JPH0996901A - Photosensitive resin composition and printed circuit board using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the glass transition temp. of the insulating layer of a printed circuit board produced by a built-up method and to improve the peeling resistance of the plating layer by using a specified compd. as a curing agent. SOLUTION: In this photosensitive resin compsn. contg. epoxy acrylate resin, a photopolymerizable monomer, a photopolymn. initiator, a curing agent and a solvent, the curing agent contains 2,6-naphthalene-dicarboxylic acid dihydrazide(NDH) represented by the formula. Since this NDH is used, the glass transition temp. of an insulating layer formed from the photosensitive resin compsn. rises and the peeling resistance of a plating layer on the insulating layer is improved. Terminal active hydrogen of each molecule of the NDH reacts with the epoxy groups, etc., of the epoxy acrylate resin and the NDH is incorporated into the polymer matrix of the insulating layer. The NDH is crystal powder having a high m.p. of >=300 deg.C and the glass transition temp. of the insulating layer with the incorporated NDH rises.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive resin composition particularly suitable for forming an insulating layer of a printed wiring board by a build-up method, a curing agent for an epoxy resin used therein, and a printed wiring board using the same. Regarding

[0002]

2. Description of the Related Art As a main manufacturing method for a high-density printed wiring board such as a substrate for mounting a semiconductor chip, a build-up method in which an insulating layer and a wiring layer are alternately stacked on a base material is widely used. Has been adopted.

The insulating layer of a printed wiring board according to the conventional build-up method is not formed by impregnating a core material such as glass cloth with an insulating resin, and a photosensitive resin composition without using the core material. Is formed on the base material by photo-curing.

As such a photosensitive resin composition, a composition comprising an epoxy acrylate resin, a photopolymerizable monomer, a photopolymerization initiator, a curing agent for an epoxy resin, a solvent and the like is used (Japanese Patent Laid-Open Publication No. 6-58242). -317905 publication). Here, as the curing agent for the epoxy resin, 2-
Imidazole-based curing agents such as ethyl-4-methylimidazole and amine-based curing agents such as benzyldimethylamine are generally used.

[0005]

In general, in an insulating layer of a printed wiring board, properties such as kinematic viscoelasticity coefficient, thermal expansion coefficient and dielectric constant greatly change at the glass transition point. Therefore, when the insulating layer is heated above the glass transition point, delamination may occur between the base material and the insulating layer or between the insulating layer and the wiring layer. In addition, there is concern that the electrical characteristics may change significantly.

By the way, when a semiconductor chip is mounted on the printed wiring board manufactured by the built-up method by the wire bonding method, the bonding portion is temporarily heated to a temperature of 150 ° C. or higher. In some cases, the mounted semiconductor chip is resin-sealed. In that case, the sealing portion comes into contact with the molten resin having a temperature of 180 ° C. or higher. Further, solder may be used when joining a high density printed wiring board for mounting a semiconductor chip to a mother board, in which case the connection portion of the high density printed wiring board is exposed to a temperature of about 240 ° C.

Therefore, the glass transition point of the insulating layer of a high-density printed wiring board for mounting semiconductor chips or the like is required to be at least about 160 ° C. practically.

Further, most of the wiring layers on the insulating layer of the printed wiring board manufactured by the built-up method or the conductive layer on the inner surface of the via hole formed in the insulating layer is formed by the plating method. In order to prevent the plated layer from peeling off due to history, the peel strength of the plated layer on the insulating layer is required to be practically 600 g / cm or more.

However, in the case of a printed wiring board produced by the built-up method using the conventional photosensitive resin composition, the glass transition point of the insulating layer is only about 150 ° C., and the plating layer on the insulating layer is Has a peel strength of 4
It was about 00 g / cm, and there was a problem that the above requirements could not be satisfied.

The present invention is intended to solve the above-mentioned problems of the prior art, and raises the glass transition point of the insulating layer of the printed wiring board produced by the build-up method and further improves the peel strength of the plating layer. The task is to let them do it.

[0011]

The present inventors have found that the above-mentioned problems can be solved by using a specific compound as a curing agent, and have completed the present invention.

That is, according to the first aspect of the present invention, in the photosensitive resin composition containing an epoxy acrylate resin, a photopolymerizable monomer, a photopolymerization initiator, a curing agent and a solvent, the curing agent is of the formula ( 1)

[0013]

Embedded image A 2,6-naphthalenedicarboxylic acid dihydrazide (hereinafter abbreviated as NDH) is provided.

