JPH04195051A - Photosetting resist composition and printing plate using same - Google Patents

Abstract

PURPOSE:To facilitate manufacture of a high-density printed circuit plate using a partly additive method by using a mixture of a multifunctional unsaturated compound being solid at room temperature, a multifunctional unsaturated compound being liquid at room temperature, a photopolymerization initiator, an epoxy agent and its hardener, and cyanamide. CONSTITUTION:A photosensitive solder resist ink for screen printing is prepared by putting a diallyl phthalate resin as the multifunctional unsaturated compound being solid at room temperature into a separable flask, adding an organic solvent, mixing and stirring them at about 80 - 100 deg.C for about 0.5 - 2hr to dissolve it, then cooling the solution to room temperature, mixing multifunctional acrylate as the multifunctional unsaturated compound being liquid at room temperature, the photopolymerization initiator, the epoxy agent and its hardener, and cyanamide, sufficiently stirring and mixing them, and kneading the mixture in 2 - 4 times with a 3-roll mill, thus permitting coatability, contact-exposability, developability, resistances to offset, alkali, plating, elution due to plating, and heat, and insulation property to be all enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photocurable resist composition and a printed circuit board using the same.

[Conventional technology]

UV exposure used in conventional printed circuit board manufacturing.

For development type resists, for example,
No. 0451, Japanese Patent Publication No. 52-30969, Japanese Patent Publication No. 1983-
No. 208377, JP-A-62-4390, JP-A-62
-253613 etc. can be mentioned. Such a resist was mainly used in the method of manufacturing a printed circuit board shown in FIG. FIG. 2 shows a printed circuit board manufacturing method known as the subtract method, using a 4M board as an example. In this process, starting material is a copper-clad laminate with an inner layer and copper foil laminated on the top and bottom surfaces, holes are drilled at predetermined positions, a catalyst is applied inside the holes, and then the entire surface including the through-holes is electroplated with copper. A predetermined circuit pattern is formed by etching, and finally a solder resist is applied. Until now, such solder resists have been made of thermosetting epoxy resins that form patterns by screen printing, but as the wiring density of printed circuit boards increases, U
A V-exposure and development type solder resist has been developed.

On the other hand, the part-reactive printed circuit board manufacturing method shown in Figure 1 has a plating reactivity resistance that is completely different from that of the solder resist used in the subtract method printed circuit boards shown in Figure 2. It is essential to use solder resist.

In the part-reactive method, unlike the subtract method, holes are drilled at predetermined positions in a copper-clad laminate, a catalyst is applied, and a conductor circuit is first formed. Next, after forming a solder resist with resistance to plating reactivity at predetermined parts, finally, plating is applied to only necessary parts such as through-holes, lands, and connectors using scientific copper plating.

This manufacturing method is cheaper and cheaper than the subtract method.
It has the advantage of high precision. In other words, it does not plate the entire surface as in the subtract method, but only partially plates where it is needed, and it suffices to etch only the thin copper foil of the copper-clad laminate when forming conductor circuits. Therefore, the process is simple, there is little loss, and high-precision wiring is possible.

However, in order to take advantage of these advantages, the solder resist used in the part additive method requires special functions. In other words, it is immersed in a high temperature, strong alkaline harsh chemical copper plating solution for a long time, and the chemical copper plating has a deposition potential of -0.6 on the copper wiring pattern under the solder resist.
~-0,9V (see saturated calomel electrode) acts for a long time. Even after going through such a harsh process, it still maintains the heat resistance necessary as a solder resist and the insulation properties necessary to protect printed circuit boards as a permanent resist.

This is an extremely advanced function that must not deteriorate.

As a solder resist having plating reactivity resistance suitable for such purposes, an epoxy resin-based thermosetting solder resist in which a pattern is formed by screen printing is known, and an example thereof is disclosed in JP-A-58-147416. ing. Also,
UV exposure and development type solder resists with plating reactivity resistance are also known, an example of which is disclosed in Japanese Patent Application Laid-open No. 62-26532.
It is disclosed in No. 1.

A UV exposure/development type solder resist having such plating reactivity resistance has extremely high precision because a pattern is formed by UV exposure and development, and is suitable for manufacturing high-density printed circuit boards. However, in mass production where a large number of printed circuit boards are plated, the resist contains dicyandiamide, so during the long scientific copper plating process, trace amounts of dicyandiamide dissolve into the chemical copper plating solution, causing problems with copper plating. This had the problem of severely affecting the precipitation state and deteriorating the reliability of through holes.

