JPS63205649A - Liquid photo solder resist composition - Google Patents

Abstract

PURPOSE:To improve solder plating resistance by compounding an ester compd. obtd. from monohydric alcohol and (or) monovalent epoxy compd., cresol and phenol novolak type epoxy compd., and radical-polymerizable novolak type epoxy compd. having no epoxy groups except ester. CONSTITUTION:This compdsn. is compounded with 100pts.wt. mixture composed of the esterified compds. (A) obtd. by bringing the radical-polymerizable monohydric alcohol and (or) monovalent epoxy compd. and non-radical- polymerizable monohydric alcohol and (or) monovalent epoxy compd. at 0.05-0.95mol. ratio per mol. of a copolymerized maleic anhydride and itaconic anhydride component and one or >=two kinds of the epoxy compds. (B) selected from triglycidyl isocyanurate, cresol novolak type epoxy resin and phenol novolak type epoxy resin, etc., and 10-100pts.wt. radical-polymerizable compd. (C) having no epoxy groups except the above-mentioned (A). The solder plating resistance is thereby improved.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is suitably used in printed circuit manufacturing processes, etc., and provides excellent The present invention relates to a liquid photosolder resist composition that exhibits solder plating resistance.

(Prior art) Conventionally, as a liquid photo solder resist, n□light 1
．． A solvent-developable type that is developed using a halogenated organic solvent such as 1,1,1-trichloroethane has been known. However, halogen-based organic solvents are highly toxic among organic solvents, and from the viewpoint of protecting the working environment and preventing air pollution, it has been desired to switch to an alkaline developing type in which development is performed using a 9 weak alkali aqueous solution.

However, the alkali-developable liquid photo solder resist compositions that have been proposed so far harden gradually even in a cool and dark place and gel in a few days to about 1 iPi, so it is necessary to mix a curing agent immediately before use. It is used as a liquid type, and has the disadvantage that it is troublesome to measure and mix the two components and that it is difficult to reuse the liquid photo solder resist composition remaining after printing and coating.

(Problems to be Solved by the Invention) The present invention improves the various drawbacks mentioned above, has excellent storage stability, can be used as a one-component type, can be developed with a slightly weak alkaline aqueous solution, and has a The present invention provides a liquid photosolder resist composition that exhibits excellent solder plating resistance.

[Structure of the invention]

(Means for Solving the Problems) The present invention is a method of copolymerizing 10 mol% or more of maleic anhydride and/or itaconic anhydride with 90 mol% or less of a radically polymerizable monomer other than maleic anhydride and itaconic anhydride. per mole of maleic anhydride and itaconic anhydride components of the copolymerized product obtained by

A radically polymerizable monohydric alcohol and (or) a monohydric epoxy compound, and optionally a non-radically polymerizable monohydric alcohol and (or) a monohydric epoxy compound are reacted at a ratio of 0.05 to 0.95 mol. The resulting esterified product (A), and one or more epoxy compounds selected from triglycidyl isocyanurate, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, Talezol novolac type epoxy resin, and phenol novolac type epoxy resin ( 100 parts by weight of a mixture consisting of B), 1 radically polymerizable compound (C) having no epoxy group other than the above (A)
0 to 200 parts by weight, and an organic solvent (D) if necessary
A liquid photosolder resist composition consisting of:

In the present invention, the radically polymerizable monomers other than maleic anhydride and itaconic anhydride to be copolymerized with maleic anhydride and/or itaconic anhydride include those that do not gel with maleic anhydride and/or itaconic anhydride. It is a copolymerizable monomer.

Epoxy groups and isocyanate groups that react with acid anhydride groups.

It is a monomer that does not have active groups such as hydroxyl groups or amino groups. Such monomers include styrene,
Styrenic monomers such as α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate,
(Meth)acrylic acid alkyl esters such as butyl (meth)acrylate, vinyl acetate, etc., or mixtures thereof can be used, but in terms of the hardness of the obtained liquid photosolder resist composition after exposure and development,
It is preferable to use a material containing styrene, α-methylstyrene, methyl methacrylate, or a mixture thereof as a main component. 2. (Meta) within the range that does not impede the performance of the liquid photosolder resist composition of the present invention.
It may also contain unsaturated acids such as acrylic acid and maleic acid.

