impact type disperser (manufactured by Masuko Sangyo Co., Ltd.) such as “massomizer X”, etc. Is mentioned. In particular, the high-speed rotating homogenizer and the high-pressure homogenizer treatment improve the efficiency of defibration.

Note that a miniaturization process combined with an ultrasonic process may be performed after the above process.
In this case, the frequency of the ultrasonic waves is, for example, 15 kHz to 1 MHz, preferably 20 kHz to 500 kHz. When the frequency of the ultrasonic wave to irradiate is 15 kHz or more, the occurrence of cavitation is good. On the other hand, when the frequency is 1 MHz or less, a fine effect can be obtained satisfactorily. Moreover, as an output of an ultrasonic wave, as an execution output density, it is 1 W / cm < ² > or more, for example, Preferably it is 10 W / cm < ² > or more. When the output of the ultrasonic wave is 1 W / cm ² or more, the miniaturization efficiency is good and the miniaturization can be performed in a short time. In addition, the upper limit of the effective output density of ultrasonic waves is 500 W / cm ² or less from the viewpoint of durability of the vibrator and the horn.

The ultrasonic irradiation method is not particularly limited, and various methods can be used. For example, by directly inserting a horn that transmits the vibration of an ultrasonic vibrator into the cellulose fiber raw material dispersion, a method for directly refining cellulose fibers, or a floor or wall of a container containing a cellulose fiber raw material dispersion. Place ultrasonic transducers on the part to make cellulose fibers fine, or put a liquid such as water in a vessel equipped with ultrasonic transducers, and immerse the vessel containing the cellulose fiber raw material dispersion in it. Thus, a method of applying ultrasonic vibration indirectly to the cellulose fiber raw material dispersion liquid through a liquid such as water can be employed.

Further, the ultrasonic waves may be irradiated continuously or intermittently at a predetermined interval.
In addition, after performing the defibrating treatment, it is preferable to separate and remove the defibrated cellulose fibers in the fine cellulose fiber dispersion using centrifugation. By centrifuging, a supernatant of a more uniform and fine fine cellulose fiber dispersion can be obtained. The conditions for the centrifugation are not particularly limited because they depend on the miniaturization process used, but it is preferable to apply a centrifugal force of, for example, 3000 G or more, preferably 10,000 G or more. The time is preferably 1 minute or longer, preferably 5 minutes or longer. When the centrifugal force is 3000 G or more, when the time is 1 minute or more, separation / removal of cellulose fibers with poor defibration is sufficient.

In addition, when performing centrifugation, from the viewpoint of separation efficiency, the viscosity of the fine cellulose fiber dispersion is, for example, a viscosity at a shear rate of 10 s ⁻¹ measured at 25 ° C., for example, 500 mPa · s or less, particularly 100 mPa · s. It is preferable that it is s or less.

(Method for producing sheet-like cellulose nanofiber)
Sheet-like cellulose nanofibers are usually produced using fine cellulose fibers obtained as described above. The sheet-like cellulose nanofibers can be obtained with high transparency, low linear expansion coefficient, and high elastic modulus when produced using fine cellulose fibers rather than using the cellulose fiber raw material before defibration. Specifically, the sheet-like cellulose nanofiber is obtained by filtering a dispersion (fine cellulose fiber dispersion) containing fine cellulose fibers obtained by performing the above-described defibrating treatment, or an appropriate substrate. It is manufactured as a sheet-like product by applying to.

When producing sheet-like cellulose nanofibers by filtering a fine cellulose fiber dispersion, the fine cellulose fiber concentration of the dispersion used for filtration is usually 0.01% by mass or more, preferably 0.05% by mass. % Or more. When the concentration of the fine cellulose fiber is 0.01% by mass or more, it can be easily filtered. Moreover, the density | concentration of a fine cellulose fiber is 10 mass% or less normally, Preferably it is 5 mass% or less. When the concentration of fine cellulose fibers is 10% by mass or less, a uniform sheet can be obtained satisfactorily.

When filtering the fine cellulose fiber dispersion, it is important that the fine cellulose fibers do not pass through and the filtration speed is not too slow as a filter cloth at the time of filtration. As such a filter cloth, a sheet made of an organic polymer, a woven fabric, and a porous membrane are preferable. As the organic polymer, non-cellulosic organic polymers such as polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene (PTFE) and the like are preferable. More specifically, a porous film of polytetrafluoroethylene having a pore diameter of 0.1 to 20 μm, for example 1 μm, polyethylene terephthalate or polyethylene fabric having a pore diameter of 0.1 to 20 μm, for example 1 μm, and the like can be mentioned. Moreover, the paper base material which consists of cellulose which is a natural fiber can be used as a filter medium. The paper base material is very preferable because it can easily produce wide and long materials and can control the amount of water passing through the paper by changing the type of pulp as the raw material and the beating degree of the pulp. In addition, it is possible to easily impart water resistance to the base with a water-proofing agent or a hydrophobizing agent.