According to a second aspect of the present invention, there is provided an epoxy resin curing agent for use in the photosensitive resin composition, which is characterized by containing NDH. To be done.

According to a third aspect of the present invention, in a printed wiring board in which wiring layers and insulating layers are alternately formed on an insulating substrate, the insulating layer has the above-mentioned photosensitive insulating resin composition. Provided is a printed wiring board, which is characterized in that it is made of a product.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

First, the photosensitive resin composition according to the first aspect of the present invention will be described.

In this photosensitive resin composition, NDH of the formula (1) is used as the main component of the curing agent. By using NDH, the glass transition point of the insulating layer formed from the photosensitive resin composition rises and the peel strength of the plating layer on the insulating layer improves. The reason why the glass transition point is increased and the peel strength of the plating layer on the insulating layer is improved by using NDH is not clear, but it can be considered as follows.

That is, the NDH has a property that active hydrogen at the molecular end thereof is reacted with the epoxy group of the epoxy acrylate resin and taken into the polymer matrix of the insulating layer. Here, this NDH is a crystal powder having a very high melting point of 300 ° C. or higher. Therefore,
It is considered that the glass transition point of the insulating layer incorporating NDH is improved.

Since NDH is a powder insoluble in most solvents, it also functions as an organic filler. Therefore, it is considered that the surface of the insulating layer is roughened, which improves the peel strength of the plating layer. In this case, it is considered that the inside of the particles did not contribute to the curing reaction.

When the amount of NDH used in the photosensitive resin composition of the first aspect of the present invention is too small, the effect of the present invention is not sufficiently obtained, and when it is too large, the resolution is lowered.
The amount is preferably 1 to 8 parts by weight, more preferably 2 to 4 parts by weight, based on 100 parts by weight of the epoxy acrylate resin.

Since NDH is insoluble in most solvents as described above, it is also blended in the photosensitive resin composition in the form of particles to function as an organic filler. In this case, if the average particle size of the particles is too small, the glass transition point tends to be low, and if it is too large, the resolution of the photosensitive resin composition at the time of exposure is lowered, and therefore, it is preferably 0.25 to 5.0 μm. , And more preferably 0.25 to 0.
5 μm.

Although only NDH may be used as a curing agent, it may be used in combination with a conventionally known curing agent for epoxy resin in order to lower the curing temperature and further shorten the curing time. Examples of such known curing agents for epoxy resins include amine-based curing agents such as benzyldimethylamine, 2-
Methylimidazole, 2-ethyl-4-methylimidazole, 2,4-diamino-6- (2-undecyl-1-
Imidazolylethyl) -1,3,5-triazine, 1-
Imidazole-based curing agents such as cyanoethyl-2-ethyl-4-methylimidazole trimellitate, 1-cyanoethyl-2-methylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, dicyandiamide, third Examples thereof include amine salts, imidazole salts, amine imides and the like. Among them, an imidazole-based curing agent, which has a low curing temperature, is low in acquisition cost, and can improve the electrical characteristics of the photosensitive resin composition, can be preferably used. In this case, the blending amount of the imidazole-based curing agent is ND
If the amount is too small, the curing temperature cannot be lowered sufficiently, and if the amount is too large, the curing of the resin proceeds too much to make the composition brittle, so that it is preferably 0.5 to 1.5 parts by weight, more preferably 0. 8 to 1.2 parts by weight.

As the epoxy acrylate resin used in the photosensitive resin composition of the first aspect of the present invention, known epoxy acrylate resins used in conventional photosensitive resin compositions can be used, for example, phenol. Novolac type epoxy acrylate, cresol novolac type epoxy acrylate, dicyclopentadiene modified epoxy acrylate, naphthalene type epoxy acrylate,
Bisphenol A type epoxy acrylate, tetraglycidyl aminophenyl methane, etc. can be used.

If the average molecular weight of these epoxy acrylate resins is too low, the dryness to the touch is reduced and the workability during exposure is reduced, and if it is too high, the viscosity is adjusted to a predetermined viscosity (for example, 200 ps). A large amount of solvent has to be added, which lowers the solid content and reduces the coating film thickness, making it impossible to secure the intended film thickness. Therefore, 400 to 1500 is preferable, and 500 to 1 is more preferable.
000.

If the acrylate ratio of the epoxy acrylate resin is too small, the resolution will be poor, and if it is too large, the epoxy group will be small and the thermosetting property will be insufficient. Moreover, the acrylate group will increase, and electroless copper plating will occur. Therefore, it is preferably 30 to 80%, more preferably 40 to 60%.

