WO2021210589A1 - Dry film - Google Patents

Abstract

Provided is a curable resin composition with which conductor layer coating can be excellently carried out, and which is suitable for use as an underlayer coating film of an adhesiveness-imparting coating that has excellent adhesion with the coated conductor layer, even when surface irregularities (surface roughness) are small (e.g., even when Ra is 200nm or less). A curable resin composition according to the present invention is for forming an underlayer coating film provided between a base material and an adhesiveness-imparting coating provided in order to improve the adhesion of a coating layer to the base material, the curable resin composition characterized in that: the curable resin composition comprises an epoxy resin (A) and an active ester compound (B); the adhesiveness-imparting coating comprises a catalyzing metal-containing silicon oligomer; and the catalyzing metal-containing silicon oligomer is obtained by subjecting a tetraalkoxy silane and a polyvalent alcohol, in which a hydroxy group is bonded to at least the n and n+1 sites or n and n+2 sites (where n is an integer of at least 1), to a condensation reaction in the presence of a catalyzing metal.

Description

Dry film

The present invention relates to a dry film preferably used as an insulating material, which forms a plating layer on the surface.

As a manufacturing method of a multi-layer printed wiring board, a build-up method is manufactured in which an insulating layer and a conductor layer are alternately stacked on an inner layer circuit board (so-called copper-clad laminated board) formed by pressing a prepreg and a copper foil. The technology is known. For example, an epoxy resin composition is applied to an inner layer circuit board in which a circuit is formed, and heat-cured to form an insulating layer, and then an uneven roughened surface is formed on the surface of the insulating layer with a roughening agent. , A method of forming a conductor layer by electroless plating and electrolytic plating has been proposed (see Patent Document 1 and Patent Document 2).

Further, an adhesive sheet of an epoxy resin composition is laminated on an inner layer circuit board in which a circuit is formed, and heat-cured to form an insulating layer, and then an uneven roughened surface is formed on the surface of the insulating layer with a roughening agent. Then, a method for manufacturing a multilayer printed wiring board in which a conductor layer is formed by electroless plating and electrolytic plating has been proposed (see Patent Document 3).
All of the techniques related to such proposals improve the adhesion between the plating layer (conductor circuit layer) and the insulating layer by roughening the surface of the insulating layer.

On the other hand, in recent high-definition conductor circuit patterns, for example, when an unnecessary electrolytically plated portion under a plating resist is removed by an etching process when forming a conductor circuit, the etching solution enters a recess on the surface of the insulating layer. In addition, the conductor circuit may be peeled off by eroding the circuit bottom of the conductor layer, and there is a problem that a fine conductor circuit cannot be formed with high accuracy.
Further, since the contact area between the conductor layer and the insulating layer increases due to the surface unevenness of the insulating layer, there is also a problem that the transmission loss of a high frequency electric signal becomes particularly large.

Further, in the laminated structure of the wiring board, since the surface unevenness is formed in the insulating layer, the thickness of the layer required for electrically insulating the upper and lower conductor layers is increased by the height of the unevenness, and the wiring board is made lighter. There is also the problem that it becomes difficult.
From such a problem, in order to obtain a wiring board having a thinner film and higher definition, a technique for realizing excellent adhesion to a conductor circuit without roughening the insulating layer is required.

On the other hand, an invention has been proposed in which a plating layer is formed without roughening the surface of the base material by treating the surface of the base material with a coating agent containing a catalytic metal oligomer (Patent Documents). 4).

Japanese Unexamined Patent Publication No. 7-304931 Japanese Unexamined Patent Publication No. 7-304933 Japanese Unexamined Patent Publication No. 11-87927 International Publication 2016/017792

However, when the inventors evaluated the coating agent proposed in Patent Document 4 in order to deposit a plating layer (conductor layer) on the insulating layer without going through the roughening treatment step, the coating agent was used as a base for the coating agent. It has been clarified that the adhesion of the plating layer cannot always be obtained depending on the type of the insulating layer.

Therefore, the present invention provides an insulating material that can obtain excellent adhesion to a plating layer (conductor layer) even if the surface unevenness (surface roughness) is small (for example, Ra is 200 nm or less). That is the issue.

As a result of diligent research to solve the above problems, the present inventors have formed a film of a layer made of a thermosetting resin composition having a specific component composition and a layer made of a plating adhesion-imparting coating composition having a specific component composition. We have found that the above problems can be solved by a dry film having a resin layer having a two-layer structure laminated on a base material, and have completed the present invention.
That is, the present invention is as follows.

The dry film of the present invention
A two-layer structure composed of a layer of a curable resin composition containing an epoxy resin and an active ester compound and a layer of an adhesion-imparting coating composition containing an acrylic resin and a catalytic metal-containing silicon oligomer on a film substrate. In the dry film having the resin layer of the above, the catalyst-containing metal silicon oligomer has a polyhydroxy group bonded to tetraalkoxysilane at least at the n, n + 1 position or the n, n + 2 position (where n is an integer of 1 or more). It is characterized in that it is a catalytic metal silicon oligomer obtained by subjecting a valent alcohol to a condensation reaction in the presence of a metal having catalytic properties for electroless plating.

