JP7332049B2 - Laminate for semi-additive construction method and printed wiring board using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a planar laminate for semi-additive construction method used for electrically connecting both surfaces of a base material, and a printed wiring board using the same.

A printed wiring board is formed by forming a metal layer having a circuit pattern on the surface of an insulating base material. 2. Description of the Related Art In recent years, along with the demand for smaller and lighter electronic products, thinner printed wiring boards (films) and higher-definition circuit wiring are required. Conventionally, as a method of manufacturing circuit wiring, an etching resist having a circuit pattern shape is formed on the surface of a copper layer formed on an insulating base material, and the copper wiring is formed by etching the copper layer in the circuit-unnecessary portion. Subtractive methods of forming have been widely used. However, in the subtractive method, copper tends to remain at the bottom of wiring, and when the distance between wirings is shortened due to the high density of circuit wirings, there are problems such as short circuits and poor insulation reliability between wirings. If the etching is further advanced for the purpose of preventing short circuits or improving insulation reliability, the etchant will flow into the lower part of the resist, and as a result of the progress of side etching, the wiring width direction will become narrower. was a problem. In particular, when regions with different wiring densities coexist, fine wiring present in regions with low wiring densities has a problem of disappearing as etching progresses. In addition, the cross-sectional shape of the wiring obtained by the subtractive method is not rectangular, but is trapezoidal or triangular with a wider base toward the base material. There was also a problem with the transmission line.

A semi-additive method has been proposed as a method for solving these problems and fabricating fine wiring circuits. In the semi-additive method, a conductive seed layer is formed on an insulating substrate, and a plating resist is formed on the non-circuit-forming portion of the seed layer. After the wiring portion is formed by electroplating through the conductive seed layer, the resist is peeled off and the seed layer in the non-circuit forming portion is removed to form the fine wiring. According to this method, the plating is deposited along the shape of the resist, so that the cross-sectional shape of the wiring can be rectangular, and the wiring of the desired width can be deposited regardless of the density of the pattern. Therefore, it is suitable for forming fine wiring.

In the semi-additive method, a method of forming a conductive seed layer on an insulating substrate by electroless copper plating using a palladium catalyst or electroless nickel plating is known. In these methods, for example, when using a build-up film, in order to ensure the adhesion between the film substrate and the copper plating film, the surface of the substrate is roughened using a strong chemical such as permanganic acid, which is called desmear roughening. By forming the plated film from the formed voids, the anchor effect is utilized to ensure the adhesion between the insulating substrate and the plated film. However, when the substrate surface is roughened, it becomes difficult to form fine wiring, and there are problems such as deterioration of high-frequency transmission characteristics. For this reason, it has been studied to reduce the degree of roughening, but in the case of low roughening, there is a problem that the required adhesion strength between the formed wiring and the substrate cannot be obtained.

On the other hand, a technique is also known in which electroless nickel plating is applied to a polyimide film to form a conductive seed. In this case, by immersing the polyimide film in a strong alkali, the imide ring of the surface layer is opened to make the film surface hydrophilic, and at the same time, a modified layer is formed in which water permeates. A seed layer of nickel is formed by impregnating a palladium catalyst in the layer and performing electroless nickel plating (see, for example, Patent Document 1). In this technology, adhesion strength is obtained by forming nickel plating from the modified layer of the polyimide outermost layer, but since the modified layer is in a state where the imide ring is opened, has a problem of physically and chemically weak structure.

On the other hand, as a method that does not roughen the surface or form a modified layer on the surface layer, a method of forming a conductive seed such as nickel or titanium on an insulating substrate by a sputtering method is also known (for example, , see Patent Document 2). This method can form a seed layer without roughening the substrate surface, but it requires the use of an expensive vacuum device, requires a large initial investment, and depends on the size and shape of the substrate. There were problems such as restrictions and a complicated process with low productivity.

As a method of solving the problem of the sputtering method, a method of using a coating layer of conductive ink containing metal particles as a conductive seed layer has been proposed (see, for example, Patent Document 3). In this technique, a conductive ink in which metal particles having a particle diameter of 1 to 500 nm are dispersed is coated on an insulating substrate made of a film or sheet, and heat treatment is performed to obtain the coated ink. A technique is disclosed in which metal particles in a conductive ink are fixed as a metal layer onto an insulating base material to form a conductive seed layer, and the conductive seed layer is plated.

In Patent Document 3, pattern formation by a semi-additive method is proposed, and in Examples, a conductive ink in which copper particles are dispersed is applied, and a heat treatment is performed to form a copper conductive seed layer. A photosensitive resist is formed on the conductive seed layer, and after exposure and development, the pattern formation area is thickened by electrolytic copper plating, and the resist is removed. Etching away the conductive seed layer of . Further, in the case of forming a printed wiring board by the semi-additive method, which has been studied in the past, a substrate obtained by providing a thin copper foil or a copper plating film as a conductive seed on an insulating substrate is a semi-additive method. It is used as a base material for construction methods.
Thus, when the conductive seed layer and the conductive layer of the circuit pattern are formed of the same metal, such as the combination of the conductive seed layer of copper and the circuit pattern of copper, the conductive seed layer in the non-patterned portion is When removing, the conductive layer of the circuit pattern is also etched at the same time, so it is known that the circuit pattern becomes finer and thinner, and the surface roughness of the circuit conductive layer increases. This was a problem to be solved in manufacturing wiring for high-frequency transmission.
In order to solve these problems, the present inventors have found that, in the seed layer etching process, by using a base material having a conductive silver particle layer formed on the surface of an insulating base material as a base material for a semi-additive method, Invented a technique for forming a printed wiring board having a smooth circuit layer surface without thinning or thinning of the circuit pattern and good reproducibility of design. (Non-Patent Documents 1 and 2)
The technology can not only form a circuit on one side, but also connect circuits on both sides, and can be multi-layered and connected to the conductor circuit layer of the inner layer printed wiring base material. In order to connect with the circuit layer, a conventionally used direct plating method is used when forming holes in a base material for a semi-additive method having conductive silver particle layers on both sides of an insulating base material and performing double-sided connection. However, the conductive silver particle layer is damaged in the micro-etching process that removes the conductive material such as palladium, conductive polymer, and carbon adsorbed on the conductive seed layer. In some cases, it becomes difficult to use it as a conductive seed layer for forming a circuit pattern because the conductivity decreases as a result.

WO2009/004774 JP-A-9-136378 JP 2010-272837 A Akira Murakawa, Norimasa Fukasawa, Wataru Fujikawa, Jun Shiraga: "Copper pattern formation technology by semi-additive method using silver nanoparticles as a base", Proceedings of the 28th Microelectronics Symposium, pp285-288, 2018. Akira Murakawa, Shota Shinbayashi, Norimasa Fukasawa, Wataru Fujikawa, Jun Shiraga, ``Copper wiring formation by semi-additive method with silver as seed layer'', Proc.

The problem to be solved by the present invention is to achieve high adhesion between a substrate and a conductor circuit without using a vacuum device, without roughening the surface with chromic acid or permanganic acid, forming a surface modification layer with an alkali, or the like. Multi-layer printed wiring that is electrically connected to the conductive circuit layer of the inner layer printed wiring base material, which has good reproducibility of design, has good reproducibility of design, and has a rectangular cross-sectional shape as a circuit wiring. An object of the present invention is to provide a laminate for a semi-additive construction method for forming a board, and a printed wiring board using the same.

As a result of intensive studies by the present inventors to solve the above problems, a conductive silver particle layer (M1) and a copper layer (M2) are sequentially formed on both surfaces of the insulating substrate (A). By using a laminated body in which the thickness of the copper layer (M2) is 0.1 μm to 2 μm, there is no need for complicated surface roughening or surface modification layer formation, and without using a vacuum device. , It has high adhesion between the substrate and the conductive circuit, less undercut, good design reproducibility, and a rectangular cross-sectional shape that is good for circuit wiring. The present invention has been completed by finding that a printed wiring board connected to .

That is, the present invention
1. A laminate for a semi-additive method for manufacturing a multilayer printed wiring board by electrically connecting the conductive circuit layer (CM1) on the surface of the substrate and the conductive circuit layer (CM2) on the inner printed wiring substrate,
A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm.

2. 2. The laminate for semi-additive construction method according to 1, further comprising a primer layer (B) between the surface (S1) of the insulating layer (A) and the conductive silver particle layer (M1).

3. A laminate for a semi-additive method for manufacturing a multilayer printed wiring board by electrically connecting the conductive circuit layer (CM1) on the surface of the substrate and the conductive circuit layer (CM2) on the inner printed wiring substrate,
A conductive silver particle layer (M1) on the surface of the insulating layer (A) laminated on the inner layer printed wiring substrate in which the conductive circuit layer (CM2) is formed on the insulating material;
Furthermore, it has a hole extending from the insulating layer (A) to the conductor circuit layer (CM2),
A laminate for a semi-additive construction method, wherein the surface of the holes is a substrate whose conductivity is ensured by any one of palladium, a conductive polymer, and carbon.

4. 4. The laminate for semi-additive construction method according to 3, further comprising a primer layer (B) between the insulating layer (A) and the conductive silver particle layer (M1).

5. 5. The laminate for semi-additive construction method according to any one of 1 to 4, wherein the silver particles constituting the silver particle layer (M1) are coated with a polymer dispersant.

6. The primer layer (B) described in 2 and 4 above is a layer composed of a resin having a reactive functional group [X], and the polymer dispersant has a reactive functional group [Y], 5. The laminate for semi-additive construction method according to 2 or 4, wherein the reactive functional group [X] and the reactive functional group [Y] are capable of forming a bond with each other by reaction.

7. 7. The laminate for semi-additive construction method according to 6, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group.

8. 6. Semi-permeable according to 6, wherein the polymer dispersant having the reactive functional group [Y] is one or more selected from the group consisting of polyalkyleneimine and polyalkyleneimine having a polyoxyalkylene structure containing oxyethylene units. Laminate for additive construction method.

9. 1 wherein the reactive functional group [X] is selected from the group consisting of a keto group, an acetoacetyl group, an epoxy group, a carboxyl group, an N-alkylol group, an isocyanate group, a vinyl group, a (meth)acryloyl group and an allyl group; 7. The laminate for semi-additive construction method according to 6, which is more than seed.

10. A printed wiring board characterized by being formed using the laminate for a semi-additive construction method according to any one of 1 to 9.

11. A multilayer printed wiring board in which a conductive circuit layer (CM1) on the substrate surface and a conductive circuit layer (CM2) on an inner printed wiring substrate are electrically connected,
A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the thickness of the copper layer (M2) is 0.1 μm to 2 μm,
Furthermore, it has a hole extending from the insulating layer (A) to the conductor circuit layer (CM2),
The surface of the hole has a connection structure to the conductor circuit layer (CM2) of the inner layer printed wiring substrate laminated with any one of palladium, a conductive polymer, and carbon, and a copper layer. multilayer printed wiring board

12. 12. The printed wiring board according to 11, further comprising a primer layer (B) between the insulating layer (A) and the silver particle layer (M1).

13. A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm,
Step 1 of forming a hole reaching the conductive circuit layer (CM2) from the insulating layer (A);
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the substrate having holes extending from the insulating layer (A) to the conductor circuit layer (CM2) to make the hole surfaces conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
A method for producing a laminate for a semi-additive method for producing a multilayer printed wiring board according to any one of 3 to 9, characterized by having

14. 14. The method for producing a laminate for a semi-additive construction method according to 13, wherein a primer layer (B) is further laminated between the insulating substrate (A) and the silver particle layer (M1).

15. A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm,
Step 1 of forming a hole reaching the conductive circuit layer (CM2) from the insulating layer (A);
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the substrate having holes extending from the insulating layer (A) to the conductor circuit layer (CM2) to make the hole surfaces conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
Step 4 of forming a pattern resist on the conductive silver particle layer (M1);
Step 5 of electrically connecting the surface layer and the inner conductor circuit layer (CM2) by electrolytic copper plating and forming a circuit pattern.
11. The method for producing a multilayer printed wiring board according to 10, characterized by comprising a step 6 of stripping off the pattern resist and removing the silver particle layer (M1) in the non-conductor circuit pattern formation portion with an etchant.

16. 11. The printed wiring board according to 10, further comprising a primer layer (B) between the insulating substrate (A) and the silver particle layer (M1).

By using the laminate for the semi-additive construction method of the present invention, an inner layer having a circuit wiring having a good rectangular cross-sectional shape with a smooth surface and high adhesion on various smooth substrates without using a vacuum device It is possible to manufacture a printed wiring board electrically connected to the conductor circuit layer of the printed wiring base with good design reproducibility. Therefore, by using the technology of the present invention, it is possible to provide a multilayered printed wiring board with high density, high performance, and high frequency transmission at low cost, and industrial application in the field of printed wiring. highly sexual. Moreover, the printed wiring board manufactured using the laminate for the semi-additive construction method of the present invention can be used not only for ordinary printed wiring boards but also for various electronic members having a patterned metal layer on the substrate surface. For example, it can be applied to connectors, electromagnetic wave shields, RFID antennas, film capacitors, and the like.

FIG. 1 is a schematic diagram of a laminate for a semi-additive construction method according to claim 1. FIG. FIG. 2 is a schematic diagram of a laminate for semi-additive construction method according to claim 2, which has a primer layer on the silver particle layer of FIG. FIG. 3 is a schematic diagram of a laminate for a semi-additive construction method according to claim 3. FIG. FIG. 4 is a schematic diagram of a laminate for semi-additive construction method according to claim 4, which has a primer layer on the silver particle layer of FIG. FIG. 5 is a process diagram of manufacturing a printed wiring board using the laminate for the semi-additive method shown in FIG. 6A and 6B are schematic diagrams of the comb-teeth electrode and the pad pattern produced in Production Example 1. FIG. FIG. 7 is a schematic diagram of inner layer and outer layer circuit patterns in printed wiring boards produced in Examples 22 to 26. FIG.

In the laminate for semi-additive construction method of the present invention, conductive silver A particle layer (M1) and a copper layer (M2) are sequentially laminated,
The layer thickness of the copper layer (M2) is characterized by being 0.1 μm to 2 μm.

