JP2571800B2 - Photosensitive adhesive for electroless plating and printed wiring board - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photosensitive resin composition and a printed wiring board using the photosensitive adhesive for electroless plating, and more particularly, to electroless plating of a multilayer printed wiring board. The present invention proposes a photosensitive resin composition used for forming an adhesive layer for use in a multilayer printed wiring board having an adhesive layer for electroless plating formed using the photosensitive adhesive for electroless plating.

(Prior Art) In recent years, multilayer printed wiring boards in which wiring circuits are formed in multiple layers have come into the spotlight in response to higher density and higher speed operation of the printed wiring boards.

Conventionally, as such a multilayer printed wiring board, a plurality of circuit boards on which an inner layer circuit is formed are laminated and pressed using a prepreg as an insulating layer and bonded, and then the respective inner layer circuits are connected by through holes to conduct. Things were typical.

However, in such a multilayer printed wiring board, a plurality of inner-layer circuits are connected and conducted through through-holes, so that the wiring circuit becomes too complicated to achieve high density. There was a problem that it is.

As a multilayer printed wiring board capable of solving such problems, a multilayer printed wiring board in which conductive circuits and organic insulating layers are alternately built up has recently been developed. Certainly, this multilayer printed wiring board is suitable for ultra-high density. However, there is a drawback that it is actually difficult to form a plating film on the organic insulating layer with high reliability. Therefore, in such a multilayer printed wiring board, a conductor circuit is formed by a PVD method or a PD method.
It was formed by a combined method of VD and electroless plating. However, such a conductor circuit forming method by the PVD method is
There is a disadvantage that the productivity is low and the cost is high.

For this reason, development of a photosensitive resin composition capable of solving the above-mentioned disadvantages and forming an organic insulating layer capable of firmly adhering a plating film has been desired.

On the other hand, as the photosensitive resin composition used for the organic insulating layer of the printed wiring board as described above, conventionally, (1) a photosensitive resin composition containing an acrylic polymer and a photopolymerizable monomer as main components; There has been a photosensitive resin composition containing an epoxy resin to which a photoreactive group is added as a main component.

However, the resin composition of (1) can be developed with a flame-retardant developer (for example, 1,1,1-trichloroethane or the like) and can form a highly accurate solder mask.
The heat resistance of the cured film is not sufficient because it contains a large amount of acrylic polymer.

Since the resin composition of the above (2) is based on a novolak type epoxy resin, the cured film has sufficient heat resistance, but has a problem that the molecular weight distribution of the resin is large and sufficient resolution cannot be obtained. .

(Problems to be Solved by the Invention) An object of the present invention is to advantageously solve the above-mentioned unsolved problems, and in particular, has excellent resolution, heat resistance, and electrical insulation, and has a strong plating film. An object of the present invention is to provide a photosensitive adhesive for electroless plating that can form an organic insulating layer that can be adhered to.

Another object of the present invention is to provide a printed wiring board having an adhesive layer for electroless plating which has excellent heat resistance and electrical insulation and can firmly adhere a plating film.

(Means for Solving the Problems) The inventors of the present invention have conducted intensive studies for solving the above-mentioned problems, and as a result, based on an epoxy resin having excellent heat resistance and electric insulation and an extremely small molecular weight distribution. The above problem has been solved by constructing a conductive resin composition and by adding resin fine particles that can be dissolved and removed by a chemical conversion treatment to the photosensitive adhesive for electroless plating.

That is, the present invention relates to (a) one or more compounds having a molecular weight of 462 to 635 selected from the compounds represented by the following formula 1 (m is an integer of 1 to 3, n is 3 or 4): A photopolymerizable compound obtained by (meth) acrylic modification of at least one of epoxy groups contained in the compound;
(B) a polymerizable compound having at least two terminal ethylene groups, (c) an initiator and a sensitizer which generate radicals by actinic rays, (d) an epoxy curing agent, and (e) a fine particle filling which is insoluble in chemical conversion treatment. A photosensitive adhesive for electroless plating, comprising: an agent; and (f) a resin fine particle filler that can be dissolved and removed by a chemical conversion treatment.

The photosensitive adhesive for electroless plating of the present invention comprises, as an essential component, one or two compounds having a molecular weight of 462 to 635 selected from the compounds represented by Formula 1 (m is an integer of 1 to 3, n is 3 or 4).
At least one of the epoxy groups contained in the compound is a (meth) acryl-modified photopolymerizable compound (hereinafter referred to as an essential component (a)).