The dry film can be made into a cured product by curing the constituent resin layer.

It can be an electronic component having an insulating layer made of the cured product.

According to the present invention, there is provided an insulating material that can obtain excellent adhesion to a plating layer (conductor layer) even if the surface unevenness (surface roughness) is small (for example, Ra is 200 nm or less). It becomes possible.

The curable resin composition and the plating adhesion-imparting coating composition constituting each layer of the dry film of the present invention will be described in detail.

The curable resin composition and the coating composition for imparting plating adhesion of the present invention can be produced according to a known method, and can be obtained, for example, by blending, stirring and homogenizing each component.

Further, in the present invention, the solid content means a component other than the solvent (particularly an organic solvent) of each raw material in the curable resin composition and the plating adhesion-imparting coating composition, or the mass or volume thereof. do.

In the present invention, when the compound name is simply indicated, all isomers thereof are included.

<<< Curable resin composition >>>
<< Ingredients >>
The curable resin composition forming the first layer (insulating layer) of the dry film of the present invention contains an epoxy resin and an active ester compound. The resin layer made of this curable resin composition is a layer that serves as a base for the layer made of the plating adhesion-imparting coating composition described later, and is an insulating layer provided on the circuit-formed base material.

<Epoxy resin>
The epoxy resin is not particularly limited, and may be bifunctional or trifunctional or higher. It can also contain a monofunctional epoxy resin as a reactive diluent.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, and bisphenol Z type epoxy resin. Novolak type epoxy resin such as epoxy resin, bisphenol A novolak type epoxy resin, phenol novolac type epoxy resin, cresol novolac epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, arylalkylene type epoxy resin, tetraphenylol ethane type epoxy Resin, naphthalene type epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, trihydroxyphenylmethane type epoxy resin, hydantin type epoxy resin, tetraphenylol ethane type epoxy resin, With brominated epoxy resin, hydrogenated (bisphenol) type resin, glycidylamine type epoxy resin, alicyclic epoxy resin, diglycidyl phthalate resin, tetraglycidyl xylenoyl ethane resin, glycidyl methacrylate copolymer epoxy resin, cyclohexyl maleimide Epoxy resin copolymerized with glycidyl methacrylate, epoxy-modified polybutadiene rubber derivative, CTBN-modified epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene Examples thereof include epoxy resins such as glycol or propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, and triglycidyltris (2-hydroxyethyl) isocyanurate. These epoxy resins can be used alone or in combination of two or more.

Among them, biphenyl type epoxy resin and naphthalene type epoxy resin from the viewpoint of thermal dimensional stability of the obtained cured product, dicyclopentadiene type epoxy resin from the viewpoint of low dielectric property, and novolac type epoxy from the viewpoint of heat resistance. It is preferable to use a resin.

These can be used alone or in combination of two or more.

<< Active ester compound >>
The active ester compound may be any compound having an active ester group, but a compound having at least two active ester groups in the molecule is preferable.

The active ester group in the active ester compound can react with the epoxy group by heating and acts as a curing agent for the epoxy resin used in the present invention.

As the active ester compound, an active ester compound obtained by reacting a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound is preferable from the viewpoint of enhancing the heat resistance of the obtained cured product. .. The active ester compound is obtained by reacting a carboxylic acid compound with one or more selected from the group consisting of aromatic compounds having a phenolic hydroxyl group (phenolic compounds, naphthol compounds, etc.) and thiol compounds. An active ester compound is more preferable, and an aromatic compound obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group and having at least two active ester groups in the molecule is particularly preferable.

Specific examples of the carboxylic acid compound for forming the active ester compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid and the like. Among these, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, and terephthalic acid are preferable, and phthalic acid, isophthalic acid, and terephthalic acid are more preferable, from the viewpoint of enhancing the heat resistance of the obtained electrically insulating layer. Isophthalic acid and terephthalic acid are more preferable.

Specific examples of the thiocarboxylic acid compound for forming the active ester compound include thioacetic acid and thiobenzoic acid.

Specific examples of the hydroxy compound for forming an active ester compound include dihydroxybenzene, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, and cresol. , Naftor, dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, benzenetriol, dicyclopentadienyldiphenol, phenol novolac and the like.

Among these, from the viewpoint of improving the solubility of the active ester compound and increasing the heat resistance of the obtained cured product, the hydroxy compounds for forming the active ester compound include dihydroxynaphthalene, dihydroxynaphthalene, dihydroxybenzophenone and tri. Hydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadienyldiphenol, phenol novolac are preferred, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadienyldiphenol, phenol novolac are more preferred, and dicyclopentadienyl. Diphenol and phenol novolac are more preferred.

Specific examples of the thiol compound for forming the active ester compound include benzenedithiol, triazinedithiol and the like.