[Problem to be solved by the invention]

The purpose of the present invention is to realize a UVi light-developable solder resist that has plating reactivity resistance without the drawbacks of the prior art described above, and to facilitate the production of high-density printed circuit boards using the par-1 to rear-deative process. 6 There are a wide variety of properties that a practical resist should have, and if even one of them is missing, its practicality will be significantly impaired. Therefore, an object of the present invention is to provide a resist composition that simultaneously satisfies many properties that cannot be achieved simply by combining conventional techniques. The issues to be solved for this purpose are listed below.

a) It is essential that the resist of the present invention does not contain dicyandiamide. In mass production, where a large number of printed circuit boards are plated, if the resist contains dicyandiamide, a trace amount of dicyandiamide will dissolve into the chemical steel plating solution during the long chemical steel plating process, causing a deposit in the copper plating. This has a significant impact and deteriorates the reliability of the through hole.

Therefore, the resist of the present invention must simultaneously satisfy the following problems without containing dicyandiamide.

b) It is essential that the resist of the present invention is cured by exposure to UV light. That is, it is necessary to cause a crosslinking reaction by irradiating UV light (ultraviolet light) of 300 to 400 nm, which is suitable for manufacturing printed circuit boards, and to cure only the irradiated portion. In addition, the practical irradiation dose is 0.02~IOJ/a&
It is desirable to cure within this range.

C) It is essential that the resist of the present invention has an appropriate difference in solubility in a developer between a portion cured by UV irradiation and an uncured portion, and has good resolution after development. In other words, it must have excellent developability using a suitable solvent.

d) It is essential that the resist of the present invention can be applied to both sides of a printed circuit board and exposed simultaneously to both sides. That is, there must be no so-called show-through, in which UV light exposed from one side passes through the resist and the base material and hardens the resist on the other side.

Unless this problem is solved, the difference between the negative mask patterns used on both sides of the base material will also appear on the opposite side, significantly impairing its practicality.

e) It is essential that the resist of the present invention can be exposed with a negative mask in close contact with the resist during UV exposure. If such problems are not solved, the resist and the negative mask will adhere to each other due to the adhesiveness of the resist itself or the softening of the resist due to temperature rise during exposure. In this case, it becomes necessary to clean the negative mask after each exposure, which significantly impairs practicality.

f) It is essential that the resist of the present invention has good coating properties. In other words, when applying resist to one side of a printed circuit board using screen printing or a roll coater, it is necessary to have an appropriate viscosity characteristic as an ink so that the thickness is uniform and no voids remain. .

g) The resist of the present invention must be able to be coated on one side, pre-dried, and then coated on the other side. If pre-drying is insufficient, it becomes impossible to print resist on the other side while the viscous resist remains applied on one side. If the pre-drying is excessive, the reaction of the resist progresses, resulting in a difference in the properties of the resist on both sides. To avoid such problems, it is essential to be able to perform preliminary drying appropriately.

h) The resist 1 of the present invention is formed on a printed circuit board as a product, and as a solder resist, it is essential to have good heat resistance to withstand repeated soldering. That is, even after repeating solder dipping for 10 seconds at approximately 260°C approximately 10 times, or equivalently hot air,
It is essential that no abnormality such as blistering or peeling occurs in the resist on the printed circuit board even when soldering is performed using infrared rays, solvent vapor, or the like. It should be emphasized that such properties are required of the resist after undergoing the harsh chemical copper plating process.

i) The resist of the present invention is formed on a printed circuit board as a product, and it is essential that it can maintain high insulation properties. In other words, it has excellent insulation properties that do not cause insulation deterioration between wires, especially when moisture is absorbed! ! It is necessary to be able to maintain relationships. It is emphasized that such characteristics are required for resists that have undergone the harsh chemical copper plating process.