The sheet-like cellulose nanofibers obtained by the filtration are then dried, but in some cases, the process may proceed to the next step without drying.
That is, for example, when the heat-treated fine cellulose fiber dispersion is filtered, it can be directly used for the next step without passing through the drying step.
Moreover, also when filtering a fine cellulose fiber dispersion liquid and heat-processing the obtained sheet-like cellulose nanofiber, it can also carry out without passing through a drying process.
However, it is preferable to perform drying also in the sense of controlling the porosity, film thickness, and strengthening the structure of the nonwoven fabric. This drying may be air drying, vacuum drying, pressure drying, or freeze drying. Moreover, you may heat-dry. When heating, the temperature is preferably 50 ° C or higher, more preferably 80 ° C or higher, 250 ° C or lower is more preferable, and 150 ° C or lower is more preferable. When the heating temperature is 50 ° C. or higher, it can be easily dried. On the other hand, when heating temperature is 250 degrees C or less, it can suppress that a cellulose nonwoven fabric colors or a cellulose decomposes | disassembles. Moreover, when pressurizing, 0.01 MPa or more is preferable and 0.1 MPa or more is more preferable. When the pressure is 0.01 MPa or more, the drying is good. On the other hand, when the pressure is 10 MPa or less, the cellulose nonwoven fabric can be prevented from being crushed or the cellulose being decomposed.

Alternatively, the sheet-like cellulose nanofibers may be produced as a sheet-like material by applying a fine cellulose fiber dispersion to an appropriate substrate. In this case, usually, the dispersion is applied onto a predetermined substrate, and the dispersion medium is evaporated to a specific amount and removed. The coating method is not particularly limited, and examples thereof include spin coating, blade coating, wire bar coating, spray coating, and slit coating. In particular, the spin coating method is preferable in that a thin film having a uniform thickness can be obtained. In addition, it does not specifically limit as a board | substrate, A glass substrate, a plastic substrate, etc. are mentioned.

In addition, the sheet-like cellulose nanofiber may contain other components other than the cellulose fiber as long as the intended effect of the present invention is not impaired. The other components may be components originally contained as raw material components such as hemicellulose and lignin, for example, binders such as glue materials, plasticizers, various fillers, various pigment sheets, and the like. May be various components used when producing the cellulose nanofibers, for example, various components used after producing the sheet-like cellulose nanofibers, such as functional group-containing silanes and alkylsilazanes. .

The sheet-like cellulose nanofiber produced as described above is preferably contained in the wiring board material of the present invention in a proportion of 0.1 to 40% by volume, based on the solid content of the entire wiring board material, in particular. Is preferably 5 to 35% by volume. When the content is 0.1% by volume or more, it becomes easy to obtain the effect of reducing the thermal expansibility. On the other hand, when the content is 40% by volume or less, the water absorption can be kept low.

(Binder component)
The binder component is obtained by drying a liquid composition, and the liquid composition contains a thermosetting resin, a thermoplastic resin, a photocurable resin, an organic solvent, and the like. In other words, the binder component is a component obtained by substantially removing the organic solvent from the liquid composition. However, depending on the drying method of the liquid composition, the organic solvent may remain in the binder component.
In the present invention, a composition containing a thermosetting resin can be particularly preferably used as the liquid composition.

(Thermosetting resin)
The thermosetting resin may be a resin that is cured by heating and exhibits electrical insulation properties. For example, 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 type epoxy resin such as bisphenol Z type epoxy resin, novolac type epoxy resin such as bisphenol A novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolac epoxy resin, biphenyl type epoxy resin , Biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, tetraphenylol ethane type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, Enoxy-type epoxy resin, dicyclopentadiene-type epoxy resin, norbornene-type epoxy resin, adamantane-type epoxy resin, fluorene-type epoxy resin, glycidyl methacrylate-copolymerized epoxy resin, copolymerized epoxy resin of cyclohexyl maleimide 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, ethylene Diglycidyl ether of glycol or propylene glycol, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, Oil modification modified with glycidyl tris (2-hydroxyethyl) isocyanurate, phenol novolac resin, cresol novolac resin, novolac type phenol resin such as bisphenol A novolac resin, unmodified resole phenol resin, tung oil, linseed oil, walnut oil, etc. Phenol resin such as resole phenol resin such as resole phenol resin, Triazine ring-containing resin such as phenoxy resin, urea resin, melamine resin, unsaturated polyester resin, bismaleimide resin, diallyl phthalate resin, silicone resin, benzoxazine Ring-containing resin, norbornene resin, cyanate resin, isocyanate resin, urethane resin, benzocyclobutene resin, maleimide resin, bismaleimide triazine resin, polyazo Chin resins, and polyimide resins. Among these, an epoxy resin or a polyimide resin is particularly preferable because of its excellent reliability as an insulating layer.