The method for producing the active ester compound is not particularly limited, and the active ester compound can be produced by a known method. For example, it can be obtained by a condensation reaction between the above-mentioned carboxylic acid compound and / or thiocarboxylic acid compound and a hydroxy compound and / or thiol compound.

In the present invention, examples of the active ester compound include aromatic compounds having an active ester group disclosed in JP-A-2002-12650 and polyfunctional polyesters disclosed in JP-A-2004-277460. , Commercial products can be used. Examples of commercially available products include the product names "EXB9451, EXB9460, EXB9460S, Epicron HPC-8000-65T" (above, manufactured by DIC, "Epicron" is a registered trademark), and the product name "DC808" (manufactured by Japan Epoxy Resin). , Product name "YLH1026" (manufactured by Japan Epoxy Resin Co., Ltd.) and the like.

These can be used alone or in combination of two or more.

<Other ingredients>
(Phenol resin)
As a component other than the above-mentioned epoxy resin and active ester compound, it is preferable to contain a phenol resin. Since the cured product of the epoxy resin and the active ester compound is hard and brittle, cracks may occur due to physical impact and peeling may occur. However, by combining the phenol resin, the cured product is given flexibility and cracks. A curable resin composition having excellent production stability, which is less likely to cause problems such as peeling and peeling, can be obtained.

The phenol resin is not particularly limited, and may be bifunctional or trifunctional or higher. Specifically, phenol novolac resin, alkylphenol novolac resin, triazine structure-containing phenol novolac resin, bisphenol A novolac resin, dicyclopentadiene structure-containing phenol resin, zyloc-type phenol resin, terpene-modified phenol resin, polyvinylphenols, etc. Examples thereof include a naphthalene structure-containing phenol-based curing agent and a fluorene structure-containing phenol-based curing agent.

These can be used alone or in combination of two or more.

(Other resin components)
Examples of other resin components of the curable resin composition include polyester resins, phenoxy resins, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, and polybutadiene resins. , Polycarbonate resin, polyimide resin, polyamide resin, acrylic resin, polyamideimide resin, fluorine resin and the like.

These can be used alone or in combination of two or more.

(Ingredients other than resin components)
Ingredients other than the resin component of the curable resin composition include known and commonly used components such as inorganic fillers, curing accelerators, organic solvents, colorants, thickeners, defoamers, leveling agents, and adhesion imparting agents. You may be.

Inorganic fillers include barium sulfate, barium titanate, silica (atypical silica, crystalline silica, fused silica, spherical silica, etc.), talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, alumina, and silicon nitride. Examples include silicon, boron nitride, aluminum nitride and the like. These can be used alone or in combination of two or more.

Among them, the inorganic filler is preferably silica and has excellent filling property because it has a small specific gravity, can be blended in a high proportion in a curable resin composition, and is excellent in thermal dimensional stability (low thermal expansion). From the point of view, spherical silica is particularly preferable.

The average particle size of the inorganic filler is preferably 3 μm or less, and more preferably 1 μm or less. The average particle size of the inorganic filler can be determined by a laser diffraction type particle size distribution measuring device.

Examples of the curing accelerator include imidazole, 2-methylimidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 4-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazole, 1-. Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Amines, amine compounds such as 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide, sebacate dihydrazide; phosphorus compounds such as triphenylphosphine, guanamine, acetguanamine, benzoguanamine, melamine, 2,4 -Diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine isocyanuric acid adduct, 2,4- Examples thereof include S-triazine derivatives such as diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adduct. These can be used alone or in combination of two or more.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, cellosolves such as cellosolve and butyl cellosolve, and calvi. Examples thereof include carbitols such as toll and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, and dimethylformamide and dimethylacetamide. These can be used alone or in combination of two or more.

Examples of the colorant include phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and the like. These can be used alone or in combination of two or more.

Examples of the thickener include asbestos, olben, and benton. These can be used alone or in combination of two or more.

Examples of the defoaming agent include silicone-based defoaming agents, fluorine-based defoaming agents, and polymer-based defoaming agents. These can be used alone or in combination of two or more.

Examples of the adhesion-imparting agent include a thiazole-based adhesion-imparting agent, a triazole-based adhesion-imparting agent, and a silane coupling agent. These can be used alone or in combination of two or more.

<< Content >>
The blending amount of the epoxy resin and the active ester in the curable resin composition is not particularly limited. Generally, the ratio (Eq2 / Eq1) of the epoxy equivalent of the epoxy group (Eq1) contained in the epoxy resin to the active ester group equivalent (Eq2) contained in the active ester is 0.7 to 1.4. It can be, more preferably 0.8 to 1.2. When the equivalent ratio is in such a range, the cured product of the curable resin composition has excellent adhesion to the base material and the layer composed of the plating adhesion-imparting coating composition, and is an insulating material. The characteristics as can be satisfied.