If the blending amount of the epoxy acrylate resin in the photosensitive resin composition is too small, the workability is lowered, and further, the film properties such as the lowered insulating property and the increased dielectric constant are lowered,
When the amount is too large, the film forming property is deteriorated, the film quality becomes brittle, and the adhesion is also deteriorated.

Next, as the photopolymerizable monomer, known bifunctional or higher functional monomers used in conventional photosensitive resin compositions can be used. For example, 1,
Bifunctional acrylates such as 6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, etc. , Trifunctional acrylates such as ditrimethylolpropane tetraacrylate, and pentafunctional acrylates such as dipentaerythritol pentaacrylate,
A hexafunctional acrylate such as dipentaerythritol hexaacrylate can be used.

If the amount of the photopolymerizable monomer used is too small, the resolution is not sufficient, and if it is too large, the copper plating strength is adversely affected. Therefore, it is preferably 5 to 20 parts by weight per 100 parts by weight of the epoxy acrylate resin. It is more preferably 8 to 15 parts by weight.

As the photopolymerization initiator, known photopolymerization initiators used in conventional photosensitive resin compositions can be used. Diazo compounds, azido compounds, acetophenones, benzyl dimethyl ketals, benzophenone compounds, etc. can be used.

If the amount of the photopolymerization initiator used is too small, the resolution becomes insufficient, and if it is too large, not only the effect of addition cannot be expected, but also the film properties such as insulation and resolution deteriorate. It is preferably 5 to 20 with respect to 100 parts by weight of the total of the epoxy acrylate resin and the photopolymerizable monomer.
By weight, more preferably 7 to 15 parts by weight.

The solvent used in the photosensitive resin composition is butyl cellosolve, ethyl cellosolve,
Carbitol, petroleum solvent, methyl ethyl ketone,
Cyclohexanone, diglyme, toluene, xylene,
Ethyl cellosolve acetate and the like can be used alone or in an appropriate mixture.

An inorganic filler may be further added to the photosensitive resin composition of the first aspect of the present invention in order to suppress shrinkage during photocuring and prevent peeling of the insulating layer from the base material. preferable. As such an inorganic filler, those similar to those conventionally added to the photosensitive resin composition can be used, and for example, silica, alumina, talc, barium sulfate, etc. can be used.

If the average particle size of such an inorganic filler is too small, the acquisition cost will increase, and if it is too large, the resolution will decrease, so 0.3 to 10.0 μm is preferable, and 0.5 to 3 is more preferable. 0.0 μm. Further, if the amount of the inorganic filler used is too small, the film forming property becomes insufficient,
Since the film quality becomes brittle, and the adhesiveness also deteriorates, if it is too much, the workability deteriorates, and further, the film properties such as the deterioration of the insulating property and the increase of the dielectric constant are deteriorated.
The amount is preferably 10 to 50 parts by weight, more preferably 20 to 40 parts by weight, based on 00 parts by weight.

By the way, in order to suppress the delay of the electric signal flowing through the wiring pattern, the dielectric constant of the insulating layer is practically 4.0 or less with respect to the insulating layer of the printed wiring board manufactured by the built-up method. Is required to be. Therefore, the photosensitive resin composition of the present invention preferably contains an organic filler in order to reduce the dielectric constant of the insulating layer. Here, as described above, since NDH also functions as an organic filler, the use of NDH can reduce the dielectric constant of the insulating layer.

Preferred examples of other organic fillers include polymethylmethacrylic acid fine particles and silicone resin fine particles.

When the insulating layer having such an organic filler added thereto is surface-treated with an aqueous potassium permanganate solution,
The surface is sufficiently roughened. Therefore, the peel strength of the plated layer formed thereon can be improved.

If the average particle size of such an organic filler is too small, the manufacturing cost will be high, and if it is too large, the resolution will be lowered, so that it is preferably 0.1 to 5.0 μm, more preferably 0.5 to 1 μm. 0.0 μm. If the amount of the organic filler used is too small, the dielectric constant cannot be sufficiently reduced and the surface roughening effect cannot be expected.
With respect to 0 parts by weight, the film quality becomes brittle and the adhesiveness also deteriorates.
Parts by weight.

Further, known additives may be added to the photosensitive resin composition, for example, a thermal polymerization inhibitor, a pigment, a color former, a coatability improving agent, a defoaming agent, an adhesion improving agent. , Leveling agents and the like can be added as appropriate.

