JPS62292815A - Photosensitive curable composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in resistance to processing after development such as etching or plating, by mixing a specified thermoplastic polymer binder with an addition-polymerizable compound and a hotoinitiator. CONSTITUTION:A thermoplastic polymer binder (A) or a glass transition point of 40-120 deg.C is obtained by copolymerizing 4-40wt% carboxyl group-containing addition-polymerizable monomer (a) (e.g., methacrylic acid) with at least 5wt% nonacidic addition-polymerizable monomer (b) which is a (meth)acrylate of formula I (wherein R1 is H or methyl, R2 is a 1-5C alkylene, R3 is H, a 1-5C alkyl or a halogen and n is 1-20) and a nonacidic addition-polymerizable mono mer (C) having Q and e values satisfying the formula II [wherein QA and eA are the Q and e values of component (a) and QC and eC are those of component (c)]. 100pts.wt. component A is mixed with 5-100pts.wt. addition-polymerizable compound (B) of formula III (wherein R4 is H is H, a 1-6C alkyl or an aryl, R5-6 are each H or methyl, at least either or R5 and R6 is methyl, x is 0-3 and l+m+n=3-30) and 0.01-30pts.wt. photoinitiator (C) (e.g., 2- ethylanthraquinone).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive curable composition that is cured by irradiation with light and developable with an alkaline aqueous solution. More specifically, the present invention relates to a photopolymerizable curable composition that has improved resistance to treatments such as etching and plating after development.

[Conventional technology and problems]

In general, photopolymerized cured products are laminated by coating, laminating, etc. on a substrate, such as a copper-clad laminate or a metal surface to be subjected to microfabrication, and when exposed to active light, the exposed areas are cured.
The unexposed areas are dissolved and removed with a solvent having appropriate solubility. Solvents can be roughly divided into 1 degree.

In recent years, photopolymerizable curable compositions that are developed using aqueous solvents have been increasingly used in view of work environment, surrounding environment, and manufacturing cost.

However, compared to the case of using a conventional organic solvent-developable photopolymerizable composition, there are many restrictions on etching and plating processes, which often causes problems during use.

In particular, in the case of alkaline processing liquids, their use is severely limited because they basically use acidic thermoplastic polymer binders.

Furthermore, the removability of the resist after pattern formation by etching or plating is better than when using a conventional organic solvent development type photosensitive polymer composition.
is known to be inferior.

In other words, organic solvent development type resist stripping is generally performed with a solvent such as methylene chloride, which results in small pieces that are easy to clean and reduce the possibility of re-adhesion to the product or stripping machine. At least, the stripping solution can be easily regenerated by filtration. On the other hand, the aqueous solvent-developed type is peeled off using a heated aqueous sodium hydroxide solution or potassium hydroxide aqueous solution, but the peeled pieces do not break into small pieces and form a so-called "seaweed" shape, resulting in redeposited glue and: ill jN solution. The difficulty of regeneration through filtration is a major operational problem.

Therefore, even in aqueous development type photosensitive polymer compositions, it is desired that the peeled pieces can be broken into small pieces when the resist is peeled off.

Means for Solving Problem C] As a result of intensive studies by the present inventors to solve such problems, an addition polymerizable compound obtained by copolymerizing an addition polymerizable monomer having a specific structure has been developed. The inventors have discovered that by combining a type of thermoplastic polymer binder with an addition polymerizable compound having a specific structure, both resistance and fragmentation of peeled pieces can be satisfied, and the present invention has been achieved.