Further, when the phenol resin is further used in combination, the blending amount of the phenol resin is not particularly limited. Generally, the ratio {(Eq2 + Eq3) / Eq1} of the epoxy equivalent (Eq1) and the sum of the active ester equivalent (Eq2) and the hydroxyl group equivalent of the phenolic hydroxyl group contained in the phenol resin (Eq3) is calculated. It can be 0.4 to 1.2, more preferably 0.5 to 1.0, and the ratio (Eq3 / Eq2) of the active ester equivalent (Eq2) to the phenolic hydroxyl group equivalent (Eq3) is It can be 0.05 to 10, more preferably 0.1 to 1.0. Within such a range, the cured product of the curable resin composition is imparted with excellent flexibility (stretchability), and the manufacturing stability and reliability as an electronic component (multilayer printed wiring board, etc.) are improved.

<<< Plating adhesion-imparting coating composition >>>
<< Ingredients >>
The plating adhesion-imparting coating composition forming the second layer (plating adhesion layer) of the dry film of the present invention contains an acrylic resin and a catalytic metal silicon oligomer. As such a coating composition for imparting plating adhesion, a commercially available product can be used, and examples thereof include SIPAC300 manufactured by JCU.
In the present invention, the layer made of the plating adhesion-imparting coating composition is formed on the base material via the layer made of the curable resin composition described above, and a metal plating layer is formed on the layer.

<Acrylic resin>
The acrylic resin is a polymer containing a structural unit derived from at least one (meth) acrylic monomer selected from the group consisting of (meth) acrylic acid and its derivatives. In addition, in this specification, (meth) acrylic means acrylic, methacryl, or both acrylic and methacryl. For example, homopolymers of (meth) acrylic monomers such as (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, (meth) acrylonitrile, or copolymers of two or more of these, and (meth). ) Examples thereof include a copolymer obtained by polymerizing an acrylic monomer and another monomer copolymerizable with the monomer. The acrylic resin can also polymerize the above (meth) acrylic monomer and / or other monomers copolymerizable with these by a conventionally known method. Among them, (meth) acrylic acid alkyl ester copolymer, colloidal silica / acrylic composite, ethylene / acrylic acid copolymer ammonium salt are preferable, and (meth) acrylic acid alkyl ester copolymer is more preferable. One kind or two or more kinds of these resins can be used. Further, these resins may be in the form of a solution or a powder.

<Catalyst-containing metal silicon oligomer>
The catalytic metal silicon oligomer contains a tetraalkoxysilane and a polyhydric alcohol in which a hydroxy group is bonded to at least the n, n + 1 position or the n, n + 2 position (where n is an integer of 1 or more), which is a metal having catalyst (catalytic property. Hereinafter, those obtained by conducting a condensation reaction in the presence of a catalyst metal) will be used.

The tetraalkoxysilane used in the catalytic metal silicon oligomer is not particularly limited, and for example, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, and the like can be used. Of these, tetraethoxysilane is preferable. These tetraalkoxysilanes can be used alone or in combination of two or more.

Further, the polyhydric alcohol in which a hydroxy group is bonded to at least the n, n + 1 position or the n, n + 2 position (where n is an integer of 1 or more) used in the catalytic metal silicon oligomer is not particularly limited, and for example, n is 1. Examples thereof include divalent to tetrahydric alcohols having an integer of to 3, preferably divalent to trihydric alcohols having n having an integer of 1 to 2. Specific examples of these polyhydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, and 2,3-butylene glycol. 2-Methyl-1,3-propylene glycol, 1,2-pentylene glycol, 1,3-pentylene glycol, 2,3-pentylene glycol, dihydric alcohol such as 2,4-pentylene glycol, glycerin, etc. Examples of trihydric alcohols such as erythritol and tetrahydric alcohols such as erythritol can be mentioned. Among these polyhydric alcohols, dihydric alcohols are preferable, ethylene glycol and / or 1,3-propylene glycol are more preferable, and ethylene glycol is particularly preferable. These polyhydric alcohols can be used alone or in combination of two or more.

Further, the catalytic metal used in the catalytic metal silicon oligomer is not a metal having a catalytic action for the condensation reaction of tetraalkoxysilane and a polyhydric alcohol, but a metal having a self-catalytic action for the precipitation reaction of plating described later. Therefore, it is different from the metal catalysts referred to in WO2014 / 207885 and WO2014 / 27886.

Examples of such catalyst metals include iron, nickel, cobalt, copper, palladium, silver, gold, platinum and the like. Among these catalyst metals, iron, nickel, cobalt, copper and palladium are preferable, iron, nickel, copper and palladium are more preferable, and palladium is particularly preferable. The catalyst metal is preferably present in a state of being dissolved in the polyhydric alcohol during the condensation reaction. In that case, for example, iron chloride, nickel chloride, copper chloride, palladium chloride, gold chloride ( It is preferable to use a metal salt containing a catalytic metal such as III), silver (I) chloride, and platinum (IV) chloride. If the catalyst metal is difficult to dissolve in the polyhydric alcohol, it can be dissolved in an inorganic acid such as hydrochloric acid in advance. These catalyst metals can be used alone or in combination of two or more, in which case it is preferable to contain at least palladium.