J) The resist of the present invention is formed on a printed circuit board as a product, and it is essential that it has excellent chemical resistance. That is, in soldering used in the mounting process of mounting components on a printed circuit board, it is necessary that the resist is not dissolved or deteriorated by flux, cleaning solvent, or the like. It should be emphasized that such properties are required of the resist after undergoing the harsh chemical copper plating process.

k) It is essential that the resist of the present invention has good alkali resistance after being formed on a printed circuit board as a product. That is, since the resist undergoes a harsh chemical copper plating process, it is necessary that the resist does not dissolve or change in quality due to the high temperature, strong alkaline chemical copper plating solution.

(2) It is essential that the resist of the present invention has good plating reactivity after being formed on a printed circuit board as a product. Specifically, such characteristics are as follows. When manufacturing printed circuit boards using the part-reactive method, it is essential that the resist on the conductor circuits does not peel off during the chemical copper plating process. The printed circuit board on which the resist has been formed is immersed in a harsh high-temperature, strong alkaline chemical copper plating solution for a long time, and the copper wiring pattern under the solder resist has a deposition potential of -〇, 6~-.
0.9v works for a long time. Even after such a harsh process, there must be no reduction in adhesion or peeling at the interface between copper and resist.

The mechanism that causes the decrease in adhesion and peeling is not clear, but experience has shown that the deposition potential of chemical copper plating acts as the force behind the peeling reaction, and that the presence of copper oxide at the interface between copper and resist causes peeling. It is known that the disease progresses extremely rapidly. From these facts, the oxides at the interface between the circuit copper foil and the resist are electrochemically reduced by the chemical copper plating deposition potential, which destroys the bond between the copper and resist, which is the cause of adhesion, and causes peeling. It is estimated that Therefore, plating reactivity resistance (peeling resistance) is also a type of cathode peeling resistance.

Such plating reactivity should be strictly distinguished from what is generally referred to as plating resistance. Generally, what is referred to as plating resistance often refers to the above-mentioned alkali resistance, which is completely different from plating reactivity resistance (peeling resistance).

The problem of plating reactivity (peeling resistance) is the most important point to keep in mind when manufacturing printed circuit boards using the part-reactive method. peels off, rendering it completely impractical.

m) After the resist of the present invention is formed on a printed circuit board as a product, it is essential that harmful components are not eluted or extracted from the resist into the plating solution during the chemical copper plating process. If the problem of plating elution resistance is unresolved,
Components eluted or extracted from the resist adversely affect the precipitation reaction of copper plating, resulting in stopping or delaying the plating reaction or significantly deteriorating the crystal orientation and physical properties of the deposited copper. Therefore, the connection reliability and solder wettability of through-holes on printed circuit boards are reduced.
It loses all practicality.

Harmful ingredients have a negative effect on the precipitation reaction of copper plating.
Since the plating reaction includes a catalytic reaction of the reducing agent on the copper surface, it is extremely complicated, and it is necessary to select the composition of the resist empirically to ensure resistance to plating elution.

The problem of plating elution resistance is one of the most important points to keep in mind when manufacturing printed circuit boards using the part-additive method.If this problem is not resolved, the manufactured printed circuit boards will simply become unusable. Otherwise, the chemical mesh plating solution will be contaminated, and a large amount of the plating solution will have to be disposed of, resulting in significant losses.

An object of the present invention is to provide a photocurable resist composition that satisfies all of the above-mentioned problems from a) to m).

Another object of the present invention is to provide a printed circuit board using a photocurable resist composition that satisfies all of the above-mentioned problems from a) to m).

[Means to solve the problem]

In order to achieve the above object, the present invention provides a photosensitive Tsurudaregis l-composition having plating resistance, which comprises a polyfunctional unsaturated compound that is solid at room temperature, a polyfunctional unsaturated compound that is liquid at room temperature, and a photosensitive resin composition having plating resistance. A photocurable resist composition is used, which is characterized by containing a polymerization initiator, an epoxy resin, a curing agent for the epoxy resin, cyanamide, an antifoaming agent, a pigment, and an organic solvent.

The polyfunctional unsaturated compound that is solid at room temperature used in the present invention is a compound having a large number of unsaturated groups in the molecule, such as diallyl phthalate resin. , it is possible to obtain a resist that satisfies many of the above-mentioned problems at the same time.