The epoxy resin used for the essential component (a) is a heat-resistant polyfunctional epoxy resin represented by the general formula of Formula 1. Such resins are commercially available, and examples thereof include Epicoat 1031S manufactured by Yuka Shell, YL-931 manufactured by Yuka Shell, and YL-933 manufactured by Yuka Shell. These resins are
The molecular weight calculated from the number m and n of carbon atoms in Formula 1 is 462 to 635, and has a feature that the molecular weight distribution is extremely small as compared with a novolak-type epoxy resin whose molecular weight distribution does not become small due to synthesis.

By the way, such a resin having a small molecular weight distribution can be obtained by purifying a resin having a large molecular weight distribution, but the purification cost is extremely high and is not practical. Further, as such a resin having a small molecular weight distribution, for example, glycidylamine type epoxy resin, bisphenol A type epoxy resin, and the like are commercially available, and when these resins are examined, heat resistance and electric properties when wet are obtained. It turned out that there was a problem and it could not be used.

The present inventors have further studied various resins, and as a result, have found a group of heat-resistant polyfunctional epoxy resins represented by Formula 1 as resins capable of overcoming the above-mentioned problems.

The essential component (a) can be obtained by subjecting such a heat-resistant polyfunctional epoxy resin to (meth) acrylic modification using an acrylic acid or a methacrylic acid by an ordinary method.

As the acrylic acid or methacrylic acid used here, known ones can be used, but it is preferable to use acrylic acid from the viewpoint of sensitivity and resolution. In the present invention, the degree of (meth) acrylic modification is desirably 20 to 90%, and more desirably 30 to 80%. (Meta)
If the degree of acrylic modification is less than 20%, the photocured film is easily swelled and peeled off by development after image exposure, while
If it exceeds 90%, heat resistance and adhesion will be reduced.

The photosensitive adhesive for electroless plating of the present invention contains, as an essential component, a polymerizable compound having at least two terminal ethylene groups (hereinafter, referred to as an essential component (b)).

The essential component (b) includes, for example, dipentaerythritol hexaacrylate, 1,6-hexanediol diacrylate, tris (2-acryloxyethyl) isocyanurate, neopentyl glycol diacrylate,
Diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, bentaerythritol tetramethacrylate, diallyl terephthalate, N, N
-Methylenebisacrylamide and the like can be used.

The amount of the essential component (b) is 1 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the photopolymerizable compound of the essential component (a). The reason for this is that if the amount of the essential component (b) is less than 1 part by weight based on 100 parts by weight of the photopolymerizable compound, the heat resistance of the cured film decreases, and if it exceeds 30 parts by weight, the thermal shock resistance deteriorates. Because.

The photosensitive adhesive for electroless plating of the present invention contains, as essential components, an initiator that generates radicals by actinic rays and a sensitizer (hereinafter, referred to as an essential component (c)).

Here, as the initiator, for example, benzophenone,
1-hydroxycyclohexylphenyl ketone, benzyl dialkyl ketal, 2-hydroxy-2-methylpropiophenone, Michler's ketone, benzoin ethyl ether, 2,4-dialkylthioxanthone, 2-methyl-1 [4- (methylthio) phenyl] -2 A photoinitiator such as morpholinopropanone can be used.

It is desirable to use such photopolymerization initiators in combination with sensitizers having different absorption wavelengths of active light. Thereby, the polymerization initiation efficiency can be improved and the sensitivity can be further increased. Examples of the sensitizer include benzophenone and triethanolamine, 2-methyl-1
Examples include [4- (methylthio) phenyl] -2-morpholinopropanone and thioxanthone, and a combination of benzyldialkyl ketal and Michler's ketone.

The amount of the essential component (c) is 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the photopolymerizable compound of the essential component (a).

The photosensitive adhesive for electroless plating of the present invention comprises, as an essential component, an epoxy curing agent (hereinafter referred to as an essential component (d)).
Is contained in an amount of 1 to 10 parts by weight.

Examples of the essential component (d) include imidazoles such as 1-methylimidazole, 1-phenylimidazole, 1-benzyl-2-methylimidazole,
Bis (hydrazinocarboethyl) -5-isopropylhydantoin, boron trifluoride monoethylamine, adibic acid, dihydrazide, dicyandiamide and the like can be mentioned. In particular, use of imidazole or dicyandiamide is preferred from the viewpoint of electrical characteristics.