As the epoxy resin, a known and commonly used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be used. The epoxy resin may be liquid, and may be solid or semi-solid. Among them, bisphenol A type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin or a mixture thereof is particularly preferable. These epoxy resins may be used individually by 1 type, and may be used in combination of 2 or more type. Specific examples of the epoxy resin include jER828 manufactured by Mitsubishi Chemical Corporation, but are not limited thereto.

The wiring board material of the present invention may further contain a compound having two or more phenolic hydroxyl groups for the purpose of improving the mechanical strength and heat resistance of the cured product of the wiring board material.
Examples of the compound having two or more phenolic hydroxyl groups include phenol novolac resins, alkylphenol volac resins, bisphenol A novolac resins, dicyclopentadiene type phenol resins, Xylok type phenol resins, terpene-modified phenol resins, and polyvinylphenols. A phenol resin can be used individually or in combination of 2 or more types. When the phenol resin is used together with an epoxy resin, the phenolic hydroxyl group is desirably blended at a ratio of 0.1 to 1.2 equivalents with respect to 1 equivalent of the epoxy group.

When forming a cured product using a wiring board material containing an epoxy resin, the liquid composition preferably contains at least one of a curing agent and a thermosetting catalyst in addition to the epoxy resin. Common compounds can be used as the curing agent and the thermosetting catalyst. Examples of the curing agent include 2-ethyl-4-methylimidazole (2E4MZ), 2-phenylimidazole (2PZ), 2-phenyl-4- Imidazole-based curing agents such as methyl-5-hydroxymethylimidazole (2P4MHZ), diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, metaxylenediamine, isophoronediamine, norbornenediamine, 1,3-bisaminomethylcyclohexane Amine curing agents such as N-aminoethylpiperazine, phenolic curing agents such as polyamide, vinylphenol, aralkyl type phenol resins, phenol phenyl aralkyl resins, phenol biphenyl aralkyl resins, Hydrophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, methyl nadic anhydride, dodecyl succinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride , Ethylene glycol bis (anhydrotrimate), acid anhydride curing agents such as methylcyclohexene tetracarboxylic anhydride, cyanate ester resin, active ester resin, aliphatic or aromatic primary or secondary amine, polyamide resin A known curing agent such as a polymercapto compound can be used. The compounding amount of the curing agent is preferably 0.1 to 150 parts by mass, more preferably 0.5 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin. By setting the blending amount of the curing agent to 0.1 parts by mass or more, the resin composition can be sufficiently cured, and by setting the blending amount to 150 parts by mass or less, an effect commensurate with the blending amount can be efficiently obtained. Can do.

Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N- Examples thereof include amine compounds such as dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide, and phosphorus compounds such as triphenylphosphine. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used.

As a polyimide resin, what is obtained via a polyamic acid (polyimide precursor) by a synthetic reaction of a generally known aromatic polyvalent carboxylic acid anhydride or derivative thereof and an aromatic diamine, What is marketed as what is called a polyimide varnish of the state by which the polyamic acid composition was melt | dissolved in the organic solvent is mentioned.

Specific examples of the aromatic polycarboxylic acid anhydride include, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3 ′. -Benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis ( 2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3 , 4- Carboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic Acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic acid Anhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride and the like can be mentioned. These may be used alone or in combination of two or more. Among these, it is particularly preferable to use pyromellitic dianhydride as at least one of the components.

Specific examples of aromatic diamines to be reacted with polyvalent carboxylic acids such as aromatic polycarboxylic anhydrides include, for example, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p -Aminobenzylamine, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) Sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) ( 4-aminophenyl) sulfone, bis (4-a Nophenyl) sulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diamino Diphenylmethane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1, 1-bis [4- (4-aminophenoxy) phenyl] -ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl ] Ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4- Minophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3 3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-amino Phenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis ( 3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) Bis) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [ 4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) Phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) Benzoyl] benzene, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenylate 4,4′-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′- Bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4 -Aminophenoxy) phenoxy] -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene and the like. These are used individually or in mixture of 2 or more types. Among these, it is particularly preferable to use 4,4'-diaminodiphenyl ether as at least one of the components.

