JP3012367B2 - Alkali-developing photosensitive resin composition - Google Patents

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 suitably used for producing printed wiring boards and the like. More specifically, etching resist,
It can be suitably used as a plating resist, etc.
The present invention relates to a photosensitive resin composition which is suitable for forming a secondary circuit on a stepped substrate after circuit formation and is capable of forming an alkali development type 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, when laminating the photosensitive element to the substrate, when the preheating temperature of the substrate is insufficient and the workability temperature range of the temperature of the pressure roll is narrow, the substrate Adhesion with
There is a problem that the followability is deteriorated, the formed printed wiring board is chipped, disconnected, short-circuited, and the like, and the manufacturing efficiency and the yield are significantly reduced.

[0003] When a film-shaped transparent electrode plate is used as a base material, there is a problem that a dimensional error from a 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 considered that the surface temperature of the base material was around room temperature, and even if the difference in the temperature of the pressure roll was large, the adhesion to the base material was large. As a result of intensive studies to obtain a photosensitive resin composition that is capable of forming a resist that is excellent in adhesiveness and followability, and that is excellent in adhesion and followability to a substrate that has a large dimensional change due to temperature change, as a result, The present inventors have found a conductive resin composition and completed the present invention.

[0005]

That is, the present invention provides:
(A) 100 parts by weight of a carboxyl group-containing thermoplastic resin, (B) 5 to 40 parts by weight of a urethane acrylic oligomer obtained by reacting a polyester polyol or a polyether polyol with a polyvalent isocyanate and then reacting a (meth) acrylic monomer. % , Mono (meth) acrylate of long-chain polyalkylene glycol 10 to 60
% And a mixture of ethylenically unsaturated compounds 20 to 60 wt% containing an ethylenically unsaturated monomer other than these 4
The present invention relates to an alkali-developable photosensitive resin composition containing 5 to 60 parts by weight and (C) 0.01 to 15 parts by weight of a photopolymerization initiator.

[0006]

Action and Examples As described above, the alkali-developable photosensitive resin composition of the present invention is obtained 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) acrylate of a long-chain polyalkylene glycol and an ethylenically unsaturated compound containing other ethylenically unsaturated monomers, 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 carboxyl group-containing vinyl monomer include, for example, acrylic acid, methacrylic acid,
Examples thereof include cinnamic acid, crotonic acid, sorbic acid, itaconic acid, fumaric acid, and their partial esters and anhydrides. These monomers are usually used alone or in combination of two or more.

Specific examples of the vinyl monomer 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, which are usually used alone or in combination of two or more.

The proportion of the carboxyl group-containing monomer in the carboxyl group-containing thermoplastic resin is adjusted so as to be 15 to 45% by weight, preferably 17 to 40% by weight. The ratio of such a carboxyl group-containing monomer is 15% by weight.
If it is less than 45%, the developability with an aqueous alkali solution tends to decrease, and if it exceeds 45% by weight, the chemical resistance of the cured resist tends to decrease.

The carboxyl group-containing thermoplastic resin has a weight average molecular weight of 20,000 to 300,000, preferably 40,000.
It is preferably from 000 to 150,000. When the weight average molecular weight is smaller than the above range, the fluidity becomes too large, and the phenomenon of exudation of the resist from the roll end face of the dry film called edge fusion becomes remarkable. In the meantime, developability deteriorates.

The mixture of the ethylenically unsaturated compounds used in the present invention is obtained by reacting a polyester polyol or a polyether polyol with a polyvalent isocyanate and then reacting a (meth) acrylic monomer as described above. Urethane acrylic oligomers, mono (meth) acrylates of long-chain polyalkylene glycols and other ethylenically unsaturated monomers.

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

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

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

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

The weight average molecular weight of the polyester polyol is usually preferably from 1,000 to 3,000. When the weight average molecular weight of such a polyester polyol exceeds the above range, the curing tends to be insufficient due to insufficient curing at the time of photocuring, and when it is smaller than the above range, the curing is performed. The resist after etching tends to be hard and brittle.