The method for subjecting the tetraalkoxysilane and the polyhydric alcohol to the condensation reaction in the presence of the catalyst metal is not particularly limited. For example, the catalyst metal is mixed with the above-mentioned polyhydric alcohol at 0.01 to 20 g / kg, preferably 0.01 to 20 g / kg. After adding and dissolving at 0.1 to 10 g / kg, the mixture can be heated to the reaction temperature with stirring, and then tetraalkoxysilane can be added and reacted. The reaction temperature is 25 to 150 ° C., preferably 30 to 70 ° C., and the reaction time is 30 minutes to 8 hours, preferably 2 hours to 4 hours. At the time of the reaction, it is important to react tetraalkoxysilane with the polyhydric alcohol in a molar ratio of 4: 1 to 1: 4, preferably 1: 2 to 1: 4. As a result, a polyhydric alcohol is incorporated between the tetraalkoxysilane and the tetraalkoxysilane.

Alcohol is produced during the above reaction, but it is preferable not to fractionate the alcohol because the polymerization reaction is controlled by not fractionalizing the alcohol.

Further, in the above reaction, the tetraalkoxysilane and the polyhydric alcohol are separated into two layers before the condensation reaction, but when the reaction is completed, the layers become one, so the reaction should be terminated when the layers become one. Can be done.

The catalyst-containing metal silicon oligomer thus obtained is one in which the catalyst metal is incorporated into a silicon oligomer in which 2 to 4 of tetraalkoxysilane and 1 to 13 of polyhydric alcohol are condensed and reacted.

The catalytic metal-containing silicon oligomer is a condensation reaction of one or two of the alkoxy group of the tetraalkoxysilane and the hydroxy group at the n, n + 1 or n, n + 2 position present in the polyhydric alcohol. It has the following partial structures (a) to (d). Further, in the catalyst-containing silicon oligomer, it is presumed that the catalyst metal exists between oxygen atoms and forms a 5-membered ring structure or a 6-membered ring structure having the catalyst metal at the apex and is stabilized. Therefore, no precipitation of the catalytic metal is observed even one year after the formation of the catalytic metal-containing silicon oligomer of the present invention.

The catalytic metal silicon oligomer can be identified by a known method such as NMR, IR, MASS, etc. such as 1HNMR and 29SiNMR. Specifically, in the case of NMR, the present invention is obtained by confirming the alcohol produced by the condensation reaction of tetraalkoxysilane and polyhydric alcohol by 1HNMR, and further confirming the number of silicon in the catalytic metal silicon oligomer by 29SiNMR. Catalytic metal silicon oligomers can be identified. Further, the fact that the catalyst metal is incorporated into the silicon oligomer can be confirmed by the fact that no precipitation of the catalyst metal is observed after a lapse of a certain period of time, for example, one year after the formation of the silicon oligomer.

The catalyst-containing metal silicon oligomer was prepared by using two or more types of catalyst-containing metal silicon oligomers having different catalyst metals in combination, or in the presence of two or more types of catalyst metals when preparing the catalyst-containing metal silicon oligomer. It is preferable to use one because the catalytic action of the catalytic metal is enhanced. The combination of the catalyst metal is not particularly limited, but for example, a combination of palladium and one or more selected from iron, nickel, cobalt, and copper is preferable.

<Other ingredients>
(Resin components other than acrylic resin)
The coating composition for imparting plating adhesion may contain a resin component other than the acrylic resin. Such a resin component is not particularly limited as long as it is soluble or dispersed in the coating composition for imparting plating adhesion, and examples thereof include urethane-based resins, phenol-based resins, and epoxy-based resins.

(Ingredients other than resin components)
The plating adhesion-imparting coating composition may contain a known and commonly used solvent, a colorant, a friction coefficient adjusting agent, a film-thinning agent, and other additives that impart functionality, as long as the effects of the present invention are not impaired. Can be done.
For example, examples of the solvent include water, isopropyl alcohol, ethyl cellosolve and the like.

<< Content >>
The blending amount of the acrylic resin and the catalyst-containing metal silicon oligomer in the coating composition for imparting plating adhesion is not particularly limited. Generally, in the plating adhesion-imparting coating composition, the concentration of the metal catalyst derived from the catalyst-containing metal silicon oligomer is in the range of 50 to 200 ppm, and the acrylic resin and the resin component other than the acrylic resin adhere to the plating. It is blended in the range of 50% by mass or less, preferably 0.1 to 50% by mass, and more preferably 1 to 20% by mass in the sex-imparting coating composition.

<<< Dry film >>>
The dry film of the present invention is obtained by forming a resin layer having a two-layer structure composed of a layer of a curable resin composition and a layer of a coating composition for imparting plating adhesion on a film base material.