Polyimide varnishes include Rika Coat SN20, Rika Coat PN20, Rika Coat EN20 from Shin Nippon Rika Co., Ltd., Trenys from Toray Industries, U-Varnish from Ube Industries, Optomer from JSR, Nissan SE812 manufactured by Chemical Co., Ltd. and CRC8000 manufactured by Sumitomo Bakelite Co., Ltd. may be mentioned.

The polyamic acid solution obtained by the synthesis reaction or marketed is treated by heating or the like, whereby cyclization (imidization) from the polyamic acid to the polyimide is performed. The polyamic acid can be imidized by a method only by heating or a chemical method. In the case of the method using only heating, the polyamic acid is imidized by heat treatment at 200 to 350 ° C., for example. In addition, the chemical method is a method in which the polyamic acid is heat-treated and completely imidized while using a basic catalyst in order to rapidly advance imidization. The basic catalyst is not particularly limited, and a conventionally known basic catalyst is used. Examples thereof include pyridine, diazabicycloundecene (DBU), diazabicyclononene (DBN), various tertiary amines, and the like. It is done. These basic catalysts may be used alone or in combination of two or more.

As thermoplastic resins, polyesters, polyamides, polyethers, polyimides, polysulfides, polysulfones, polyacetals, butyral resins, NBR, phenoxy resins, polybutadienes, various engineering plastics, etc. can be used alone or in combination of two or more. Can be used.
These thermoplastic resins are uniformly dispersed or dissolved in the wiring board material at room temperature, regardless of whether the thermosetting resin in the wiring board material is cured and then uniformly dispersed or phase-separated. Those are preferred. These thermoplastic resins contribute to the prevention of repelling during coating and the improvement of transferability, and are effective in increasing the thickness of the coating. Effective in reducing warpage. Furthermore, the melt viscosity at the time of molding can be increased, which is effective for controlling the amount of resin oozing after molding.

In addition, as an organic solvent used to dissolve each of the above components or to make a slurry, and to dissolve other components, ordinary solvents such as ketones such as acetone, methyl ethyl ketone, and cyclohexanone; toluene , Xylene, tetramethylbenzene and other aromatic hydrocarbons; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol Glycol ethers such as monoethyl ether; ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and the above-mentioned glycols Esters such as esterified esters; alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; 1-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε- Amides such as caprolactam, formamide, N-methylformamide, N, N-dimethylformamide, acetamide and N-methylacetamide; ethers such as tetrahydrofuran and dioxane; nitriles such as acetonitrile, benzonitrile and propionitrile; chloroform; Halogens such as dichloromethane, bromobenzene, dibromobenzene, chlorobenzene, dichlorobenzene; N-methyl-2-pyrrolidone, dimethylaniline, dibutylaniline, diisopropylaniline, etc. Amines; Sulfur containing compounds such as dimethyl sulfoxide and sulfolane; Aliphatic hydrocarbons such as octane and decane; Petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha alone or in combination Can be used in combination.

If necessary, photocurable resin, photoacid generator, photobase generator, radical scavenger, defoaming / leveling agent, thixotropy imparting agent / thickening agent, dispersant, coupling agent, UV absorber , Flame retardant, peroxide decomposer, thermal polymerization inhibitor, adhesion promoter, rust inhibitor, surface treatment agent, surfactant, lubricant, antistatic agent, pH adjuster, antioxidant, dye, pigment, Components such as a fluorescent agent may be included as long as the object of the present invention is not impaired.

The content of the binder component is not particularly limited, but it is preferably 5 to 60% by volume, particularly 10 to 50% by volume, based on the solid content of the entire wiring board material. When the content is 5% by volume or more, the curability of the resin composition is good, and the moisture resistance of the wiring board obtained using the wiring board material is improved. Moreover, when content is 60 volume% or less, the heat resistance of wiring board material improves.

(Low water-absorbing inorganic filler)
As the low water-absorbing inorganic filler used in the present invention, silica can be suitably used.
Moreover, although the said silica is not specifically limited, It is preferable that it is hydrophobic. Thereby, aggregation of a silica can be suppressed and a silica can be favorably disperse | distributed in the wiring board material of this invention. Moreover, since the affinity between the binder component and silica is improved and the adhesion between the surface of the binder component and silica is improved, a wiring board material having excellent strength can be obtained. As a method for making silica hydrophobic, for example, a method in which silica is surface-treated with a functional group-containing silane or alkylsilazane in advance is exemplified.
In addition, the silica is preferably used as a slurry previously dispersed in an organic solvent. Thereby, the dispersibility of a silica can be improved and the fall of the fluidity | liquidity which arises when using another low water absorption inorganic filler can be suppressed.
The silica is not particularly limited, but is preferably spherical silica having an average particle diameter (d50) of 5 to 2000 nm. For example, Admafine SO-E1, SO-E2, SO- Use commercially available products such as E3, SO-E5, SO-C1, SO-C2, SO-C3, SO-C5, SFP-20M, SFP-30M, SFP-30MHE, SFP-130MC manufactured by Denki Kagaku Kogyo Co., Ltd. Can do. The shape of the silica is not limited to a spherical shape, and may be amorphous silica.