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

The polyether polyol has a hydroxyl value of 30 to 120 KOH mg / g, preferably 50 to 80 KOH mg / g.
/ G, and the weight average molecular weight is usually preferably from 1,000 to 3,000.

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

The mixing ratio of the polyester polyol or polyether polyol to the polyvalent isocyanate when the polyester polyol or polyether polyol / polyisocyanate (molar ratio) is 1/2 to 4/5, preferably 2/4 It is preferable to adjust so as to be 3 to 3/4. When the molar ratio is smaller than the above range, it causes crosslinking failure at the time of photocuring. When the molar ratio exceeds the above range, a resist image having sufficient hardness cannot be obtained.

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

The mixing ratio of the reactant and the (meth) acrylic monomer is usually such that the reactant / (meth) acrylic monomer (molar ratio) is 1 / 2.2 to 1 / 1.8, preferably 1/2. It is adjusted to be 2. If the molar ratio is smaller than the above range, the curing will be insufficient, and if it exceeds the 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 , 2 -hydroxyethyl acryloyl phosphate, 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.

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

Representative examples of the mono (meth) acrylate of a long-chain polyalkylene glycol contained in the ethylenically unsaturated compound include, for example, a compound represented by the following general formula (I):

[0027]

Embedded image

(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 preferably an integer of 5 to 10 from the viewpoint of followability of the resist to the base material and flexibility and stability of the cured product.

The amount of the mono (meth) acrylate of the long-chain polyalkylene glycol is usually 10 to 60% by weight, preferably 15 to 50% by weight, based on the mixture of the ethylenically unsaturated compounds. . If the amount is less than 10% by weight, the fluidity to the substrate will be poor, and if it exceeds 60% by weight, the hardness of the resist will be insufficient.

In the present invention, the mixture of the ethylenically unsaturated compounds includes, 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 is usually 20 to 60% by weight, preferably 30 to 50% by weight, based on the mixture of the ethylenically unsaturated monomers. When the amount is less than 20% by weight, the hardness of the cured product becomes insufficient and the flexibility becomes inadequate. When the amount exceeds 60% by weight, edge fusion tends to occur. And the resist stripping time tends to be longer.

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, benzylketanol, 1,1-dichloroacetophenone, para-t-butyldichloroacetophenone, 2-chloro Thioxanthone, 2,2-diethoxyacetophenone, Michler's ketone, 2,2-dichloro-4-phenoxyacetophenone, phenylglyoxylate, α-hydroxyisobutylphenone, dibenzosparone, benzophenoneamine-based compounds (N-methyldiethanolamine, triethylamine, etc.) And so on. The compounding amount of the photopolymerization initiator is selected from the range of 0.01 to 15 parts by weight based on 100 parts by weight of the carboxyl group-containing thermoplastic resin. When the amount is less than 0.01 part by weight, the sensitivity is insufficient. When the amount exceeds 15 parts by weight, the strength of the cured product and the stability of the composition tend to be poor.

The alkali-developable photosensitive resin composition of the present invention may optionally contain, for example, a coloring agent such as a dye or a pigment, a plasticity, a stabilizer, and the like.

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. Even if there is a large difference in roll temperature variation, a resist excellent in adhesion to a base material and 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 present invention is not limited to only such embodiments.

Production Example (Production of Urethane Acrylic Oligomer) A 2 liter flask is charged with 1.0 mol of adipic acid, 0.56 mol of ethylene glycol and 0.1 mol of 1,4-butanediol.
The mixture was heated to 230 ° C. for 17 hours while stirring, and the reaction was stopped at an acid value of 0.6 KOH mg / g.
Upon cooling, the hydroxyl value was 55.6 KOH mg / g.
The number average molecular weight of this polyester polyol was 2080 (measured by high performance liquid chromatography, GPC packed column).

Next, put the isophorene b Nji isocyanate 3 moles with respect to the polyesterols 2 moles, temperatures
Stir at 60-90 ° C, 1.8% by weight of remaining isocyanate groups
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 the above, and the mixture was stirred at 50 ° C. for 11 hours.
The reaction was stopped when the weight% remained. The hydroxyl value of the obtained urethane acrylic oligomer is 3.3 KOHmg / g
Met.

