JPS62226145A - Solder resist - Google Patents

Abstract

PURPOSE:To obtain a resist having superior developability and dimensional accuracy as well as superior electric characteristics, general purpose heat resistance and moisture resistance, etc., by forming a solder resist from a specified partially (meth)acrylated epoxy resin, specified reaction products, photosensitizer, and a heat curing agent. CONSTITUTION:Partially (meth)acrylated cresol novolak type epoxy resin contg. 0.3-0.8 equiv. (meth)acrylic acid basing on 1 epoxy equiv. of the cresol novolak type epoxy resin, and a reaction product between diisocyanate trimer contg. at least three isocyanate groups and at least one isocyanure ring and a compd. having at least two (meth)acryloyl groups and at least one OH group, is incorporated into a solder resist as its essential components. The resist can be cured easily by heating or irradiation with light after it is coated on a substrate. The developability in the image forming stage is also superior.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention can be easily cured by light irradiation and heating, and the cured film has excellent mechanical properties, electrical properties, and heat resistance. The present invention relates to a solder resist for printed wiring boards that has good properties, moisture resistance, and developability.

(Prior art) Conventionally, in the production of printed wiring boards, an image-shaped protective film using solder resist is formed on the board to protect circuits and prevent bridging when various parts are soldered to the board. ing.

As such a solder resist, one whose main component is generally a thermosetting epoxy resin or a photocurable acrylate or methacrylate resin is used. Among these resins, thermosetting epoxy resins have excellent electrical properties, soldering heat resistance, moisture resistance, and adhesive properties. There is a problem in that high-density and fine patterns cannot be formed due to poor dimensional accuracy.

In addition, photocurable acrylate or methacrylate resins have excellent workability because they can be cured in a short time by light irradiation, and the above-mentioned screen printing method or photographic method can be applied as an image forming method. can.

In this photography method, a resist containing a photocurable resin layered on a printed wiring board is exposed through a negative mask, and then the unexposed areas are removed with a solvent.

This is a method of forming an image corresponding to a negative mask.

Since it is possible to obtain images with high dimensional accuracy, this method is preferable as a method for forming high-density fine patterns. As described above, photocurable acrylate resin has excellent properties as a solder resist material, but its electrical properties
The solder heat resistance, moisture resistance, etc. cannot be fully satisfied.

In order to solve the above-mentioned problems with the solder resist, JP-A-60-208377 discloses a reaction product of a phenol novolac type epoxy resin and an unsaturated basic acid,
A resin composition comprising a reaction product of a cresol novolac type epoxy resin and an unsaturated basic acid, an organic solvent, a photopolymerization initiator, and an amine curing agent is disclosed. However, the phenol novolac type epoxy resin used here has lower solubility in organic solvents than the cresol novolac type epoxy resin, and the solubility of the reaction product obtained by reacting it with an unsaturated basic acid further decreases. Therefore, when the above composition is used as a solder resist, the types of solvents that can be used as a developer are limited. That is, it is widely used from the viewpoint of ensuring safety in the manufacturing process of printed wiring boards. There are problems such as difficulty in dissolving in nonflammable developers such as 1,1.1-trichloroethane, trichloroethylene, and tetrachloroethane, and the time required for development due to poor solubility. This is also a major hindrance in actual work.

(Problems to be Solved by the Invention) As mentioned above, conventional photocurable solder resists have poor developability and dimensional accuracy when forming images using them, and also have The membrane's electrical properties, single-use heat resistance, moisture resistance, etc. were not sufficient.

Therefore, the present invention solves the above problems and also
The object of the present invention is to provide a solder resist that also has excellent mechanical properties.

[Structure of the Invention] The present invention provides a partial acrylic resin to which 0.3 to 0.8 equivalents of acrylic acid and/or methacrylic acid is added per 1 epoxy equivalent of a cresol novolac type epoxy resin as a main component of a solder resist. and/or methacrylated Talesol novolac type epoxy resin; a trimer of diisocyanate containing at least one isocyanuric ring and at least three isocyanate groups; and at least two Agel IJQyl groups and/or methacryloyl groups. The above object is achieved by containing a reaction product with a compound containing at least one hydroxyl group.

