JPH0527435A - Alkali developing type photosensitive resin composition - Google Patents

Abstract

PURPOSE:To provide an alkali developing photosensitive resin from which such a resist can be obtd. having excellent adhesion property and followup property even when the surface temp. of a substrate is normal temp. and the variation in the press roll temp. is large, and also excellent adhesion property and followup property to a substrate which shows large dimensional change due to temp. change. CONSTITUTION:This compsn. consists of a photopolymn. initiator and a mixture of carboxyl group-contg. thermoplastic resin, urethane acryl oligomer obtd. by effecting the reaction of polyester polyol or polyether polyol with polyhydric isocyanate and then effecting the reaction with (meth)acryl monomers, mono(meth)acrylate of long-chain polyalkylene glycol, and ethylene unsatd. compd. containing other ethylene unsatd. monomers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkali-developable photosensitive resin composition which can be preferably used in the production of printed wiring boards and the like. More specifically, etching resist,
It can be suitably used as a plating resist,
The present invention relates to a photosensitive resin composition suitable for forming a secondary circuit on a stepped substrate after forming a circuit and capable of forming an alkali-developing dry film photoresist having excellent adhesion to a substrate.

[0002]

2. Description of the Related Art Generally, a photosensitive resin composition is used as a resist material when manufacturing a printed wiring board or the like. However, the resist formed by the conventional photosensitive resin composition is used when the photosensitive element is laminated on the substrate and the preheating temperature of the substrate is insufficient and the workability temperature range of the pressure roll is narrow. Adhesion with
There is a problem in that the followability is deteriorated, chipping, disconnection, short circuit, etc. occur on the formed printed wiring board, and the manufacturing efficiency and the yield are remarkably lowered.

Further, when a transparent film electrode made of a film is used as a substrate, there is a problem that a dimensional error with the mask film becomes large due to a large dimensional change when heated. ..

[0004]

Therefore, in view of the above-mentioned prior art, the present inventors have found that the surface temperature of the base material is near room temperature and the close contact with the base material is large even if the difference in temperature fluctuation of the pressure bonding roll is large. As a result of earnestly researching a photosensitive resin composition capable of forming a resist which is excellent in adhesiveness and conformability and has excellent adhesiveness and conformability to a substrate having a large dimensional change due to temperature change, The present invention has completed the present invention by finding a resin composition.

[0005]

That is, the present invention is
(A) a carboxyl group-containing thermoplastic resin, (B) a polyester acrylic or polyether polyol is reacted with a polyvalent isocyanate, and then a (meth) acrylic monomer is reacted to obtain a urethane acrylic oligomer, a long-chain polyalkylene glycol The invention relates to a mixture of an ethylenically unsaturated compound containing a mono (meth) acrylic acid ester and an ethylenically unsaturated monomer other than these, and (C) a photopolymerization initiator-containing alkali-developable photosensitive resin composition. ..

[0006]

[Functions and Examples] As described above, the alkali-developable photosensitive resin composition of the present invention is prepared by reacting (A) a carboxyl group-containing thermoplastic resin, (B) a polyester polyol or a polyether polyol with a polyvalent isocyanate. After that, a urethane acrylic oligomer obtained by reacting a (meth) acrylic monomer, a mono (meth) acrylic ester of a long-chain polyalkylene glycol, and an ethylenically unsaturated compound containing an ethylenically unsaturated monomer other than these, And (C) a photopolymerization initiator.

The carboxyl group-containing thermoplastic resin used in the present invention is obtained by copolymerizing a carboxyl group-containing vinyl monomer and another vinyl monomer.

Specific examples of the vinyl monomer containing a carboxyl group include acrylic acid, methacrylic acid,
Examples thereof include cinnamic acid, crotonic acid, sorbic acid, itaconic acid, fumaric acid, partial esters and anhydrides thereof, and these monomers are usually used alone or in admixture of two or more.