That is, the present invention comprises: (1) addition polymerization monomers having carboxyl groups as main components (4 to 40 weight percent At and non-acidic addition polymerization monomer FB described below) and at least 5 weight percent or more of the following non-acidic addition polymerization monomers; For 100 parts by weight of a thermoplastic polymer binder copolymerized with an acidic addition polymerization monomer (c), a non-acidic addition polymerization monomer (B): represented by the following general formula (1) At least one type of acrylic ester or methacrylic ester monomer C)i, =(:: +11(R,
is a hydrogen atom or a methyl group, R1 is a fullkylene group having 1 to 5 carbon atoms, R1 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, 10 atoms, n is an integer from 1 to 20) Non-acidic Addition polymerization monomer (C): At least one non-acidic addition polymerization monomer having a Q value and an e value that satisfy the following formula (11) value, Qc+
6 (Q value and e value of addition polymerizable monomer (C)) (2) Addition polymerizable compound CH, -(OCHCH)yO-C-CH: CH2R,
-C-(CHold-0CHCHryu-0-C-CH=CH.

(R, is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, R,, R,+, a hydrogen atom, or a methyl group, but at least one must be a methyl group.R,
, R,, R, is a hydrogen atom or a methyl group X is an integer from 0 to 3! , m, and n are integers from 3 to 30.

First, the thermoplastic polymer binder used in the present invention will be explained in detail. In the addition-polymerizable compound type photopolymerizable curable composition according to the present invention, the resistance of the resist film largely depends on the properties of the polymeric binder. The acidic addition polymerized monomer having a carboxyl group in the copolymer constituting the polymeric binder of the present invention imparts developability to the copolymer, and its proportion in the copolymer composition is 4-4
In the range of 0 weight percent.

The appropriate ratio varies depending on the type of developer, and for example, a range of 4 to 15 weight percent for a so-called semi-aqueous solution development type containing ethylene glycol monobutyl ether, and 15 to 40 weight percent for a fully aqueous solution development type is a tentative guideline. can do.

Of course, the optimum copolymerization rate of acidic addition polymerizable monomers, whether semi-aqueous or fully aqueous, varies depending on the developer and development conditions.

In the present invention, the addition polymerization monomer (5) having a carboxyl group is preferably methacrylic acid or a mixture of methacrylic acid and acrylic acid.

Since such an acidic addition polymerization monomer is copolymerized, the thermoplastic polymer binder essentially swells and dissolves in an alkaline liquid. Therefore, it is essential to copolymerize a non-acidic addition monomer in order to impart resistance.

In particular, the non-acidic addition polymerization monomer (B), which is an acrylic ester or methacrylic ester having a specific structure, is effective for improving the resistance to alkaline aqueous solutions.

Examples of such are 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenoxypropyl acrylate, 3-phenoxypropyl acrylate, phenoxyjethoxy acrylate, phenoxytriethoxy acrylate, Enoxylepropoxy, P-chlorophenoquinoethyl acrylate, P-methylphenoxyethyl acrylate, Meccrylic acid 2
-Fenoquinpropyl, 3-phenoxypropyl methacrylate, phenoxyjethoxy methacrylate, fenoquine triethoxy methacrylate, phenoxylepropoquine methacrylate, P-chlorphenoquinethyl methacrylate, P-methylphenokylethyl methacrylate, etc. (You can list, but are not limited to)
. These non-acidic addition polymerization monomers (B) must be contained in the copolymer in an amount of at least 5% by weight or more.

The non-acidic addition polymerization monomer (C) is an addition polymerization monomer jB)
Together with this, it serves as a component that imparts resistance, but in addition, it also plays a role in controlling the glass transition point (Tg) of the copolymer.

A suitable copolymer Tg is between 40°C and 120°C; below 40'C, the photosensitive layer will deteriorate over time when used as a "dry film" in which the photosensitive layer is sandwiched between a support film and a protective film. "Cold flow" development occurs in which the photosensitive layer flows out, and at temperatures above 120° C., the adhesion of the photosensitive layer to the substrate is significantly impaired.