A copolymer is obtained by copolymerizing 10 mol% or more of maleic anhydride and/or itaconic anhydride with 90 mol% or less of a monomer other than maleic anhydride and itaconic anhydride. If the amount of maleic anhydride and/or itaconic anhydride is less than 10 mol%, after exposure, the solubility of the unexposed part in a weak alkaline aqueous solution becomes low, and the solder plating resistance of the exposed part becomes low. .

radically polymerizable monohydric alcohol and/or monohydric epoxy compound per mol of maleic anhydride and itaconic anhydride components of the obtained copolymer.

and, if necessary, a monohydric alcohol and/or monohydric epoxy compound that is not radically polymerizable.
The esterified product (A) is obtained by reacting at a ratio of 95 moles.

Examples of radically polymerizable monohydric alcohols include hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate, allyl alcohol, etc. , or a mixture thereof can be used, since the esterification reaction with the maleic anhydride and itaconic anhydride components of the resulting copolymer is fast, and the curing reaction of the esterified product (A) upon exposure is fast.

It is preferable to use 2-hydroxyethyl (meth)acrylate, and as the radically polymerizable monovalent epoxy compound, glycidyl (meth)acrylate, allyl glycidyl ether, cyclohexene vinyl monoepoxide, etc., or a mixture thereof may be used. Can be done.

Further, in order to adjust the density of ethylenic double bonds of the obtained esterified product (A), that is, the balance between curability upon exposure and solubility in a weak alkaline aqueous solution.

A non-radically polymerizable monohydric alcohol and/or monohydric epoxy compound can also be used in combination with the above-mentioned radically polymerizable monohydric alcohol and/or monohydric epoxy compound. Such monohydric alcohols that are not radically polymerizable include aliphatic monohydric alcohols such as methanol, ethanol, propyl alcohol, butanol, benzyl alcohol, aromatic alcohols such as alkylene oxide adducts of phenol and alkylphenols,
Alicyclic alcohols such as cyclohexanol or mixtures thereof can be used. In addition, monovalent epoxy compounds that are not radically polymerizable include alkyl glycidyl ethers such as n-butyl glycidyl ether, aryl glycidyl ethers such as phenyl glycidyl ether, alkylene oxides such as styrene oxide, propylene oxide, and octylene oxide, and tertiary carbon Examples include acid glycidyl esters.

2 radically polymerizable monohydric alcohols and/or monohydric epoxy compounds reacted with 1 mol of the maleic anhydride and itaconic anhydride components of the above copolymer, and if necessary, a non-radically polymerizable monohydric alcohol. And/or when the proportion of the monovalent epoxy compound is less than 0.05 mol, the solubility of the unexposed part in a weak alkaline aqueous solution becomes low after exposure, and the solder plating resistance of the exposed part becomes low.

When the amount exceeds 0.95 mol, the solder plating resistance of the exposed portion becomes low.

In the present invention, the epoxy compound (B) includes:

Triglycidyl isocyanurate (TG I G),
One or more selected from hydroquinone dicrycidyl ether, bisphenol S diglycidyl ether, Talezol novolac type epoxy resin, and phenol novolac type epoxy resin is used, but TGI
Those containing C as a main component have particularly high storage stability, and it is most preferable to use such resins. Typical examples of the above Talesol novolac type epoxy resins include:
"Epicron N-695" (manufactured by Dainippon Ink & Chemicals, trade name).

A typical example of a phenol novolac type epoxy resin is "Epicron N-775J (manufactured by Dainippon Ink & Chemicals, trade name)".

"Epicoat 154J (made by Yuka Shell Epoxy ■)"
Examples include rDEN431j, rDEN438J (manufactured by Dow Chemical Company), and rEPN1138J (manufactured by Ciba Corporation) (all trade names).

There is no particular restriction on the amount of the epoxy compound (B) relative to the esterified product (A), but the equivalent ratio of the epoxy compound (B) to the maleic anhydride and itaconic anhydride components of the esterified product (A) is 0. It is preferable to use them at a ratio of 5 to 1.5, particularly preferably at an equivalent ratio of around 1.0. When the epoxy compound (B) is used at an equivalent ratio of less than 0.5 or more than 1.5, the solder plating resistance tends to be slightly lowered.