Specific examples of vinyl monomers other than the carboxyl group-containing vinyl monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2
-Hydroxyethyl (meth) acrylate, lauryl (meth) acrylate, (meth) acrylamide, (meth) acrylonitrile, dimethylamino (meth) acrylate, styrene, vinyltoluene, α-styrene, N
-Vinylpyrrolidone and the like are used, and these are usually used alone or in admixture of two or more.

The proportion of the carboxyl group-containing monomer in the carboxyl group-containing thermoplastic resin is adjusted to be 15 to 45% by weight, especially 17 to 40% by weight. The proportion of such carboxyl group-containing monomer is 15% by weight
If it is less than 40%, the developability with an alkaline aqueous solution tends to be lowered, and if it exceeds 45% by weight, the chemical resistance of the resist cured product tends to be lowered.

The weight average molecular weight of the carboxyl group-containing thermoplastic resin is 20000 to 300,000, especially 40
It is preferably 000 to 150,000. If the weight average molecular weight is smaller than the above range, the fluidity becomes too large, and the phenomenon of resist bleeding from the roll end surface of the dry film called edge fusion becomes remarkable, and if it is larger than the above range. In the meantime, the developability becomes poor.

The mixture of ethylenically unsaturated compounds used in the present invention is obtained by reacting a polyester polyol or a polyether polyol with a polyisocyanate and then reacting with a (meth) acrylic monomer, as described above. And a urethane acrylic oligomer, a mono (meth) acrylic acid ester of a long-chain polyalkylene glycol, and an ethylenically unsaturated monomer other than these.

The polyester polyol is a reaction product of a dicarboxylic acid and a diol, and is a linear one.

Specific examples of the dicarboxylic acid include aliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid and sebacic acid, phthalic acid, tetrahydro (anhydrous) phthalic acid and hexahydro (anhydrous) phthalic acid. These dicarboxylic acids are usually used alone or
It is used as a mixture of two or more species.

Specific examples of the diol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol. These diols are usually used alone or in admixture of two or more.

The mixing ratio of the dicarboxylic acid and the diol is such that the obtained polyester polyol has a hydroxyl value of 30 to 30.
It is preferably adjusted to 120 KOHmg / g, especially 50 to 80 KOHmg / g. If the hydroxyl value of the polyester polyol is smaller than the above range, the photocurability is insufficient, and if it exceeds the above range, the cured resist tends to be too hard.

The weight average molecular weight of the polyester polyol is usually preferably 1000 to 3000. When the weight average molecular weight of the polyester polyol exceeds the above range, the curing tends to be insufficient during photocuring and tack tends to remain, and when the weight average molecular weight is less than the above range, the polyester polyol is cured. The resist after it tends to be hard and brittle.

Specific examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

The hydroxyl value of the polyether polyol is 30 to 120 KOHmg / g, especially 50 to 80 KOHmg.
/ G is preferable, and the weight average molecular weight is usually preferably 1000 to 3000.

The polyisocyanate to be reacted with the polyester polyol or polyether polyol is
It is a compound having two isocyanate groups in one molecule. Specific examples of the polyvalent isocyanate include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, diphenylmethane 4,4'-diisocyanate and hexamethylene diisocyanate. , Isophorone diisocyanate, lysine diisocyanate, modified diisocyanates thereof, hydrogenated diisocyanate, etc., which may be used alone or in combination of two or more.

When the polyester polyol or polyether polyol is reacted with the polyisocyanate, the compounding ratio is such that the polyester polyol or polyether polyol / polyisocyanate (molar ratio) is 1/2 to 4/5, especially 2 / It is preferable to adjust so as to be 3 to 3/4. If the molar ratio is less than the above range, crosslinking failure during photocuring may be caused, and if it exceeds the above range, a resist image having sufficient hardness cannot be obtained.

Next, the reaction product of the polyester polyol or polyether polyol and the polyvalent isocyanate is reacted with a (meth) acrylic monomer.