(a) Partially acrylated and/or methacrylated epoxy resin, which is the first component constituting the solder resist of the present invention, is obtained by subjecting a cresol novolak type epoxy resin to an addition reaction with acrylic acid, methacrylic acid, or a mixture thereof. It is something that can be done.

The epoxy resins that can be used in this case are limited to cresol novolak type, other types of epoxy resins,
For example, partially acrylated and/or methacrylated epoxy resins obtained using epoxy resins such as bisphenol A type, bisphenol F type, phenol novolac type, hydrogenated bisphenol A type, and diglycidyl ester type of aromatic carboxylic acids. The solder resist used as raw material.

Cannot be used because the cured film has poor solder heat resistance.

The reaction method can be carried out by a conventional method, and in the reaction, 0.3 to 0.8 equivalents of acrylic acid etc., preferably 0.4 to 0.8 equivalents, per 1 epoxy equivalent of the cresol novolac type epoxy resin. Addition reaction is carried out using If the equivalent weight of acrylic acid or the like used in the reaction is less than 0.3, the resulting epoxy resin will have poor photocurability, and blisters will occur in the cured film during the after-cure process after development. Also,
If it exceeds 0.8, developability will be extremely reduced when a commonly used developer containing 95% or more of 1,1,1-trichloroethane is used.

The amount of acrylic acid, etc. reacted with the epoxy resin is defined within the above range, but by appropriately changing this reaction amount, an epoxy resin with a desired acrylation rate or methacrylation rate can be obtained. . The developability can be improved by appropriately adjusting this acrylation rate depending on the type of developer. For example, when using a trichloroethane-alcohol complex developer.

When the acrylation rate of the epoxy resin is adjusted to about 80% and trichloroethane is used as a developer, the acrylation rate can be adjusted to about 50%.

The second component constituting the solder resist of the present invention (b) is a trimer of diisocyanate containing at least one isocyanuric ring and at least three incyanate groups, and at least two 7-acryloyl groups and/or Alternatively, a reaction product of a methacryloyl group and a compound containing at least one hydroxyl group can provide the solder resist of the present invention with excellent sensitivity during exposure, and also has excellent solubility in organic solvents. It also has excellent developability due to its high . Furthermore, excellent heat resistance, surface hardness, and solvent resistance can be added to the cured film after heat curing.

As the diisocyanate which is a raw material for synthesis of one of the reaction products which is component (b), either aliphatic diisocyanate or aromatic diisocyanate can be used.
Examples of aliphatic diisocyanates include 2,2-isocyanatoethane, 3-diisocyanatopropane,
1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatobutane, 1.7-
Examples of aromatic silicyanates include 2,4-tolylene diisocyanate, 2゜6-tolylene diisocyanate, 3,
Examples include 3-bitrylene-4°4'-diisocyanate, diphenylmethane-4,4-diisocyanate, and 3,3ξdimethyldiphenylmethane-4,4'-diisocyanate.

In addition, compounds containing at least two acrylic groups and/or methacrylic groups and at least one hydroxyl group include:
Mention may be made of glycerin diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and the corresponding methacrylates. Moreover, the above-mentioned compound can also contain both an acryloyl group and a methacryloyl group in one compound.

The mixing ratio of component (b) to component (a) is 5 to 80 parts by weight, preferably 1 part by weight per 1.00 parts by weight of component (a).
If the blending ratio of 0 to 50 parts by weight is less than 5 parts by weight, the photocurability of the solder resist will be poor, the sensitivity will decrease, and the surface hardness, heat resistance, and solvent resistance of the cured film obtained after heat curing will be poor. decreases. Moreover, when the blending ratio exceeds 80 parts by weight.

The cured film obtained after heat curing loses its flexibility, causing cracks at the cut edges during the kernel test, and furthermore causes problems such as migration of the solder resist to the negative mask side during exposure.