The photosensitive adhesive for electroless plating of the present invention contains, as an essential component, a fine particle filler that is insoluble in chemical conversion treatment (hereinafter, referred to as an essential component (e)). The reason why the essential component (e) is a fine particle filler that does not dissolve in the chemical conversion treatment is that if the filler is soluble in the chemical treatment, the dissolved residue contains an ionic substance when the filler is inorganic. Therefore, the electrical insulation is deteriorated. As a result, problems such as a decrease in insulation resistance between circuits are caused.

As the essential component (e), any fine particle filler having a property of being insoluble in a specific chemical solution such as chromic acid used for the chemical conversion treatment may be used. For example, silica, alumina, talc,
Antimony trioxide, antimony pentoxide, aluminum hydroxide, or the like can be used as appropriate.

The average particle size of the fine particle filler as the essential component (e) is preferably from the viewpoint of resolution, adhesion of an oxide film, and the like.
It is 0.01 to 15 μm, more preferably 0.01 to 2.5 μm.

The amount of the essential component (e) is preferably 10 to 60 parts by weight based on 100 parts by weight of the photopolymerizable compound of the essential component (a).

It is desirable that the essential component (e) is uniformly dispersed in the photosensitive adhesive for electroless plating. Therefore, the surface of the fine particle filler is coated with a cup having a functional group such as an amino group or a hydroxyl group. It can also be treated with a ring agent. Examples of the coupling agent include γ-aminopropyltriethoxysilane, β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like.

The photosensitive adhesive for electroless plating of the present invention contains, as an essential component, a resin fine particle filler that can be dissolved and removed by a chemical conversion treatment (hereinafter, referred to as an essential component (f)).

As the essential component (f), it is particularly desirable to use heat-resistant resin fine particles. When the heat-resistant resin fine particles are used, heat-resistant resin fine particles that have been previously cured are used. The reason for using heat-cured resin fine particles that have been pre-cured is that if heat-resistant resin fine particles that have not been pre-cured are used, they will dissolve in the resin liquid when dispersed in the photosensitive adhesive for electroless plating. Therefore, the chemical conversion treatment makes it impossible to selectively dissolve and remove. In that respect, if heat-resistant resin fine particles that have been previously cured are used, they will not dissolve in the resin solution even when dispersed in the photosensitive adhesive for electroless plating, and the insulating layer in which the heat-resistant resin fine particles are uniformly dispersed. Is formed. As a result, if a chemical conversion treatment is performed on such an insulating layer to dissolve and remove the heat-resistant resin fine particles, the surface of the insulating layer can be uniformly roughened,
The plating film can be reliably formed on the insulating layer.

The material of the essential component (f) has excellent heat resistance and electrical properties,
A resin that does not dissolve even when dispersed in a photosensitive adhesive for electroless plating by a curing treatment and has a property of dissolving in a specific chemical solution used for a chemical conversion treatment may be used, for example, an epoxy resin, a polyester resin, and a screw. Maleimide-triazine resin and the like can be mentioned. Examples of the curing method include a method of curing by heating and a method of curing by adding a catalyst. Further, as a specific chemical used for the chemical conversion treatment, for example, an oxidizing agent such as chromate, chromate, permanganate, or the like, hydrofluoric acid, hydrochloric acid, or the like can be used.

The average particle size of the heat-resistant resin fine particles as the essential component (f) is preferably 15 μm or less, more preferably 5 μm or less. The reason is that the roughened surface formed by dissolving and removing the fine particles having a particle size of more than 15 μm becomes non-uniform, which makes it impossible to form a plated film with high reliability.

The compounding amount of the essential component (f) is 10 to 60 parts by weight based on 100 parts by weight of the photopolymerizable compound of the essential component (a).

Further, the photosensitive adhesive for electroless plating of the present invention may contain other secondary components. Examples of the secondary component include a thermal polymerization inhibitor, a pigment, a color former, a coating improver, an antifoaming agent, an adhesion improver, and a leveling agent.

The photosensitive resin agent for electroless plating of the present invention can be applied to a substrate by a conventional method such as a dip coating method, a flow coating method, and a screen printing method. Upon application, the composition may be diluted with a solvent if necessary. Examples of the solvent include butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, methyl ethyl ketone, cyclohexanone, and the like.