Regarding the blending ratio of the reaction product and the (meth) acrylic monomer, the reaction product / (meth) acrylic monomer (molar ratio) is usually 1 / 2.2 to 1 / 1.8, and especially 1 / 2.1-1 to 1/1. It is adjusted to be 2. If the molar ratio is smaller than the above range, the curing tends to be insufficient, and if it exceeds the above range, the stability of the composition solution tends to be poor.

Specific examples of the (meth) acrylic monomer include, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, N-vinylpyrrolidone and 2-hydroxyethyl. Acryloyl phosphate, acrylamide,
Methacrylamide, N-methylolacrylamide, N
-Methylol methacrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, ethylene glycol monoacrylate, dipropylene glycol monoacrylate, N, N-dimethylaminoethyl acrylate, etc., and these (meth) acrylic monomers are They may be used alone or in combination of two or more.

The amount of the urethane acrylic oligomer compounded is usually 5 with respect to the mixture of ethylenically unsaturated compounds.
-40% by weight, especially 8 to 35% by weight is desirable. When the content is less than 5% by weight,
When it exceeds 40% by weight, the fluidity to the substrate becomes poor, and the curing tends to be insufficient.

Typical examples of the mono (meth) acrylic acid ester of long-chain polyalkylene glycol contained in the ethylenically unsaturated compound include, for example, general formula (I):

[0027]

[Chemical 1]

(Wherein R ¹ is a hydrogen atom or a methyl group,
R ² is an alkyl group having 1 to 5 carbon atoms, m is an integer of 5 to 50,
n represents an integer of 0 to 20) and polyalkylene glycol mono (meth) acrylate. In the general formula (I), m is an integer of 10 to 40, n
Is particularly preferably an integer of 5 to 10 in terms of the followability of the resist to the substrate and the flexibility and stability of the cured product.

The content of the long chain polyalkylene glycol mono (meth) acrylic acid ester is usually 10 to 60% by weight, preferably 15 to 50% by weight, based on the mixture of ethylenically unsaturated compounds. .. When the content is less than 10% by weight, the fluidity to the substrate becomes poor, and when it exceeds 60% by weight, the hardness of the resist becomes insufficient.

In the present invention, in the mixture of the ethylenically unsaturated compounds, for example, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 2,2'-bis [4-
(Methacryloxypolyethoxy) phenyl] propane,
Other ethylenically unsaturated monomers such as pentaerythritol triacrylate, pentaerythritol tetraacrylate and polypropylene glycol di (meth) acrylate are contained. The amount of the ethylenically unsaturated monomer compounded is usually 20 to 60% by weight, preferably 30 to 50% by weight, based on the mixture of the ethylenically unsaturated monomers. When the compounding amount is less than 20% by weight, the hardness of the cured product becomes insufficient and the flexibility becomes insufficient, and when it exceeds 60% by weight, edge fusion easily occurs. As a result, the resist stripping time tends to be long.

Examples of the photopolymerization initiator used in the present invention include benzoin, benzoin methyl ether,
Benzoin isopropyl ether, benzoin n-butyl ether, benzoin phenyl ether, anthraquinone, naphthoquinone, benzophenone, bivaloin ethyl ether, benzoin peroxide, benzyl ketanol, 1,1-dichloroacetophenone, para-t-butyldichloroacetophenone, 2-chloro. Thioxanthone, 2,2-diethoxyacetophenone, Michler's ketone, 2,2-dichloro-4-phenoxyacetophenone, phenylglyoxylate, α-hydroxyisobutylphenone, dibenzoparone, benzophenone amine compounds (N-methyldiethanolamine, triethylamine, etc.) Etc. The blending amount of the photopolymerization initiator is selected from the range of 0.01 to 15 parts by weight with respect to 100 parts by weight of the carboxyl group-containing thermoplastic resin. If the amount is less than 0.01 part by weight, the sensitivity tends to be insufficient, and if it exceeds 15 parts by weight, the strength of the cured product and the stability of the composition tend to be poor.