The photosensitive resin composition of the first aspect of the present invention can be manufactured by a conventional method, and can be manufactured by uniformly mixing the respective components. In this case, after the components other than the curing agent are uniformly mixed, the curing agent may be mixed immediately before use.

Such a photosensitive resin composition can be preferably applied when the insulating layer of the printed board is formed by the build-up method.

Next, the curing agent for epoxy resin according to the second aspect of the present invention will be described.

The curing agent for epoxy resin is characterized by containing NDH. By containing NDH, as described above, the glass transition point of the epoxy resin molded article can be improved.

The epoxy resin curing agent may be composed of only NDH. However, as described above, in order to lower the curing temperature and further shorten the curing time, a conventional curing agent for epoxy resin may be used. You may use together. For specific examples and blending amounts of such known curing agents for epoxy resins,
It is as described in the description of the photosensitive resin composition of the first aspect of the present invention.

This epoxy resin curing agent is manufactured by
Since H does not dissolve in a general solvent, NDH, if necessary, other curing agent and a diluent, for example, an epoxy acrylate resin having a degree of acrylate of 100% may be mixed with a solvent.

Next, a printed wiring board according to the third aspect of the present invention will be described.

This printed wiring board is formed on an insulating substrate,
In a printed wiring board in which a wiring layer and an insulating layer are alternately formed, the insulating layer is formed of the photosensitive resin composition of the first aspect of the present invention described above. As described above, the printed wiring board having the insulating layer composed of the photosensitive resin composition according to the first aspect of the present invention is excellent in heat resistance because the insulating layer has a high glass transition point, and moreover, between the layers. It has the advantage of high peel strength.

The structure of the invention other than the insulating layer of the printed wiring board can be the same as that of the conventional printed circuit board. Further, the printed wiring board can be preferably manufactured by the conventional build-up method.

[0049]

The present invention will be described below in more detail with reference to examples.

Example 1 A photosensitive resin composition was prepared by uniformly mixing the components shown in Table 1.

[0051]

[Table 1] Ingredients by weight Epoxy acrylate resin (Ripoxy SPB-50 (Acrylation rate 50%), Showa High Polymer Co., Ltd.) 100 Photopolymerizable monomer (M-400, Toa Gosei Co., Ltd.) 4.5 (3002A, Kyoeisha Chemical Co., Ltd.) 3.5 Photoinitiator (DETX, Nippon Kayaku Co., Ltd.) 3.5 (Irgacure 907, Ciba Geigy Co., Ltd.) 7.5 Curing agent (NDH (average particle size 0.5 μm) 2.0 ( 2-Ethyl-4-methylimidazole) 1.0 Solvent (solvent naphtha) 40 (Butyl cellosolve) 12 Inorganic filler (talc (Microace L-1, manufactured by Nippon Talc Industry Co., Ltd.)) 20 (Barium sulfate (B-34, Sakai) (Chemical company) 20

Example 2 14 parts by weight of a solvent butyl cellosolve was used, and NHD having an average particle size of 0.25 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 4 parts by weight of DH was used.

Example 3 A photosensitive resin composition was prepared in the same manner as in Example 1 except that 16 parts by weight of the solvent butyl cellosolve and 8 parts by weight of NDH were used.

Example 4 12 parts by weight of butyl cellosolve as a solvent was used, and NHD having an average particle size of 0.35 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 2 parts by weight of DH was used.

Example 5 14 parts by weight of a solvent butyl cellosolve was used, and N having an average particle size of 0.35 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 4 parts by weight of DH was used.

Example 6 16 parts by weight of butyl cellosolve as a solvent was used, and NHD having an average particle size of 0.35 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 8 parts by weight of DH was used.

Example 7 Instead of NDH having an average particle size of 0.5 μm, an average particle size of 0.25
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 2 parts by weight of NDH of μm was used.

Example 8 14 parts by weight of butyl cellosolve as a solvent was used, and NHD having an average particle size of 0.25 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 4 parts by weight of DH was used.

Example 9 16 parts by weight of butyl cellosolve as a solvent was used, and NHD having an average particle size of 0.25 μm was used in place of NDH having an average particle size of 0.5 μm.
A photosensitive resin composition was prepared in the same manner as in Example 1 except that 8 parts by weight of DH was used.

Example 10 First, the components shown in Table 2 were uniformly mixed to prepare a precursor composition for a photosensitive resin composition.