The printed wiring board of the present invention is a printed wiring board formed by forming a conductive circuit layer made of electroless plating on a substrate via an adhesive layer for electroless plating. The agent layer is formed by the above-described photosensitive adhesive for electroless plating according to the present invention. That is, each of the electroless plating adhesive layers is coated with the photosensitive adhesive for electroless plating according to the present invention on the substrate,
After being exposed, developed and cured, the surface is roughened by a chemical conversion treatment.

(Effect of the Invention) The photosensitive adhesive for electroless plating of the present invention has a molecular weight distribution of a photopolymerizable compound constituting a main part which is extremely small as compared with the conventional photosensitive adhesive for electroless plating, and is excellent in developability. There is a feature in the point. Therefore, when a film is formed on a desired portion by a photographic method, the film can be formed with high precision. Further, since the composition contains a polymerizable compound having two or more functionalities, the crosslink density at the time of curing as a film increases,
The heat resistance and chemical resistance of the cured film can be improved.
Furthermore, the contained fine particle filler suppresses thermal expansion, and makes the adhesion between the formed film and the underlying conductor excellent. Further, since a resin fine particle filler which can be dissolved and removed by a chemical conversion treatment is included, when the coating after curing is subjected to the chemical conversion treatment, minute irregularities are formed on the surface of the cured film, and the irregular surface acts as an anchor, and the above problem is caused. The adhesion strength between the insulating layer pointed out and the plating film formed thereon can be significantly improved. The effect of the photosensitive adhesive for electroless plating according to the present invention is presumed to occur for the reasons described above.

In the printed wiring board according to the present invention, since the adhesive layer for electroless plating is formed by the above-described photosensitive adhesive for electroless plating according to the present invention, the adhesive layer for electroless plating has heat resistance. And excellent electrical insulation,
The adhesive layer for electroless plating can firmly adhere to the plating film, which is a conductor circuit, and this printed wiring board has excellent heat resistance as a whole and high reliability of electrical connection etc. is there.

(Examples) Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. In addition,
Parts used as numerical units in the examples mean parts by weight.

Example 1 (1) 100 parts of a 50% acrylate of a polyfunctional epoxy resin (manufactured by Yuka Shell, trade name: Epicoat 1031S), 15 parts of diallyl terephthalate, 2-methyl-1- [4- (methylthio) phenyl]- 4 parts of 2-morpholinopropanone-1 (manufactured by Ciba Geigy, trade name: Irgacure 907), 4 parts of imidazole (manufactured by Shikoku Chemicals, trade name: 2P4MHZ), silica fine powder (manufactured by Nippon Shokubai Chemical Industry, trade name: NS silica) X-0
5, 25 parts of an average particle size of 0.5 μm), 25 parts of epoxy resin fine powder (trade name: Trepal EP-B, manufactured by Toray, average particle size of 0.5 μm)
After mixing the parts, while adding butyl cellosolve,
Adjust the viscosity to 250 cps with a homodisper stirrer.
The mixture was kneaded with this roll to prepare a solution of a photosensitive adhesive for electroless plating.

(2) Next, a solution of the photosensitive adhesive for electroless plating is applied using a knife coater on a printed wiring board obtained by photoetching the surface of a copper-clad laminate by a conventional method, and is horizontally placed. After leaving it to stand for 20 minutes, it was touch dried at 70 ° C. to form a photosensitive adhesive layer having a thickness of about 50 μm.

(3) Next, a photomask film on which a black circle of 100 μmφ was formed was brought into close contact with the film, and 800 mj / cm was applied with an ultra-high pressure mercury lamp.
^Two exposures were made. This was subjected to ultrasonic development treatment with a mixed solution of chlorocene / butyl cellosolve in the same amount to form a via hole of 100 μmφ on the printed wiring board. Next, this wiring board is exposed to about 3000 mj / cm ² with an ultra-high pressure mercury lamp,
Further, by performing a heat treatment at 100 ° C. for 1 hour and then at 150 ° C. for 10 hours, an adhesive layer for electroless plating having excellent dimensional accuracy and corresponding to a photomask film was obtained.