Specifically, diallyl phthalate resin comprises a prepolymer of diallyl ester of ortho, iso, or terephthalic acid. The Gagaru prepolymer is also called a β-polymer, and its detailed manufacturing method and properties are described, for example, in Naoki Yoshimi, "Diallyl Phthalate Resin," Nikkan Kogyo Sha Series (1962). It is also possible to obtain commercially available products from Daiso. Preferred prepolymers for use in the present invention have a molecular weight of about 30
00 to 30,000, and if it is less than 3,000, the adhesion exposure property with a negative mask is poor, and if it is more than 30,000, there will be problems in developability. Furthermore, even when a prepolymer is used, a small amount of diallyl phthalate monomer or γ-polymer having a three-dimensional network structure that remains or is produced during the synthesis of the prepolymer may be included.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains a polyfunctional unsaturated compound that has at least two or more ethylene bonds in its molecule and is liquid at room temperature. Such a compound can be obtained, for example, by an esterification reaction between an unsaturated carboxylic acid and a divalent or higher polyhydroxy compound. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, etc., while polyhydroxy compounds with a valence of more than 2 include ethylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol, and divalent acid. Pentaerythritol and its derivatives can be mentioned.

Examples of the compounds obtained by the esterification reaction between an unsaturated carboxylic acid and a polyhydroxy compound include diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, 1.5bentanediol diacrylate, 1.
6 hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, diethylene glycol dimethacrylate,
1.3 Diacrylates represented by butanediol dimethacrylate, dimethacrylate compounds, dipentaerythritol tri, tetra, penta, hexaacrylate or methacrylate-1~, sorbitol tri,
Examples include polyfunctional acrylates and methacrylate compounds represented by tetra, penta, hexaacrylate, and methacrylate, oligoester acrylate, oligoester methacrylate-1, and the like.

Furthermore, a compound produced by an addition reaction between a divalent or higher epoxy resin and an unsaturated carboxylic acid can also be used as a polyfunctional unsaturated compound that is liquid at room temperature. Examples of such compounds include polyfunctional unsaturated compounds that are liquid at room temperature and are produced by the addition reaction of bisphenol A type or nophorac type epoxy resins with acrylic acid or methacrylic acid.

The above examples do not limit the addition of monofunctional unsaturated compounds, and mixtures with polyfunctional unsaturated compounds can also be used if necessary.

Further, preferred polyfunctional unsaturated compounds that are liquid at room temperature are those containing two or more functional groups, more preferably three or more, and even more preferably six or more functional groups in the molecule.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains a photopolymerization initiator.

Examples of photopolymerization initiators include acetophenone, benzophenone, Michler's ketone, benzyl, hengeine, benzoin alkyl ether, benzoin alkyl ketal, thioxanthone, thioxanthone, anthraquinone, anthraquinone and its derivatives or analogues, 1-hydroxycyclohexylphenyl ketone and its derivatives. or analogues, α typified by 2-methyl-1-[4-(methylthio)phenyl]-2-morphelinopropene-1
-aminoketone compounds and the like. If desired, mixtures of photoinitiators can be used. Furthermore, if necessary, it is also possible to use an amine compound or the like that sensitizes the action of the photopolymerization initiator.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains an epoxy resin.

Epoxy resins have an average of two or more epoxy groups per molecule, such as bisphenol A
, polyglycidyl ether or polyglycidyl ester, novolak type, obtained by reacting a polyhydric phenol such as halogenated bisphenol A, catechol, resorcinol, etc. or a polyhydric alcohol such as briselin with epichlorohydrin in the presence of a basic catalyst. Examples include epoxy novolank obtained by condensing a phenol resin and epichlorohydrin, epoxidized polyolefin epoxidized by a peroxidation method, epoxidized polybutadiene, dicyclopentagenated oxide, and epoxidized vegetable oil.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains an epoxy resin curing agent. As curing agents for epoxy resins, amine compounds and imidazoles are suitable. Examples of amine compounds include typical resin compounds such as ethylenediamine, hexamethylenediamine, and triethylenetetramine, and representative aromatic compounds such as 4,4'-diaminodiphenylmethane and phenylenediamine. Imidazoles include alkylimidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole, and imidazole derivatives include purine, 2,6-diamitpurine, and 2-aminopurine. Typical examples include benzimidazole, and 2-vinyl-4,6-cyamizole.
2,4-diamino-6(2'-methylimidazole-(1'))ethyl-5-triazine, 2,4-diamino-6(2'ethyl- 4'-Methylimidazole-
(1')) ethyl-5-triazine, 2,4-diamino-6(2'-undecylimidazole-(1'))ethyl-5-triazine, 2,4-diamino-6(2'-phenylimidazole) -(1'')) ethyl-s-triazine or 2,4-diamino-6(2'-methylimidazole-(1'))ethyl-s-triazine/isocyanuric acid adduct.