As the low water-absorbing inorganic filler used in the present invention, a known and commonly used low water-absorbing inorganic filler can be blended as long as the moisture absorption rate of the low water-absorbing inorganic filler alone is 3% or less. Here, the moisture absorption rate refers to using a water vapor atmosphere differential thermal balance apparatus, putting a container with a sample at a constant temperature of 80 ° C. in a nitrogen atmosphere, drying at 2% RH for 1 hour, and then humidifying at 60% RH for 1 hour. Thus, it means the difference in sample weight (increase rate) after drying and after humidification.
The low water-absorbing inorganic filler is not particularly limited in addition to silica having an average particle size of 5 to 2000 nm. Examples thereof include titanium oxide, alumina, silica having an average particle size larger than 2000 nm, and amorphous silica. Oxides, metal hydroxides such as talc, aluminum hydroxide, boehmite and calcium hydroxide, sulfates such as barium sulfate and calcium sulfate, nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride, strontium titanate Various powders such as titanates such as barium titanate, silicon powder, and fluorine powder can be contained. Among these, titanium oxide, barium sulfate, and calcium sulfate are preferable. In addition, as said low water absorption inorganic filler, 1 type can also be used independently and 2 or more types can also be used together.
In addition, as long as the effect of this invention is not inhibited, you may mix | blend a well-known inorganic filler. Known inorganic fillers include, for example, carbonates such as calcium carbonate, magnesium carbonate, hydrotalcite, sulfites such as magnesium hydroxide, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, Examples thereof include borate salts such as calcium borate and sodium borate, and silica gel.

The low water-absorbing inorganic filler is preferably contained in a proportion of 10 to 60% by volume, particularly 20 to 50% by volume, based on the solid content of the entire wiring board material. When content is 10 volume% or more, the shape retainability at the time of forming an insulating layer in a wiring board improves. On the other hand, when content is 60 volume% or less, adhesiveness with the copper foil at the time of forming an insulating layer in a wiring board becomes favorable, and it can use favorably as a wiring board material.

In the wiring board material of this invention, it is preferable that the volume content of a low water absorption inorganic filler is larger than the volume content of a sheet-like cellulose nanofiber. More preferably, the low water-absorbing inorganic filler: sheet-like cellulose nanofibers preferably has a volume ratio of 95: 5 to 55:45, and a volume ratio of 90:10 to 60:40. More preferably. By setting the relationship between the two in the above range, good characteristics can be obtained with a good balance.
The volume content of the low water-absorbing inorganic filler and the sheet-like cellulose nanofiber is preferably 50 to 65 vol% based on the total capacity of the wiring board material.

(Manufacture of wiring board materials)
The wiring board material of the present invention is obtained by mixing a low water-absorbing inorganic filler and a liquid composition, impregnating the mixture into a sheet-like cellulose nanofiber, and then drying the impregnated material (wiring board material before drying). Can be obtained. The wiring board material of the present invention is applied and impregnated with, for example, a mixture containing a low water-absorbing inorganic filler and a liquid composition in a state in which sheet-like cellulose nanofibers are arranged on an object to be coated such as a carrier film. And it can also manufacture as a dry film by carrying out the volatile drying of the organic solvent contained in a mixture, and you may bond a cover film on it further as desired.
Specific examples of the coating method include a dropping method using a pipette, a dip coating method, a bar coater method, a spin coating method, a curtain coating method, a spray coating method, a roll coating method, a slit coating method, a blade coating method, a lip coating. And various coating methods such as screen printing, spray printing, ink jet printing, letterpress printing, intaglio printing, and planographic printing.
In this case, the above-mentioned mixture can be applied by adjusting, mixing, dispersing, and diluting each component as necessary to a viscosity suitable for the application method. As described above, the mixture is not particularly limited as long as it can be impregnated by impregnating the sheet-like cellulose nanofibers and can be brought into close contact with copper foil (copper wiring) or the like.