The obtained coating is made of silica fine particles insoluble in chromic acid,
Because it contains soluble epoxy resin fine particles, the surface of the coating is treated with chromic acid to form a rough surface with a very complicated shape. When a conductor is formed on the coating, it exhibits high adhesion. .

For example, when the adhesive layer for electroless plating is
The resultant is roughened with chromic acid having a concentration of 500 g / l for 15 minutes, immersed in a neutralizing solution (trade name: PM950, manufactured by Shipley) and washed with water. Then
As a pretreatment for chemical plating, a palladium catalyst (manufactured by Shipley Co., trade name: Cataposit 44) was applied to activate the surface, and immersed in chemical copper plating of the following composition for 15 minutes,
20μ in via hole with electrolytic copper plating solution of the following composition
When copper of m is deposited, the peel strength under normal condition is 1.80kg
/ cm.

In addition, the obtained coating contains inorganic silica fine particles, so that the coating has a high hot hardness and suppresses thermal expansion, and thus has a characteristic of being particularly excellent in thermal shock resistance.

For example, as a result of subjecting the copper-plated adhesive layer for electroless plating to a thermal shock test in accordance with MIL-STD-202 Method 107 Condition B, no breakage occurs even after 500 cycles, so long-term reliable It became clear that it was also excellent.

Furthermore, the diallyl terephthalate contained in the resin solution increases the crosslink density at the time of curing, so that the cured film exhibits excellent heat resistance. This can be seen from the fact that the soldering heat test was performed at 260 ° C. for 30 seconds, but no peeling or discoloration of the insulating film was observed.

(Chemical plating solution composition)

Shipley Co. 328A 12.5% produced by Shipley Company 328L 12.5% produced by Shipley Company 328C 1.5% Pure water 73.5% Temperature 25 ° C. [copper plating solution composition] _{CuSO 4 -5H 2 O 150g / H} 2 SO 4 40g / Cl - 20ppm added Agent Predetermined amount Temperature 25 ° C Cathode current density 2 A / dm ² Example 2 (1) 100 parts of epoxy resin (manufactured by Yuka Shell, trade name: Epicoat 1001) was added to 100 parts of epoxy curing agent (manufactured by Shikoku Chemicals, trade name:
The resin to which 5 parts of (2PZ) was added was dried and cured in a hot air dryer at 100 ° C. for 1 hour and subsequently at 150 ° C. for about 10 hours.
This cured epoxy resin is roughly pulverized, then finely pulverized using a supersonic jet pulverizer while being frozen with liquid nitrogen, and further classified using an air classifier to have an average particle size of 1.6.
A μm epoxy resin fine powder was prepared.

(2) 100 parts of 75% acrylate of polyfunctional epoxy resin (manufactured by Yuka Shell, trade name: Epicoat 1031S), 25 parts of dipentaerythritol hexaacrylate, benzyl alkyl ketal (manufactured by Ciba Geigy, trade name: Irgacure)
651) 5 parts, imidazole (Shikoku Chemicals, trade name: 2P4MH
Z) 3 parts, benzoguanamine fine powder (manufactured by Nippon Shokubai Chemical Co., Ltd., trade name: Eposter S-6, average particle size 0.5 μm) 15
Part, and the epoxy resin fine powder 35 prepared in the above (1).
After mixing the parts, the viscosity was adjusted to 250 cps with a homodisper stirrer while adding butyl cellosolve, and then kneaded with three rolls to prepare a solution of a photosensitive adhesive for electroless plating.

(3) Next, a solution of the photosensitive adhesive for electroless plating is applied using a knife coater onto a printed wiring board obtained by photoetching the surface of a copper-clad laminate by a conventional method, and is horizontally applied. After leaving it to stand for 20 minutes, it was touch dried at 70 ° C. to form a photosensitive adhesive layer having a thickness of about 50 μm.

(4) Next, a photomask film on which a black circle of 100 μmφ was formed was brought into close contact with this, and 800 mj / cm was applied with an ultra-high pressure mercury lamp.
^Two exposures were made. This was subjected to ultrasonic development treatment with a mixed solution of chlorocene / butyl cellosolve in the same amount to form a via hole of 100 μmφ on the printed wiring board. Next, this wiring board is exposed to about 3000 mj / cm ² with an ultra-high pressure mercury lamp,
Further, by performing a heat treatment at 100 ° C. for 1 hour and then at 150 ° C. for 10 hours, an adhesive layer for electroless plating having excellent dimensional accuracy and corresponding to a photomask film was obtained.