In addition, a laminate for a semi-additive construction method in a more preferred embodiment of the present invention is characterized by further comprising a primer layer (B) between the insulating layer (A) and the conductive silver particle layer (M1). It is something to do.

In the laminate for semi-additive construction method of the present invention, a conductive A silver particle layer (M1) and a copper layer (M2) are sequentially laminated, and the insulating layer (A), the conductive silver particle layer (M1), and the copper layer (M2) are It may be formed on one side of the inner layer printed wiring base material, or may be laminated on both sides.

Materials for the insulating layer (A) include, for example, polyimide resin, polyamideimide resin, polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile-butadiene-styrene (ABS) resin, Polyarylate resin, polyacetal resin, acrylic resin such as polymethyl(meth)acrylate, polyvinylidene fluoride resin, polytetrafluoroethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride obtained by graft copolymerization of acrylic resin Resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, urethane resin, cycloolefin resin, polystyrene, liquid crystal polymer (LCP), polyether ether ketone (PEEK) resin, polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), cellulose nano Fiber, silicon, silicon carbide, gallium nitride, sapphire, ceramics, glass, diamond-like carbon (DLC), alumina and the like.

A resin substrate containing a thermosetting resin and an inorganic filler can also be suitably used as the insulating layer (A). Examples of the thermosetting resin include epoxy resin, phenol resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, Examples include silicone resins, triazine resins, melamine resins, and the like. On the other hand, examples of the inorganic filler include silica, alumina, talc, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate, and borosilicate glass. These thermosetting resins and inorganic fillers can be used either singly or in combination of two or more.

As the form of the insulating layer (A), a commercially available material molded into a film, sheet, or plate may be used, or a planar material molded from the above resin solution, melt, or dispersion liquid may be used. may be used. Alternatively, the insulating layer (A) may be produced by coating the printed wiring base material on which the conductive circuit layer (CM2) is formed with the solution, melt, or dispersion of the resin described above.

The insulating layer (A) may be used as a single layer, or may be used by laminating a plurality of layers. When laminating a plurality of layers, a single material may be laminated, or a plurality of layers of different materials may be laminated.

The insulating layer (A) may be directly laminated on the printed wiring base on which the conductor circuit layer (CM2) is formed, or may be laminated via an adhesive layer. As the adhesive layer, any material can be used without particular limitation as long as it has insulating properties, and materials commercially available as bonding sheets or interlayer adhesive sheets can be suitably used. When the insulating adhesive layer is used, it corresponds to the case of laminating a plurality of layers of different materials, and the entire laminated insulating material can be used as the insulating layer (A).

When the commercially available bonding sheet or interlayer adhesive sheet is used as an adhesive layer and the insulating layer (A) is laminated on the inner layer printed wiring substrate on which the conductor circuit layer (CM2) is formed, the product Lamination may be performed according to the procedures and heating/pressurizing conditions described in catalogs, specifications, instructions for use, and the like.

The inner layer printed wiring base material on which the conductive circuit layer (CM2) is formed, which is used in the present invention, can be used by appropriately selecting a rigid base material or a flexible base material as necessary. A clad laminate material having a copper foil on which a circuit pattern is formed can be used.

The silver particle layer (M1) is used in the production of a printed wiring board using the printed wiring board laminate of the present invention. becomes the plating base layer.

The silver particles constituting the silver particle layer (M1) can contain metal particles other than silver within a range in which the plating process described later can be performed without problems. 5 parts by mass or less is preferable, and 2 parts by mass or less is more preferable with respect to 100 parts by mass of silver, because the etching removal property of the non-circuit forming part can be further improved.

As a method of forming the silver particle layer (M1) on both sides of the planar insulating layer (A), for example, a method of coating a silver particle dispersion liquid on both sides of the insulating layer (A) can be used. mentioned. The method of coating the silver particle dispersion is not particularly limited as long as the silver particle layer (M1) can be formed satisfactorily. can be selected as appropriate. Specific coating methods include, for example, a gravure method, an offset method, a flexographic method, a pad printing method, a gravure offset method, a letterpress method, a letterpress inversion method, a screen method, a microcontact method, a reverse method, an air doctor coater method, Blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, inkjet method, die coater method, spin coater method, bar coater method, dip coater method etc. At this time, the silver particle layer (M1) may be formed on both sides of the insulating layer (A) simultaneously, or may be formed on one side of the insulating layer (A) and then formed on the other side. good.

The insulating layer (A) and the primer layer (B) formed on the insulating layer (A) improve the coatability of the silver particle dispersion and serve as the base for the conductive circuit layer (CM1) formed in the plating process. For the purpose of improving adhesion to the material, surface treatment may be performed before applying the silver particle dispersion. The method for treating the surface of the insulating layer (A) is not particularly limited as long as the roughness of the surface is increased, and signal transmission loss due to fine pitch pattern formability and rough surface is not a problem, and various methods are appropriately selected. You can choose. Examples of such surface treatment methods include UV treatment, vapor phase ozone treatment, liquid layer ozone treatment, corona treatment, and plasma treatment. These surface treatment methods can be carried out by one method, or two or more methods can be used in combination.

After coating the silver particle dispersion on the insulating layer (A) or the primer layer (B), the coating film is dried to volatilize the solvent contained in the silver particle dispersion, and The silver particle layer (M1) is formed on the insulating layer (A) or the primer layer (B).

The above drying temperature and time may be appropriately selected according to the heat resistant temperature of the base material to be used and the type of solvent used in the metal particle dispersion described later. A range of 1 to 200 minutes is preferred. In order to form a silver particle layer (M1) with excellent adhesion on the base material, the drying temperature is more preferably in the range of 0 to 250°C.

The insulating layer (A) on which the silver particle layer (M1) is formed or the insulating layer (A) on which the primer layer (B) is formed may, if necessary, after the drying described above, the electrical resistance of the silver particle layer Annealing may be further performed for the purpose of reducing the . The temperature and time of annealing may be appropriately selected depending on the heat resistance temperature of the base material used, the required electrical resistance, productivity, etc., and may be performed at a temperature of 60 to 350° C. for 1 minute to 2 weeks. . In the temperature range of 60 to 180° C., the time is preferably 1 minute to 2 weeks, and in the temperature range of 180 to 350° C., the time is preferably 1 minute to 5 hours.

In the above drying, air may be blown, or air may not be blown. Drying may be performed in the air, in an atmosphere replaced with an inert gas such as nitrogen or argon, in an air stream, or in vacuum.

Drying of the coating film can be carried out by natural drying at the coating factory, or by air blowing or drying in a dryer such as a constant temperature dryer. Further, when the insulating layer (A) is a roll film or a roll sheet, the roll material is continuously moved in an installed non-heated or heated space following the coating step, thereby drying and baking. It can be performed. Heating methods for drying and baking at this time include, for example, a method using an oven, a hot air drying furnace, an infrared drying furnace, laser irradiation, microwaves, light irradiation (flash irradiation device), and the like. These heating methods can be used singly or in combination of two or more.

The amount of the metal particle layer (M1) formed on the insulating layer (A) or the primer layer (B) is preferably in the range of 0.01 to 30 g/m ² , more preferably 0.01 to 10 g/m2. /m ² range is more preferred. Further, the range of 0.05 to 5 g/m ² is more preferable because the conductive circuit layer (CM1) can be easily formed by the plating process described later, and the seed layer removing process by etching described later can be easily performed.

The amount of the silver particle layer (M1) formed can be confirmed using a known and commonly used analytical method such as a fluorescent X-ray method, an atomic absorption method, an ICP method, and the like.

In addition, in the step of exposing a circuit pattern to a resist layer to be described later with active light, the silver particle layer (M1) can be formed for the purpose of suppressing reflection of active light from the silver particle layer (M1), which will be described later. Graphite, carbon, cyanine compounds, phthalocyanine compounds, dithiol metal complexes, and naphthoquinone compounds that absorb the active light are contained in the silver particle layer (M1) to the extent that electrolytic plating can be performed without problems and the etching removability described later can be secured. , a diimmonium compound, an azo compound, or a pigment that absorbs light, or a dye may be contained as a light absorber. These pigments and dyes may be appropriately selected according to the wavelength of the active light used. These pigments and dyes can be used alone or in combination of two or more. Furthermore, in order to incorporate these pigments and dyes into the silver particle layer (M1), these pigments and dyes may be blended in the silver particle dispersion described below.

The silver particle dispersion used for forming the silver particle layer (M1) is a solvent in which silver particles are dispersed. The shape of the silver particles is not particularly limited as long as it satisfactorily forms the silver particle layer (M1). Silver particles can be used. These silver particles can be used in one kind of single shape, or can be used in combination of two or more kinds with different shapes.

When the shape of the silver particles is spherical or polyhedral, the average particle size is preferably in the range of 1 to 20,000 nm. In addition, when forming a fine circuit pattern, the uniformity of the silver particle layer (M1) is further improved, and the removability with an etching solution described later can be further improved, so the average particle diameter is in the range of 1 to 200 nm. is more preferred, and one in the range of 1 to 50 nm is even more preferred. The "average particle size" of nanometer-sized particles is the volume average value obtained by diluting the metal particles with a good dispersing solvent and measuring them by a dynamic light scattering method. For this measurement, "Nanotrack UPA-150" manufactured by Microtrack can be used.

On the other hand, when the silver particles have a lens-like, rod-like, wire-like shape, etc., the minor axis thereof preferably ranges from 1 to 200 nm, more preferably from 2 to 100 nm, and more preferably from 5 to 50 nm. is more preferable.

The silver particles preferably contain silver particles as a main component. Part of the silver constituting the silver particles may be substituted with other metals, or metal components other than silver may be mixed.

Metals to be substituted or mixed include one or more metal elements selected from the group consisting of gold, platinum, palladium, ruthenium, tin, copper, nickel, iron, cobalt, titanium, indium and iridium.

The ratio of the metal to be substituted or mixed with the silver particles is preferably 5% by mass or less in the silver particles, and is 2% by mass from the viewpoint of the plating properties of the silver particle layer (M1) and the removability with an etchant. % or less is more preferable.

The silver particle dispersion liquid used for forming the silver particle layer (M1) is obtained by dispersing silver particles in various solvents, and the particle size distribution of the silver particles in the dispersion liquid is uniform and monodisperse. It may also be a mixture of particles having the above average particle size ranges.

An aqueous medium or an organic solvent can be used as the solvent used for the dispersion liquid of the silver particles. Examples of the aqueous medium include distilled water, ion-exchanged water, pure water, ultrapure water, and mixtures with organic solvents that are miscible with water.

Examples of the water-miscible organic solvent include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol, diethylene glycol, and propylene. alkylene glycol solvents such as glycol; polyalkylene glycol solvents such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; and lactam solvents such as N-methyl-2-pyrrolidone.
Moreover, alcohol compounds, ether compounds, ester compounds, ketone compounds and the like can be used as the organic solvent when the organic solvent is used alone.

Examples of the alcohol solvent or ether solvent include methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butanol, tert-butanol, heptanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol. , tridecanol, tetradecanol, pentadecanol, stearyl alcohol, allyl alcohol, cyclohexanol, terpineol, terpineol, dihydroterpineol, 2-ethyl-1,3-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, Propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol Monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether and the like.

Examples of the ketone solvent include acetone, cyclohexanone, methyl ethyl ketone and the like. Examples of the ester solvent include ethyl acetate, butyl acetate, 3-methoxybutyl acetate, and 3-methoxy-3-methyl-butyl acetate. Furthermore, other organic solvents include hydrocarbon solvents such as toluene, particularly hydrocarbon solvents having 8 or more carbon atoms.

Examples of the hydrocarbon solvent having 8 or more carbon atoms include nonpolar solvents such as octane, nonane, decane, dodecane, tridecane, tetradecane, cyclooctane, xylene, mesitylene, ethylbenzene, dodecylbenzene, tetralin, and trimethylbenzenecyclohexane. and can be used in combination with other solvents as necessary. Furthermore, mixed solvents such as mineral spirits and solvent naphtha can be used in combination.

The solvent stably disperses the silver particles, and the silver particle layer (M1) is formed on the insulating layer (A) or a primer layer (B) formed on the insulating layer (A) described later. There is no particular limitation as long as it forms well. Moreover, the said solvent can be used by 1 type, and can also use 2 or more types together.

The content of silver particles in the silver particle dispersion is such that the amount of the silver particle layer (M1) formed on the insulating layer (A) is 0.01 to 30 g/m2 using the various coating methods described above. ² , and the viscosity may be adjusted so as to have optimum coating suitability according to the various coating methods described above, but the range of 0.1 to 50% by mass is preferable. , more preferably in the range of 0.5 to 20 mass %.

In the silver particle dispersion liquid, the silver particles preferably maintain long-term dispersion stability without aggregating, coalescing, or precipitating in the various solvent media. It preferably contains a dispersing agent to allow As such a dispersant, a dispersant having a functional group coordinating with metal particles is preferable. Examples include dispersants having functional groups such as groups.

As the dispersant, a commercially available or independently synthesized low-molecular-weight or high-molecular-weight dispersant can be used. ) can be appropriately selected according to the purpose. For example, dodecanethiol, 1-octanethiol, triphenylphosphine, dodecylamine, polyethylene glycol, polyvinylpyrrolidone, polyethyleneimine, polyvinylpyrrolidone; fatty acids such as myristic acid, octanoic acid, stearic acid; cholic acid, glycyrrhizic acid, avintic acid, etc. A polycyclic hydrocarbon compound having a carboxyl group of is preferably used. Here, when the silver particle layer (M1) is formed on the primer layer (B), which will be described later, the adhesion between these two layers is improved. It is preferable to use a compound having a reactive functional group [Y] capable of forming a bond with the functional group [X].

Examples of compounds having a reactive functional group [Y] include an amino group, an amide group, an alkylolamide group, a carboxyl group, an anhydride carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, and an oxetane ring. , a vinyl group, an allyl group, a (meth)acryloyl group, a (blocked) isocyanate group, a (alkoxy)silyl group, and a silsesquioxane compound. In particular, the reactive functional group [Y] is preferably a basic nitrogen atom-containing group because it can further improve the adhesion between the primer layer (B) and the metal particle layer (M1). Examples of the basic nitrogen atom-containing group include an imino group, a primary amino group, a secondary amino group and the like.

