JPH04151158A - Alkali development type liquid photosolder-resist ink composition - Google Patents

Abstract

PURPOSE:To provide the above compsn. adaptable to the production of printed circuit boards of high-density patterns, etc. by incorporating a specific photosetting resin having novolak type resin skeleton, a photopolymn. initiator, a diluent, and a specific resin having photosetting and thermosetting properties into this compsn. CONSTITUTION:The specific photosetting resin having the novolak type resin skeleton and the specific novolak type epoxy acrylate resin having the photosetting and thermosetting properties are used as the essential binder. Namely, the reaction product (A-3) obtd. by bringing the novolak type epoxy acrylate (A-1) and a satd. or unsatd. polybasic acid anhydride (A-2) into reaction, the photopolymn. initiator (B), the diluent (C), and the reaction product (D) of the novolak type epoxy and the unsatd.-base acid which is esterified by the unsatd.- basic acid of 0.3 to 0.8mol per 1equiv. epoxy group existing in the novolak type epoxy are incorporated as the essential components into the above- mentioned compsn. The compsn. adequate in the production of the printed circuit board is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field J] The present invention relates to a new and useful resist ink composition. , a diluent, and a specific photocurable and thermosetting resin as essential components, an alkaline-developable liquid photo solder resist ink composition particularly suitable for producing printed wiring boards with high-density patterns, etc. Regarding.

[Conventional technology and its solutions] Screen printing has traditionally been widely used as a method for forming resist patterns on printed wiring boards, but screen printing has low resolution, so it is necessary to improve resolution. To achieve this, dry film photoresists and liquid developable resist inks have been developed.

However, these resist inks have not been able to overcome the essential problem of not being able to provide satisfactory resolution in response to the demand for high resolution that accompanies the recent increase in the density of printed wiring boards.

[Problems to be solved by the invention] Conventionally known alkali-developable solder resist inks are
As the main binder, a photocurable resin that can be developed by alkali radiation and a thermosetting epoxy resin are used in combination. In such known resist inks, since the thermosetting epoxy resin that is the binder component does not have photocurability, when the amount of the epoxy resin added is increased, the resolution of the resulting resist ink is significantly reduced. It has the disadvantage of reducing the

Further, when only a photocurable resin is used without using a thermosetting epoxy, there is a drawback that the adhesion to copper is considerably lower than that of a resist ink that uses a thermosetting epoxy resin in combination.

Therefore, the object of the present invention is to provide a liquid resist ink composition that does not have the above-mentioned drawbacks in terms of high resolution and adhesion to copper, that is, it is photocurable and has excellent thermosetting properties, and in particular, An object of the present invention is to provide an alkali-developable liquid photosolder resist ink composition that is characterized by high resolution.

Furthermore, the resist ink composition has a cured coating film having excellent properties such as hardness, solvent resistance, acid resistance, electrical properties, heat resistance, and plating resistance in addition to the above-mentioned excellent properties. The goal is to obtain The object of the present invention is to provide a liquid photosolder resist ink composition that can be developed with an alkaline aqueous solution and is suitable for manufacturing printed wiring boards that require more complicated pattern formation due to increased density.

[Means for Solving the Problems 1 In view of the above technical background, the present inventors have made extensive studies to solve the problems of the prior art, and as a result, we have developed a specific photocurable resin having a novolac type resin skeleton and a photocurable resin. High resolution and
Adhesion, hardness, solvent resistance, acid resistance, electrical properties, heat resistance,
The inventors have discovered that it is possible to obtain an alkali-developable liquid photo solder resist ink composition that has excellent processing properties such as plating resistance and alkali developability, and has completed the present invention.

That is, 5 the present invention is +1) novolac type epoxy acrylate (A-1
) and a saturated or unsaturated polybasic acid anhydride (A-2) (A-3) (2) a photopolymerization initiator (D) (3) a diluent (C), and (4) a reaction product of a novolak-type epoxy and an unsaturated monobasic acid, which is esterified by 0.3 mol to 0.8 mol of unsaturated monobasic acid per equivalent of epoxy group present in the novolac-type epoxy. The present invention relates to an alkali-developable liquid photosolder resist ink composition containing as a main component the following ([1)].