The photosensitizer (Q), which is the third component constituting the solder resist of the present invention, is a component that polymerizes components (a) and (b) by irradiation with light, and there are no particular restrictions on this photosensitizer. However, for example, bisacetyl, acetophenone, benzophenone, benzyl, benzoin isobutyl ether, benzyl dimethyl ketal, benzoyl peroxide, (1-hydroxycyclohexyl) phenyl ketone, (1-hydroxy-1-methylethyl) phenyl ketone, p-isopropyl - Complex system of carbonyl compounds such as α-hydroxyisobutylphenone, ketones such as diethylthioxanthone, and ethyl anthraquinone, and amines such as bis(diethylamino)benzophenone, ethyl(diethylamino)benzoate, benzyldimethylamine, and triethanolamine. Mention may be made of photosensitizers.

The mixing ratio of component (Q) to component (a) is 2 to 15 parts by weight, preferably 5 parts by weight per 100 parts by weight of component (a).
~10 parts by weight. If the blending ratio is less than 2 parts by weight, the photocurability of components (a) and (b) will be poor, and if the blending ratio exceeds 15 parts by weight, the heat resistance, moisture resistance, and electrical properties of the cured resist product will deteriorate. deteriorates.

The thermosetting agent (d), which is the fourth component constituting the solder resist of the present invention, is produced by crosslinking the epoxy groups in the partially acrylated and/or methacrylated epoxy resin, which is the component (a), by heating. It is a component that imparts excellent heat resistance, electrical properties, moisture resistance, etc. to the resin.

Component (d) is not particularly limited, but includes, for example, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N-aminoethylpiperazine, benzyldimethylamine, and tris(dimethylaminomethyl)phenol (DMP-30).

DMP-30-tri(2-ethyl acrylate) 2, hetaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, aromatic amine eutectic mixture modified curing agent; polyamide resin, dicyandiamide, boron trifluoride, monoethylamine, methane Examples include amine derivatives such as diamine, xylene diamine, bisaminopropyltetraoxaspirone undecane adduct, and imidazole derivatives such as ethylmethylimidazole; one or more of these may be used.

The mixing ratio of component (d) to component (a) is 0.5 to 5 parts by weight, preferably 2 to 4 parts by weight, per 100 parts by weight of component (a). If the blending ratio is less than 0.5 parts by weight, the curing properties of component (a) will be poor, and if it exceeds 5 parts by weight, the heat resistance will be poor, the solder resist will deteriorate quickly, and the manufacturing cost will increase. I end up.

In the solder resist of the present invention, a compound having an acryloyl group and/or a methacryloyl group can also be included as a constituent component in addition to the components (a) to (d) above. This compound is used for the purpose of adjusting the viscosity of the solder resist, improving the surface curability, improving the photocurability, and imparting flexibility to the cured product.

Such a compound is preferably one that can be copolymerized with component (a). This is because if the compound cannot copolymerize with component (a), the electrical properties, soldering heat resistance, moisture resistance, solvent resistance, etc. of the cured product will be significantly reduced. Acrylic acid esters are generally known as compounds having such an acryloyl group and/or methacryloyl group.

Methacrylic esters, acrylate resins, and methacrylate resins can be used.

Specific examples include methyl acrylate, ethyl acrylate, propyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate, Propyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-3
- Phenoxypropyl methacrylate, tetrahydrofurfuryl methacrylate, methoxydiethylene glycol methacrylate, methoxydiethylene glycol acrylate, methoxytetraethylene glycol methacrylate, methoxytetraethylene glycol acrylate, phenoxyethyloxyethyl methacrylate, phenoxyethyloxyethyl acrylate, phenoxypolyethylene glycol methacrylate, phenoxypolyethylene glycol Acrylate, 3-chloro-2-
Hydroxypropyl methacrylate, 3-chloro-2-
Hydroxypropyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol Diacrylate, propylene glycol dimethacrylate, dipropylene glycol diacrylate, dipropylene glycol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate.