The basic nitrogen atom-containing group may be present singly or plurally in one molecule of the dispersant. By containing a plurality of basic nitrogen atoms in the dispersant, some of the basic nitrogen atom-containing groups interact with the metal particles to contribute to the dispersion stability of the metal particles, and the remaining basic nitrogen atoms The atom-containing group contributes to improving adhesion with the insulating layer (A). Further, when a resin having a reactive functional group [X] is used for the primer layer (B) described later, the basic nitrogen atom-containing group in the dispersant is between this reactive functional group [X] can form a bond, and the adhesion of the metal pattern layer (M2) to the insulating layer (A), which will be described later, can be further improved.

Since the dispersant can form a silver particle layer (M1) exhibiting good adhesion on the insulating layer (A), the stability of the dispersion of silver particles, the coatability, and the high adhesiveness of the dispersant A molecular dispersant is preferable, and as the polymer dispersant, a polyalkyleneimine such as polyethyleneimine or polypropyleneimine, or a compound obtained by adding polyoxyalkylene to the above-mentioned polyalkyleneimine is preferable.

The compound in which polyoxyalkylene is added to the polyalkyleneimine may be a compound in which polyethyleneimine and polyoxyalkylene are bonded in a straight chain. The chain may be grafted with polyoxyalkylene.

Specific examples of the compound in which polyoxyalkylene is added to the polyalkyleneimine include, for example, a block copolymer of polyethyleneimine and polyoxyethylene, and ethylene oxide as a part of the imino group present in the main chain of polyethyleneimine. Introduced polyoxyethylene structure by addition reaction, and those obtained by reacting the amino group of polyalkyleneimine, the hydroxyl group of polyoxyethylene glycol and the epoxy group of epoxy resin.

Examples of commercially available polyalkyleneimines include "PAO2006W", "PAO306", "PAO318", and "PAO718" of "Epomin (registered trademark) PAO series" manufactured by Nippon Shokubai Co., Ltd.

The number average molecular weight of the polyalkyleneimine is preferably in the range of 3,000 to 30,000.

The amount of the dispersant necessary for dispersing the silver particles is preferably in the range of 0.01 to 50 parts by mass with respect to 100 parts by mass of the silver particles, and Since a silver particle layer (M1) exhibiting good adhesion can be formed on the primer layer (B) described later, it is preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the silver particles. The range of 0.1 to 5 parts by mass is more preferable because the plating properties of the silver particle layer (M1) can be improved.

The method for producing the dispersion of silver particles is not particularly limited, and various methods can be used. Alternatively, a dispersion of silver particles may be directly prepared by reducing the silver compound in the liquid phase. In both the gas phase method and the liquid phase method, it is possible to change the solvent composition of the dispersion during production and the dispersion during coating by solvent exchange or solvent addition, if necessary. Of the gas phase and liquid phase methods, the liquid phase method is particularly preferred because of the stability of the dispersion and the simplicity of the manufacturing process. As a liquid phase method, for example, it can be produced by reducing silver ions in the presence of the polymer dispersant.

Organic compounds such as surfactants, leveling agents, viscosity modifiers, film-forming aids, antifoaming agents and preservatives may be added to the dispersion of silver particles, if necessary.

Examples of the surfactant include nonions such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene/polyoxypropylene copolymers. surfactant; fatty acid salt such as sodium oleate, alkyl sulfate, alkylbenzene sulfonate, alkyl sulfosuccinate, naphthalene sulfonate, polyoxyethylene alkyl sulfate, alkanesulfonate sodium salt, sodium alkyldiphenyl ether sulfonate anionic surfactants such as salts; cationic surfactants such as alkylamine salts, alkyltrimethylammonium salts and alkyldimethylbenzylammonium salts.

As the leveling agent, a general leveling agent can be used, and examples thereof include silicone-based compounds, acetylene diol-based compounds, fluorine-based compounds, and the like.

As the viscosity modifier, a general thickening agent can be used. Urethane resin, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, hydrogenated castor oil, amide wax, polyethylene oxide, metal soap, dibenzylidene sorbitol and the like.

As the film-forming aid, a general film-forming aid can be used. For example, anionic surfactants such as dioctylsulfosuccinate soda salt, hydrophobic nonionic surfactants such as sorbitan monooleate, etc. , polyether-modified siloxane, and silicone oil.

As the antifoaming agent, general antifoaming agents can be used, and examples thereof include silicone antifoaming agents, nonionic surfactants, polyethers, higher alcohols, polymer surfactants, and the like.

As the antiseptic, a general antiseptic can be used, for example, isothiazoline preservative, triazine preservative, imidazole preservative, pyridine preservative, azole preservative, pyrithione preservative, and the like. is mentioned.

Further, as a more preferred embodiment of the laminate for semi-additive construction method of the present invention, a laminate further having a primer layer (B) between the insulating layer layer (A) and the conductive silver particle layer (M1) is provided. can be mentioned. The laminate for semi-additive construction method provided with this primer layer is preferable because it can further improve the adhesion of the conductive circuit layer (CM1) to the insulating layer (A).

The primer layer (B) can be formed by applying a primer to part or all of the surface of the insulating layer (A) and removing solvents such as an aqueous medium and an organic solvent contained in the primer. . Here, the primer is used for the purpose of improving the adhesion of the conductive circuit layer (CM1) to the insulating layer (A), and is a liquid composition obtained by dissolving or dispersing various resins described later in a solvent. It is a thing.

The method for applying the primer to the insulating layer (A) is not particularly limited as long as the primer layer (B) can be formed satisfactorily. , depending on the degree of stiffness and the like. Specific coating methods include, for example, a gravure method, an offset method, a flexographic method, a pad printing method, a gravure offset method, a letterpress method, a letterpress inversion method, a screen method, a microcontact method, a reverse method, an air doctor coater method, Blade coater method, air knife coater method, squeeze coater method, impregnation coater method, transfer roll coater method, kiss coater method, cast coater method, spray coater method, inkjet method, die coater method, spin coater method, bar coater method, dip coater method etc.

In addition, the method of applying the primer to both surfaces of the insulating layer (A) in the form of a film, sheet, or plate is not particularly limited as long as the primer layer (B) can be formed satisfactorily, and the coating methods exemplified above. can be selected as appropriate. At this time, the primer layer (B) may be formed on both surfaces of the insulating layer (A) at the same time, or may be formed on one surface of the insulating layer (A) and then formed on the other surface.

The insulating layer (A) may be subjected to a surface treatment before applying the primer for the purpose of improving the coatability of the primer and improving the adhesion of the conductive circuit layer (CM1) to the substrate. As the surface treatment method for the insulating layer (A), the same method as the surface treatment method for forming the silver particle layer (M1) on the insulating layer (A) can be used.

After coating the primer on the surface of the insulating layer (A), the solvent contained in the coating layer is removed to form the primer layer (B). A common method is to volatilize the solvent. The drying temperature may be set to a temperature in which the solvent can be volatilized and which does not adversely affect the insulating layer (A). Drying at room temperature or drying by heating may be used. A specific drying temperature is preferably in the range of 20 to 350°C, more preferably in the range of 60 to 300°C. The drying time is preferably in the range of 1 to 200 minutes, more preferably in the range of 1 to 60 minutes.

In the above drying, air may be blown, or air may not be blown. Drying may be performed in the air, in a replacement atmosphere such as nitrogen or argon, in an air stream, or in vacuum.

When the insulating layer (A) is a single-leaf film, sheet, or plate, it can be naturally dried at a coating factory, blown air, or dried in a dryer such as a constant temperature dryer. Further, when the insulating layer (A) is a roll film or roll sheet, drying is performed by continuously moving the roll material in an installed non-heated or heated space following the coating step. be able to.

The film thickness of the primer layer (B) may be appropriately selected depending on the specifications and applications of the printed wiring board produced using the present invention. The range of 10 nm to 30 μm is preferable, the range of 10 nm to 1 μm is more preferable, and the range of 10 nm to 500 nm is even more preferable, because the properties can be further improved.

The resin forming the primer layer (B) has a reactive functional group that is reactive with the reactive functional group [Y] when a dispersant for the metal particles that has a reactive functional group [Y] is used. Resins having [X] are preferred. Examples of the reactive functional group [X] include amino group, amide group, alkylolamide group, keto group, carboxyl group, carboxyl anhydride group, carbonyl group, acetoacetyl group, epoxy group, alicyclic epoxy group, oxetane A ring, vinyl group, allyl group, (meth)acryloyl group, (blocked) isocyanate group, (alkoxy)silyl group and the like can be mentioned. Moreover, a silsesquioxane compound can also be used as a compound which forms a primer layer (B).

In particular, when the reactive functional group [Y] in the dispersant is a basic nitrogen atom-containing group, the adhesiveness of the conductive circuit layer (CM2) on the insulating layer (A) can be further improved. The resin forming the layer (B) has a keto group, a carboxyl group, a carbonyl group, an acetoacetyl group, an epoxy group, an alicyclic epoxy group, an alkylolamide group, an isocyanate group, and a vinyl group as the reactive functional group [X]. , (meth)acryloyl group and allyl group are preferred.

Examples of the resin forming the primer layer (B) include urethane resin, acrylic resin, core-shell type composite resin having a shell made of urethane resin and acrylic resin as a core, epoxy resin, imide resin, amide resin, and melamine resin. , phenol resin, urea-formaldehyde resin, blocked isocyanate polyvinyl alcohol obtained by reacting polyisocyanate with a blocking agent such as phenol, and polyvinylpyrrolidone. A core-shell type composite resin having a urethane resin shell and an acrylic resin core can be obtained, for example, by polymerizing an acrylic monomer in the presence of a urethane resin. Moreover, these resins can be used alone or in combination of two or more.

Among the resins for forming the primer layer (B), a resin that generates a reducing compound by heating is preferable because it can further improve the adhesion of the conductive circuit layer (CM2) onto the insulating layer (A). Examples of the reducing compound include phenol compounds, aromatic amine compounds, sulfur compounds, phosphoric compounds, aldehyde compounds, and the like. Among these reducing compounds, phenol compounds and aldehyde compounds are preferred.

When a resin that generates a reducing compound by heating is used as a primer, a reducing compound such as formaldehyde or phenol is generated in the heat drying process when forming the primer layer (B). Specific examples of resins that generate reducing compounds upon heating include, for example, resins obtained by polymerizing monomers containing N-alkylol(meth)acrylamide, and N-alkylol(meth)acrylamide containing urethane resin as a shell. Core-shell type composite resin with polymerized monomer resin as core, urea-formaldehyde-methanol condensate, urea-melamine-formaldehyde-methanol condensate, poly N-alkoxymethylol (meth) acrylamide, poly (meth) Formaldehyde adducts of acrylamide, resins that generate formaldehyde when heated, such as melamine resins; resins that generate phenol compounds when heated, such as phenol resins and phenol-blocked isocyanates. Among these resins, from the viewpoint of improving adhesion, a core-shell type composite resin, melamine resin, phenol Blocked isocyanates are preferred.

In the present invention, "(meth)acrylamide" refers to one or both of "methacrylamide" and "acrylamide", and "(meth)acrylic acid" refers to "methacrylic acid" and "acrylic acid". One or both.

A resin that generates a reducing compound by heating is obtained by polymerizing a monomer having a functional group that generates a reducing compound by heating by a polymerization method such as radical polymerization, anionic polymerization, or cationic polymerization.

Examples of the monomer having a functional group that generates a reducing compound by heating include N-alkylolvinyl monomers, specifically N-methylol(meth)acrylamide, N-methoxymethyl ( meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide, N-isopropoxymethyl (meth)acrylamide, Nn-butoxymethyl (meth)acrylamide, N-isobutoxymethyl (meth)acrylamide ) acrylamide, N-pentoxymethyl(meth)acrylamide, N-ethanol(meth)acrylamide, N-propanol(meth)acrylamide and the like.

Further, when producing a resin that generates a reducing compound by heating, various other compounds such as (meth)acrylic acid alkyl esters are used together with a monomer having a functional group that generates a reducing compound by heating. Monomers can also be copolymerized.

When the blocked isocyanate is used as the resin forming the primer layer (B), the isocyanate groups self-react to form uretdione bonds, or the isocyanate groups and functional groups possessed by other components. forms a bond to form the primer layer (B). The bond formed at this time may be formed before the metal particle dispersion is applied, or may not be formed before the metal particle dispersion is applied. may be formed by heating after coating.

Examples of the blocked isocyanate include those having a functional group formed by blocking an isocyanate group with a blocking agent.

The blocked isocyanate preferably has the functional group in the range of 350 to 600 g/mol per 1 mol of the blocked isocyanate.

From the viewpoint of improving adhesiveness, the blocked isocyanate preferably has 1 to 10 functional groups, more preferably 2 to 5 functional groups per molecule.

The number average molecular weight of the blocked isocyanate is preferably in the range of 1,500 to 5,000, more preferably in the range of 1,500 to 3,000, from the viewpoint of improving adhesion.

Further, the blocked isocyanate preferably has an aromatic ring from the viewpoint of further improving adhesion. A phenyl group, a naphthyl group, etc. are mentioned as said aromatic ring.

The blocked isocyanate can be produced by reacting part or all of the isocyanate groups of the isocyanate compound with a blocking agent.

Examples of isocyanate compounds that are raw materials for the blocked isocyanate include 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and the like. Polyisocyanate compounds having an aromatic ring; aliphatic polyisocyanate compounds such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, or polyisocyanates having an alicyclic structure compound and the like. Burettes, isocyanurates, adducts, and the like of the polyisocyanate compounds mentioned above are also included.

Moreover, as said isocyanate compound, the thing obtained by making the polyisocyanate compound illustrated above and the compound etc. which have a hydroxyl group or an amino group react is mentioned.

When introducing an aromatic ring into the blocked isocyanate, it is preferable to use a polyisocyanate compound having an aromatic ring. Among polyisocyanate compounds having an aromatic ring, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, isocyanurate of 4,4'-diphenylmethane diisocyanate, and isocyanurate of tolylene diisocyanate are preferable.