Component (A-3), which is the above-mentioned photocurable resin, is produced by reacting the novolac type epoxy acrylate (A-1) with the saturated or unsaturated polybasic acid anhydride (A-2). Here, the novolac type epoxy resin that is the constituent raw material of component (A-1) includes phenol,
A novolac resin obtained by reacting phenols such as cresol with formaldehyde in the presence of an acid catalyst is further reacted with epichlorohydrin or methylepichlorohydrin to produce various reaction products. The epoxy equivalent of the novolac type epoxy resin is usually 1.
It is about 80 to 250, and the number of novolac nuclei is 3 to 1.
It is 0. For example, Araldite ECN-1299 (
Ciba Geigy), Araldite EPN-1) 38 (
Ciba Geigy), Evotote YDCN-704f
Examples include Tobu Kasei (trade name), Evotote YDPN-638 (manufactured by Tobu Kasei Corporation), Guatrex 3710 (manufactured by DuPont), and Sumiepoxy ESCN-220 (manufactured by Sumitomo Chemical Corporation).

Examples of the unsaturated monobasic acid which is another constituent raw material of component +A-1) include acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid, among which acrylic acid is preferred.

Component +A-1) can be easily produced by subjecting the novolac type epoxy resin to an esterification reaction with the unsaturated monobasic acid. The reaction ratio is preferably 0.95 to 1.05 equivalents of unsaturated monobasic acid to 1 equivalent of epoxy group in the novolac type epoxy resin, and all epoxy groups are unsaturated. Preferably, it is completely esterified with a monobasic acid.

The reaction product (A-3) is obtained by reacting component 1A-1), which is a novolak-type epoxy acrylate, with component (A-2), which is a saturated or unsaturated polybasic acid anhydride, in predetermined amounts as described below. It is.

-F, component (A-2) includes maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
Tribasic acid anhydrides such as methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. Examples include aromatic polycarboxylic acid anhydrides, among which are tetrahydrophthalic anhydride and hexahydrophthalic anhydride.

The purpose of using component (A-2), which is preferably succinic anhydride, is to impart alkaline developability to the reaction product (A-3) by providing component 1A-1) with a carboxyl group.

The amount of component (A-2) used in the reaction product (A-3) cannot be determined in part, but from the viewpoint of developability during alkaline development, component (A-1) which is a novolac type epoxy acrylate ), the amount of component (A-2) which is a saturated or unsaturated polybasic acid anhydride is usually 0.
The one obtained by reacting about 3 to 1.0 mol, preferably 0.5 to 0.8 mol, is good.

If the amount is less than 0.3 mol, good developability cannot be obtained.
Furthermore, if the amount is 1.0 mol or more, unreacted acid anhydride will remain.

Component (A-:1) is component (A-1) and component (A-2)
is usually 50 to 100% in the presence of a polymerization inhibitor such as hydroquinone or methoquinone, an amine esterification catalyst such as dimethylbenzylamine or triethylamine, and a solvent.
It is obtained by reacting at ℃ for 1 to 8 hours. Note that the reaction method described above is an example, and the reaction method is not limited to the above method, and any method can be used as long as the desired photocurable resin can be obtained.

Component (A-3), which is the photocurable resin thus obtained, preferably has an acid value of 50 to 160 gKOH/g; if it is less than 50 II g to 007 g, the alkali developability will be poor; If the amount exceeds 0.07 g to 160 mg, the properties of the cured film, such as alkali resistance, tend to deteriorate.

In addition, if necessary, the remaining a of the photocurable resin (A-3) may be added.
In order to reduce the number of hydroxyl groups, it may be further modified with alkyl ketene dimers or isocyanates.

As the component (Bl) which is a photopolymerization initiator used in the present invention, various known components can be used without particular limitation.For example, benzoin and its monoalkyl ethers such as benzoin, benzoin ethyl ether, and benzoin isopropyl ether; Acetophenone, 2.2-dimethoxy-2-phenylacetophenone, 2.2-jethoxy-2-phenylacetophenone, 1.1-dichloroacetophenone, ■-hydroxycyclohexylphenyl ketone, 2-methyl-1(41methylthio)phenyl ]
Acetophenones such as -2-morpholino-propan-1-one, anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, l-chloroanthraquinone, and thioxanthone such as 2,4-dimethylthioxanthone Examples include ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenones such as benzophenone, and xanthones. In addition, such component IB
) can be used in combination with a benzoic acid-based or tertiary amine-based photopolymerization accelerator.The amount of component IB+ used is 1 to 15 parts by weight, preferably 4 to 10 parts by weight, per 100 parts by weight of the resulting ink composition. Parts by weight.