Other amine curing agents include boron trifluoride monoethylamine. Mixtures of amine curing agents can be used if desired. Especially in terms of storage stability of the resist and the fact that it does not gel when drying.
Compounds obtained by addition reaction of -vinyl-4,6-diaminos-triazine and alkylimidazole are preferred.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains cyanamide.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains an antifoaming agent. As such an antifoaming agent, an organic silicon compound containing a siloxane bond, typified by silicone oil, is mainly used.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains a pigment. As such pigments, phthalocyanine, phthalocyanine green, phthalocyanine blue, etc., which are pigments having a phthalocyanine skeleton with excellent heat resistance, are mainly used.

Furthermore, the photosensitive solder resist composition having plating resistance of the present invention contains an organic solvent. As such organic solvents, methyl, ethyl, butyl cellosolve and its acetate, methyl, ethyl, butyl calpitol, etc., and high boiling point solvents such as terpineol are mainly used.

Furthermore, the performance of the photosensitive solder resist composition having plating resistance of the present invention can be further improved by adding other additives as necessary.

Such additives include thixotropic agents to adjust the viscosity of the resist, fillers to adjust the heat resistance of the resist, ultraviolet absorbers to adjust the resolution of the resist, and storage stability of the resist. Examples include polymerization inhibitors for adjusting the .

An example of such a thixotropic agent is ultrafine quartz powder, an example of such a filler is fine quartz powder, and an example of such an ultraviolet absorber is 4-t-butyl-4'-methoxy-di Benzoylmethane, 2-ethylhexyl-P-methoxycinnamate, 2-(2'-hydroxy-3', 5'
-di-tert-butylphenyl)benzotriazole, 2-(2'hydroxy-3' tert-butyl-
5'-methylphenyl)-5-chlorobenzotriazole, 2(2+-hydroxy-3',5'-dit
ert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hir~roxy3-(311,
411, 511, 611-tetrahydrophthalimidomethyl)-5''-methylphenyl)benzotriazole, etc. Examples of such polymerization inhibitors (7) include hydroquinone or its derivatives.

The preferred blending ratio for constituting the composition of the present invention is 100 parts by weight of the polyfunctional unsaturated compound that is solid at room temperature and 5 to 30 parts by weight of the polyfunctional unsaturated compound that is liquid at room temperature. , 2 to 12 parts by weight of a photopolymerization initiator, 5 to 40 parts by weight of an epoxy resin, 0.1 to 5 parts by weight of a curing agent for the epoxy resin, 2 to 20 parts by weight of cyanamide, and 0.0 parts by weight of an antifoaming agent. 5 to 10 parts by weight, 0.2 to 10 parts by weight of pigment,
The amount of organic solvent is 50 to 100 parts by weight.

The upper and lower limits of this blending ratio are the problems of the present invention (
A) to (m) were selected from carefully selected results so that they were all simultaneously satisfactory.

Next, referring to FIG. 1, a method for manufacturing a printed circuit board by a part additive method using the above-mentioned photosensitive solder resist composition having plating resistance, which is the second object of the present invention, will be described.

After drilling holes in a copper-clad laminate (Fig. 1, 1) using a method well known to those skilled in the art, a catalyst for chemical copper plating is applied to the entire surface of the board, including the inside of the through holes [Fig. 1, 2). .

Next, conductor circuits are formed on both sides of the board by etching the predetermined portions by a method well known to those skilled in the art [Fig. 1, 3)]
.

Next, the photosensitive solder resist composition having plating resistance of the present invention is applied to one side of the substrate including the conductor circuit, and the substrate coated with the resist is dried to solidify the resist.

This method is repeated on the back side, or a photosensitive solder resist composition having plating resistance is simultaneously applied to both sides of the substrate and then dried to form solidified resist layers on both sides of the substrate. Drying temperature is 60 to 10
At 0°C, the drying time is preferably 0.2 to 2 hours.