In addition, as the carrier film and the cover film, any known materials used for the dry film can be used, and examples thereof include a polyethylene film and a polypropylene film. The carrier film and the cover film may use the same film material or different film materials, but the cover film preferably has a smaller adhesiveness to the resin than the carrier film.
A wiring board can be obtained by bringing the wiring board material of the present invention into close contact with a substrate. Examples of the base material include a metal foil substrate, a circuit-formed wiring board, and the like, and an insulating layer can be formed by thermally adhering to the surface of the base material. ) And an insulating layer can also be laminated. The wiring board material may be laminated with the wiring board materials when manufactured on the carrier film, or may be laminated with the wiring board materials when in close contact with the copper foil or the like. In that case, a method of heat-curing after impregnation, in the case of a dry film, the cover film is peeled off, the wiring board material is thermally adhered to the substrate surface, and then the carrier film is peeled off and then heat-cured. Can be manufactured. In addition, when laminating | stacking, a copper foil layer and an insulating layer may be heat-hardened one by one, and may be laminated | stacked and heat-cured collectively. Moreover, about the heating temperature at the time of heating, if a cellulose nanofiber, a binder component, etc. are the range which does not decompose | disassemble by high heat, there will be no restriction | limiting in particular in a minimum and an upper limit.

Moreover, when producing the wiring board material of this invention, when a binder component is a thermoplastic resin, the method of heating or heating and crimping | bonding a pellet-shaped or sheet-shaped thermoplastic resin can also be used. Here, in order to impregnate a sheet-like cellulose nanofiber with a liquid composition containing a thermoplastic resin, it is not an essential requirement to apply pressure using an apparatus. Penetration into the sheet-like cellulose nanofiber becomes easier. When pressurization is performed, there is no particular upper limit of pressure unless the shape of the intended wiring board material is impaired. The wiring board material can be molded by heat-adhering to the substrate surface, and can be produced in the same manner as described above when molding using a dry film.
In the above, examples of the apparatus used at the time of drying, heat-curing or heat-pressing include a hot-air circulating drying furnace, an IR furnace, a hot plate, a convection oven, a heating / pressurizing roll, and a press machine.

The thickness of the sheet-like cellulose nanofiber that is a component of the wiring board material of the present invention, or the thickness of the wiring board material comprising the sheet-like cellulose nanofiber, the liquid composition, and the low water-absorbing inorganic filler is particularly limited. However, the thickness is preferably 5 to 100 μm for sheet-like cellulose nanofibers, and preferably 10 to 250 μm for wiring board materials.
The wiring board material obtained by forming the wiring board material of the present invention on the substrate surface can be used as a core material for wiring boards. In addition, as described above, it can be used as an interlayer insulating material for multilayer wiring boards, and the wiring board material is formed on the surface of the wiring board on which the circuit is formed, and is patterned so as to cover only the circuit wiring. If cured, it can also be used as a solder resist or cover lay which is the outermost layer of the wiring board.
As described above, the wiring board material of the present invention as described above can be applied to a wiring board for an electronic device, for example, can be suitably applied to an interlayer insulating material for a wiring board, a solder resist, etc. Thereby, the desired effect of the present invention can be obtained.

FIG. 1 is a partial cross-sectional view showing a configuration example of a wiring board obtained by using the wiring board material according to the present invention. Here, although the case where the wiring board material of this invention is used as an interlayer insulation material of a wiring board is demonstrated, it is not restricted to this.
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 wiring pattern 1 is formed. The through hole can be formed by an appropriate means such as a drill, a die punch, or laser light. Then, a roughening process is performed using a roughening agent. Generally, the roughening treatment is carried out by swelling with an organic solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, or methoxypropanol, or an alkaline aqueous solution such as caustic soda or caustic potash. It is carried out using an oxidizing agent such as salt, ozone, hydrogen peroxide / sulfuric acid or nitric acid.

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

Next, on the core substrate 2 having the wiring pattern 3, the wiring board material of the present invention is laminated or hot-plate pressed and cured by heating to form an interlayer insulating layer 6. Next, vias 7 for electrically connecting the connection portions of the conductor layers are formed by an appropriate means such as laser light, and the wiring pattern 8 is formed by the same method as the wiring pattern 3 described above. Further, the interlayer insulating layer 9, the via 10 and the wiring pattern 11 are formed by the same method. Then, a multilayer printed wiring board is manufactured by forming the solder resist layer 12 in the outermost layer. In the above, the example in which the interlayer insulating layer and the conductor layer are formed on the multilayer substrate has been described. However, a single-sided substrate or a double-sided substrate may be used instead of the multilayer substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. In addition, all the compounding quantities in the following table | surfaces show a mass part.