If necessary, the alkali-developable photosensitive resin composition of the present invention may be appropriately blended with a coloring agent such as a dye or a pigment, a plasticizer and a stabilizer.

The thus obtained alkali-developable photosensitive resin composition of the present invention can be suitably used for photoresists such as etching resists and plating resists, the surface temperature of the base material is room temperature, and the pressure bonding is performed. Even if there is a large difference in roll temperature fluctuation, a resist having excellent adhesion to the substrate and excellent followability can be formed.

Next, the alkali-developable photosensitive resin composition of the present invention will be described in more detail with reference to Examples.
The invention is not limited to only such embodiments.

Production Example (Production of Urethane Acrylic Oligomer) 1.0 mol of adipic acid, 0.56 mol of ethylene glycol and 0.14 of 1,4-butanediol were added to a 2-liter flask.
Charge 56 moles, heat with stirring at a temperature of 230 ° C for 17 hours, stop the reaction when the acid value is 0.6 KOHmg / g,
Upon cooling, the hydroxyl value was 55.6 KOHmg / g.
The number average molecular weight of this polyester polyol was 2080 (measured by high performance liquid chromatography, GPC packed column).

Next, 3 mol of isophorodine isocyanate was added to 2 mol of the polyesterol, and the mixture was stirred at a temperature of 60 to 90 ° C. to 1 mol of the oligomer formed when the residual isocyanate group was 1.8% by weight. 2.06 mol of 2-hydroxyethyl acrylate, 0.04% by weight of monomethyl ether hydroquinone was added to the solid content contained, and the mixture was stirred at 50 ° C. for 11 hours, and the isocyanate group was 0.
The reaction was stopped when 2% by weight remained. The hydroxyl value of the obtained urethane acrylic oligomer is 3.3 KOHmg /
It was g.

Examples 1 to 5 and Comparative Examples 1 to 4 (A) Carboxyl group-containing thermoplastic resin and (B) polyester polyol or polyether polyol were reacted with polyisocyanate so as to have the compositions shown in Table 1. A urethane acrylic oligomer, a mixture of ethylenically unsaturated compounds containing a long-chain polyalkylene glycol mono (meth) acrylic acid ester and an ethylenically unsaturated monomer other than these, and (C) a photopolymerization initiator, Add to a solvent consisting of 160 parts by weight of methyl ethyl ketone and 40 parts by weight of 1-methoxy-2-propanol, and further, as an auxiliary agent, 1 part by weight of leuco crystal violet, 1 part by weight of tribromomethylphenyl sulfone, 0.1 part by weight of malachite green, 2, 2'-methylenebis (4-methyl-6-t-butyl) phenol 0.5 It was added in an amount unit and p- dimethylaminobenzoic acid isoamyl ester, 3 parts by weight to give a photosensitive resin composition.

Next, the composition was dried on a polyethylene terephthalate film (thickness: 23 μm) so that the film thickness after drying was 50 μm.
After being coated so as to have a thickness of m and dried, a polyethylene film (thickness: 35 μm) was attached to form a photosensitive element.

Next, while peeling the polyethylene film from the obtained photosensitive element, it was laminated on the copper surface of the copper clad laminate whose photosensitive layer surface was polished and cleaned to obtain a test piece. Laminate, substrate temperature 20 ℃, lamination temperature 70 ℃
(50 ° C. in Example 2, 90 ° C. in Comparative Example 4), pressure 3 kg /
It was carried out under the conditions of cm ² and speed of 3 m / min.

The physical properties of the composition are 30 ° C., 70 ° C. or 90 ° C.
Edge viscosity and defective rate were examined according to the following methods as the viscosity and the physical properties of the test piece.
The results are shown in Table 1.

(A) Viscosity The viscosity is measured by the flow tester method.

(B) Edge fusion It is stored in a roll state (120 m length) in an atmosphere of 30 ° C. and 60% RH (relative humidity), and the number of days required until the resist oozes from the end face of the roll is examined.