1.4-Butylene gelicol diacrylate, 1゜4-
Butylene gelicol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, 2-hydroxy-1,3-diacryloxypropane, 2 -Hydroxy-1,3-dimethacrylokydi-propane, 2,
2-bis[4-(acryloxyjethoxy)phenyl]
Propane, 2,2-bis[4-(methacryloxyjethoxy)phenyl]propane, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethanetetramethacrylate, tetramethylolmethanetetraacrylate, Tetramethylolmethane tetramethacrylate, polyester diacrylate, polyester dimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri(methacryloxyethoxy) cyanurate, tri(acryloxyjethoxy) cyanurate, tri(methacryloxyjethoxy) cyanurate Toxy) cyanurate, tri(1,3-diacryloxy 2-propoxy) cyanurate, tri(1゜3-dimethacryloxy 2)
-propoxy) cyanurate, tri(2-acryloxyethyl) phthalate, di(2-methacryloxyethyl)
Phthalate, di(2-acryloxyethyl) isophthalate, di(2-methacryloxyethyl) isophthalate, di(2-acryloxyethyl) terephthalate, di(
Examples include 2-methacryloxyethyl) terephthalate, glycidyl acrylate, and glycidyl methacrylate, and one or more of these can be used.

The compounding ratio of this compound having an acryloyl group and/or methacryloyl group is the total amount of components (a) to (d) 1
0 to 20 parts by weight, preferably 0 to 1 part by weight
5 parts by weight. If the blending ratio exceeds 20 parts by weight, the electrical properties, heat resistance, moisture resistance, etc. of the cured film will deteriorate.

In addition, the solder resist of the present invention further contains a flame retardant agent, a dye, a pigment, a leveling agent, an antifoaming agent, an inorganic filler, and an adhesion agent, if necessary.

Polymerization inhibitors, solvents, etc. can be blended, but the blending ratio is 50% by weight or less, preferably 40% by weight or less, based on the weight of the solder resist.

If the blending ratio exceeds 50% by weight, the curing properties of the resist will be poor, which is not preferable.

The solder resist of the present invention can be obtained by adding each of the components (a) to (d) and other components as necessary and mixing them until uniform.

When manufacturing a printed wiring board using the solder resist of the present invention, either a screen printing method or a photographic method can be applied.

In these methods, the wavelength of the light used during exposure is usually 180 to 700 nm, preferably 180 to 40 nm.
It is 0 nm. In addition, the temperature during heat curing is usually 50 to 2
20°C, preferably 100-200'C.

(Example) The present invention will be further explained in detail with reference to Examples and Comparative Examples below. In addition, all "parts" in Examples and Comparative Examples are "parts by weight."
represents.

Example 1 1000 parts of Epiclon N-673 (trade name: manufactured by Dainippon Ink Co., Ltd.; cresol novolak type epoxy resin) and 100 parts of n-butyl cellosolve were heated to 120°C,
After dissolving, 1 part of p-methoxyphenol and 5 parts of triphenylphosphine were further added and dissolved. Next, 170 parts of acrylic acid was added while blowing air into the solution while maintaining the temperature at 95°C. Then, after reacting at this temperature for 6 hours, dimethylformamide 10
0 parts was added and cooled to room temperature to obtain a 50% acrylated epoxy resin.

Next, a solder resist of the present invention was manufactured.

First, 100 parts of the above 50% acrylated epoxy resin,
■Acrylic resin 20 which is a reaction product of 6-dicyanatohexane trimer and glycerin diacrylate
5 parts of n-butyl cellosolve, 10 parts of dimethylformamide, 1.5 parts of phthalocyanine green, 2 parts of silica powder, 20 parts of talc, 5 parts of benzyl dimethyl ketal, and 2 parts of dicyandiamide, and further kneaded with a roll to form a solder resist. I got it. The viscosity of this resist is 2
It was 140 cPs at 5°C.

This solder resist was applied uniformly over the entire surface of the IPC-B-25 test circuit board, dried at 80°C for 1 hour, and then exposed to ultraviolet light at an illuminance of 10 mW/cn using a high-pressure mercury lamp through a negative ask. . Next, the film was developed using 1,1,1-trichloroethane for 30 seconds, and then heated and cured at 150°C for 1 hour. As a result, an accurate cured film compatible with negative masks was obtained. The following tests were conducted on this circuit board. The results are shown in the table.