[Production Example of Sheet-like Cellulose Nanofiber (CNF)]
Cellulose fiber raw material (KC Flock manufactured by Nippon Paper Chemicals Co., Ltd.) is diluted with water to a concentration of 0.5% by mass, and using a high-speed rotating homogenizer (CLM0.8S manufactured by M Technique Co., Ltd.) at a rotational speed of 2000 rpm for 60 minutes. A fibrillation treatment was performed to obtain a fine cellulose fiber dispersion. The obtained fine cellulose fiber dispersion was diluted with water to a concentration of 0.13% by mass, and 150 g was put into a 90 mm diameter filter using PTFE having a pore diameter of 1 μm. When the solid content reached about 5% by mass, 2 -Replaced with 30 ml of propanol. Then, it press-dried at 120 degreeC and 0.14 MPa for 5 minutes, and obtained the white sheet-like cellulose nanofiber. The film thickness of the sheet-like cellulose nanofiber was 20 μm, the number average fiber diameter of the cellulose fibers was 400 nm, and the density was 1.5 g / cm ³ .

[Preparation of liquid composition]
Table 1 below shows the blending contents used as the low water-absorbing inorganic filler and the liquid composition. In accordance with the description of Examples 1 to 6 and Comparative Examples 1 to 3 in Table 1 below, after blending each component, the mixture is stirred using a rotation / revolution mixer, and each low water-absorbing inorganic filler and liquid composition are mixed. A mixture containing was prepared.

[Production of wiring board materials and cured products]
First, sheet-like cellulose nanofibers were allowed to stand on a copper foil having a thickness of 18 μm, and the mixture prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was applied and impregnated using an applicator. Next, it was dried at 90 ° C. for 10 minutes in a hot air circulation drying oven to obtain the wiring board material of the present invention.
Thereafter, the wiring board material was heated at 180 ° C. for 30 minutes to obtain a cured product. Thereafter, the copper foil was removed to obtain a single film (thickness: 50 to 250 μm) of the cured product.

[Evaluation of thermal expansion (TMA test)]
The single film of the produced cured product was cut into 3 mm width × 30 mm length. This was heated at a rate of 5 ° C./minute from 20 to 250 ° C. under a nitrogen atmosphere of 10 mm between chucks, a load of 50 mN using a TMA (Thermal Mechanical Analysis) 7100 manufactured by Hitachi High-Tech Science Co., Ltd., and then 250 The temperature was lowered to -20 ° C at 5 ° C / min. Thereafter, an average linear expansion coefficient α1 of 50 to 100 ° C. when the temperature was raised from 20 to 250 ° C. at 5 ° C./min was determined. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(◯: α1 ≦ 10 ppm / K, Δ: 10 ppm / K <α1 <30 ppm / K, ×: α1 ≧ 30 ppm / K)

[Evaluation of elongation at break (tensile test)]
The single film of the produced cured product was cut into 10 mm width × 100 mm length. Using an autograph AGS-5kNG manufactured by Shimadzu Corporation, the chuck is 50 mm in length and the tensile speed is 1 mm / min. The elongation (breaking elongation) of the test piece at the time of fracture was recorded. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(○: 4% or more, △: 3% or more and less than 4%, ×: less than 3%)

[Evaluation of water absorption (hygroscopicity test)]
A single film of the cured product thus prepared is put into an aluminum container for measurement, and a container with a sample is put under a constant temperature of 80 ° C. in a nitrogen atmosphere using a Rigaku steam atmosphere differential thermobalance TG-DTA / HUM-1. The sample was dried at 2% RH for 1 hour and then humidified at 60% RH for 1 hour, and the difference in weight of the sample (weight increase rate) after drying and after humidification was determined as the moisture absorption rate of each sample. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(◎: Less than 0.5%, ○: 0.5% or more and less than 1%, Δ: 1% or more and less than 2%, ×: 2% or more)

[Preparation of wiring board 1]
The mixture prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was applied in the same manner as in the production of the wiring board material, except that the sheet-like cellulose nanofiber was placed on a polypropylene film having a thickness of 38 μm. Then, the wiring board material of the present invention was produced on a polypropylene film. After that, the coated surface was pasted on a FR-4 copper clad laminate with a thickness of 0.8 mm, and thermocompression bonded at 60 ° C. and 0.5 MPa for 2 minutes with a vacuum press machine. After cooling to room temperature, the polypropylene film was peeled off. did. Thereafter, the wiring board material was heated at 180 ° C. under atmospheric conditions for 30 minutes to obtain a wiring board 1 containing a cured product (thickness: 50 to 250 μm) of the wiring board material.