(C) Defect rate Using a base material having an average surface roughness of 9.5 μm, a copper thickness of 35 μm and a negative pattern having a line width of 100 μm and a line length of 100 mm (1000 independent lines), a 3 KW ultra high pressure mercury lamp was used. After exposing to 80 mj / cm ² and leaving it for 15 minutes after exposure, peel off the polyethylene terephthalate film, develop with 1% sodium hydrogen carbonate aqueous solution (30 ° C, spray pressure 1.5 kg / cm ² ) for 45 seconds, and acid etch. The evaluation substrate is obtained by removing the resist, and the incidence of chipping and wire breakage is determined.

The abbreviations in the table mean the following.

MBA: methyl methacrylate / n-butyl acrylate / methacrylic acid terpolymer (weight ratio:
50/25/25, weight average molecular weight: 80,000) MEEM: methyl methacrylate / ethyl acrylate /
2-ethylhexyl acrylate / methacrylic acid quaternary copolymer (weight ratio: 50/10/16/24, weight average molecular weight: 71
000) UAO: Urethane acrylic oligomer obtained in the production example PPGMA: Polypropylene glycol methacrylate (in the general formula (I), R ¹ is a methyl group, R ² is a methyl group, m is 40, and n is 0) PPTMGA: Polypropylene glycol polytetramethylene glycol methacrylate (in the general formula (I), R
¹ and R ² are methyl groups, m is 15, and n is 10) AMP: phenoxy polyethylene glycol acrylate TMP-TA: trimethylolpropane triacrylate BPE: 2,2-bis [4- (methacryloxypolyethoxy) phenyl ] Propane 4EG-A: Tetraethylene glycol monoacrylate BPH: Benzophenone EAB: 4,4'-bis (diethylamino) benzophenone

[0046]

[Table 1]

From the results shown in Table 1, Example 1 of the present invention
It can be seen that the compositions obtained from ~ 5 have excellent edge fusion, and the defective rate is extremely small.

[0048]

EFFECT OF THE INVENTION The photosensitive resin composition of the present invention has a substrate having a surface temperature of room temperature, which is excellent in adhesion and followability with a substrate even when there is a large variation in the temperature of the pressure-bonding rolls. It is possible to form a resist having excellent adhesiveness to a base material that undergoes a large dimensional change due to, and excellent followability.

[Procedure amendment]

[Submission date] September 1, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

Specific examples of the (meth) acrylic monomer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate , 2 -hydroxyethyl acryloyl phosphate and acrylamide. , Methacrylamide, N-
Methylolacrylamide, N- methylolmethacrylamide, N- methoxymethyl acrylamide, N- ethoxymethyl acrylamide, ethylene glycol monoacrylate, dipropylene glycol monomethyl acrylated DOO
Do etc. are mentioned, these (meth) acrylic monomers may be used alone or in combination.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Next, put the isophorene b Nji isocyanate 3 moles with respect to the polyesterols 2 moles, temperatures
1.8% by weight of residual isocyanate groups after stirring at 60-90 ℃
2.06 mol of 2-hydroxyethyl acrylate and 0.04 wt% of monomethyl ether hydroquinone were added to 1 mol of the oligomer produced at the time of, and the mixture was stirred at 50 ° C. for 11 hours to give an isocyanate group of 0.2
The reaction was stopped when the weight% remained. The hydroxyl value of the obtained urethane acrylic oligomer is 3.3 KOHmg / g
Met.

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Claims (1)

Claims: (A) A carboxyl group-containing thermoplastic resin,
(B) After reacting a polyester polyol or polyether polyol with a polyvalent isocyanate, (meth)
Urethane acrylic oligomers obtained by reacting acrylic monomers, mono (meth) acrylic acid esters of long-chain polyalkylene glycols, and mixtures of ethylenically unsaturated compounds containing ethylenically unsaturated monomers other than these,
And (C) an alkali-developing photosensitive resin composition containing a photopolymerization initiator.