Furthermore, as the diluent component CI, at least one of various known organic solvents, photopolymerizable oligomers, and photopolymerizable monomers may be used without particular limitation.

Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, cellosolves such as cellosolve and butyl cellosolve, calpitols such as calpitol and butyl calpitol, ethyl acetate, butyl acetate, and cellosolve acetate. , butyl cellosolve acetate, carpitol acetate, butyl carpitol acetate, and other acetate esters.

Examples of photopolymerizable oligomers include oligomers such as urethane acrylate.

Photopolymerizable monomers include 2-hydroxyl acrylate, 2-hydroxypropyl acrylate, N-vinylpyrrolidone, acryloylmorpholine, methoxytetraethylene glycol acrylate, methoxypolyethylene glycol acrylate, polyethylene glycol diacrylate, N,N-dimethylacrylamide, and Methylolacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminepropyl acrylate, N,N-diethylaminoethyl acrylate,
Ethylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate,
Tripropylene glycol diacrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate or above Examples include methacrylates corresponding to acrylates, and esterified products of polybasic acids and hydroxyalkyl (meth)acrylates. The amount of the above component (C1) used is usually 1.5 to 30 parts by weight, preferably 1 to 20 parts by weight per 100 parts by weight of the resulting ink composition.

In the present invention, the component (b), which is a photocurable and thermosetting binder resin, is a reaction product of a novolak-type epoxy and an unsaturated monobasic acid, and is a reaction product of a novolak-type epoxy and an unsaturated monobasic acid, and is one equivalent of the epoxy group present in the novolac-type epoxy. It is esterified with 0.3 mol to 0.48 mol of an unsaturated monobasic acid. Although it is a compound similar to component (A-1), which is the novolac type epoxy acrylate mentioned above,
They differ in the following points. That is, the former component (Dl) maintains photocurability and thermosetting properties due to the coexistence of an acrylic group and an epoxy group.On the other hand, the latter component (A-1) has no acrylic group and no residual epoxy group. If the esterification rate is less than 30 mol%, high resolution cannot be obtained, and if it exceeds 80 mol%, the adhesion to copper will decrease. The amount of Dl used is 20 to 100 parts by weight, preferably 30 to 80 parts by weight, per 100 parts by weight of component FA-3 described above.

The significance of using component +01 is that the drawbacks of thermosetting epoxy resins, which are thermosetting binder components conventionally used in well-known resist inks, are the disadvantages of thermosetting epoxy resins, which are the thermosetting binder components used in conventional resist inks. The object of the present invention is to eliminate the disadvantage of significantly lowering the resolution of images.

Since it maintains necessary and sufficient thermosetting and photocuring properties within the above usage range, the resulting resist ink can have high resolution and adhesion to copper surfaces.

The composition of the present invention may optionally contain fillers such as talc and clay-silicon dioxide, as well as pigments, antifoaming agents, adhesion imparting agents, etc.
Various additives can be added, such as a leveling agent, a chicken-like agent, and an epoxy curing agent. Furthermore, various epoxy compounds can be used in combination to the extent that resolution is not reduced.

The ink composition can be prepared in a one-pack type or a two-pack type, but the two-pack type is preferable from the viewpoint of storage stability. Furthermore, there are no particular restrictions on the method of dispersing fillers, pigments, etc., and the ink composition can be easily prepared by dispersing the fillers, pigments, etc. to a particle size of 10μ or less using a known dispersing machine such as a daysilver or three-roll mill. Vine.

Irradiation light sources for curing the composition of the present invention include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, and the like.

The composition of the present invention is applied onto a printed wiring board substrate by a screen printing method, a roll coater method, a curtain lid method, an electrostatic spray method, etc., and is irradiated with the above-mentioned active energy rays to harden the necessary portions. Thereafter, by dissolving and removing the unexposed areas with an alkaline aqueous solution, a resist pattern film is formed, and then the desired resist film can be formed by further post-curing.