The resulting adhesive layer contains benzoguanamine resin fine powder insoluble in chromic acid and soluble epoxy resin fine powder,
Further, since the contained fine particles are resin powder, the fine particles have good dispersibility and do not settle to the lower part of the fine particles, so that a very complicated roughened surface can be obtained by treating the surface with chromic acid. . Therefore, when a conductor is formed on this adhesive layer, the insulating layer and the conductor are characterized by exhibiting extremely high adhesion.

For example, this adhesive layer for electroless plating is roughened with chromic acid according to the method of Example 1, a chemical copper plating is thinned, and 20 μm is formed in the via hole by electrolytic copper plating.
m, the peel strength under normal conditions is 2.3kg /
cm.

In addition, in a thermal shock test according to MIL-STD-202 Method 107 Condition B, no breakage occurred even after 500 cycles, and it was revealed that long-term reliability was excellent.

Furthermore, since dipentaerythritol hexaacrylate contained in the resin solution is hexafunctional, the crosslink density is increased during curing, and the cured film exhibits excellent heat resistance. This can be seen from the fact that the soldering heat test was performed at 260 ° C. for 30 seconds, but no peeling or discoloration of the insulating film was observed.

Example 3 (1) Polyfunctional epoxy resin (manufactured by Yuka Shell, trade name: YL)
-933), 50 parts of 50% acrylate, 15 parts of diallyl terephthalate, 4 parts of 2-hydroxy-2-methylpropiophenone (manufactured by Merck, trade name: Darocure 1173), 4 parts,
3-bis (hydrazinocarboethyl) -5-isopropylhydontoin (manufactured by Ajinomoto, trade name: Amicure VD)
H) 30 parts, talc fine powder (manufactured by Fuji Talc, product name: LN
25 parts of S # 200, average particle size of 1.5 μm, epoxy resin fine powder (manufactured by Toray, trade name: Trepal EP-B, average particle size of 0.5 μm)
m) After mixing 35 parts, while adding butyl cellosolve, the viscosity was adjusted to 250 cps with a homodisper stirrer, and then kneaded with three rolls to prepare a solution of a photosensitive adhesive for electroless plating.

(2) Next, a solution of the photosensitive adhesive for electroless plating is applied on a printed wiring board obtained by photo-etching the surface of a copper-clad laminate by a conventional method using a knife coater, and is subjected to a horizontal normal state. After leaving it to stand for 20 minutes, it was touch dried at 70 ° C. to form a photosensitive adhesive layer having a thickness of about 50 μm.

(3) Next, a photomask film on which a black circle of 100 μmφ was formed was brought into close contact with the film, and 800 mj / cm was applied with an ultra-high pressure mercury lamp.
^Two exposures were made. This was subjected to ultrasonic development treatment with a mixed solution of chlorocene / butyl cellosolve in the same amount to form a via hole of 100 μmφ on the printed wiring board. Next, this wiring board is exposed to about 3000 mj / cm ² with an ultra-high pressure mercury lamp,
Further, by performing a heat treatment at 100 ° C. for 1 hour and then at 150 ° C. for 1 hour, an adhesive layer for electroless plating having excellent dimensional accuracy and corresponding to a photomask film was obtained.

The obtained photosensitive adhesive layer has 1, as an epoxy curing agent.
Since 3-bis (hydrazinocarboethyl) -5-isopropylhydontoin was used, its curing speed was high, and one hour of final heating was sufficient. As a result, productivity was significantly improved.

In addition, since the obtained photosensitive resin layer uses YL-933 as a polyfunctional epoxy resin, it has high flexibility, and further includes talc fine powder having excellent heat resistance and impact resistance, so that it is cured. The coating was particularly excellent in thermal shock resistance.

For example, this adhesive layer for electroless plating is roughened with chromic acid according to the method of Example 1, a chemical copper plating is thinned, and 20 μm is formed in the via hole by electrolytic copper plating.
m of copper deposited, the normal peel strength is 2.2kg /
cm. Also, MIL-STD-202 Method 107 Conditi
In a thermal shock test according to on B, no peeling or cracking of the film was observed even after 1000 cycles, and it was revealed that the film had excellent long-term reliability.