Examples of blocking agents used in the production of the blocked isocyanates include phenolic compounds such as phenol and cresol; lactam compounds such as ε-caprolactam, δ-valerolactam and γ-butyrolactam; formamide oxime, acetaldoxime, acetone oxime; Oxime compounds such as methyl ethyl ketoxime, methyl isobutyl ketoxime, cyclohexanone oxime; 2-hydroxypyridine, butyl cellosolve, propylene glycol monomethyl ether, benzyl alcohol, methanol, ethanol, n-butanol, isobutanol, dimethyl malonate, diethyl malonate, aceto methyl acetate, ethyl acetoacetate, acetylacetone, butyl mercaptan, dodecyl mercaptan, acetanilide, acetic acid amide, succinimide, maleic imide, imidazole, 2-methylimidazole, urea, thiourea, ethylene urea, diphenylaniline, aniline, carbazole, ethyleneimine, polyethyleneimine, 1H-pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole and the like. Among these, a blocking agent capable of generating isocyanate groups by dissociation by heating in the range of 70 to 200°C is preferable, and a blocking agent capable of generating isocyanate groups that dissociate by heating in the range of 110 to 180°C. agents are more preferred. Specifically, phenol compounds, lactam compounds, and oxime compounds are preferable, and phenol compounds are particularly preferable because they become reducing compounds when the blocking agent is desorbed by heating.

Examples of the method for producing the blocked isocyanate include a method of mixing and reacting the previously produced isocyanate compound and the blocking agent, a method of mixing and reacting the blocking agent together with raw materials used for producing the isocyanate compound, and the like. is mentioned.

More specifically, the blocked isocyanate is produced by reacting the polyisocyanate compound with a compound having a hydroxyl group or an amino group to produce an isocyanate compound having an isocyanate group at the end, and then combining the isocyanate compound with the block It can be produced by mixing and reacting with an agent.

The content ratio of the blocked isocyanate obtained by the above method in the resin forming the primer layer (B) is preferably in the range of 50 to 100% by mass, more preferably in the range of 70 to 100% by mass.

Examples of the melamine resin include mono- or polymethylolmelamine in which 1 to 6 moles of formaldehyde is added to 1 mole of melamine; (poly)methylolmelamine such as trimethoxymethylolmelamine, tributoxymethylolmelamine and hexamethoxymethylolmelamine etherified products (the degree of etherification is optional); urea-melamine-formaldehyde-methanol condensates, and the like.

In addition to the method using a resin that generates a reducing compound by heating as described above, a method of adding a reducing compound to a resin can also be used. In this case, the reducing compound to be added includes, for example, phenol antioxidants, aromatic amine antioxidants, sulfur antioxidants, phosphoric acid antioxidants, vitamin C, vitamin E, ethylenediaminetetraacetic acid. sodium, sulfite, hypophosphorous acid, hypophosphite, hydrazine, formaldehyde, sodium borohydride, dimethylamine borane, phenol and the like.

In the present invention, the method of adding a reducing compound to the resin may result in a reduction in electrical properties due to the residual low-molecular-weight components and ionic compounds. is more preferred.

Moreover, as a preferable resin for forming the primer layer (B), a resin containing a compound having an aminotriazine ring can be mentioned. The compound having an aminotriazine ring may be a low molecular weight compound or a higher molecular weight resin.

Various additives having an aminotriazine ring can be used as the low-molecular-weight compound having an aminotriazine ring. Commercially available products include 2,4-diamino-6-vinyl-s-triazine (“VT” manufactured by Shikoku Kasei Co., Ltd.), “VD-3” and “VD-4” manufactured by Shikoku Kasei Co., Ltd. (with aminotriazine ring compound having a hydroxyl group), Shikoku Kasei Co., Ltd. "VD-5" (a compound having an aminotriazine ring and an ethoxysilyl group), and the like. These can be used as additives by adding one or more of them to the resin forming the primer layer (B).

The amount of the low-molecular-weight compound having an aminotriazine ring is preferably 0.1 parts by mass or more and 50 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the resin. .

As the resin having an aminotriazine ring, a resin in which an aminotriazine ring is covalently introduced into the polymer chain of the resin can also be preferably used. Specifically, an aminotriazine-modified novolak resin is mentioned.

The aminotriazine-modified novolak resin is a novolac resin in which an aminotriazine ring structure and a phenol structure are bonded via a methylene group. The above-mentioned aminotriazine-modified novolak resin is prepared by combining aminotriazine compounds such as melamine, benzoguanamine and acetoguanamine, phenol compounds such as phenol, cresol, butylphenol, bisphenol A, phenylphenol, naphthol and resorcin, and formaldehyde with alkylamines and the like. in the presence or absence of a weakly alkaline catalyst, or by reacting an alkyl etherified aminotriazine compound such as a methyl-etherified melamine with the phenol compound.

The aminotriazine-modified novolac resin preferably has substantially no methylol groups. Further, the aminotriazine-modified novolak resin may contain a molecule in which only the aminotriazine structure is methylene-bonded, a molecule in which only the phenol structure is methylene-bonded, and the like, which are produced as by-products during the production of the aminotriazine-modified novolac resin. In addition, it may contain some unreacted raw materials.

Examples of the phenol structure include phenol residue, cresol residue, butylphenol residue, bisphenol A residue, phenylphenol residue, naphthol residue, resorcin residue and the like. In addition, the term "residue" as used herein means a structure in which at least one hydrogen atom bonded to a carbon atom of an aromatic ring is removed. For example, phenol means a hydroxyphenyl group.

Examples of the triazine structure include structures derived from aminotriazine compounds such as melamine, benzoguanamine, and acetoguanamine.

The phenol structure and the triazine structure can be used either singly or in combination of two or more. Further, the phenol structure is preferably a phenol residue, and the triazine structure is preferably a structure derived from melamine, since the adhesion can be further improved.

Further, the hydroxyl value of the aminotriazine-modified novolak resin is preferably 50 mgKOH/g or more and 200 mgKOH/g or less, more preferably 80 mgKOH/g or more and 180 mgKOH/g or less, and 100 mgKOH/g or more and 150 mgKOH/g or more, because the adhesion can be further improved. g or less is more preferable.

The aminotriazine-modified novolak resins may be used singly or in combination of two or more.

When using an aminotriazine-modified novolac resin as the compound having an aminotriazine ring, it is preferable to use an epoxy resin together.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, cresol novolac type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolac type epoxy resin, alcohol ether type epoxy resin, tetrabrom. Bisphenol A type epoxy resin, naphthalene type epoxy resin, phosphorus-containing epoxy compound having a structure derived from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative, having a structure derived from dicyclopentadiene derivative Examples include epoxy resins and epoxidized oils and fats such as epoxidized soybean oil. These epoxy resins can be used alone or in combination of two or more.

Among the epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, and bisphenol A novolak type epoxy resin are used because they can further improve adhesion. Bisphenol A type epoxy resins are preferred, and bisphenol A type epoxy resins are particularly preferred.

The epoxy equivalent of the epoxy resin is preferably 100 g/equivalent or more and 300 g/equivalent or less, more preferably 120 g/equivalent or more and 250 g/equivalent or less, and 150 g/equivalent or more and 200 g/equivalent or less, because the adhesiveness can be further improved. More preferred.

When the primer layer (B) is a layer containing an aminotriazine-modified novolak resin and an epoxy resin, adhesion can be further improved. is preferably 0.1 or more and 5 or less, more preferably 0.2 or more and 3 or less, and even more preferably 0.3 or more and 2 or less.

When forming a layer containing an aminotriazine-modified novolac resin and an epoxy resin as the primer layer (B), a primer resin composition containing the compound having an aminotriazine ring and the epoxy resin is used.

Further, the primer resin composition used for forming the primer layer (B) containing the aminotriazine-modified novolak resin and epoxy resin may optionally include, for example, urethane resin, acrylic resin, blocked isocyanate resin, melamine resin, Other resins such as phenolic resins may be blended. These other resins can be used singly or in combination of two or more.

The primer used to form the primer layer (B) preferably contains 1 to 70% by mass of the resin in terms of coatability and film-forming properties, and contains 1 to 20% by mass. is more preferred.

Solvents that can be used for the primer include various organic solvents and aqueous media. Examples of the organic solvent include toluene, ethyl acetate, methyl ethyl ketone, and cyclohexanone, and examples of the aqueous medium include water, organic solvents miscible with water, and mixtures thereof.

Examples of the water-miscible organic solvent include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol, diethylene glycol, and propylene. alkylene glycol solvents such as glycol; polyalkylene glycol solvents such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; and lactam solvents such as N-methyl-2-pyrrolidone.

In addition, the resin forming the primer layer (B) may optionally have a functional group that contributes to a cross-linking reaction, such as an alkoxysilyl group, a silanol group, a hydroxyl group, an amino group, and the like. The crosslinked structure formed using these functional groups may already form a crosslinked structure before the step of forming the silver particle layer (M1) in the subsequent step, or the silver particle layer (M1) A crosslinked structure may be formed after the step of forming the . When forming a crosslinked structure after the step of forming the silver particle layer (M1), the crosslinked structure may be formed in the primer layer (B) before forming the conductive circuit layer (CM1), A crosslinked structure may be formed in the primer layer (B) by, for example, aging after forming the conductive circuit layer (CM1).

In the primer layer (B), if necessary, known substances such as a cross-linking agent, a pH adjuster, a film forming aid, a leveling agent, a thickener, a water repellent, and an antifoaming agent are appropriately added. can be used as

Examples of the cross-linking agent include metal chelate compounds, polyamine compounds, aziridine compounds, metal salt compounds, isocyanate compounds, and the like. Examples include thermal cross-linking agents and various photo-crosslinking agents that react at relatively high temperatures of 100° C. or higher to form a cross-linked structure, such as melamine compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds, and blocked isocyanate compounds. When the aminotriazine-modified novolac resin and the epoxy resin are used as the primer layer (B), it is preferable to use a polyvalent carboxylic acid as the cross-linking agent in the primer resin composition. Examples of the polyvalent carboxylic acid include trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and succinic acid. These cross-linking agents can be used alone or in combination of two or more. Among these cross-linking agents, trimellitic anhydride is preferable because it can further improve adhesion.

Although the amount of the cross-linking agent used varies depending on the type, from the viewpoint of improving the adhesion of the conductive circuit layer (CM1) to the base material, it is 0.01 with respect to the total of 100 parts by mass of the resin contained in the primer. It is preferably in the range of to 60 parts by mass, more preferably in the range of 0.1 to 10 parts by mass, and even more preferably in the range of 0.1 to 5 parts by mass.

When the cross-linking agent is used, the cross-linked structure may already be formed before the step of forming the silver particle layer (M1) in the subsequent step, or the cross-linked structure may be already formed after the step of forming the silver particle layer (M1). Structures may be formed. When a crosslinked structure is formed after the step of forming the silver particle layer (M1), a crosslinked structure may be formed in the primer layer (B) before forming the conductive circuit layer (CM1). A crosslinked structure may be formed in the primer layer (B) by, for example, aging after forming the circuit layer (CM1).

In the present invention, the method of forming the silver particle layer (M1) on the primer layer (B) is the same as the method of forming the silver particle layer (M1) on the insulating layer (A).

Further, the primer layer (B), like the insulating layer (A), is used for the purpose of improving the coating properties of the silver particle dispersion and improving the adhesion of the conductive circuit layer (CM1) to the substrate. A surface treatment may be performed before applying the silver particle dispersion.

The laminate for semi-additive construction method of the present invention is obtained by laminating a copper layer (M2) on the silver particle layer (M1).

By laminating the copper layer (M2) on the silver particle layer (M1), it has a connection structure to the conductor circuit layer (CM2) of the inner layer printed wiring base in the method for manufacturing a printed wiring board described later. It protects the conductive silver particle layer (M1) in the etching process for removing palladium, conductive polymer, and carbon adsorbed to surfaces other than the inner wall surface of the holes formed in the insulating layer (A).

As the layer thickness of the copper layer (M2), in the step of etching the copper layer (M2) to expose the conductive silver particle layer (M1) in the method for manufacturing a printed wiring board described later, the silver particle layer From the viewpoint of efficiently exposing (M1) without damaging it, the thickness is preferably 0.1 μm to 2 μm, more preferably 0.5 μm to 1.5 μm.

In the laminate for a semi-additive construction method of the present invention, as a method for laminating the copper layer (M2) on the conductive silver particle layer (M1), on the conductive silver particle layer (M1) , dry or wet copper plating.

Examples of the dry copper plating method include methods such as vacuum deposition, ion plating, and sputtering. Examples of wet copper plating treatment include electroless copper plating using the silver particle layer (M1) as a plating catalyst, electrolytic copper plating, and a combination of electroless copper plating and electrolytic copper plating. The use of electroplating is advantageous in that the deposition rate of plating can be increased, resulting in increased production efficiency.

The copper plating method for forming the copper layer (M2) on the silver particle layer (M1) is not particularly limited. Alternatively, it may be formed by a wet plating method such as an electroless copper plating method, an electrolytic copper plating method, or a combination of electroless copper plating and electrolytic copper plating. It may be formed by combining methods. In either case, a known and commonly used copper plating method can be suitably used.

The copper plating forms a copper layer (M2) of the same thickness on the silver particle layer (A) on both surfaces when the insulating layer (A) is formed on both surfaces of the substrate. is preferred.

In the step of forming the copper layer (M2) by the copper plating method, if necessary, the surface of the silver particle layer (M1) may be subjected to surface treatment. The surface treatment includes cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, vapor phase ozone treatment, liquid Examples include phase ozone treatment and treatment with a surface treatment agent. These surface treatments can be carried out by one method, or two or more methods can be used in combination.

In step 1 of the method for producing a multilayer printed wiring board using the laminate for a semi-additive construction method of the present invention, an insulating layer is formed on an inner layer printed wiring base material in which a conductive circuit layer (CM2) is formed on an insulating material. (A), a laminate for a semi-additive construction method in which a silver particle layer (M1) and a copper layer (M2) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm, or A hole extending from the insulating layer (A) to the conductor circuit layer (CM2) is formed in the laminate for semi-additive construction in which the primer layer (B) is further laminated between the insulating layer (A) and the silver particle layer (M1). It is a process of forming.