Examples 1 to 5 and Comparative Examples 1 to 4 A polyisocyanate was reacted with (A) a carboxyl group-containing thermoplastic resin and (B) a polyester polyol or a polyether polyol so as to have the compositions shown in Table 1. A mixture of a urethane acrylic oligomer, a mono (meth) acrylate of a long-chain polyalkylene glycol and an ethylenically unsaturated compound containing other ethylenically unsaturated monomers, and (C) a photopolymerization initiator, To a solvent consisting of 160 parts by weight of methyl ethyl ketone and 40 parts by weight of 1-methoxy-2-propanol, 1 part by weight of leuco crystal violet, 1 part by weight of tribromomethylphenylsulfone, 0.1 part by weight of malachite green, 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.

Then, the composition was dried on a polyethylene terephthalate film (thickness: 23 μm) to a thickness of 50 μm.
m and dried, and then laminated with a polyethylene film (thickness: 35 μm) to form a photosensitive element.

Next, while removing the polyethylene film from the obtained photosensitive element, the photosensitive layer was laminated on the copper surface of a copper-clad laminate whose 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 /
The test was performed under the conditions of cm ² and a speed of 3 m / min.

The physical properties of the composition are 30 ° C., 70 ° C. or 90 ° C.
And the edge fusion and the defective rate were examined in accordance with the following methods.
Table 1 shows the results.

(A) Viscosity Measured by a flow tester method.

(B) Edge fusion The roll was stored in a roll state (roll length: 120 m) in an atmosphere of 30 ° C. and 60% RH (relative humidity), and the number of days required for the resist to exude from the roll end face was examined.

(C) Defect rate Using a base material having an average surface roughness of 9.5 μm and 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), using a 3 KW ultra-high pressure mercury lamp. After exposure at 80 mj / cm ² , and after leaving for 15 minutes after exposure, the polyethylene terephthalate film was peeled off and developed with a 1% aqueous sodium hydrogen carbonate solution (30 ° C., spray pressure 1.5 kg / cm ² ) for 45 seconds to perform acid etching. Then, the resist is peeled off to obtain a substrate for evaluation, and the incidence of chipping and disconnection is determined.

Each abbreviation in the table means the following.

MBA: Methyl methacrylate / n-butyl acrylate / methacrylic acid terpolymer (weight ratio:
50/25/25, weight average molecular weight: 80000) 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 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 is a methyl group, m is 15, n is 10 ones) AMP: phenoxy polyethylene glycol acrylate TMP-TA: trimethylolpropane triacrylate BPE: 2,2-bis [4- (methacryloxy polyethoxy) 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 was obtained.
It can be seen that the compositions obtained in Nos. 1 to 5 were excellent in edge fusion and extremely low in the defective rate.

[0048]

As described above, the photosensitive resin composition of the present invention is excellent in adhesion and follow-up with the substrate even when the surface temperature of the substrate is room temperature, and there is a large variation in the temperature of the pressure roll. It is possible to form a resist excellent in adhesion and follow-up with a base material having a large dimensional change due to the above.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G03F 7/033 G03F 7/033 H05K 3/06 H05K 3/06 H (56) References JP-A-2-32353 (JP, A) JP JP-A-61-103968 (JP, A) JP-A-51-116893 (JP, A) JP-A-58-11931 (JP, A) JP-A-63-146036 (JP, A) JP-A-2-4867 (JP) , A) JP-A-3-41106 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/027 C08F 299/02 C08F 299/06 G03F 7/004 G03F 7/033

Claims (1)

(57) [Claims] 1. A carboxyl group-containing thermoplastic resin (A)
100 parts by weight , (B) 5 to 40% by weight of a urethane acrylic oligomer obtained by reacting a polyhydric isocyanate with a polyester polyol or a polyether polyol and then reacting with a (meth) acrylic monomer; (Meth) acrylic acid ester 10-60
% And a mixture of ethylenically unsaturated compounds 20 to 60 wt% containing an ethylenically unsaturated monomer other than these 4
An alkali-developable photosensitive resin composition comprising 5 to 60 parts by weight and (C) 0.01 to 15 parts by weight of a photopolymerization initiator.