[Heat-resistant]
After cutting the wiring board 1 to an appropriate size and applying a rosin flux, it is allowed to flow in a solder bath set at 260 ° C. for 30 seconds, washed with propylene glycol monomethyl ether acetate, dried, and then subjected to cellophane adhesive tape. A peel test was performed to confirm the presence or absence of peeling of the cured film. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(○: no peeling is observed, ×: peeling is recognized)

[Laser processability]
The wiring board 1 is cut into an appropriate size, a hole (via) having a diameter of 100 μm is formed on the cured product with a carbon dioxide laser, and then the via bottom (copper copper) is subjected to a desmear treatment by permanganic acid etching. The surface was observed with a scanning electron microscope (SEM, JSM-6610LV, JEOL Ltd., magnification: 3,500 times), and the presence or absence of residues (smear) on the via bottom (copper surface) was visually confirmed. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(○: no residue, △: slight residue, ×: residue on the entire surface)

[Preparation of wiring board 2]
In the production of the wiring board 1, an IPC standard B pattern comb-shaped electrode is etched by an etching method using a 0.8 mm thick FR-4 copper clad laminate instead of a 0.8 mm thick FR-4 copper clad laminate. A cured product of the wiring board material (thickness: 50 to 250 μm) so that the comb-shaped electrode portion is covered in the same manner as the production of the wiring board 1 except that the base material on which the above pattern is produced is used. A wiring board 2 containing was obtained.

[Electrical properties]
Using the wiring board 2, a direct current of 50 V was applied to the substrate with electrodes, and a standing test was performed at 130 ° C. and 85% RH. From the insulation resistance value 1 h after the start of the test, the time that became 1/100 of that was recorded. Evaluation was performed according to the following criteria, and the results are shown in Table 1 below.
(○: 100 hours or more, Δ: 50 hours or more and less than 100 hours, ×: less than 50 hours)

* 1 Admafine SO-C2 manufactured by Admatechs (density 2.2 g / cm ³ , average particle size 500 nm),
* 2 SG-2000 manufactured by Nippon Talc (density 2.7 g / cm ³ ),
* 3 ZX1059 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
* 4 XD-1000 manufactured by Nippon Kayaku Co., Ltd.
* 5 HP-4032 manufactured by DIC
* 6 YX-6554 manufactured by Mitsubishi Chemical Corporation
* 7 HF-1M manufactured by Meiwa Kasei Co., Ltd.
* 8 2E4MZ manufactured by Shikoku Chemicals,
* 9 BYK-LPD20950 manufactured by Big Chemie Japan,
* 10 KBM-402 manufactured by Shin-Etsu Chemical Co., Ltd.

As is apparent from the results shown in Table 1 above, the wiring board materials of Examples 1 to 5 including a binder component, a sheet-like cellulose nanofiber, and silica as a low water-absorbing inorganic filler have low thermal expansion properties. A cured product excellent in water absorption was obtained while maintaining a high elongation at break. Further, even with the wiring board material of Example 6 containing silica and talc as the low water-absorbing inorganic filler, a cured product having excellent water absorption while maintaining low thermal expansion and high elongation at break as in Example 1. I was able to get it.
On the other hand, Comparative Examples 1 to 3 containing sheet-like cellulose nanofibers and no silica contained significantly poor water absorption and electrical properties.
As described above, by using a wiring board material containing a binder component, a sheet-like cellulose nanofiber, and a low water-absorbing inorganic filler, curing with low water absorption while maintaining low thermal expansion and high elongation at break. It was confirmed that things could be realized. Such a wiring board material of the present invention can be applied to a wiring board for electronic equipment, and can be suitably applied to, for example, an interlayer insulating material for a multilayer wiring board, a solder resist or a coverlay.

1, 3, 8, 11 Wiring pattern 2 Core substrate 1a, 4 Wiring connection portion 5 Through hole 6, 9 Interlayer insulating layer 7, 10 Via

Claims (7)

1. A wiring board material comprising a binder component, a sheet-like cellulose nanofiber, and a low water-absorbing inorganic filler.
2. The wiring board material according to claim 1, wherein the binder component contains a thermosetting resin.
3. The wiring board material according to claim 1, wherein the low water-absorbing inorganic filler is silica.
4. The wiring board material according to claim 1, wherein a volume content of the low water-absorbing inorganic filler is larger than a volume content of the sheet-like cellulose nanofiber.
5. The wiring board material according to claim 1, which is used for an interlayer insulating material of a multilayer wiring board.
6. 2. The wiring board material according to claim 1, wherein the wiring board material is for solder resist or coverlay.
7. A wiring board comprising the wiring board material according to any one of claims 1 to 6.

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