<< Dry film manufacturing method >>
In the dry film of the present invention, the first layer (layer made of a thermosetting resin composition) described above is first formed on a film substrate, and then a second layer (adhesion) is formed on the surface of the first layer. It may be produced by forming a layer composed of a sex-imparting coating composition), or may be produced by forming a first layer on the surface of the second layer after forming the second layer. Then, the first layer and the second layer may be formed separately, and both may be bonded together.

Specifically, when a dry film is produced by forming a first layer on a film substrate and then forming a second layer on the surface of the first layer, heat is first applied on the film substrate. The first layer is formed by applying the curable resin composition to form a film. In this film formation, the thermosetting resin composition is reduced in viscosity by heating and applied onto the film substrate, or diluted with a solvent in advance and applied onto the film substrate, and then the solvent is removed by heating. Can be done by
Next, a second layer can be formed by applying a plating adhesion-imparting coating composition to the surface of the first layer formed on the film substrate to form a film, and a dry film can be produced. .. For this film formation, the same method as described above can be adopted.

Further, as described above, when the second layer is formed on the film base material and then the first layer is formed on the surface of the second layer to produce a dry film, the dry film is formed on the film base material. A second layer can be formed on the surface of the film, and then a thermosetting resin composition can be applied to the surface of the second layer to form the first layer to produce a dry film.
Further, when the first layer and the second layer are formed separately and the two layers are bonded together to produce a dry film, the adhesion-imparting coating composition and the first layer constituting the second layer are formed. The thermosetting resin composition constituting the above can be separately applied onto a film substrate to form a film, and the two can be bonded together to produce a dry film.

Here, as a coating method, a conventionally known method can be applied, and a flat plate press method, a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer coater, a gravure coater, and a spray coater. , A known means such as a dip coater can be adopted. After application, it is dried at a temperature of 25 to 130 ° C. for 1 to 30 minutes. This drying can be performed using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, or the like.

Examples of the film base material include polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonate, polyimide, and metal foils such as release paper, copper foil, and aluminum foil. The film base material may be subjected to a mold release treatment in addition to the mud treatment and the corona treatment.

In the dry film of the present invention produced in this manner, the thickness of the first layer is preferably thicker than the thickness of the conductor circuit on the base material with which the first layer is in contact as an insulating material. For example, since the thickness of the conductor circuit of the printed wiring board is about 5 to 100 μm, the thickness of the first layer is preferably 10 to 120 μm. The thickness of the second layer is not particularly limited, but is 0.01 to 5 μm, preferably 0.5 to 1 μm as a practical range.

In the dry film of the present invention, the film base material may be peeled off after forming the first layer and the second layer, but handling can be improved by leaving the film base material as it is as a support (support film). .. Further, another film base material may be attached as a protective material (protective film) to the surface of the resin layer having a two-layer structure composed of the first layer and the second layer without the film base material, and dents may be formed. It is possible to suppress problems such as adhesion of foreign matter and foreign matter. As such a protective material (protective film), the same material as the above-mentioned film base material can be used, and the protective material is bonded with a roll laminator or the like.

The dry film of the present invention is laminated on a substrate such as a printed wiring board so that a first layer (a layer made of a thermosetting composition) is in contact with the substrate.
Here, the laminating uses a roll laminator, a batch type vacuum laminator, a vacuum press device, or the like, and the conditions under which the first layer flows, for example, a temperature of 30 to 130 ° C., a pressure of 1.5 MPa or less, and a time of 180 seconds or less. implement.

<<< Cured product >>
The cured product of the present invention can be obtained by heating a resin layer laminated using the above-mentioned dry film of the present invention and performing a curing reaction.
Here, the curing method is not particularly limited, and for example, heating may be performed by an inert gas oven, a hot plate, a vacuum oven, a vacuum press, or the like. The heating temperature and time may be appropriately changed according to the reactivity of the thermosetting component, for example, 100 to 200 ° C. for 30 to 120 minutes.

<<< Electronic components >>
The electronic component of the present invention has the above-mentioned cured product. More specifically, a cured product (layer) in which the first layer and the second layer of the dry film of the present invention are laminated in this order on a circuit-formed base material such as a printed wiring board, and the second layer. It has a conductor layer (plating layer) formed by plating on the layer. Therefore, the dry film in which the above-mentioned first layer and the second layer are separately formed can be laminated on the base material in the order of the first layer and the second layer and cured.

As a method for manufacturing the electronic component of the present invention, for example, the cured product (layer) obtained by the above-mentioned dry film laminating method and curing method is _{perforated by a laser such as a CO 2} laser or a UV-YAG laser or a drill. (Hole) can be formed. The holes are through-holes for conducting the front and back of the substrate, and bottomed holes for conducting the circuit on the base material and the circuit on the second layer. Either (beer hall) may be used.

After forming the holes (holes), if necessary, remove the residue (smear) generated by processing by desmear liquid or plasma treatment. Normally, the surface of the second layer may also be roughened by removing smear, but considering the application to high-frequency communication (for example, 5G communication, etc.), the arithmetic average surface roughness Ra (JIS B 0601) is usually used. (Compliant) is required to be 200 nm or less.