Next, a negative mask is brought into close contact with the solidified resist I-layer on both sides of the substrate, and UV light of 0.1 to IJ/a& is irradiated and exposed from both sides simultaneously. Next, the negative mask is peeled off from the resist surface, and the unexposed areas are dissolved and removed by development. A nonflammable chlorinated solvent such as 1,1,1-trichloroethane is used as a suitable solvent for darkening development, and a development time of 0.5 to 5 minutes is selected.

Next, the substrate is heated to harden the patterned resist portion. Curing conditions are 120 to 180°C10,
2 to 2 hours is selected.

Preferably, the heat-cured resist is irradiated with UV light again to accelerate curing of the resist.

The exposure amount suitable for such post-exposure is 1. to 10 J/ci.

Through the above steps, a resist layer is formed on the substrate [
Figure 1, 4).

Next, the board is immersed in a chemical copper plating solution, and a thick chemical copper plating is applied only to the main parts, such as inside the through-holes and on the lands, to produce a printed circuit board using the part additive method [Figure 1] , 5) Ko. The thickness of the copper plating is usually selected to be 10 to 40 μm. It is a particularly important advantage of the present invention that no peeling of the resist on the circuit copper foil occurs during such chemical copper plating.

In manufacturing printed circuit boards by the above-described part-additive method, the resist of the present invention can simultaneously satisfy all of the above-mentioned problems (,) to (m) of the present invention. This made it possible to manufacture high-density printed circuit boards using the parti-additive method.

〔Example〕

Hereinafter, the photosensitive solder resist composition having plating resistance of the present invention and the production of a printed circuit board using the same will be specifically explained.

A photosensitive solder resist composition having plating reactivity resistance of the present invention was prepared according to Table 1, and the properties 1) to 9) above were determined. The results are shown in Table 2.

The photosensitive solder resist composition used in the following examples was manufactured by the following method.

The diallyl phthalate resin used in the present invention as a polyfunctional unsaturated compound that is solid at room temperature is weighed, placed in a separable flask, and the weighed organic solvent is added thereto, mixed, and then heated at 80 to 100°C for 30 minutes. Dissolve with stirring for 2 to 2 hours. After the melt is cooled to room temperature, the remaining resist material is added and mixed by thorough stirring. Next, kneading was performed two to four times using a three-roll mill to prepare a resist ink for screen printing.

As the polyfunctional unsaturated compound that is solid at room temperature of the present invention, diallyl phthalate resin (Daiso Tsubu A: Daiso,
Pentaerythritol tetraacrylate was used as a polyfunctional unsaturated compound which is liquid at room temperature.

A mixture of benzophenone and 4,4'-bis(N,N'-dimethylamino)benzophenone was used as a photopolymerization initiator. As an epoxy resin, bisphenol A type Nipicote 828 (manufactured by Oil 7 Hishiel Nipoxy)
was used as a curing agent for the epoxy resin, and silicone oil 5H- was added as an antifoaming agent to which the compounds shown in Table 2 were added.
203 (203) (manufactured by Resilicone, Inc.) was used, and phthalocyanine green was used as the pigment. A mixture of ethyl cellosolve acetate and butyl cellosolve acetate was used as the organic solvent.

On the other hand, the printed circuit board was manufactured according to the following method.

1. Glass epoxy double-sided copper-clad laminate with 6mm thickness and 35μm copper foil [Fig. 1, 1) After drilling holes in the predetermined positions of the substrate, chemical copper plating catalyst was applied to the substrate including the through-holes. [Fig. 1, 2)].

Next, using a dry film resist for etching, a predetermined portion is etched by a tenting method.
Conductor circuits were formed on both sides of the substrate [Fig. 1, 3)].

Next, the photosensitive solder resist ink prepared by the above method was applied by screen printing to one side of the substrate including the conductive circuit, and the substrate coated with the resist was dried to solidify the resist. This method was repeated on the back side to form solidified resist layers on both sides of the substrate. Drying temperature is 80
℃ and the drying time is 1 hour.

Next, negative masks were brought into close contact with the solidified resist layers on both sides of the substrate, and UV light of 0.5 J/d was irradiated and exposed from both sides simultaneously. Next, the negative mask was peeled off from the resist surface, and the unexposed areas were dissolved and removed by development. 1,1.1-trichloroethane was used as the developing solvent and 1 minute was selected as the developing time.