EXAMPLES The present invention will be specifically explained by showing Examples and Comparative Examples below. Note that all 5 parts are based on weight unless otherwise specified.

Implementation W41 1 equivalent of epoxy and 1 equivalent of acrylic acid of a phenol novolak type epoxy resin having an epoxy equivalent of 2) 0 and having an average of 5 phenol core residues in one molecule and an epoxy group are converted into butyl cellosolve acetate. The reaction was carried out in a conventional manner using the following as a solvent. This is a liquid mixture containing 25 parts of butyl cellosolve acetate. Hereinafter, this will be abbreviated as fat (A-1).

One equivalent of hydroxyl groups in resin (A-1) was reacted with 0.7 equivalents of tetrahydrophthalic anhydride in a conventional manner using butyl cellosolve acetate as a solvent.

This is a liquid mixture containing 25 parts of butyl cellosolve acetate. Hereinafter, this will be abbreviated as resin (8-3-1).

One equivalent of the epoxy group of the phenol novolac type epoxy resin used as the raw material was reacted with 0.5 equivalent of acrylic acid by a conventional method using butyl cellosolve acetate as a solvent. This stuff is butyl cellosolve acetate 25
It is a liquid mixture containing 1. Hereinafter, this resin (D-1
).

Resin FA-3-1) 50 parts dicyandiamide 1 part Irgacure 9075 parts Silicon dioxide 17 parts Phthalocyanine Green 1 part AC3DOf Kyoeisha oil leveling agent) 1 part Compounding component ial consisting of the above composition
75 parts were kneaded using three rolls, and then resin 1D
A resist ink composition was obtained by mixing 25 parts of the formulation component (BL) consisting of -1).The composition was applied to a copper-clad laminate having a glass epoxy base material of 35 μm of copper foil, and this was pre-etched into a pattern. A test piece was prepared by coating the entire surface of the printed wiring board with a thickness of 20 to 30 μm using a screen printer, and pre-drying at 80° C. for 20 minutes.

Example 2 The same procedure was used as in Example 1, except that the amount of the blended components (BL resin (El-1)) was changed from 25 parts to 50 parts.

Implementation fI/43 The composition was exactly the same as in Example 1 except that the amount of the BL resin (ROW 1) used was changed from 25 parts to 10 parts.

Example 4 Instead of resin 1n-1) of compounding molecule b) of Example 1, epoxy group 1 of a phenol novolak type epoxy resin was used.
The results are exactly the same except that a resin 1D-2) obtained by reacting 1.3 equivalents of acrylic acid was used.

Example 5 Epoxy group 1 of phenol novolak type epoxy resin was used instead of resin 10-1) of 1 bl of compounding components of Example 1.
It is exactly the same except that the resin fD-3) obtained by reacting 0.8 equivalents of acrylic acid with respect to the equivalent amount was used.

Example 6 The compounding components of Example 1 (resin 1A-3-2 made from a cresol novolac type epoxy resin as a starting material instead of the phenol novolac type epoxy resin as the starting material of the resin (A-3 ~!) of at) It's exactly the same except for what I used.

Example 7 Compounding components of Example 1 (except that (D-4) consisting of a cresol novolac type epoxy resin as a starting material was used instead of the phenol novolac type epoxy resin as the starting material of the resin (D-1) of BL) It's exactly the same.

Comparative Example 1 Comparative Example 1 The composition was exactly the same as in Example 1 except that resin (A-1) was used instead of resin (D-1) of BL.

Comparative Example 2 The composition was exactly the same as in Example 1 except that a phenol novolac type epoxy resin (E) was used instead of the resin (D-1) of BL.

Table 1 shows the blending ratios of the resins used in Examples 17jp41-7 and Comparative Examples 1-2.

Test Example (Resolution, Adhesion) Each of the test piece soils prepared in Examples 1 to 7 and Comparative Examples 1 to 2 had a line width/line spacing of 100/100 to 50150.
After applying ultraviolet rays using a water-cooled UV irradiation device to give an exposure amount of 500 sJ/cm, a 1% Na/COs aqueous solution was applied to the sample at a pressure of 2g/cm for 60 seconds. The film was sprayed and developed, and the resolution shown in the development, such as gaps, was evaluated based on the following criteria.