Next, the surface of the cured product (layer) can be irradiated with ultraviolet rays having an irradiation ^{intensity of at least 10 mW / cm 2.} As a result, the adhesion between the surface of the cured product (layer) and the plating layer is further improved. At this time, the main wavelength of ultraviolet rays is about 310 nm or less, preferably about 260 nm or less, and more preferably about 150 to 200 nm. In particular, it is preferable that the wavelength of ultraviolet rays is composed of two types, about 184 nm and about 254 nm.

As the ultraviolet light source, a low-pressure mercury lamp, an excimer laser, a barrier discharge lamp, a dielectric barrier discharge lamp, a microwave electrodeless discharge lamp, a transient discharge lamp, or the like can be used. For example, when a low pressure mercury lamp is used, a main wavelength of 184.9 nm and 253.7 nm is particularly effective. When an excimer lamp is used, specifically, Ar2 * (126 nm), Kr2 * (146 nm), F2 * (153 nm), ArBr * (165 nm), Xe2 * (172 nm), Arcl * (175 nm), ArF (193nm), KrBr * (207nm), KrCl * (222nm), KrF (248nm), Xel * (253nm), Cl2 * (259nm), XeBr * (283nm), Br2 * (289nm), XeCl * (308nm) ) Wavelength light is desirable. In particular, Xe2 * and KrCl * are stable, have a relatively small wavelength, and have a large energy, so that the surface modification effect is large and preferable.

The irradiation time of ultraviolet rays varies depending on the resin material used and the intensity of ultraviolet rays (irradiation amount), but is appropriately adjusted in the range of about 10 seconds to 30 minutes ^{(when the intensity of ultraviolet rays is about 5 to 20 mW / cm 2).} It can be done, and it is more preferably about 20 seconds to 10 minutes.

It should be noted that the irradiation of ultraviolet rays may be performed a plurality of times before the electroless plating treatment is performed.

Next, a plating layer is formed on the surface of the cured product (layer). The plating metal is not particularly limited to copper, scraps, solder, nickel, etc., and a plurality of plated metals can be used in combination.

In circuit formation by copper plating used for general electronic parts, electrolytic copper plating is applied to a thickness of about 0.1 to 2.0 μm as a feeding layer for electrolytic copper plating, and then electrolytic copper plating is applied. It is applied to form a conductor layer (copper layer) having a predetermined thickness. For the formation of the circuit pattern of the conductor layer, a known method such as a subtractive method or a semi-additive method can be used. It should be noted that copper plating has a drawback that the adhesion to the resin is lower than that of nickel plating or the like. However, when copper plating is applied to the surface of the insulating layer formed according to the present invention to form a conductor layer, Excellent adhesion strength can be obtained.

The electroless plating and electrolytic plating applied to the surface of the cured product may be any known method and are not limited to a specific method, but the catalyst of the electroless plating treatment step is composed of a palladium-tin mixed catalyst. The primary particle size of the catalyst is preferably 10 nm or less. Further, it is preferable that the plating composition of the electroless plating treatment step contains hypophosphorous acid as a reducing agent.

For electroless plating, for example, the methods described in JP-A-8-253869, JP-A-2002-57456, JP-A-2000-212762 and the like can be applied.

Further, a desired multilayer printed wiring board can be manufactured by repeating the formation of the insulating layer and the plating adhesion layer by the dry film of the present invention and the formation of the conductor circuit layer a plurality of times as necessary.

As an electronic component, a semiconductor element or the like can be further mounted. The electronic components obtained by the present invention have little transmission loss of high-frequency electric signals, and can be used for large-capacity high-speed communication represented by 5th generation communication systems (5G), millimeter-wave radars for automobile ADAS (advanced driver assistance systems), and the like. It can be preferably used.

Hereinafter, the present invention will be described in more detail with reference to examples. The blending amount in the table indicates the mass part as a non-volatile component.

The following were used as raw materials for the curable resin composition.

<< Raw materials >>
<Resin component>
・ Epoxy resin (A)
jER828 (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin)
NC-3000H (manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type epoxy resin)
・ Phenol resin (B)
LA-3018-50P (manufactured by DIC Corporation, aminotriazine-containing phenol novolac resin, methyl ethyl ketone solution, 50% by mass of non-volatile components, the description in Table 1 excludes volatile components)
HF-4M (manufactured by Meiwa Kasei Co., Ltd., phenol novolac resin)
-Active ester (C)
HPC-8000-65T (manufactured by DIC Corporation, toluene solution, 65% by mass of non-volatile component, description in Table 1 excludes volatile component)
<Ingredients other than resin>
-Inorganic filler Admafine SC2050 (Admatex Co., Ltd.) Spherical silica (average particle size 0.5 μm)
・ Curing accelerator Curesol 2E4MZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.)
・ Additive KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.)