Next, the substrate was heated to harden the patterned resist part 6. The curing conditions were 150°C for 1 hour.Furthermore, the heat-hardened resist was again heated with 3 J/d of U.
V light was irradiated to accelerate curing of the resist.

Through the above steps, a resist 1-layer was formed on the substrate [
Figure 1, 4)].

Next, the board was immersed in a chemical copper plating solution, and a thick chemical copper plating was applied only to the main parts, including the inside of the through holes and the top of the laminated sheet (Fig. 1, 5)].

A chemical copper plating solution having a primary composition was used.

The plating conditions were a bath temperature of 70°C and a bath pH of 12.5. The plating time was 15 hours, during which time the plating solution components were automatically replenished so that the plating solution composition and plating conditions remained constant. The deposition potential was approximately -0.7 .mu.m (reference to saturated calomel electrode), and the plating thickness was approximately 30 .mu.m.

Similarity 11g: λ) “Yono to Ai” (CuS04・5H, 0・・・・・・・・・・・・・・・
12g EDTA・2Na ・・・・・・・・・・・・
・・・・・・ 42g 37% formalin ・・・・・・・・・
・・・・・・・・・ 3mQN a OH・・・・・・
・・・・・・・・・Amount to adjust pH to 12.5 Ethoxy surfactant ・・・・・・・・・・・・・ 100mg2.2
'-Dipyridyl ・・・・・・・・・・・・ 50mg
Deionized water ・・・・・・・Quantity where the total amount is IQ Regarding the characteristics of the photosensitive solder resist composition having plating resistance of the invention and the print 1 circuit board using the same,
Judgment was made according to the following items and evaluation methods.

1) Coatability A coated film having a smooth surface without any voids or bubbles remaining in the coated film after Niscreen printing was evaluated as good.

2) Closely expose the negative mask to the resist surface.
After exposure to V light, when the negative mask was peeled off, the negative mask was rated as good if the resist did not adhere to it.

3) Developability: 1,1,1. - When the resist was spray developed with trichloroethane for 1 minute at room temperature, the unexposed areas were completely dissolved and the resist in the exposed areas did not swell, etc., and was evaluated as good.

4) Anti-bleed-through: Apply resist to a thickness of about 40 μm on both sides of a 1.6 mm thick glass epoxy laminate, dry it, and then irradiate it with UV light of 0.5 J/aJ from one side. Expose. When observed after development, the resist on the back side was evaluated as good if it was completely dissolved without hardening.

5) Alkali resistance: Resistance 1 was observed after chemical copper plating.
The surface of ~ was evaluated as good if it was not dissolved, discolored, or roughened.

6) Resistance to plating reactivity: Upon observation after chemical copper plating, those with no peeling or discoloration in the resist applied on the conductor circuit connected to the copper plating deposits were evaluated as good.

7) Plating elution resistance: 1 drr per IQ? When plating was applied to a thickness of approximately 30 μm using a chemical copper plating solution that was in contact with the resist, those with no abnormality in the crystal orientation of the deposited copper were evaluated as good.

8) Heat resistance: Apply solder flux to the printed circuit board after chemical mesh plating, immerse it in a 260°C solder bath for 10 seconds, and air cool it to room temperature. After repeating this operation 10 times, it was observed that the resist had no abnormality such as blistering or peeling, and was evaluated as good.

9) J formed on insulating glass epoxy network laminate
A resist is applied on a comb-shaped pattern according to I5-C-2519, and the insulation resistance when moisture is absorbed after chemical copper plating is 1.
Those with a resistance of 0.09Ω or more were considered good.

As a result of manufacturing a printed circuit board using the resist shown in Table 2, it was found that the cyanamide of the present invention could be used to satisfy all the characteristics.

It has also been found that the appropriate amount to be added is 2 to 20 parts by weight per 100 parts by weight of the other functionally unsaturated compound which is solid at room temperature. If it is less than 2 parts by weight, the adhesion between the resist and the conductor circuit will be insufficient, and the plating reactivity will not be sufficient. If it exceeds 20 parts by weight, excess cyanamide will slightly dissolve into the chemical copper plating solution and cause precipitation. It was found that an abnormality occurred in the crystal orientation of copper.