Furthermore, the non-acidic addition polymerization monomer (C) has the effect of forming a copolymer that is uniformly polymerized within and between molecules of the acidic addition polymerization monomer resident. If the acidic addition polymerized monomer is not uniformly polymerized, it will not only cause poor development of the hard-dispersion composition, but also cause -1 in severe cases, precipitation of the copolymer during polymerization, and copolymer precipitation during compounding of the coating solution. A precipitate is formed. Such a non-acidic addition polymerization monomer (C) is determined depending on the acidic addition polymerization monomer (A). For example, methacrylic acid (QA=2.340.e^=
0.650), methyl methacrylate (Q
c==0.740. ec=0.4001iexp
(-eA(eA-ec))-'1L69), ethyl methacrylate (Qc=0.730. ec=0.52
0゜A exp (-eA(eA-eC)) = 2.9
5) etc. In this case, Q^ n-butyl acrylate (Qc=0.500. ee=LO60,Q
cexp (-aA(eA-ec))=6.11), methacrylic acid is rapidly consumed during polymerization, resulting in a non-uniform copolymerization composition and, in some cases, precipitation.

In addition, in the present invention, a plurality of acidic addition 11ffi forms (
When A) is used, non-acidic addition polymerization monomer Hc)
is one which causes the above tnt formula to occur between at least one type of acidic addition polymerization II polymer prisoner among them.

Examples of the addition polymerizable compound represented by formula (Ill) include glycerylpropoquine triacrylate, glyceryldiropoxytriacrylate, glyceryldipropoxytriacrylate, glyceryltripropoxytrimecacrylate, trimethylolpropoquine conjugated quinoacrylate, and trimethylolpropoquine triacrylate. Methylolpropane tetrapropoquine acrylate, trimethylolpropane propoxytriacrylate, l-rimethylolpropoxytetrabu
Examples include, but are not limited to, trimethylol hexabropoquinotrimethacrylate, trimethylol hexabropoquinotrimethacrylate, and the like.

These may be used singly or in combination. These amounts are 5 to 1 per 100 parts by weight of the thermoplastic polymer binder.
00 parts by weight, particularly preferably 1 part of 10 to 80 Mj. It is also possible to add another addition polymerizable compound as required.

Photoinitiators and/or photoinitiator systems that can be used in the compositions of the invention include the following.

That is, there are substituted or unsubstituted polynuclear quinones, such as 2
-ethylanthraquinone, 2-LerL-butylanthraquinone, occumethylanthraquinone, 1,2-benzanothraquinone, 2,3-benzanthraquinone, 2
-Phenylanthraquinone, 2゜3-diphenylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-natsutaquinone, 9.10-phenanothraquinone, 2-methyl-1,4 -Natsutaquinone, 2.3-dichloronatsutaquinone, 1,4-dimethylanthraquinone, 2.3-'; methylanthraquinone, 3-chloro-2-methylanthraquinone, 7.8.9.10-tetrahydrophtacenequinone, etc. be. Other aromatic ketones, such as benzophenone, Michler's ketone (4,4'-bis(dimethylamino)benzophenone), (4,4'-bis(diethylamino)benzophenone), 4-methoxy-
Examples include 4'-dimethylaminobenzophenone. Other examples include benzoin and benzoin ethers such as benzoin methyl ether, benzoinoethyl ether, benzoin phenyl ether, methylbenzoin, and ethylbenzoin. Furthermore, combinations of 2.4.5-triarylimidazole diff1K and 2-mercaptobenzoxazole, leuco crystal violet, tris(4-diethylamino-2-methylphenyl)methane, etc. can also be used.

In addition, there are substituted or unsubstituted thiosanthones, such as 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-;methylthioxanthone, and the like. Furthermore, combinations of these thioxanotones with aliphatic or aromatic tertiary amines such as N-methylleethanolamine, P-dimethylaminobenzoic acid ethyl ester, etc. can also be used, and combinations of thioxanotones with flukyallobenzophenone, such as Also effective are combinations with Michler's ketone, and combinations of thioxate 7 and oxime esters such as benzophenone oxime acetate. These light-activated addition monomer initiators may be used alone or in combination.

Note that the present invention is not limited to these.

These are 0 parts per 100 parts by weight of thermoplastic polymer binder.
.01 to 30 parts by weight, preferably 0.1 to 15 parts by weight.