Furthermore, when the amount of the radically polymerizable monohydric alcohol and/or monohydric epoxy compound to be reacted with the copolymer is large, the amount of the epoxy compound (B) can be reduced.

In the present invention, as the radically polymerizable compound (C) having no epoxy group other than the above (A), ethyl (meth)
Acrylebutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate.

Mono (meth)acrylates such as 2-hydroxypropyl (meth)acrylate, styrene, α-alkylstyrene, oligoester (meth)monoacrylate (meth)acrylic acid, ethylene glycol di(meth)acrylate, polyethylene glycol diacrylate,
Neopentyl glycol di(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate ) acrylate, dipentaerythritol hexa(meth)acrylate, 2-hydroxy-1-(meth)acryloxy-3-(meth)acryloxypropane, polyester poly(meth)acrylate, polyurethane poly(meth)acrylate, etc. ) Acrylates, diallylphthalates, etc., or mixtures thereof can be used,
From the viewpoint of adhesion to copper foil circuits, it is preferable to use materials containing hydroxyl or carboxyl groups as the main component, and from the viewpoint of adhesion to copper foil circuits, curing properties, and plasticity, tetramethylolmethanetris is preferred. It is preferable to use a material containing acrylate as a main component.

10 to 200 parts by weight of (C) is used per 100 parts by weight of the mixture consisting of (A) and (B).

If the amount of (C) is less than 10 parts by weight, curing will be insufficient,
After exposure, the exposed area peels off during development with a weakly alkaline aqueous solution, and if the amount exceeds 200 parts by weight, the tack becomes strong.
The mask will stick and contact exposure will no longer be possible.

In the present invention, an organic solvent (D) can be used as necessary for purposes such as viscosity adjustment. Organic solvent (D)
is appropriately selected depending on the type of epoxy compound (B). Examples of such organic solvents (D) include ethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ethers, and ethylene glycol dialkyl ethers.

Diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates.

In addition to diethylene glycol monoalkyl ether acetates, when the epoxy compound (B) is triglycidyl isocyanurate, hydroquinone diglycidyl ether, or bisphenol S glycidyl ether, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

Esters such as ethyl acetate, butyl acetate, isopropyl acetate, aromatic hydrocarbons such as toluene and xylene,
Dimethylformamide and the like can be used.

The liquid photosolder resist composition of the present invention includes:

As necessary, dyes and pigments such as phthalocyanine green and titanium white may be added to make it easier to check the printing application state, thixotropic agents such as finely divided silica to adjust fluidity, and fluidity may be added to the extent that does not impede its performance. extender pigments such as talc, magnesium carbonate, calcium carbonate, natural mica, and synthetic mica to adjust and facilitate development; polymerization inhibitors to prevent dark reactions and increase storage stability;
Additives (E) such as waxes or thermal polymerization initiators
can be added. As the synthetic mica, it is preferable to use colloidal fluorine-containing magnesium silicate "Dimonite" series (manufactured by Tobie Industries, trade name), which is a synthetic mica in which the water of crystallization of natural mica is replaced with fluorine. Further, when the radiation used for exposure is ultraviolet rays, from the viewpoint of curability, it is preferable to add a photopolymerization initiator and, if necessary, a photopolymerization accelerator (F). Examples of such photopolymerization initiators include benzophenone, methylbenzophenone, and 0-hensoylbenzoin.
, benzoylethyl ether.

Examples of photopolymerization accelerators include 2,2-diethoxyacetophenone and 2,4-diethylthioxanthone.
Examples include isoamyl dimethylbenzoate, 4,4-bis(diethylamino)benzophenone, and dimethylethanolamine.

(A), (B) and (C) above, as necessary (
D), (E) and (F) are mixed and kneaded or mixed using a dispersing means such as a triple roll or a ball mill, or a stirring means such as a super mixer. The liquid photo solder resist composition obtained by kneading or mixing in this manner is used for screen printing.

Printing is applied to the entire surface of the copper foil circuit using methods such as roll coating, curtain flow coating, and spray coating.