In step 1, as a method for forming a hole reaching the conductor circuit layer (CM2) in the laminate for semi-additive construction method, a known and commonly used method may be selected as appropriate. Examples include drilling, laser processing, and laser processing. A processing method combining hole opening in the copper layer and chemical etching of the insulating layer using an oxidizing agent, an alkaline agent, an acidic agent, etc., a hole pattern etching of the copper foil using a resist, an oxidizing agent, an alkaline agent, and an acidic agent. A method such as a processing method combining chemical etching of the insulating layer using a chemical or the like can be used.

Among these hole processing methods, it is preferable to use a hole processing method by laser processing for the purpose of forming non-through holes for connecting to the conductor circuit layer (CM2) formed on the inner layer printed wiring base material. . In addition, in the multilayer printed wiring board of the present invention, not only the electrical connection to the conductor circuit layer (CM2) formed on the inner layer printed wiring base material, but also the through holes connecting both sides of the base material can be used to connect both surfaces. It may have a structure for electrical connection. The through-holes connecting the two surfaces may be formed in step 1 together with the non-through-holes for connection to the conductor circuit layer (CM2).

The hole diameter (diameter) of the hole formed by the hole punching process is preferably in the range of 0.01 to 1 mm, more preferably in the range of 0.02 to 0.5 mm, and even more preferably in the range of 0.03 to 0.1 mm. .

Organic and inorganic dust (smear) generated during drilling may cause poor plating deposition and poor plating adhesion in the plating process for forming the electrical connection on both sides and the conductive circuit layer (CM1), which will be described later. It is preferable to remove the dust (desmear) because it may cause deterioration of the appearance of the plating. Desmearing methods include, for example, plasma treatment, dry treatment such as reverse sputtering treatment, cleaning treatment with an oxidizing agent aqueous solution such as potassium permanganate, cleaning treatment with an alkaline or acid aqueous solution, and wet treatment such as cleaning treatment with an organic solvent. etc.

In step 2 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction method of the present invention, the conductive circuit layer (CM2) of the inner printed wiring base formed on the insulating layer (A) in step 1 In this step, palladium, a conductive polymer, or carbon is added to the surface of the laminate having holes connected to the substrate to make the hole surfaces conductive.

A method of making the surface of the through-hole conductive is disclosed, for example, in Minoru Toyonaga, Circuit Technology, Vol. 1 (1993) pp. 47-59 as "direct plating" can be referred to.

Methods for making the surface of the hole connected to the conductive circuit layer (CM2) conductive include (1) a palladium-tin colloid system, (2) a tin-free palladium system, and (3) a conductive Any one of the four types of polymer system and (4) graphite system may be used.

As a method for making the surface of the hole connected to the conductive circuit layer (CM2) conductive using palladium-tin colloid, the surface of the laminate having the hole formed thereon is treated with a cleaner-conditioner, and then the tin-palladium colloid is applied to the surface. It is carried out by adsorption and accelerator treatment to remove the tin. A method of further converting palladium to palladium sulfide to increase conductivity can also be used.

Moreover, as a method of making the surface of the hole connected to the conductive circuit layer (CM2) conductive with the conductive polymer, a method of oxidative polymerization of a pyrrole derivative monomer can be used. After the surface of the laminate having through-holes formed therein is treated with a conditioner, it is treated with a permanganate aqueous solution to form MnO ₂ on the surface of the through-holes formed in the insulating layer (A). After immersing the surface of the substrate in a monomer aqueous solution in which high-boiling-point alcohol is dissolved, when immersed in a dilute sulfuric acid aqueous solution, polymerization proceeds on the surface coated with MnO ₂ , and conductive polymer is formed to make it conductive.

Furthermore, as a method of making the surface of the hole connected to the conductor circuit layer (CM2) conductive with graphite, the surface of the substrate for semi-additive process construction method in which the hole connected to the conductor circuit layer (CM2) is formed is suspended. It can be carried out by treating the entire surface of the substrate with a solution of turbid carbon black to adsorb carbon. The surface of the laminate having holes connected to the conductive circuit layer (CM2) is treated with a conditioner to positively charge the surface of the base material, and then carbon black having a negative charge is adsorbed on the surface to make it conductive. can be ensured.

As a method of making the surface of the hole connected to the conductor circuit layer (CM2) conductive, any method using palladium, a conductive polymer, or carbon can be used, and a commercially available known and common process is used. be able to. For example, the tin-palladium process may employ a method known as the Crimson process, and the graphite system may employ, for example, a process known as the black hole process. Of these methods, it is preferable to use a method of making conductive using carbon from the viewpoint of material and process costs.

In the present invention, as described above, even when the substrate has through-holes connecting both sides thereof, the through-holes can be made conductive by the method using palladium, a conductive polymer, and carbon. . The through holes can be made conductive at the same time as the surfaces of the holes connected to the conductor circuit layer (CM2).

Step 3 of the printed wiring board manufacturing method using the laminate for semi-additive construction method of the present invention is a step of etching the copper layer (M2) to expose the conductive silver particle layer (M1). This step is a step of exposing the conductive silver particle layer (M1), which will be a plating seed layer for forming the conductive circuit layer (CM1) in the subsequent step, and the conductive circuit layer (CM2) in step 2. The purpose is to remove palladium, conductive polymer, and carbon used to make the connecting holes conductive from the plating seed.

In step 3, the chemical used to etch away the 0.1 μm to 2 μm thick copper layer (M2) laminated on the conductive silver particle layer (M1) efficiently etches the copper layer (M2). However, as long as it does not damage the underlying silver particle layer (M1), there is no particular limitation, and known and commonly used copper micro-etching solutions and soft etching solutions can be used. As an etchant for the copper layer (M2), an aqueous solution of persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate, or an aqueous solution of sulfuric acid/hydrogen peroxide can be used.

The concentration of the persulfate aqueous solution or the sulfuric acid/hydrogen peroxide aqueous solution is adjusted according to the layer thickness of the copper layer (M2) of the laminate for the semi-additive method used in the production of printed wiring boards, the design of the production equipment, etc. Although it may be selected as appropriate, it is preferable to set the etching rate of the copper layer to be less than 2 μm/min in the process used, so that the copper layer (M2) can be efficiently removed and the underlying layer of conductive silver can be removed. From the viewpoint of preventing damage to the particle layer (M1), 0.1 μm/min. ~1.5 μm/min. It is more preferable to set the etching rate to .

The laminate obtained by etching the copper layer (M2) through step 3 of the method for producing a printed wiring board using the laminate for the semi-additive construction method of the present invention is dried, and the silver particle layer (M1) is made conductive. It can be used as a laminate for a semi-additive construction method, which is used as a seed. That is, the laminate obtained by etching the copper layer (M2) in step 3 of the method for manufacturing a printed wiring board using the laminate for the semi-additive method of the present invention is
Having a conductive silver particle layer (M1) on the surface of the insulating layer (A) laminated on the inner layer printed wiring substrate in which the conductive circuit layer (CM2) is formed on the insulating material,
Furthermore, the insulating layer (A) has a hole connected to the conductor circuit layer (CM2), and the surface of the hole is a substrate whose conductivity is secured by any of palladium, a conductive polymer, or carbon. A laminate for a semi-additive construction method characterized by

In step 4 of the method for manufacturing a printed wiring board using the laminate for semi-additive construction method of the present invention, a circuit A patterned resist is formed.
In the step of forming a pattern resist in step 4, the surface of the silver particle layer (M1) is subjected to a cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, or corona treatment for the purpose of improving adhesion to the resist layer before forming the resist. , plasma treatment, UV treatment, vapor phase ozone treatment, liquid phase ozone treatment, treatment with a surface treatment agent, or the like. These surface treatments can be carried out by one method or two or more methods can be used in combination.

Examples of the treatment with the surface treatment agent include a method of treatment using a rust preventive agent comprising a triazole compound, a silane coupling agent and an organic acid, described in JP-A-7-258870; 2000-286546, a method of treatment using an organic acid, a benzotriazole-based rust inhibitor, and a silane coupling agent; A method in which a nitrogen-containing heterocycle and a silyl group such as a trimethoxysilyl group or triethoxysilyl group are bonded via an organic group having a thioether (sulfide) bond or the like, WO2013/186941. A method of treating with a silane compound having a triazine ring and an amino group, described in JP-A-2015-214743, a formylimidazole compound and an aminopropylsilane compound, described in JP-A-2015-214743, are reacted. A method of treatment using an imidazole silane compound obtained by, a method of treatment using an azole silane compound described in JP-A-2016-134454, and a single molecule described in JP-A-2017-203073. A method of treating with a solution containing an aromatic compound having an amino group and an aromatic ring, a polybasic acid having two or more carboxyl groups, and a halide ion, a triazole silane described in JP-A-2018-16865. A method of treating with a surface treatment agent containing a compound, or the like can be used.

In order to form a metal pattern on the surface using the laminate for semi-additive construction method of the present invention, the pattern is exposed to actinic light by passing a photomask through a photosensitive resist or using a direct exposure machine. The amount of exposure may be appropriately set as required. A pattern resist is formed by removing the latent image formed on the photosensitive resist by exposure using a developer.

Examples of the developer include dilute alkaline aqueous solutions of 0.3 to 2% by mass of sodium carbonate, potassium carbonate, and the like. A surfactant, an antifoaming agent, and a small amount of an organic solvent may be added to the dilute alkaline aqueous solution to promote development. Further, the exposed substrate is developed by immersing it in a developer or by spraying the developer onto the resist with a spray or the like, and by this development, a patterned resist from which the pattern forming portion is removed can be formed. .

When forming a pattern resist, a plasma descum process and a commercially available resist residue remover are used to remove footings at the boundary between the hardened resist and the substrate and resist deposits remaining on the substrate surface. Resist residue such as may be removed.

As the photosensitive resist used in the present invention, commercially available resist inks, liquid resists, and dry film resists can be used. It may be appropriately selected depending on the type, pH and the like.

Commercially available resist inks include, for example, “Plating Resist MA-830” and “Etching Resist X-87” manufactured by Taiyo Ink Mfg. Co., Ltd.; Etching Resist and Plating Resist manufactured by NAZDAR; Resist PLAS FINE PER" series, "Plating Resist PLAS FINE PPR" series, and the like. Examples of the electrodeposition resist include "Eagle Series" and "Pepper Series" available from Dow Chemical Company. Furthermore, commercially available dry films include, for example, the "Photech" series manufactured by Hitachi Chemical Co., Ltd.; the "ALPHO" series manufactured by Nikko Materials Co., Ltd.; the "Sunfort" series manufactured by Asahi Kasei Corporation; Liston series.

In order to manufacture a printed wiring board efficiently, it is convenient to use a dry film resist, and particularly in the case of forming a fine circuit, a dry film for a semi-additive method may be used. Examples of commercially available dry films used for this purpose include "ALFO LDF500" and "NIT2700" manufactured by Nikko Materials Co., Ltd., "Sunfort UFG-258" manufactured by Asahi Kasei Corporation, and "RD" manufactured by Hitachi Chemical Co., Ltd. series (RD-2015, 1225)", "RY series (RY-5319, 5325)", DuPont's "PlateMaster series (PM200, 300)", and the like can be used.

In step 5 of the printed wiring board manufacturing method of the present invention, the conductive silver particle layer (M1) is used as a cathode electrode for electrolytic copper plating, and the silver particle layer exposed by development as described above. (M1) is treated by electrolytic copper plating to connect non-through holes for connection to the conductive circuit layer (CM2) by copper plating, and at the same time, form the conductive circuit layer (CM1) of the circuit pattern. can do.

Before forming the conductive circuit layer (CM1) by the electrolytic copper plating method, the surface of the silver particle layer (M1) may be subjected to surface treatment, if necessary. The surface treatment includes cleaning treatment with an acidic or alkaline cleaning solution, corona treatment, plasma treatment, UV treatment, vapor phase ozone treatment, liquid Examples include phase ozone treatment and treatment with a surface treatment agent. These surface treatments can be carried out by one method or two or more methods can be used in combination.

When forming a conductive circuit layer (CM1) of a circuit pattern on an insulating layer using the laminate for semi-additive construction method of the present invention, annealing is performed after plating for the purpose of stress relaxation and adhesion improvement of the plating film. good too. Annealing may be performed before the etching process described later, after the etching process, or before and after the etching.

The annealing temperature may be appropriately selected within the temperature range of 40 to 300° C. depending on the heat resistance of the substrate to be used and the purpose of use. A range of 40 to 200° C. is more preferred. The annealing time is preferably 10 minutes to 10 days when the temperature is in the range of 40 to 200° C., and 5 minutes to 10 hours when the temperature exceeds 200° C. Further, when annealing the plated film, a rust preventive agent may be appropriately applied to the surface of the plated film.

In step 6 of the method for manufacturing a printed wiring board of the present invention, after the conductive circuit layer (CM1) is formed by plating in step 5, the pattern resist formed using the photosensitive resist is peeled off to form a non-conductive layer. The silver particle layer (M1) of the circuit pattern forming portion is removed with an etchant. The stripping of the pattern resist may be performed under the recommended conditions described in the catalog, specifications, etc. of the photosensitive resist used. As the resist stripping solution used for stripping the pattern resist, a commercially available resist stripping solution or a 1.5 to 3% by mass aqueous solution of sodium hydroxide or potassium hydroxide set at 45 to 60° C. can be used. can. Stripping of the resist can be performed by immersing the base material on which the conductive circuit layer (CM1) of the circuit pattern is formed in a stripping solution, or by spraying the stripping solution with a spray or the like.

Further, the etchant used for removing the silver particle layer (M1) in the non-conductive circuit pattern forming portion selectively etches only the silver particle layer (M1) to form the conductive circuit layer (CM1). Copper is preferably not etched. Such an etchant includes a mixture of carboxylic acid and hydrogen peroxide.

Examples of the carboxylic acid include acetic acid, formic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, Oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, oxalic acid, malonic acid, succinic acid, benzoic acid, salicylic acid, phthalic acid, isophthalic acid, terephthalic acid, gallic acid, mellitic acid, cinnamon acids, pyruvic acid, lactic acid, malic acid, citric acid, fumaric acid, maleic acid, aconitic acid, glutaric acid, adipic acid, amino acids and the like. These carboxylic acids can be used singly or in combination of two or more. Among these carboxylic acids, it is preferable to mainly use acetic acid because it is easy to manufacture and handle as an etchant.