In the present invention, in addition to the above-mentioned essential elements, stabilizers, dyes, etc. can be added as necessary. Examples of the stabilizer include hydroquinone, hydroquinone monomethyl ether, and t-butylcatechol. These can be added within a range that does not inhibit the photopolymerization reaction. Plasticizers can also be added to impart appropriate flexibility.

Examples include: phthalate esters such as diethyl phthalate, dibutyl phthalate, diethyl phthalate, and dioctyl phthalate, fatty acid esters such as dioctyl alebate and dibutyl diglycol acybate, phosphoric acid esters such as trimethylphosphine, and toluene sulfone. Examples include sulfonic acid amides such as acid amides.

Additionally, dyes may be added to facilitate visual identification of sensitization. Examples include crystal violet, malachite green, Victoria blue, and methylene blue.

In the present invention, when the photopolymerizable curable composition is solvent-free, it is usually coated on a suitable support using a printing method or a coating method, and when it is dissolved or dispersed in a solvent, it is coated on a suitable support, and then the solvent is applied. A photopolymer layer can be obtained by evaporation. In particular, when used as a "dry film", various plastic films, among which polynystyl film is suitable.

(Effects of the Invention) The details of how the present invention can provide a photocured film in which the peeled pieces become smaller pieces when peeled off compared to the conventional method will be explained in Examples.

Such photopolymer layers are cured by light from a suitable light source, such as a round low-pressure mercury lamp or an ultra-high pressure mercury lamp. The composition of the present invention can be used as a photopolymer or a photoresist when manufacturing a wiring board for Gogen Reli'7E, Yahoo'J, etc.

〔Example〕

Next, the present invention will be specifically explained using examples. It should be noted that the present invention is not subject to the same restrictions as the embodiments.

Example 1 A photosensitive curable composition is prepared by mixing the following ingredients:

Methacrylic acid: 12wt%, acrylic acid: 8w%.

Methyl acrylate 45 WE%, 2-phenoquinoethyl acrylate 35 wt% co-M combination 0g I.limethylolpropaneproboxytriacrylate 0g 2-chlorothioxanthone 1gN-
Methyljetanolamine 0.1g
Ri Tori 7 Blue -0.05 g Methyl ethyl ketone 70 g Tetrahydrofuran 10 g Thickness: 25 μm
A photosensitive film was obtained by coating on a polyethylene glycol terephthalate film support and drying at 75°C. The thickness of the photosensitive layer was 50 μm. This was laminated onto a polished copper-clad laminate using a rubber roller heated to 100°C. Place the wiring pattern mask on top of it, irradiate it with a high-pressure mercury lamp for 10 seconds from a distance of 50 cm, cure it, and then develop it with a 1% sodium carbonate aqueous solution at 30'C to form a resin relief image on the copper-clad laminate. I can get it.

Next, copper was etched using an alkaline etchant, and a good printed wiring board was obtained.

Next, in order to peel off the cured film, it was immersed in a 3% sodium hydroxide aqueous solution at 50°C, and the cured film was peeled off while being divided into about 2 to 5111111 square pieces.

Example 2 A photosensitive cured composition was obtained by mixing the following components.

Copolymer of methacrylic acid 12wL%, acrylic acid 8wt%, methyl methacrylate 45wt%, 2-phenoxyethyl acrylate 35wt0.10
50g trimethylolpropane triacrylate
15g trimethylolpropane propoxytriacrylate 5g 2-chlorothioxanthone 1gN-
Methyljetanolamine 0.1g Victoria Blue 0.05g Methyl Ethyl Keto 7 70g Te] Lahydrofurano
This was coated on a polyethylene glycol terephthalate film support having a thickness of 25 μm and dried at 75° C. to form a photosensitive film. The thickness of the photosensitive layer was 50 μm. This was laminated with a polished copper clad layer using a rubber roller heated to 100 aC. A wiring pattern mask was placed on top of the mask and cured by irradiating it with an ultra-high pressure mercury lamp from a distance of 50 cm for 10 seconds, and then developing with a 1% aqueous sodium carbonate solution at 30° C. to obtain a resin relief image on the copper-clad laminate.