[0061]

[Table 2] Ingredients by weight Epoxy acrylate resin (lipoxy SPB-50 (50% acrylate), Showa High Polymer Co., Ltd.) 95 Photopolymerizable monomer (M-400, Toa Gosei Co., Ltd.) 4.5 (3002A, Kyoeisha Chemical Co., Ltd.) 3.5 Photopolymerization initiator (DETX, Nippon Kayaku Co., Ltd.) 3.5 (Irgacure 907, Ciba Geigy Co., Ltd.) 7.5 Solvent (solvent naphtha) 40 (Butyl cellosolve) 12 Inorganic filler (talc (micro) Ace L-1, manufactured by Nippon Talc Industry Co., Ltd.)) 20 (barium sulfate (B-34, manufactured by Sakai Chemical Co., Ltd.) 20 Next, a curing agent for epoxy resin was prepared by uniformly mixing the components shown in Table 3. .

[0062]

[Table 3] Ingredients By weight 2-Ethyl-4-methylimidazole 1.0 NDH (average particle size 0.5 μm) 2.0 Diluent (epoxy acrylate resin (acrylicization rate 100%)) 5.0 (lipoxy SPB -50, Showa High Polymer Co., Ltd.) Butyl Cellosolve 1.5 Next, a photosensitive resin composition was prepared by mixing the composition of Table 2 and the curing agent of Table 3.

Comparative Example 1 The amount of butyl cellosolve used as a solvent was 10 parts by weight, and N
A photosensitive resin composition was prepared in the same manner as in Example 1 except that DH was not used.

(Evaluation) Regarding the obtained photosensitive resin composition, "peeling strength", "relative permittivity",
"Glass transition point" and "resolution" were evaluated.

(1) Peel Strength Test The compositions of Example 2 and Comparative Example 1 were applied by a screen printing method to a single-sided copper-clad laminate in which a copper foil was attached to a glass epoxy substrate, and the composition was heated to 100 ° C. It was temporarily dried for 30 minutes. After that, 800mJ / cm ² by ultra-high pressure mercury lamp
The entire surface was irradiated with the light amount of Then, at 180 ℃ 60
By baking for minutes, an insulating layer having a thickness of 40 μm was formed.

Next, the surface of this insulating layer is polished with No. 500 sandpaper, washed, and surface-roughened with permanganate, followed by electroless copper plating and electrolytic copper plating. Thus, a copper layer having a thickness of 35 μm was formed on the insulating layer. Then, it was washed with water and baked at 150 ° C. for 120 minutes to prepare a printed wiring board.

The peel strength test of the copper layer on the insulating layer of the printed wiring board thus obtained was conducted as follows.

That is, a cutting line having a width of 1 cm was put in the copper layer and the peel strength was measured.

As a result, the photosensitive resin composition of Example 2 exhibited a high peel strength of 700 g / cm, while the peel strength of Comparative Example 1 was 400 g / cm.

(2) Measurement of relative permittivity For the photosensitive resin compositions of Example 2 and Comparative Example 1, J
The dielectric constant was measured according to IS C 6481. As a result, the dielectric constant of Example 2 was as low as 4.0, while the dielectric constant of Comparative Example 1 was 4.3, which was higher than that.

(3) Measurement of glass transition point The photosensitive resin compositions of Examples 1 to 9 and Comparative Example 1 were applied on a Teflon plate and cured by the same operation as in the peel strength test described above, An insulating film having a thickness of 20 μm was produced. This insulating film was peeled off from the Teflon plate to give a width of 1.
It was cut into a strip shape having a length of 0 cm and a length of 2.0 cm. The glass transition point of the cut strip was measured by a dynamic viscoelasticity measuring device (RHEOLOGRAPH SOLID, manufactured by Toyo Seiki Seisakusho Ltd.) according to the dynamic viscoelasticity measuring method. The results are shown in Table 4.

[0072]

[Table 4] As can be seen from Table 4, all of the photosensitive insulating compositions of Examples 1 to 9 showed a glass transition point of 160 ° C or higher, but the composition of Comparative Example 1 had a glass transition point of 150 ° C. .

(5) Resolution Test First, the copper foil of a single-sided copper-clad laminate consisting of a 1 mm-thick glass epoxy substrate and an 18 μm-thick copper foil attached to one side thereof was formed into a wiring pattern by photolithography. processed.