When a mixture of carboxylic acid and hydrogen peroxide is used as an etchant, hydrogen peroxide reacts with the carboxylic acid to produce percarboxylic acid (peroxycarboxylic acid). It is presumed that the generated percarboxylic acid preferentially dissolves silver constituting the silver particle layer (M1) while suppressing dissolution of copper constituting the conductive circuit layer (CM1).

The mixing ratio of the mixture of carboxylic acid and hydrogen peroxide is in the range of 2 to 100 mol of hydrogen peroxide per 1 mol of carboxylic acid, since dissolution of the copper conductive circuit layer (CM1) can be suppressed. Preferably, the range of 2 to 50 moles of hydrogen peroxide is more preferred.

The mixture of carboxylic acid and hydrogen peroxide is preferably an aqueous solution diluted with water. In addition, the content ratio of the mixture of the carboxylic acid and hydrogen peroxide in the aqueous solution is preferably in the range of 2 to 65% by mass, and more preferably in the range of 2 to 30% by mass, because the effect of the temperature rise of the etching solution can be suppressed. is more preferred.

As the water used for the above dilution, it is preferable to use water from which ionic substances and impurities have been removed, such as ion-exchanged water, pure water, and ultrapure water.

A protective agent may be further added to the etchant to protect the copper conductive circuit layer (CM1) and suppress its dissolution. As the protective agent, it is preferable to use an azole compound.

Examples of the azole compound include imidazole, pyrazole, triazole, tetrazole, oxazole, thiazole, selenazole, oxadiazole, thiadiazole, oxatriazole, and thiatriazole.

Specific examples of the azole compounds include 2-methylbenzimidazole, aminotriazole, 1,2,3-benzotriazole, 4-aminobenzotriazole, 1-bisaminomethylbenzotriazole, aminotetrazole, phenyltetrazole, 2 -phenylthiazole, benzothiazole and the like. These azole compounds can be used singly or in combination of two or more.

The concentration of the azole compound in the etching solution is preferably in the range of 0.001 to 2% by mass, more preferably in the range of 0.01 to 0.2% by mass.

In addition, it is preferable to add polyalkylene glycol to the etching solution as a protective agent because it can suppress the dissolution of the copper conductive circuit layer (CM1).

Examples of the polyalkylene glycol include water-soluble polymers such as polyethylene glycol, polypropylene glycol, and polyoxyethylene-polyoxypropylene block copolymers. Among these, polyethylene glycol is preferred. Moreover, the number average molecular weight of the polyalkylene glycol is preferably in the range of 200 to 20,000.

The concentration of the polyalkylene glycol in the etching solution is preferably in the range of 0.001 to 2% by mass, more preferably in the range of 0.01 to 1% by mass.

Additives such as sodium salts, potassium salts, and ammonium salts of organic acids may be blended in the etching solution as necessary in order to suppress fluctuations in pH.

In the laminate for semi-additive construction method of the present invention, the silver particle layer (M1) in the non-pattern forming part is removed after the conductive circuit layer (CM1) is formed, and then the pattern resist formed using the photosensitive resist is peeled off. The etching can be performed by immersing the obtained base material in the etching liquid or by spraying the etching liquid onto the base material by spraying or the like.

When removing the silver particle layer (M1) in the non-pattern forming portion using an etching apparatus, for example, all the components of the etching solution are prepared so as to have a predetermined composition, and then supplied to the etching apparatus. Alternatively, each component of the etchant may be individually supplied to an etching apparatus and mixed in the apparatus to obtain a predetermined composition.

The etching solution is preferably used in a temperature range of 10 to 35 ° C., and in particular when using an etching solution containing hydrogen peroxide, the decomposition of hydrogen peroxide can be suppressed, so the temperature range is 30 ° C. or less. It is preferable to use in

After removing the silver particle layer (M1) with the etchant, in addition to washing with water, a washing operation is performed for the purpose of preventing the silver component dissolved in the etchant from adhering and remaining on the printed wiring board. you can go For the washing operation, it is preferred to use a washing solution that dissolves silver oxide, silver sulfide and silver chloride but hardly dissolves silver. Specifically, it is preferable to use an aqueous solution containing thiosulfate or tris(3-hydroxyalkyl)phosphine, or an aqueous solution containing mercaptocarboxylic acid or a salt thereof as the cleaning chemical.

Examples of the thiosulfate include ammonium thiosulfate, sodium thiosulfate, potassium thiosulfate, and the like. Examples of the tris(3-hydroxyalkyl)phosphine include tris(3-hydroxymethyl)phosphine, tris(3-hydroxyethyl)phosphine, tris(3-hydroxypropyl)phosphine and the like. These thiosulfates or tris(3-hydroxyalkyl)phosphines can be used alone or in combination of two or more.

When using an aqueous solution containing thiosulfate, the concentration may be appropriately set depending on the process time, the characteristics of the cleaning equipment used, etc., but is preferably in the range of 0.1 to 40% by mass, and the cleaning efficiency and continuous use. From the viewpoint of the stability of the chemical solution, the range of 1 to 30% by mass is more preferable.

The concentration of the aqueous solution containing the tris(3-hydroxyalkyl)phosphine may be appropriately set depending on the process time, the characteristics of the cleaning equipment used, etc., but the range of 0.1 to 50% by mass is preferable. It is preferably in the range of 1 to 40% by mass from the viewpoint of cleaning efficiency and stability of the chemical solution during continuous use.

Examples of the mercaptocarboxylic acid include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, cysteine, N-acetylcysteine and the like. Examples of the mercaptocarboxylic acid salts include alkali metal salts, ammonium salts, and amine salts.

When using an aqueous solution of mercaptocarboxylic acid or a salt thereof, the concentration is preferably in the range of 0.1 to 20% by mass, and from the viewpoint of cleaning efficiency and process cost when treating a large amount, 0.5 to 15% by mass. is more preferred.

Examples of the method for performing the above-described cleaning operation include a method of immersing the printed wiring board obtained by etching away the silver particle layer (M1) of the non-pattern forming portion in the cleaning chemical solution, and a method of spraying the printed wiring board. For example, a method of spraying a cleaning chemical solution, etc., can be mentioned. The cleaning chemical can be used at room temperature (25° C.), but may be used at a temperature of 30° C., for example, since the cleaning process can be stably performed without being affected by the outside air temperature.

Further, the step of removing the silver particle layer (M1) in the non-pattern forming portion with an etchant and the washing operation can be repeated as necessary.

In the printed wiring board of the present invention, as described above, after removing the silver particle layer (M1) in the non-pattern forming part with the etching solution, the insulating property of the non-pattern forming part is further improved. Further washing operations may be performed depending on the conditions. For this washing operation, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of potassium hydroxide or sodium hydroxide can be used.

The washing using the alkaline permanganate solution is carried out by immersing the printed wiring board obtained by the above method in the alkaline permanganate solution set at 20 to 60° C., or by spraying the printed wiring board to make it alkaline. A method of spraying a permanganate solution and the like can be mentioned. For the purpose of improving the wettability of the base material surface with the alkaline permanganate solution and improving the cleaning efficiency, the printed wiring board is subjected to a treatment to be brought into contact with a water-soluble organic solvent having an alcoholic hydroxyl group before cleaning. you can go Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol and isopropyl alcohol. These organic solvents can be used alone or in combination of two or more.

The concentration of the alkaline permanganate solution may be appropriately selected according to need. It is preferable to dissolve 0.1 to 10 parts by mass of sodium. From the viewpoint of cleaning efficiency, potassium permanganate or sodium permanganate is added to 100 parts by mass of an aqueous solution of 1 to 6% by mass of potassium hydroxide or sodium hydroxide. is more preferably dissolved in 1 to 6 parts by mass.

In the case of performing cleaning using the alkaline permanganate solution, it is preferable to treat the cleaned printed wiring board with a liquid having a neutralizing/reducing action after cleaning with the alkaline permanganate solution. . Examples of the liquid having a neutralizing/reducing action include an aqueous solution containing 0.5 to 15% by mass of dilute sulfuric acid or an organic acid. Examples of the organic acid include formic acid, acetic acid, oxalic acid, citric acid, ascorbic acid, and methionine.

The cleaning with the alkaline permanganate solution may be performed after cleaning for the purpose of preventing the silver component dissolved in the etching solution from adhering and remaining on the printed wiring board, or may be carried out in the etching solution. For the purpose of preventing the dissolved silver component from adhering and remaining on the printed wiring board, instead of washing, only washing with an alkaline permanganate solution may be performed.

In addition, the printed wiring board obtained using the printed wiring board laminate of the present invention may be appropriately and optionally subjected to lamination of a coverlay film on the circuit pattern, formation of a solder resist layer, and formation of the circuit pattern. As a final surface treatment, nickel/gold plating, nickel/palladium/gold plating, or palladium/gold plating may be applied.

With the laminate for the semi-additive construction method of the present invention described above, a circuit with a smooth surface having a rectangular cross-sectional shape with high adhesion on various smooth substrates, good design reproducibility, and good design reproducibility can be obtained without using a vacuum device. It is possible to produce double-sided connected multilayer printed circuit boards with patterns. Therefore, by using the laminate for the semi-additive construction method of the present invention, it is possible to satisfactorily provide high-density, high-performance printed wiring board substrates and printed wiring boards of various shapes and sizes at low cost. , and has high industrial applicability in the field of printed wiring boards. In addition, by using the laminate, not only printed wiring boards but also various members having a patterned metal layer on the planar surface of the base material, such as connectors, electromagnetic shields, antennas such as RFID, film capacitors, etc. can be manufactured.

The present invention will be described in more detail below using examples and comparative examples. In the following examples and comparative examples, "parts" and "%" are both based on mass.

[Production Example 1: Production of Primer (B-1)]
Polyester polyol (polyester polyol obtained by reacting 1,4-cyclohexanedimethanol, neopentyl glycol and adipic acid) in a nitrogen-purged vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer 100 Parts by mass, 17.6 parts by mass of 2,2-dimethylolpropionic acid, 21.7 parts by mass of 1,4-cyclohexanedimethanol and 106.2 parts by mass of dicyclohexylmethane-4,4'-diisocyanate, 178 parts by mass of methyl ethyl ketone to obtain a urethane prepolymer solution having terminal isocyanate groups.

Next, 13.3 parts by mass of triethylamine is added to the urethane prepolymer solution to neutralize the carboxyl groups of the urethane prepolymer, and 380 parts by mass of water is added and sufficiently stirred to obtain the urethane prepolymer. An aqueous dispersion was obtained.

To the aqueous dispersion of the urethane prepolymer obtained above, 8.8 parts by mass of a 25% by mass aqueous ethylenediamine solution was added and stirred to extend the chain of the urethane prepolymer. Then, by aging and removing the solvent, an aqueous dispersion of urethane resin (30% by mass of non-volatile matter) was obtained. The weight average molecular weight of the urethane resin was 53,000.

Next, 140 parts by mass of deionized water and the urethane obtained above were added to a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, a dropping funnel for dropping a monomer mixture, and a dropping funnel for dropping a polymerization catalyst. 100 parts by mass of a resin aqueous dispersion was added, and the temperature was raised to 80° C. while nitrogen was blown thereinto. Thereafter, while stirring, a monomer mixture consisting of 60 parts by mass of methyl methacrylate, 30 parts by mass of n-butyl acrylate and 10 parts by mass of Nn-butoxymethylacrylamide, and 20 parts by mass of 0.5% by mass ammonium persulfate aqueous solution were added. 1 and 2 were added dropwise from separate dropping funnels over 120 minutes while maintaining the internal temperature of the reaction vessel at 80°C.

After the dropwise addition was completed, the reaction vessel was further stirred at the same temperature for 60 minutes, then the temperature inside the reaction vessel was cooled to 40° C., and the mixture was diluted with deionized water so that the non-volatile content was 20% by mass, followed by a 200-mesh filter cloth. to obtain an aqueous dispersion of a resin composition for a primer layer, which is a core-shell type composite resin having the urethane resin as a shell layer and an acrylic resin made from methyl methacrylate or the like as a raw material as a core layer. . Next, isopropyl alcohol and deionized water are added to and mixed with this aqueous dispersion so that the mass ratio of isopropanol and water is 7/3 and the non-volatile content is 2% by mass, and primer (B-1) is obtained. got

[Production Example 2: Production of primer (B-2)]
200 parts by weight of water and 350 parts by weight of methanol were added to 600 parts by weight of formalin containing 37% by weight formaldehyde and 7% by weight methanol in a reaction flask equipped with a reflux condenser, a thermometer and a stirrer. Next, a 25% by mass sodium hydroxide aqueous solution was added to this aqueous solution to adjust the pH to 10, 310 parts by mass of melamine was added, the liquid temperature was raised to 85° C., and a methylolation reaction was carried out for 1 hour.

After that, formic acid was added to adjust the pH to 7, and then the mixture was cooled to 60° C. to carry out an etherification reaction (secondary reaction). A 25% by mass sodium hydroxide aqueous solution was added at a cloudiness temperature of 40° C. to adjust the pH to 9 to stop the etherification reaction (reaction time: 1 hour). The remaining methanol was removed under reduced pressure at a temperature of 50° C. (demethanolization time: 4 hours) to obtain a primer resin composition containing a melamine resin having a nonvolatile content of 80% by mass. Next, methyl ethyl ketone was added to this resin composition and diluted and mixed to obtain a primer (B-2) having a non-volatile content of 2% by mass.

[Production Example 3: Production of primer (B-3)]
9.2 parts by mass of 2,2-dimethylolpropionic acid and polymethylene polyphenyl polyisocyanate (manufactured by Tosoh Corporation "Millionate MR- 200") and 233 parts by mass of methyl ethyl ketone were charged and reacted at 70° C. for 6 hours to obtain an isocyanate compound. Then, 26.4 parts by mass of phenol was supplied as a blocking agent into the reaction vessel and reacted at 70° C. for 6 hours. Then, it was cooled to 40° C. to obtain a blocked isocyanate solution.