Next, copper was etched using an alkaline etchant, and a good printed wiring board was obtained.

Next, in order to peel off the cured film, it was immersed in a 50' C3% sodium hydroxide aqueous solution, and the cured film was peeled off while being divided into pieces of approximately 2 to 5 mm square.

Example 3 7) Prepare a photosensitive curable composition by mixing the following ingredients.

Copolymer of methacrylic acid 10wt%, acrylic acid 10w%, methyl methacrylate 5QwL%, 2-phenoxyethyl acrylate 30w% 50g trimethylolpropane triacrylate 15g glyceryl propoxy trimethacrylate 15g benzophenone 15g Michler's ketone 0.15 'g victoria blue
0.05g methyl ethyl ketone
70g tetrahydrofuran 1
Evaluation was made in the same manner as in Example 1, and a good printed wiring board was obtained. The cured film was peeled off while being subdivided into 2 to 511111 squares.

Comparative example 1 A photosensitive cured composition was obtained by mixing the following components.

Acrylic acid 2QwL%, Methyl methacrylate 3QwL%
Copolymer of 50g trimethylolpropane triacrylate 15g trimethylolpropane propoxytriacrylate 5g 2-chlorothioxanthone 1gN-
Methyljetanolamine 0.1 g Victoria Blue o, osg Methyl ethyl ketone 70 g Tetrahydrofurano
10g Evaluation was performed in the same manner as in Example 1, but the cured film did not withstand the alkali etchant and a good printed wiring board could not be obtained.

Comparative Example 2 A photosensitive curing composition was prepared by mixing the following components.
.

Methacrylic acid 12WL%, acrylic acid 8wt! 4. Copolymer of 45 wL% methyl methacrylate and 35 wt% 2-phenoquinethyl acrylate s
og trimethylolpropane tri7 acrylate 3
0g2-chlorothioxanthone 1g
N-Methylgetanolamine 011 g Victoria Blue o, osg Methyl ethyl ketone 170 g Tetrahydrofuran 10 g Evaluation was carried out in the same manner as in Example 1. Although it withstood the alkaline etchant, the cured film peeled off in the same shape (so-called "wakame-like" shape).

Claims (1)

[Scope of Claims] (1) Addition polymerization monomer (A) having a carboxyl group as a main component (4)
~40 weight percent and the following non-acidic addition polymerized monomers (
Thermoplastic polymer binder non-acidic addition polymerized monomer (B) obtained by copolymerizing at least 5 weight percent or more of B) with the following non-acidic addition polymerized monomer (C): The following general formula ( At least one type of acrylic ester or methacrylic ester monomer represented by
to 5 alkylene group, R_3 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, n is an integer from 1 to 20) Non-acidic addition polymerization monomer (C): The following formula (II) At least one non-acidic addition polymerization monomer having satisfactory Q value and e value 0.25<Q_A/Q_CEXP{-e_A(e_A-
e_C)}<4.00(II) (Q_A, e_A are the Q value and e value of the addition polymerization monomer (A), Q_C, e_C are the Q value and e value of the addition polymerization monomer (C)) (2 ) At least an addition polymerizable compound represented by the following formula (III) ▲ Numerical formula, chemical formula, table, etc. ▼ (III) (R_4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms,
The aryl groups R_5 and R_6 are hydrogen atoms or methyl groups, and at least one must be a methyl group. R_7, R_8, R_9 are hydrogen atoms or methyl groups; A photosensitive curable composition characterized by: 2 100 parts by weight of a thermoplastic polymer binder as the main component,
Photosensitive cured composition 3 according to claim 1, which contains 10 to 200 parts by weight of an addition polymerizable compound and a photoinitiator, wherein the addition polymerizable monomer (A) having a carboxyl group is methacrylic acid alone or methacrylic acid. The photosensitive curable composition according to claim 2, which is a mixture of acid and acrylic acid.