0: There are no gaps and the resist is very clearly resolved.

×-...Kits are visible and one part of the resist is missing.

This was then post-baked at 150°C for 30 minutes.

After forming the final cured coating film, cross-cuts were made on the coating film on the copper surface according to the test method specified in JIS D-02 (12), peeled off with cellophane tape, and the adhesion was evaluated by visual judgment. The above evaluation results are shown in Table 1.

(Other performance evaluations) In addition, other performances as solder resists were evaluated according to the following methods. The evaluation results are also listed in Table 1.

(Pencil hardness) Determined according to the test method specified in JIS K-5400.

(Solder Heat Resistance) According to the test method specified in JIS C-6481, the test piece was floated in a solder bath at 260°C for 10 seconds, and then allowed to cool to room temperature, which was repeated 5 times, and the coating III state was visually determined. . The evaluation criteria are as follows.

O: There is no change at all.

x-: Blistering and peeling are observed.

(Alkali resistance) The test piece was immersed in a 5% NaOH aqueous solution at 25° C. for 1 hour, and then the state of the coating film was visually evaluated. The evaluation criteria are as follows.

○...No change at all.

x-: Blistering and peeling are observed.

(Acid resistance) Place the test piece in 10% H, SO, aqueous solution at 25℃ for 30 minutes.
After immersion for 1 minute, the state of the coating film was visually evaluated. The evaluation criteria are as follows.

O... Total (no change.

×...Blistering and peeling can be seen.

(Solvent resistance) Immerse the test piece in methylene chloride at 25℃ for 1 hour TI4
Afterwards, the state of the coating film was visually judged. The evaluation criteria are as follows.

○...No change at all.

×...Blistering and peeling can be seen.

(Gold plating resistance) Use the test piece as Aurobase AC-4 (manufactured by Nippon Seiko).
Gold plating was carried out for 6 minutes at a current density of 2 A/dm'', and a peeling test was conducted using cellophane tape on the coating film after gold plating.The evaluation criteria were as follows.

○...Complete (does not peel off.

×...There is peeling.

(Insulation resistance) Using comb-shaped electrodes with a line width/line spacing of 200/200 μ-,
500 hours at 85°C and 85% RH (7).
0V (7) The insulation resistance after applying the applied voltage was measured.

The measurement is DC: 500V"l' (7) This is a 1 minute value.

[Blank 1 below] [Effect of the invention 1 The present invention provides excellent physical properties such as hardness, solvent resistance, acid resistance, electronegative properties, heat resistance, and plating resistance, as well as
It is possible to provide an alkali-developable liquid photosolder resist ink composition that is excellent in image quality and adhesion to copper.

Therefore, by using the composition, a great effect can be achieved in that printed wiring boards that require more complicated pattern forming ability can be easily produced, especially due to higher tz density.

Arakawa Chemical Co., Ltd. Procedural Sleeve (Method) Name of the Invention Relationship with the Case of Person Who Amends Alkaline Developable Liquid Photosolder Resist Ink Composition

Claims (1)

[Claims] [1] (1) Novolac type epoxy acrylate (A-
A reaction product (A-3) obtained by reacting 1) with a saturated or unsaturated polybasic acid anhydride (A-2), (2) a photopolymerization initiator (B), (3) a diluent ( C), and (4) a reaction product of a novolac-type epoxy and an unsaturated monobasic acid, which is 0.3 mol to 0.8 mol of an unsaturated monobasic acid per equivalent of epoxy group present in the novolac-type epoxy. An alkali-developable liquid photosolder resist ink composition containing as a main component (D) esterified with an acid. [2] The ink according to claim 1, wherein the reaction product (A-3) is obtained by reacting with the (A-2) in an amount of 0.3 mol or more per equivalent of hydroxyl group present in the molecule thereof. Composition. [3] The ink composition according to [1] to [2], wherein the reaction product (D) is used in a proportion of 20 to 100 parts by weight based on 100 parts by weight of the reaction product (A-3). [4] The ink composition according to any one of [1] to [3], wherein the (C) is at least one of an organic solvent, a photopolymerizable oligomer, and a photopolymerizable monomer.