Next, to the blocked isocyanate solution obtained above, 7 parts by mass of triethylamine is added at 40° C. to neutralize the carboxyl groups of the blocked isocyanate, water is added, and the mixture is thoroughly stirred, and methyl ethyl ketone is distilled off. Thus, a resin composition for a primer layer containing blocked isocyanate having a nonvolatile content of 20% by mass and water was obtained. Next, methyl ethyl ketone was added to this resin composition and diluted and mixed to obtain a primer (B-3) having a non-volatile content of 2% by mass.

[Production Example 4: Production of primer (B-4)]
35 parts by mass of novolac resin ("PHENOLITE TD-2131" manufactured by DIC Corporation, hydroxyl equivalent weight 104 g/equivalent), epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy equivalent weight 188 g/equivalent ) 64 parts by mass and 1 part by mass of 2,4-diamino-6-vinyl-s-triazine (“VT” manufactured by Shikoku Kasei Co., Ltd.) are mixed, and then diluted with methyl ethyl ketone so that the non-volatile content is 2% by mass. By mixing, primer (B-4) was obtained.

[Production Example 5: Production of primer (B-5)]
35 parts by mass of novolac resin ("PHENOLITE TD-2131" manufactured by DIC Corporation, hydroxyl equivalent weight 104 g/equivalent), epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy equivalent weight 188 g/equivalent ) 64 parts by mass and 1 part by mass of a silane coupling agent having a triazine ring (“VD-5” manufactured by Shikoku Kasei Co., Ltd.) are mixed, and then diluted and mixed with methyl ethyl ketone so that the nonvolatile content is 2% by mass. Thus, a primer (B-5) was obtained.

[Production Example 6: Production of primer (B-6)]
750 parts by mass of phenol, 75 parts by mass of melamine, 346 parts by mass of 41.5% by mass formalin, and 1.5 parts by mass of triethylamine were added to a flask equipped with a thermometer, condenser, fractionating tube, and stirrer. The temperature was raised to 100°C with caution. After reacting at 100° C. for 2 hours under reflux, the temperature was raised to 180° C. over 2 hours while removing water under normal pressure. Next, unreacted phenol was removed under reduced pressure to obtain an aminotriazine-modified novolak resin. The hydroxyl equivalent weight was 120 g/equivalent.
After mixing 65 parts by mass of the aminotriazine novolac resin obtained above and 35 parts by mass of an epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent weight 188 g/equivalent), the mixture was treated with methyl ethyl ketone. A primer composition (B-6) was obtained by diluting and mixing so that the non-volatile content was 2% by mass.

[Production Example 7: Production of primer (B-7)]
After mixing 48 parts by mass of the aminotriazine novolak resin obtained in Production Example 6 and 52 parts by mass of an epoxy resin ("EPICLON 850-S" manufactured by DIC Corporation; bisphenol A type epoxy resin, epoxy group equivalent weight 188 g/equivalent), A primer composition (B-7) was obtained by diluting and mixing with methyl ethyl ketone so that the non-volatile content was 2% by mass.

[Production Example 8: Production of primer (B-8)]
A primer composition having a non-volatile content of 2% by mass was prepared in the same manner as in Production Example 78, except that the amounts of the aminotriazine novolac resin and the epoxy resin were changed from 48 parts by mass to 39 parts by mass and from 52 parts by mass to 61 parts by mass. (B-8) was obtained.

[Production Example 9: Production of primer (B-9)]
A primer composition with a non-volatile content of 2% by mass was prepared in the same manner as in Production Example 8, except that the amounts of the aminotriazine novolac resin and the epoxy resin were changed from 48 parts by mass to 31 parts by mass and from 52 parts by mass to 69 parts by mass. (B-9) was obtained.

[Production Example 10: Production of primer (B-10)]
Anhydrous After mixing 1 part by mass of trimellitic acid, the mixture was diluted with methyl ethyl ketone so that the non-volatile content was 2% by mass, thereby obtaining a primer (B-10).

[Production Example 11: Production of primer (B-11)]
350 parts by mass of deionized water in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, and a surfactant (“Latemul E-118B” manufactured by Kao Corporation: 25% by mass of active ingredient). 4 parts by mass was added, and the temperature was raised to 70° C. while blowing nitrogen.

A vinyl monomer mixture consisting of 47.0 parts by mass of methyl methacrylate, 5.0 parts by mass of glycidyl methacrylate, 45.0 parts by mass of n-butyl acrylate, and 3.0 parts by mass of methacrylic acid was placed in a reaction vessel while stirring. And a part of the monomer pre-emulsion obtained by mixing 4 parts by mass of a surfactant (“Aqualon KH-1025” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.: 25% by mass of active ingredient) and 15 parts by mass of deionized water ( 5 parts by mass) was added, followed by the addition of 0.1 parts by mass of potassium persulfate, and polymerization was carried out for 60 minutes while maintaining the temperature in the reaction vessel at 70°C.

Next, while maintaining the temperature in the reaction vessel at 70° C., the remaining monomer pre-emulsion (114 parts by mass) and 30 parts by mass of an aqueous solution of potassium persulfate (active ingredient 1.0% by mass) were added dropwise to each other. Add dropwise over 180 minutes using a funnel. After the dropwise addition was completed, the mixture was stirred at the same temperature for 60 minutes.

The temperature in the reaction vessel is cooled to 40° C., then deionized water is used so that the non-volatile content is 10.0% by weight, and then filtered through a 200 mesh filter cloth to be used in the present invention. A resin composition for a primer layer was obtained. Next, water was added to the resin composition to dilute and mix to obtain a primer (B-11) having a non-volatile content of 5% by mass.

[Preparation Example 1: Preparation of silver particle dispersion]
In a mixed solvent of 45 parts by mass of ethylene glycol and 55 parts by mass of ion-exchanged water, silver particles having an average particle size of 30 nm are dispersed using a compound obtained by adding polyoxyethylene to polyethyleneimine as a dispersing agent. A dispersion containing the agent was prepared. Then, ion-exchanged water, ethanol and a surfactant were added to the resulting dispersion to prepare a 5% by mass silver particle dispersion.

[Preparation Example 2: Preparation of copper etching solution]
A copper etchant was prepared by mixing 37.5 g/L of sulfuric acid and 13.5 g·L of hydrogen peroxide with ion-exchanged water.

[Preparation Example 3: Preparation of etching solution for silver]
2.6 parts by mass of acetic acid was added to 47.4 parts by mass of water, and 50 parts by mass of 35% by mass hydrogen peroxide solution was further added to prepare etching liquid (1) for silver. The molar ratio of hydrogen peroxide to carboxylic acid (hydrogen peroxide/carboxylic acid) in this etching solution for silver (1) was 13.6. The content ratio of the mixture was 22.4% by mass.

[Preparation Example 4: Preparation of conductive polymer dispersion]
A polypyrrole/polyvinylpyrrolidone (PPy/PVP(SO ₄ ²⁻ )) colloid doped with sulfate ions was synthesized based on the patent document (JP-A-2003-231991). Sodium sulfate was used as dopant, ammonium persulfate as oxidant and polyvinylpyrrolidone as surfactant. Pyrrole was used as the monomer.
0.85 g of PVP (polyvinylpyrrolidone, manufactured by Wako Pure Chemical Industries, Ltd., special grade) was dissolved in 500 ml of warm water at a temperature of 40° C., and the resulting solution was added with 7.0 g of ammonium persulfate as an oxidizing agent and 32 g of sodium sulfate as a dopant. .2 g was added, and more water was added to obtain a total volume of 1 L of aqueous solution. 5 mL of pyrrole (manufactured by Tokyo Kasei Co., Ltd., special grade) was added to the obtained aqueous solution, and the mixture was stirred at room temperature for about 12 hours to carry out chemical oxidation polymerization to obtain a polymerization reaction mixture. By centrifuging this, a black sediment was obtained. The sediment obtained was washed several times with water and redispersed in 50 ml of water to obtain a 10 g/L (PPy/PVP(SO ₄ ²⁻ )) aqueous colloidal liquid.

[Creation example 1]
Using a glass epoxy substrate (manufactured by Panasonic Corporation “Multilayer substrate material R-1766”; thickness 0.8 mm) laminated with 12 μm thick copper foil on both sides, L / S = 100 / A copper circuit pattern (FIG. 5) having 100 μm comb electrodes and 5 mm square pads at the ends was produced by a subtractive method.

(Manufacture of laminate for semi-additive method)
(Example 1)
A prepreg (insulating layer (A)) was overlaid on both sides of the glass epoxy base material having the comb-teeth electrode and the pad pattern prepared in Preparation Example 1, and a polyimide film ("Upilex 50S" manufactured by Ube Industries, Ltd.) was further placed. The cured prepreg (insulating layer ( A)) was laminated to prepare a substrate.

The silver particle dispersion obtained in Preparation Example 1 was applied to the surface of the cured prepreg (insulating layer (A); prepreg (“R-1661” manufactured by Panasonic Corporation, thickness 100 μm)) on the glass epoxy substrate. was coated using a small desktop coater (“K Printing Profer” manufactured by RK Print Coat Instrument Co., Ltd.) so that the silver particle layer (M1) after drying was 0.5 g/m ² . Then, it was dried at 160° C. for 5 minutes using a hot air dryer. Furthermore, the film was turned inside out, and the silver particle dispersion obtained in Preparation Example 1 was coated in the same manner as described above so that the silver particle layer (M1) was 0.5 g/m ² . A silver particle layer (M1) was formed on the cured prepreg (insulating layer (A)) on both surfaces by drying at 160° C. for 5 minutes. The film substrate thus obtained was baked at 250° C. for 5 minutes, and the conductivity of the silver particle layer was confirmed with a tester.

The glass epoxy substrate having conductive silver particle layers on both surfaces obtained above was placed in an electroless copper plating solution (“Circuposit 6550” manufactured by Rohm and Haas Electronic Materials Co., Ltd.) at 35 ° C. Immersed for 10 minutes to form an electroless copper plating film (M2; thickness 0.2 μm) on both surfaces, laminated on an inner layer printed wiring base material in which a conductor circuit layer (CM2) is formed on an insulating material. On the surface of the insulating layer (A), a conductive silver particle layer (M1) and a copper layer (M2) having a thickness of 0.2 μm were successively laminated to prepare a laminate for a semi-additive method.

(Example 2)
An electroless copper plating film having a thickness of 0.5 μm was formed on the silver particle layer (M1) in the same manner as in Example 1, except that the immersion time in the electroless copper plating solution was changed from 10 minutes to 25 minutes. A conductive silver particle layer (M1) is formed on the surface of the insulating layer (A) laminated on the inner layer printed wiring substrate in which the conductor circuit layer (CM2) is formed on the insulating material by forming, and a copper layer (M2) of 0.5 μm, a laminate for a semi-additive construction method was produced.

(Example 3)
A conductive silver particle layer (M1) and a copper layer with a thickness of 0.2 μm are formed on the surfaces of the cured prepreg (insulating layer (A)) on both sides of the glass epoxy substrate prepared in Example 1. The resulting laminate was fixed to a copper frame, an electroless copper plating layer was placed on the cathode, phosphorous copper was used as the anode, and an electrolytic plating solution containing copper sulfate (60 g / L of copper sulfate, 190 g / L of sulfuric acid, Electroplating is performed for 4 minutes at a current density of 2 A / dm ² using 50 mg / L of chlorine ions and an additive (Coppergleam ST-901 manufactured by Rohm and Haas Electronic Materials Co., Ltd.), so that the insulating material is coated with A conductive silver particle layer (M1) and a 2 μm copper layer (M2) are formed on the surface of the insulating layer (A) laminated on the inner layer printed wiring base on which the conductive circuit layer (CM2) is formed. , a laminate for the semi-additive construction method, which was sequentially laminated, was produced.

(Example 4)
Cured ^{double -} sided prepreg on a glass epoxy substrate ( A conductive silver particle layer (M1) was formed on the surface of the insulating layer (A)), baked at 250° C. for 5 minutes, and the conduction of the silver particle layer was confirmed with a tester. The base material having conductive silver particle layers on both surfaces thus obtained is placed on the surface of the silver particle layer as a cathode, phosphorous copper is used as an anode, and an electrolytic plating solution containing copper sulfate ( Using copper sulfate 60 g / L, sulfuric acid 190 g / L, chloride ion 50 mg / L, additive (Rohm and Haas Electronic Materials Co., Ltd. Copper Gleam ST-901"), current density 2 A / dm2 4.5 By performing minute electrolytic plating, a conductive silver particle layer ( M1) and a 2 μm copper layer (M2) were sequentially laminated to prepare a laminate for a semi-additive construction method.

(Example 5)
In the same manner as in Example 1, a prepreg (insulating layer (A)) was layered on both sides of the glass epoxy base material having the comb-teeth electrode and the pad pattern prepared in Preparation Example 1, and a polyimide film (manufactured by Ube Industries, Ltd.) Upilex 50S") is placed on the glass epoxy base material (insulating material) having the conductive circuit layer (CM2) by thermocompression bonding (170° C., 60 minutes) and peeling off the polyimide film. A substrate laminated with the cured prepreg (insulating layer (A)) was produced.

The primer (B-1) obtained in Production Example 1 is applied to the surface of the cured prepreg (insulating layer (A)) on the glass epoxy base material, using a desktop small coater (RK Printcoat Instrument Co., Ltd.) K printing prober"), it was coated so that the thickness after drying was 120 nm, and then dried at 80 ° C. for 5 minutes using a hot air dryer. The primer (B-1) obtained in Production Example 1 was applied in the same manner as above so that the thickness after drying was 120 nm, and dried at 80 ° C. for 5 minutes using a hot air dryer to cure. A primer layer was formed on the prepreg (insulating layer (A)) on both surfaces.

On the conductive silver particle layer (M1) in the same manner as in Example 2, except that the substrate with the primer layer formed on the cured prepreg (insulating layer (A)) on both surfaces obtained above is used. On the surface of the insulating layer (A) laminated on the inner layer printed wiring substrate in which the conductive circuit layer (CM2) is formed on the insulating material by forming an electroless copper plating film with a thickness of 0.5 μm on the surface In addition, a laminate for semi-additive construction method was produced in which a primer layer (B), a conductive silver particle layer (M1), and a copper layer (M2) having a thickness of 0.5 μm were sequentially laminated.