Next, the photosensitive resin compositions of Examples 1, 4 and 7 and N of the compounding amount and the average particle diameter as shown in Table 5 were used.
A photosensitive resin composition (Examples 11 to 16) having the same composition as in Example 1 except that DH was used was adjusted with butyl cellosolve so that the viscosity was 150 ps, and the wiring pattern of the single-sided copper-clad laminate was prepared. It was applied twice by screen printing on top, prebaked at 90 ° C for 30 minutes, and then 80 μm
Diameter, 90 μm diameter or 120 μm diameter via a mask having 20 via hole patterns, 2000 mJ / cm
^It was exposed with a light amount of ² . Then, the resin in the via hole portion was removed by developing with γ-butyrolactone, washed with water, and then baked at 180 ° C. for 60 minutes to be cured. Then, the shape of the via hole in that state was examined, and the resolution was evaluated according to the following evaluation criteria.

Resolution Evaluation Criteria Rank State O: When all 20 via holes are in good shape. X: When there is at least one via hole that does not reach the wiring layer, or even one of them has a bad shape. If there is

[0076]

[Table 5] The photosensitive resin compositions of the examples listed in Table 5 all showed good results.

Example 17 (Production Example of Multilayer Printed Wiring Board) The copper foil of a single-sided copper-clad laminate consisting of a glass epoxy substrate of 1 mm thickness and a copper foil of 18 μm attached to one side thereof was subjected to photolithography. Processed into a wiring pattern.

Next, the photosensitive resin composition of Example 1 was adjusted with butyl cellosolve so that the viscosity was 200 ps, and it was applied twice on the wiring pattern of the single-sided copper-clad laminate by screen printing, After prebaking at 90 ° C. for 30 minutes, exposure was performed with a light amount of 2000 mJ / cm ² through a mask having a via hole pattern having a diameter of 80 μm. Then, the resin in the via hole portion is removed by developing with γ-butyrolactone, and after washing with water, the temperature is 180 ° C.
And baked for 60 minutes to cure and form an insulating film.

The surface of this insulating film is numbered from 800 to 240.
Polishing was sequentially performed using a buff having a roughness of about 0 to smooth the unevenness of the insulating film caused by the unevenness of the existence portion and the non-existence portion of the wiring pattern and finely roughen the surface.
The thickness of the insulating film thus formed was about 40 μm.

Next, the substrate on which the insulating film is formed is heated to 70 ° C.
KMnO ₄ (70 g / l) and NaOH (4
0 g / l) was dipped in a solution containing 1 to 10 minutes to roughen the surface.

Next, for the surface-roughened substrate,
Electroless copper plating, then electrolytic copper plating, 10μ
An m-thick copper layer was formed on the insulating layer.

Next, a 40 μm-thick dry film was attached onto the copper layer, exposed through a mask having a desired wiring pattern, and subsequently developed.

Next, a wiring pattern was formed by etching the copper layer with a copper chloride etchant, and the dry film was peeled off with an alkaline aqueous solution.

Further, by repeating the above operation (build-up method), a printed wiring board in which a plurality of insulating layers and wiring patterns were alternately laminated was obtained.

The wire bonding property of the obtained printed wiring board was evaluated. It showed good bonding characteristics.

[0086]

According to the present invention, a printed wiring board having an insulating layer having a high glass transition temperature and good peel strength of plating can be obtained.

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Claims (8)

[Claims] 1. A photosensitive resin composition comprising an epoxy acrylate resin, a photopolymerizable monomer, a photopolymerization initiator, a curing agent and a solvent, wherein the curing agent is represented by the formula (1): 2. A photosensitive resin composition containing 2,6-naphthalenedicarboxylic acid dihydrazide. 2. The compounding amount of 2,6-naphthalenedicarboxylic acid dihydrazide is 100% by weight of epoxy acrylate resin.
The photosensitive resin composition according to claim 1, which is 1 to 8 parts by weight with respect to parts by weight. 3. The photosensitive resin composition according to claim 1 or 2, wherein the curing agent contains 2,6-naphthalenedicarboxylic acid dihydrazide in the form of particles. 4. The photosensitive resin composition according to claim 3, wherein the 2,6-naphthalenedicarboxylic acid dihydrazide has an average particle diameter of 0.25 to 0.5 μm. 5. The photosensitive resin composition according to claim 1, wherein the curing agent further contains an imidazole curing agent. 6. A curing agent for an epoxy resin, which comprises 2,6-naphthalenedicarboxylic acid dihydrazide. 7. The epoxy resin curing agent according to claim 6, further comprising an imidazole curing agent. 8. In a printed wiring board in which wiring layers and insulating layers are alternately formed on an insulating substrate, the insulating layer is composed of the photosensitive resin composition according to any one of claims 1 to 4. A printed wiring board characterized by being provided.