(a) Crosscut tape peeling test: According to the test method of JISD-0202, a crosscut in the shape of a crosscut was made on a test piece, and then a peeling test using cellophane tape was performed.

(b) Pencil hardness: Changes in appearance and adhesiveness of the coating film were observed after immersion in a solder bath at 260° C. for a total of three times for 20 seconds each time.

(d) Insulation: (i) IPC-8M-840metho
Electrical resistance was measured under normal conditions according to d2.5.23 and (ii) after being held for 7 days in an atmosphere of 50° C. and 95% relative humidity.

Example 2 Epicron N-673, 1000 parts and toluene 100
1 part of D-methoxyphenol, 10 parts of choline chloride and 170 parts of acrylic acid were dissolved at 120°C.
After adding 50% of the mixture, the mixture was reacted at 95°C for 4 hours. After washing the reaction solution with water and removing remaining water and toluene, 100 parts of n-butyl cellosolve and 100 parts of dimethylformamide were added, and after further removing remaining toluene, it was cooled to room temperature and partially acrylated. An epoxy resin was obtained.

Next, a solder resist was obtained using the acrylated epoxy resin obtained by the above method and using the same method as in Example 1 except for the other components. The viscosity of this resist is 153 cPs at 25°C.
Met. Using this solder resist, coating, drying, exposure, development, and heat curing were performed in the same manner as in Example 1. As a result, an accurate cured film compatible with negative masks was obtained. Further, each of the tests (a) to (d) similar to those in Example 1 were conducted on this cured film. The results are shown in the table.

Example 3 Example 2 except that the amount of acrylic acid added was 238 parts.
A 70% acrylated epoxy resin was obtained in the same manner as above.

100 parts of the above 70% acrylated epoxy resin, ■, 6
- 30 parts of an acrylic resin which is the reaction product of a trimer of dicyanatohexane and glycerin diacrylate, n
- 5 parts of butyl cellosolve, 20 parts of dimethylformamide, 1.5 parts of phthalocyanine green, 2 parts of silica powder,
20 parts of talc, 5 parts of benzyl dimethyl ketal, and 2 parts of dicyandiamide were mixed and further kneaded with a roll to obtain a solder resist. The viscosity of this resist was 154 cPs at 25°C.

This solder resist was applied to the substrate in the same manner as in the example, dried, and exposed to light, then developed with a mixed solution of 1,1.1-trichloroethane and methanol (95:5) for 30 seconds, and then heated at 150°C for 1 hour. hardened. As a result, an accurate cured film compatible with negative masks was obtained. This cured film was treated in the same manner as in Example 1 (a) to (d).
Each test was conducted. The results are shown in the table.

Example 4 Except that the amount of acrylic acid added was 272 parts.

An 80% acrylated epoxy resin was obtained in the same manner as in Example 2.

Next, 100 parts of the epoxy resin, 20 parts of an acrylic resin which is a reaction product of a trimer of 1,6-dicyanatohexane and glycerin diacrylate, 5 parts of n-butyl cellosolve, 20 parts of dimethylformamide, 1. 5 parts, 2 parts of silica powder, 20 parts of talc,
5 parts of benzyl dimethyl ketal and 2 parts of dicyandiamide
The components were mixed and further kneaded with a roll to obtain a solder resist.

This solder resist, which had a viscosity of 173 cPs at 25° C., was applied to a substrate in the same manner as in Example 3, and subjected to exposure, development, and heat curing treatments. As a result, an accurate cured film compatible with negative masks was obtained. Each of the tests (a) to (d) was conducted on this cured film in the same manner as in Example 1. The results are shown in the table. Note that (a) in the table indicates that all 100 rows were not peeled off.

As is clear from the table, the solder resists obtained in Examples 1 to 4 exhibited excellent properties in terms of contact strength with the substrate, hardness, soldering heat resistance, and insulation properties.