(Example 6)
In Example 5, the silver particle layer was changed from 0.5 g/m ² to 0.8 g/m ² , and electrolytic copper plating was performed in the same manner as in Example 4. A primer layer (B), a conductive silver particle layer (M1), and a 0.5 μm A laminate for a semi-additive construction method in which the copper layers (M2) of were sequentially laminated was produced.

(Examples 7-16)
Insulating properties were obtained in the same manner as in Example 6, except that the type of primer used in the primer layer (B), its drying conditions, and the amount of silver in the silver particle layer (M1) were changed to those shown in Table 1 or 2. A primer layer (B), a conductive silver particle layer (M1), and a The copper layer (M2) produced the laminated body for semi-additive construction methods laminated|stacked one by one.

(Example 17)
A conductive silver particle layer (M1 ), and a copper layer (M2) of 0.5 μm, using a laminate in which the 0.5 μm copper layer (M2) is sequentially laminated, at the pad position of the inner conductor circuit layer (CM2), using a laser, to the inner conductor circuit layer (CM2) A connecting via with a diameter of 70 μm was formed.
The base material with vias connected to the inner conductive circuit layer (CM2) thus obtained is passed through MacDermid's black hole process (conditioning-carbon adsorption treatment-etching) to deposit carbon on the surfaces of the via holes. The conductive silver particle layer on the insulating layer (A) is formed by removing the copper layer (M2) with carbon attached by etching using the sulfuric acid/hydrogen peroxide aqueous solution prepared in Preparation Example 2. (M1) was exposed. In this way, on the surface of the insulating layer (A) laminated on the inner layer printed wiring base material in which the conductive circuit layer (CM2) is formed on the insulating material, a conductive silver particle layer (M1), Furthermore, a laminate for semi-additive construction was obtained, which had vias extending from the insulating layer (A) to the conductive circuit layer (CM2), and in which the surfaces of the vias were made conductive by carbon.

(Example 18)
An inner layer in which a conductor circuit layer (CM2) is formed on an insulating material in the same manner as in Example 17, except that the laminate produced in Example 6 is used instead of the laminate produced in Example 2. A conductive silver particle layer (M1) on the surface of the insulating layer (A) laminated on the printed wiring substrate, and a via extending from the insulating layer (A) to the conductor circuit layer (CM2), A laminate for a semi-additive construction method was obtained in which the surface of the via had conductivity secured by carbon.

(Example 19)
An inner layer in which a conductor circuit layer (CM2) is formed on an insulating material in the same manner as in Example 17, except that the laminate produced in Example 11 is used instead of the laminate produced in Example 2. A conductive silver particle layer (M1) on the surface of the insulating layer (A) laminated on the printed wiring substrate, and a via extending from the insulating layer (A) to the conductor circuit layer (CM2), A laminate for a semi-additive construction method was obtained in which the surface of the via had conductivity secured by carbon.

(Example 20)
In the same manner as in Example 19, a conductive silver particle layer ( M1), and a copper layer (M2) of 0.5 μm, using a laminate in which the pad position of the inner conductor circuit layer (CM2) is sequentially laminated, using a laser, the inner conductor circuit layer (CM2) A via with a diameter of 70 μm was formed to connect to the .

Instead of passing the thus-obtained substrate with vias connected to the inner conductor circuit layer (CM2) through the black hole process, 1 g/l of palladium chloride, 1 ml/l of hydrochloric acid and 1 g/l of dimethylthiourea It was immersed for 3 minutes at 25° C. in the catalyst solution containing. Next, the substrate was washed with water and treated with a reducing solution containing 10 g/l of dimethylamine borane and 5 g/l of sodium hydroxide at 50° C. for 2 minutes to make the surface of the through-hole conductive with palladium, thereby forming a conductive film on the insulating material. On the surface of the insulating layer (A) laminated on the inner layer printed wiring base on which the conductive circuit layer (CM2) is formed, a conductive silver particle layer (M1), and further, a conductive circuit from the insulating layer (A) A laminate for a semi-additive method was obtained, which had vias reaching the layer (CM2) and whose surfaces were electrically conductive with palladium.

(Example 21)
In Example 20, the (PPy/PVP(SO ₄ ²⁻ )) aqueous colloid solution prepared in Preparation Example 4 was used instead of making the substrate with vias connected to the inner conductive circuit layer (CM2) conductive with palladium. immersed for 2 minutes at room temperature to attach colloidal particles to the surface of the through-hole, thereby making the surface of the through-hole conductive with a conductive polymer. In this way, on the surface of the insulating layer (A) laminated on the inner layer printed wiring base material in which the conductive circuit layer (CM2) is formed on the insulating material, a conductive silver particle layer (M1), Furthermore, a laminate for semi-additive construction was obtained, which had vias extending from the insulating layer (A) to the conductor circuit layer (CM2), and in which the surfaces of the vias were made conductive by the conductive polymer.

(Manufacture of printed wiring boards)
(Examples 22-26)
Using the laminate for the semi-additive method prepared in Examples 17 to 21, a dry film resist (“Photech RD-1225” manufactured by Hitachi Chemical Co., Ltd.; resist film thickness 25 μm) was applied on the silver particle layer (M1), Pressing at 100° C. using a roll laminator, then using a direct exposure digital imaging device (“Nuvogo 1000R” manufactured by Orbottec), as shown in the figure *, connect to the pad part of the inner layer conductor circuit (CM2). A land with a diameter of 200 μm and a TEG pattern of a conductive circuit layer (CM1) having a width of 50 μm and a length of 5 cm from the land were exposed to the via portion. Then, the silver particle layer (M1) of the TEG pattern was exposed by performing development using a 1% by mass sodium carbonate aqueous solution.

Next, the silver particle layer (M1) surface of the substrate on which the pattern resist was formed was placed on the cathode, and phosphorous copper was used as the anode, and an electrolytic plating solution containing copper sulfate (copper sulfate 60 g / L, sulfuric acid 190 g / L , Chlorine ion 50 mg / L, an additive (Rohm and Haas Electronic Materials Co., Ltd. Copper Gleam ST-901") is used to perform electrolytic plating for 27 minutes at a current density of 2 A / dm ² to remove the resist. A conductive circuit layer (CM1) having a thickness of 12 μm was formed by electrolytic copper plating on the TEG pattern portion thus formed.Then, these substrates were immersed in a 3% by mass sodium hydroxide aqueous solution set at 50° C. , the pattern resist was stripped.

Then, the substrate obtained above is immersed in the silver etching solution obtained in Preparation Example 2 at 25° C. for 30 seconds to remove the silver particle layer (M1) other than the conductive circuit layer pattern, A printed wiring board was obtained. The cross-sectional shape of the conductive circuit layer of the manufactured printed wiring board is a rectangular shape without reduction in wiring height and wiring width and without undercut, and the conductive circuit layer (CM1) has a smooth surface. there were.

(Comparative example 1)
In Example 1, instead of forming a silver particle layer on the surface of the cured prepreg (insulating layer (A); prepreg (“R-1661” manufactured by Panasonic Corporation, thickness 100 μm)) on the glass epoxy substrate, On both sides of the glass epoxy base material prepared in Preparation Example 1, the above prepreg and a 12 μm thick rolled copper foil (BHY-82F-HA-V2) manufactured by JX Metals Co., Ltd. were overlaid and thermocompression bonded (170° C., 60 minutes). A substrate was prepared by laminating a cured prepreg (insulating layer (A)) and copper foil on a glass epoxy base material (insulating material) having a conductive circuit layer (CM2). The copper foil on the surface layer of this substrate was etched to 3 μm using the sulfuric acid/hydrogen peroxide-based copper etchant prepared in Preparation Example 2, and then, in the same manner as in Examples 22 to 26, the copper foil plating base layer. A 12 μm thick conductive circuit layer of copper was formed thereon.

Then, when the copper seed was removed by immersion in a sulfuric acid/hydrogen peroxide flash etchant used for copper seed etching, the conductive circuit layer was etched, the film thickness was reduced by about 3 μm, and the wiring width was reduced. was also reduced by about 6 μm, and the cross-sectional shape became “trapezoidal” because the rectangular shape could not be maintained. Moreover, the surface of the conductive layer of copper was roughened by etching and the smoothness was lowered.

(Comparative example 2)
In Comparative Example 1, the copper foil on the surface layer of the substrate in which the cured prepreg (insulating layer (A)) and copper foil were laminated on the glass epoxy base material (insulating material) having the conductor circuit layer (CM2) was When the conductive circuit layer was formed by the subtractive method using ferric chloride etchant without etching, the cross-sectional shape of the circuit layer became "trapezoidal" instead of being rectangular, resulting in the copper conductive layer. The surface was significantly roughened by etching.

[Confirmation of presence or absence of undercut and cross-sectional shape of wiring part]
The cross section of the comb-teeth electrode portion of the printed wiring board obtained above was observed with a scanning electron microscope ("JSM7800" manufactured by JEOL Ltd.) at a magnification of 500 to 10,000 times to determine the presence or absence of undercuts. The cross-sectional shape of the tooth electrode portion was confirmed.

By observing the wiring surface of the produced printed wiring board with a laser microscope (manufactured by Keyence Corporation, VK-9710), the surface roughness of the wiring surface is confirmed, and those with Rz of 3 μm or less are smooth (smoothness : ○), and those with an Rz exceeding 3 μm were evaluated as not smooth (smoothness: ×). In addition, when the difference between the design width of the wiring by the resist used for wiring formation and the upper surface width of the formed wiring was 2 μm or less, side etching was suppressed and the rectangular shape could be maintained (rectangularity: ◯). Those with a difference of more than 2 μm were evaluated as unable to retain the rectangular shape (short formation: ×), and Examples, Comparative Examples, and evaluation results are shown in Tables 1 to 3.

1: Insulating substrate 2: Silver particle layer (M1)
3: Cover layer (copper layer)
4: Conductor circuit layer (CM2)
5: blind via 6: palladium, conductive polymer, carbon 7: pattern resist 8: conductive layer (electrolytic copper plating layer)
(a) Laminate for semi-additive construction method (constitution of claim 1)
(b) Step 1: Non-through hole (blind via hole) formation (c) Step 2: Blind via hole conductivity (d) Step 3: Exposure of conductive silver particle layer (e) Step 4: Pattern resist formation (f) step 5: Conductive layer formation by electrolytic copper plating (g) Step 6: Pattern resist stripping (h) Step 6: Silver seed removal (structure of claim 11)

Claims (12)

A laminate for a semi-additive method for manufacturing a multilayer printed wiring board by electrically connecting the conductive circuit layer (CM1) on the surface of the substrate and the conductive circuit layer (CM2) on the inner printed wiring substrate,
A conductive silver particle layer (M1) and a copper layer ( M2) are sequentially laminated, the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm, and the copper layer (M2) is removed in an etching process for removing palladium, a conductive polymer, and carbon. A laminate for a semi-additive construction method, which protects a conductive silver particle layer (M1). The laminate for semi-additive construction method according to claim 1, further comprising a primer layer (B) between the surface (S1) of the insulating layer (A) and the conductive silver particle layer (M1). body. 3. The laminate for semi-additive construction method according to claim 1, wherein the silver particles constituting the silver particle layer (M1) are coated with a polymer dispersant. 3. The laminate for a semi-additive construction method according to claim 2, wherein the primer layer (B) is a layer composed of a resin having a reactive functional group [X], and silver particles constituting the silver particle layer (M1). The polymer dispersant for dispersing has a reactive functional group [Y], and the reactive functional group [X] and the reactive functional group [Y] can form a bond with each other by reaction. The laminate for semi-additive construction method according to claim 2 . 5. The laminate for semi-additive construction method according to claim 4, wherein the reactive functional group [Y] is a basic nitrogen atom-containing group. 4. or wherein the polymeric dispersant having the reactive functional group [Y] is one or more selected from the group consisting of polyalkyleneimine and polyalkyleneimine having a polyoxyalkylene structure containing oxyethylene units; 5. The laminate for semi-additive construction method according to 5. 1 wherein the reactive functional group [X] is selected from the group consisting of a keto group, an acetoacetyl group, an epoxy group, a carboxyl group, an N-alkylol group, an isocyanate group, a vinyl group, a (meth)acryloyl group and an allyl group; The laminate for semi-additive construction method according to claim 4, which is more than seed. A printed wiring board formed using the laminate for a semi-additive construction method according to any one of claims 1 to 7. A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm,
Step 1 of forming a hole reaching the conductive circuit layer (CM2) from the insulating layer (A);
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the substrate having holes extending from the insulating layer (A) to the conductor circuit layer (CM2) to make the hole surfaces conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
A method for producing a laminate for a semi-additive method for producing a multilayer printed wiring board according to any one of claims 5 to 7, comprising: 10. The method for producing a laminate for a semi-additive construction method according to claim 9, further comprising laminating a primer layer (B) between the insulating layer (A) and the silver particle layer (M1). A conductive silver particle layer (M1) and a copper layer (M2 ) are sequentially laminated, and the layer thickness of the copper layer (M2) is 0.1 μm to 2 μm,
Step 1 of forming a hole reaching the conductive circuit layer (CM2) from the insulating layer (A);
Step 2 of applying palladium, a conductive polymer, or carbon to the surface of the substrate having holes extending from the insulating layer (A) to the conductor circuit layer (CM2) to make the hole surfaces conductive;
Step 3 of etching the copper layer (M2) to expose the conductive silver particle layer (M1);
step 4 of forming a pattern resist on the conductive silver particle layer (Application M1);
Step 5 of electrically connecting the surface layer and the inner conductive circuit layer (CM2) by electrolytic copper plating and forming the conductive circuit layer (CM1).
Step 6 of removing the pattern resist and removing the silver particle layer (M1) of the non-conductive circuit pattern forming portion with an etchant
9. The method of manufacturing a multilayer printed wiring board according to claim 8, characterized by comprising: 12. The method of manufacturing a multilayer printed wiring board according to claim 11, further comprising a primer layer (B) between the insulating layer (A) and the silver particle layer (M1).

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