After printing and applying, if necessary, use far infrared rays or warm air to
The organic solvent (D) is removed by prebaking at about 0 to 80° C., and exposure to radiation is performed using a negative mask that does not allow radiation to pass through only the portion to be soldered. Negative film is used as a negative mask when the radiation is ultraviolet rays.

In the case of electron beams, metal masks are used, and in the case of X-rays, lead masks are used, but it is preferable to use ultraviolet rays as the radiation because 9M negative film can be used. The intensity of ultraviolet rays is 700 to 600 mJ
/-. Next, it is developed by means such as spraying with a weakly alkaline developer such as an aqueous sodium carbonate solution.
A solder resist substrate having solder plating resistance can be obtained by boss-baking with hot air at about 150 to 170° C. for about 1 hour or with infrared rays at 170 to 180° C. for about 7 to 8 minutes.

(Example) The present invention will be explained below with reference to Examples. In the examples, 1 part means part by weight, and 1% means % by weight.

Synthesis Example 1 Styrene-maleic anhydride copolymer rsMA1000J
(manufactured by ARCO, trade name, maleic anhydride content 5
404 parts of 2-hydroxyethyl acrylate (hereinafter referred to as 2-HEA) was heated and dissolved in 425 parts of diethylene glycol dimethyl ether (hereinafter referred to as diglyme) while blowing air.
After dropping 4 parts and reacting by heating at 110°C for 18 hours,
The mixture was cooled to 80°C, 50 parts of ethanol was added dropwise, and the reaction mixture was heated at 80°C for 8 hours. The obtained esterified product solution (a) is.

It was a viscous brown liquid with a solid content of 54% and an acid value of 160.

Synthesis Example 2 404 parts of rsMAloooJ was heated and dissolved in 500 parts of diglyme while blowing air.

50 parts of 2-HEA was added dropwise and reacted at 110°C for 18 hours. The obtained esterified product solution (b) had a solid content of 50
It was a brown viscous liquid with an acid value of 165% and an acid value of 165.

Synthesis Example 3 Add 90 parts of styrene to 400 parts of diglyme heated to 90°C.
parts, 60 parts of methyl methacrylate, 1 part of maleic anhydride
50 parts of azobisisobutyronitrile and 3 parts of isooctylmercaptopropionate were added dropwise over 30 minutes, and the mixture was reacted at 90° C. for 2 hours in a nitrogen stream.

Next, 2-HEA was added to the styrene-methyl methacrylate-maleic anhydride copolymer solution thus obtained.
Drop 100 parts.

After reacting at 100°C for 18 hours, it was cooled to 80°C, 20 parts of toluene diisocyanate was added, and the mixture was reacted at 80°C for 2 hours.
The mixture was heated for a period of time to cause unreacted 2-HEA to react with toluene diisocyanate. Next, 20 parts of tetramethylolmethane triacrylate was added dropwise.

The mixture was heated at 80° C. for 2 hours to cause unreacted toluene diisocyanate to react with a portion of tetramethylolmethane triacrylate. The obtained esterified product solution (C) is
Solid content 52%, ester content 46.3%, acid value 1
52 brown viscous liquid.

Synthesis Example 4 90 parts of styrene was added to 430 parts of diglyme heated to 90°C.
parts, 50 parts of methyl methacrylate, 1 part of maleic anhydride
50 parts of azobisisobutyronitrile and 3 parts of isooctylmercaptopropionate were added dropwise over 30 minutes, and after reacting at 90°C for 2 hours in a nitrogen stream, 2-
Add 156 parts of hydroxyethyl methacrylate dropwise,
The reaction was carried out at 100° C. for 20 minutes while blowing air.

The obtained esterified product solution (d) was a brown viscous liquid with a solid content of 51% and an acid value of 132.

Synthesis Example 5 Styrene-maleic anhydride copolymer (Moleic anhydride content: 12.5 mol%, molecular weight: 3,600) 860 parts dissolved in 942 parts of butyl cellosolve acetate was prepared by dissolving 10
The mixture was heated to 0°C, 116 parts of 2-HEA was added dropwise thereto, and the mixture was reacted at 100°C for 18 hours while blowing air. The obtained esterified product solution (e) was a viscous liquid with a solid content of 50% and an acid value of 120.