Comparative Example 1 Epicuron N-673, 100 parts and acrylic acid 340
Example 2
A 100% acrylated epoxy resin was obtained in the same manner as above.

Next, 100 parts of the epoxy resin, 20 parts of an acrylic resin which is a reaction product of a trimer of 1,6-dicyanatohexane and glycerin diacrylate, 5 parts of n-butyl cellosolve, 1.5 parts of phthalocyanine green, and silica powder. 2 parts, 20 parts of talc and 5 parts of benzyl dimethyl ketal
A solder resist obtained by mixing the parts and kneading with a roll was applied, dried, and exposed in the same manner as in Example 4.

Thereafter, development was performed for 5 minutes using 1.1.1-trichloroethane, but sufficient development could not be performed. Also, 1,1.1
- When developing with a mixed solution of trichloroethane and methanol (95:5), sufficient development could not be achieved within 2 minutes. Development was possible in 3 minutes, but at 140°C after development.
When heated, the cured film blistered.

Comparative Example 2 Same composition as Example 4 except that 80 parts of the 100% acrylated epoxy resin obtained in Comparative Example 1 and 20 parts of Epicron N-673 were used instead of the 80% acrylated epoxy resin in Example 4. A solder resist was prepared.

Using this solder resist, it was applied to a substrate in the same manner as in Example 4, dried, exposed, developed, and heat-treated. As a developer, 1,1.1-trichloroethane and 1,1.1-trichloroethane and methanol (95%
: The mixture of 5) was used and the heating temperature was 140°C. As a result, the cured film partially blistered during the heat treatment.

Comparative Example 3 A solder resist having the same composition as in Example 1 was produced except that the acrylic resin obtained by reacting the trimer of 1,6-dicyanatohexane with glycerin diacrylate was removed.

This solder resist was applied to a substrate in the same manner as in Example 1, dried, exposed, developed, and then heated.

At this time, blistering occurred in a part of the coating film during the heat treatment. Further, the pencil hardness of the coating film in the area where no blistering occurred was 2H.

Comparative Example 4 A solder resist having the same composition as in Example 4 was produced except that the acrylic resin obtained by reacting the trimer of 1,6-dicyanatohexane with glycerin diacrylate was removed.

This solder resist was applied to a substrate in the same manner as in Example 4, dried, exposed, and developed.

It was then heat treated.

When the obtained test piece was tested for soldering heat resistance,
Blistering occurred on the paint film.

Comparative Example 5 Except that 20 parts of a 100% acrylated phenol novolac type epoxy resin was used instead of 20 parts of an acrylic resin obtained by reacting a trimer of 1.6-dicyanatohexane with glycerin diacrylate. A solder resist having the same composition as in Example 1 was prepared.

This solder resist was applied to a substrate in the same manner as in Example 1, dried, exposed and then developed, but sufficient development was not achieved even after 3 minutes of development.

[Effect of the invention] As explained above, the solder resist of the present invention has the following effects:
After being applied to a substrate, it can be easily cured by light irradiation and heating, and this cured film exhibits excellent properties such as bonding strength to the substrate, hardness, soldering heat resistance, and insulation properties.

It also has excellent developability during image formation. Therefore, the solder resist of the present invention is extremely useful as a solder resist for manufacturing printed wiring boards.

Claims (2)

[Claims] (1) (a) Cresol novolac type epoxy resin 1
Partially acrylated and/or methacrylated epoxy resin to which 0.3 to 0.8 equivalents of acrylic acid and/or methacrylic acid are added relative to the epoxy equivalent; (b) at least one isocyanuric ring and at least three isocyanuric rings; reaction product of a trimer of diisocyanate containing isocyanate groups and a compound containing at least two acryloyl and/or methacryloyl groups and at least one hydroxyl group; (c) a photosensitizer; and ( d) A solder resist comprising a thermosetting agent. (2) The blending ratio of each component in the solder resist is 5 to 80 parts by weight of component (b), 2 to 15 parts by weight of component (c), and 0.5 parts by weight of component (d) to 100 parts by weight of component (a).
5 parts by weight of the solder resist according to claim (1).