Regarding the crystal orientation of copper, it was determined whether it was normal or abnormal based on the following criteria. As a result of X-ray diffraction of the copper plating film, the orientation of the (111) plane is preferential in a normal copper plating film, whereas the (200) plane is preferentially oriented in an abnormal copper plating film. Although such abnormalities may not be noticeable in the mechanical properties such as tensile strength or elongation of the plating film, they may cause cracks in the copper plating through-holes when soldering and mounting printed circuit boards. Therefore, from the viewpoint of through-hole reliability, this is an abnormality that should not occur.

Furthermore, as is clear from Table 2, the appropriate range of 2-phenylimidazole used as a curing agent for epoxy resin is 0.
The amount was 1 to 5 parts by weight. If there is not enough curing agent, the resist will not have sufficient alkali resistance in the chemical copper plating solution due to lack of effectiveness, and if it is in excess, the effect reaction will proceed when the resist dries, resulting in unused parts during development. The exposed area was not completely dissolved.

It was also found that if the amount of curing agent is appropriate, the properties can be changed to the same extent regardless of the type of curing agent. [Comparative Example] Photosensitive solder resist composition with plating reactivity resistance of the present invention In order to compare with the conventional resist using dicyandiamide, a resist using conventional dicyandiamide was prepared according to Table 3, and
) characteristics were determined.

As shown in Table 4, although resists using dicyandiamide have good plating reactivity, copper plating with an abnormal crystal orientation in which the (200) plane is preferentially oriented may be deposited. It was found that it lacked plating elution resistance.

This abnormality also occurred when the amount of dicyandiamide blended was small, and it was also found that the use of dicyandiamide itself was not appropriate.

Below is a blank Table 3 [Effects of the Invention] As specifically explained above, the photosensitive solder resist composition having plating reactivity resistance of the present invention has excellent coating properties, adhesion exposure properties, developability, and anti-bleed-through properties. , has excellent alkali resistance, plating reaction resistance, plating elution resistance, heat resistance, and insulation properties, and is able to satisfy all of these properties at the same time, making it possible to apply the part-reactive method to printed circuit board manufacturing.

A high-density printed circuit board suitable for practical use can be obtained in a simplified manner.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the manufacturing order of a part-reactive printed circuit board according to the present invention. FIG. 2 is a diagram showing the manufacturing order of a subtract method printed circuit board. $ 1 Illustration

Claims (8)

[Claims] 1. It is characterized by containing a polyfunctional unsaturated compound that is solid at room temperature, a polyfunctional unsaturated compound that is liquid at room temperature, a photopolymerization initiator, an epoxy resin, a curing agent for the epoxy resin, and cyanamide. A photocurable resist composition. 2. In claim 1, the polyfunctional unsaturated compound that is solid at room temperature is a prepolymer of diallyl phthalate,
A photocurable resist composition characterized in that the polyfunctional unsaturated compound that is liquid at room temperature is a polyfunctional acrylate or methacrylate compound. 3. Claim 2, characterized in that the prepolymer of diallyl phthalate has a molecular weight of 3,000 to 30,000, and the polyfunctional unsaturated compound that is liquid at room temperature is a polyfunctional acrylate or methacrylate compound with a functional group number of 3 or more. A photocurable resist composition. 4. The photocurable resist composition according to claim 1, wherein the curing agent for the epoxy resin is an imidazole derivative. 5. In claim 1, cyanamide is 2 to 20 parts by weight per 100 parts by weight of diallyl phthalate prepolymer.
A photocurable resist composition characterized in that the parts by weight are parts by weight. 6. For 100 parts by weight of diallyl phthalate prepolymer, the amount of polyfunctional acrylate or methacrylate compound that is liquid at room temperature is 5 to 30 parts by weight, the amount of photopolymerization initiator is 2 to 12 parts by weight, and the epoxy resin is mixed. A photocurable resist composition characterized in that the amount of the curing agent for epoxy resin is 0.1 to 5 parts by weight, and the amount of cyanamide is 2 to 20 parts by weight. 7. A printed board characterized by using the photocurable resist composition according to any one of claims 1 to 6. 8. 8. The printed circuit board according to claim 7, wherein a photocurable resist is formed on the copper foil circuit, and then through-hole connections are made by chemical copper plating.