Synthesis Example 6 To a solution of 404 parts of rsMAloooJ in 400 parts of diglyme, 113.0 parts of glycidyl methacrylate was added.
6 parts were added dropwise, and the mixture was reacted at 80° C. for 6 hours in an oxygen stream. The obtained esterified product solution (f) is.

It was a viscous liquid with a solid content of 57% and an acid value of 188.

Comparative Synthesis Example 92 parts of ethanol was added dropwise to a solution of 404 parts of rsMAloooJ in 400 parts of diglyme.

The reaction was carried out at 80°C for 18 hours. The obtained esterification solution (g) was a brown viscous liquid with a solid content of 55% and an acid value of 154.

Examples 1 to 6 and Comparative Examples 1 to 5 Esterified product solutions (a) to (g) obtained in Synthesis Examples 1 to 6 and Comparative Synthesis Examples with the compositions shown in Table 1, epoxy compound (B), and radical polymerizability Mixture 10 of compound (C)
0 parts, 2.0 parts of 2.4-diethylthioxanthone, p
-0.5 parts of isoamyl dimethylbenzoate, 1.2 parts of phthalocyanine green, 1.2 parts of finely divided silica, 12 parts of talc
and kneaded with three rolls to obtain a liquid photo solder resist composition. Table 1 also shows the results of testing the storage stability of the obtained liquid photosolder resist composition.
Shown below. Result is.

It was expressed as the time until gelation.

The obtained liquid photo solder resist composition.

Screen printing was performed on the entire surface of the W44 epoxy-glass fiber laminate using a 150-mesh polyester screen plate, and after pre-baking at 80°C for 30 minutes, a test negative film "Fuji Step Guide 215 Step" (Fuji Photo) was applied. (trade name) made of film (trade name) was brought into contact with a high-pressure mercury lamp at an exposure intensity of 13°5 mW/ct.
1, and was exposed to ultraviolet light at an exposure dose of 700 mJ/aJ. After exposure, development was performed using a 1.5% aqueous sodium carbonate solution (liquid temperature: 30°C) at a spray pressure of 3 kHz/cd for 20 seconds.

Table 1 also shows the number of steps remaining after exposure and development.

After development, post-baking was performed at 150°C for 1 hour. After boiling, apply Franks rLONCO Resin Flux 77-25J (manufactured by LONCO, trade name), dry at 80℃ for 2 minutes, air cool for 1 minute,
After immersion in a solder bath at ℃ for 20 seconds and air cooling, 1.1.
After washing with 1-1-lichloroethane, adhesion was evaluated by a cellophane adhesive tape substrate peel test.

This was the first time, and the cycle from second and subsequent immersion in the solder bath to the cellophane adhesive tape substrate peeling test was repeated. The results are also shown in Table 1.

In Table 1, the abbreviations are as follows.

HQDGE: Hydroquinone diglycidyl ether B
PSDGE: Bisphenol S diglycidyl ether Epicor) 828: Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy ■, trade name) TMPTA nitrimethylolpropane triacrylate TMMTA: Tetramethylolmethane triacrylate TEC; DA: Tetraethylene glycol diacrylate (Hereinafter, blank spaces) [Effects of the Invention] The present invention has excellent storage stability, can be used as a one-component type, and can be developed with a weakly alkaline aqueous solution. A liquid photosolder resist composition that exhibits excellent solder plating resistance after development can now be obtained.

Claims (1)

[Claims] Maleic anhydride and itaconic anhydride, which are copolymers obtained by copolymerizing 10 mol% or more of maleic anhydride and/or itaconic anhydride with 90 mol% or less of a radically polymerizable monomer other than maleic anhydride and itaconic anhydride. For one mol of acid components, the amount of alcoholic alcohol of radical polymerization, (or) perimed epoxy compounds, and unrealistic alcohol, and (or) perimed epoxy compounds, which are not radical polarization, as needed. Esterified product (A) obtained by reacting at a ratio of 95 moles, and one or more selected from triglycidyl isocyanurate, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, cresol novolac type epoxy resin, and phenol novolac type epoxy resin Mixture 100 consisting of two or more epoxy compounds (B)
A liquid photosolder resist composition comprising: parts by weight, 10 to 200 parts by weight of a radically polymerizable compound (C) having no epoxy group other than the above (A), and, if necessary, an organic solvent (D).