<< Preparation of curable resin composition >>
The above-mentioned raw materials were blended in the blending amounts shown in Table 1, and after stirring, they were uniformly dispersed by a three-roll mill to prepare a curable resin composition according to each Example and each Comparative Example.

<< Preparation of coating composition for imparting plating adhesion >>
A commercially available SIPAC300 manufactured by JCU was prepared.

<< Preparation of sample (board) >>
Next, using each curable resin composition, a sample (substrate) for evaluation was produced according to the following procedure.

<< Preparation of dry film >>
First, each curable resin composition is sufficiently stirred and defoamed using a rotation / revolution mixer, then applied on a PET film with an applicator so that the dried film thickness is 40 μm, and the temperature is 90 ° C. in a drying furnace. It was dried for 10 minutes to prepare a dry film provided with a layer (insulating layer) made of each curable resin composition.
Next, a dry film provided with an insulating layer on the PET film was dip-coated on an adhesion-imparting coating composition (SIPAC300), and dried in a drying furnace at 30 ° C. for 3 minutes while suspended vertically to 0.6 μm. By forming the plating adhesion layer, a dry film in which the PET film, the insulating layer, the plating adhesion layer, and the PET film were laminated in this order was produced.

Next, the PET film in contact with the insulating layer of the produced dry film was peeled off, installed so that the insulating layer was in contact with the copper-clad laminate, and the temperature was adjusted using a vacuum laminator (MVLP-500 manufactured by Meiki Seisakusho Co., Ltd.). Lamination was performed at 100 ° C., a pressure of 0.5 MPa, and a pressurization time of 30 seconds. Then, the PET film on the plating adhesion layer side was peeled off, heated in a drying furnace at 90 ° C. for 30 minutes, and further heated at 170 ° C. for 30 minutes to prepare substrates for each plating.

Table 1 shows the surface average roughness Ra of each plating substrate. The surface average roughness Ra was measured according to the following method.
(Measuring method)
Measuring equipment: White interference microscope (Bruker Contour GT-I)
Measurement conditions: VSI mode, 50x lens, measurement range 174.6 × 130.9 μm, the average value of 5 measurement points was used as the measurement value.

Next, each of the prepared substrates for plating was subjected to electroless plating treatment and electrolytic plating treatment to form a conductor layer. Specifically, as an electroless plating treatment, it is immersed in a cleaner treatment liquid (manufactured by JCU, ES-100) at 50 ° C. for 3 minutes, and immersed in a catalyst-imparting treatment liquid (manufactured by JCU, ES-100) at 50 ° C. for 2 minutes. A power feeding layer was formed by immersing in a reduction treatment liquid (manufactured by JCU, ES-400) at 35 ° C. for 5 minutes and immersing in an electroless plating treatment liquid (manufactured by JCU, PB-507F) at 35 ° C. for 15 minutes. Immerse in a 5% aqueous sulfuric acid solution at room temperature for 10 seconds, form an electrolytic plating layer with a copper sulfate plating solution (CU-BRITE21 manufactured by JCU) at a room temperature of 45 minutes and a current density of 3 A / dm ^2. A sample (substrate) in which the insulating layer, the plating adhesion layer, and the plating layer were laminated in this order was prepared.

<< Evaluation >>
<Peel strength (P / S) test: Plating adhesion evaluation>
The peel strength was evaluated for each sample. Peel strength was carried out as follows. First, a notch having a width of 10 mm and a length of 60 mm was made in the copper plating layer of each sample. Peel off one end and pinch the peeled part with a gripper, and use a desktop tensile tester (EZ-SX manufactured by Shimadzu Corporation) to make the copper plating layer 35 mm long at a 90 degree angle and a speed of 50 mm / min. The copper was peeled off and the peel strength (N / cm) was measured.

As shown in the above results, a two-layer structure having a layer made of a curable resin composition containing an epoxy resin and an active ester compound and a layer made of a composition for forming a plating layer containing an acrylic resin and a catalyst-containing metal silicon oligomer. It was confirmed that by using the dry film of No. 1, it is possible to form an insulating layer having good adhesion to the conductor layer even if the surface roughness is small (even if Ra is 200 nm or less).

Claims (3)

Two layers on the film substrate, consisting of a layer of a curable resin composition containing an epoxy resin and an active ester compound, and a layer of a coating composition for imparting plating adhesion containing an acrylic resin and a catalyst-containing metal silicon oligomer. A dry film having a resin layer with a structure
The catalyst-containing metal silicon oligomer is obtained by subjecting tetraalkoxysilane and a polyhydric alcohol in which a hydroxy group is bonded to at least the n, n + 1 position or the n, n + 2 position (where n is an integer of 1 or more) to electroless plating. A dry film characterized by being a catalytic metal silicon oligomer obtained by conducting a condensation reaction in the presence of a catalytic metal. A cured product obtained by curing the resin layer constituting the dry film according to claim 1. An electronic component having an insulating layer made of the cured product according to claim 2.