Furthermore, since it contained diallyl phthalate, it had excellent heat resistance as shown in Example 1. For example, about 30 at 260 ° C
A solder heat resistance test was performed for 2 seconds, but no peeling or discoloration of the adhesive layer film was observed.

Comparative Example 1 (1) 63 parts of a copolymer of 93% of methyl methacrylate and 7% of methacrylic acid, 37 parts of 2,2-bis (4-dimethacryloxydithioxyphenyl) propane, 6 parts of benzophenone,
40 parts of methyl ethyl ketone were uniformly mixed to obtain a solution of the photosensitive resin composition.

(2) Next, a solution of the photosensitive resin composition is applied using a flow coater on a printed wiring board obtained by photo-etching the surface of a copper-clad laminate by a conventional method, and is horizontally held for 20 minutes. After standing, the mixture was dried by touch at 70 ° C. to form a photosensitive adhesive layer having a thickness of about 40 μm.

(3) Next, a photomask film on which a black line having a line width of 100 μm is formed is brought into close contact with this, and 800 mj /
cm ^{2 was} exposed. This was subjected to ultrasonic development treatment with a chlorocene solution to form a 100 μm pattern on the printed wiring board. Next, the wiring board was exposed to an ultra-high pressure mercury lamp for about 3000 mj / cm ² and then heated at 150 ° C. for 1 hour to obtain a film corresponding to a photomask film.

When this wiring board was immersed in a solder bath at 260 ° C., swelling occurred in 20 seconds.

Comparative Example 2 (1) 100 parts of 100% acrylate of cresol novolac type epoxy resin (manufactured by Asahi Kasei Corporation, trade name: ECN299), 2-
4 parts of methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone (Ciba Geigy, trade name: Irgacure 907), benzoguanamine resin fine powder (Nippon Shokubai Chemical Industry, trade name: Eposter S-6) After mixing 50 parts of butyl cellosolve with a homodisper stirrer, the viscosity was 200 cps.
And kneaded with three rolls to prepare a photosensitive adhesive solution for electroless plating.

Thereafter, the same processing as in Comparative Example 1 was performed, but a pattern of 100 μm could not be resolved.

(Effects of the Invention) As described above, when the photosensitive adhesive for electroless plating of the present invention is used as an adhesive layer for electroless plating of a printed wiring board, resolution, heat resistance and electrical insulation are improved. Excellent, and the plating film can be firmly adhered.

Therefore, according to the present invention, the adhesion between the conductor circuit formed of the plating film and the insulating layer is extremely excellent, and the heat resistance,
A printed wiring board having excellent thermal shock resistance and the like can be provided.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-40516 (JP, A) JP-A-55-79439 (JP, A) JP-A-55-127097 (JP, A) JP-A-62 265321 (JP, A) JP-A-58-174943 (JP, A)

Claims (2)

(57) [Claims] (A) one or more compounds having a molecular weight of 462 to 635 selected from the compounds represented by the following formula 1 (m is an integer of 1 to 3, n is 3 or 4); A photopolymerizable compound obtained by (meth) acrylic modification of at least one or more epoxy groups contained in the compound; (b) a polymerizable compound having at least two terminal ethylene groups; and (c) a radical by actinic rays. (D) an epoxy curing agent, (e) a fine particle filler that does not dissolve in the chemical conversion treatment, and (f) a resin fine particle filler that can be dissolved and removed by the chemical conversion treatment. A photosensitive adhesive for electroless plating. 2. A printed wiring board comprising a conductive circuit layer made of electroless plating formed on a substrate via an adhesive layer for electroless plating, wherein the adhesive layer for electroless plating comprises: a) 1 having a molecular weight of 462 to 635 selected from the compounds represented by the following formula 1 (m is an integer of 1 to 3, n is 3 or 4)
A kind or two or more kinds of photopolymerizable compounds obtained by (meth) acryl-modifying at least one or more epoxy groups contained in the compound; (B) a polymerizable compound having at least two terminal ethylene groups, (c) an initiator and a sensitizer that generate radicals by actinic rays, (d) an epoxy curing agent, and (e) a fine particle filling that is insoluble in a chemical conversion treatment. A photosensitive adhesive for electroless plating, comprising: (f) a resin fine particle filler that can be dissolved and removed by a chemical conversion treatment; and exposing, developing, and curing the photosensitive adhesive. A printed wiring board formed by roughening.