JPH093283A - Conductor paste composition and its cured material - Google Patents

Abstract

PURPOSE: To obtain the subject composition comprising a specific reaction product, a diluent, a photopolymerization initiator and conductor powder, excellent in developing properties in formation of a circuit pattern by ultraviolet rays and in pattern accuracy after development, low in the resistance value of the circuit pattern and excellent in adhesivity. CONSTITUTION: This conductor paste composition comprises (A) a reaction product of a copolymer of styrene and maleic anhydride and an OH-containing mono(meth)acrylate such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth) acrylate, etc., (B) a diluent such as ethyl (meth)acrylate, an (α-alkyl) styrene, etc., (C) a photopolymerization initiator such as 2,4-diethylthioxanthone, benzyldimethylketal, etc., and (D) conductor powder such as copper powder, silver powder, palladium powder, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is preferably used in a circuit manufacturing process and the like, and after exposure with ultraviolet rays and development with a weak alkaline aqueous solution, baking at 400 to 1000 ° C. forms a circuit having good conductivity. The present invention relates to a conductor paste composition and a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, as a conductor paste (a conductive material such as copper powder or silver powder is made into a paste), a circuit pattern is printed by a printing method such as screen printing, and then baked to form a circuit. What is known is. However, these cannot cope with the recent miniaturization of circuit boards and formation of higher density patterns.

[0003]

DISCLOSURE OF THE INVENTION The present invention improves the above-mentioned drawbacks and enables fine pattern formation, and after curing with ultraviolet rays, development with a weak alkaline aqueous solution to form a circuit pattern, firing, and excellent A circuit having high conductivity is formed. Provided are a conductor paste composition and a cured product thereof.

The present invention comprises a reaction product (A) of a copolymer (a) of styrene and maleic anhydride and a mono (meth) acrylate having a hydroxyl group (b), a diluent (B), and a light source. The present invention relates to a conductor paste composition containing a polymerization initiator (C) and a conductor powder (D) and a composition thereof.

Hereinafter, the present invention will be described in detail. Reaction product (A) of a copolymer (a) of styrene and maleic anhydride and a hydroxyl group-containing mono (meth) acrylate (b) used in the present invention
Can be obtained by reacting the component (a) with the component (b). The copolymer (a) of styrene and maleic anhydride can be easily obtained from the market. For example, EIf Atochem North America, Inc. SMA Resin,
SMA-1000, SMA-2000, SMA-3000, etc. can be mentioned. Specific examples of the hydroxyl group-containing mono (meth) acrylate (b) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate and the like. You can It is preferable to react 0.5 to 2 equivalents of the hydroxyl group of the hydroxyl group-containing mono (meth) acrylate (b) with 1 equivalent of the anhydride group in the copolymer (a), and ethyl methyl is used as a diluent during the reaction. Ketones, ketones such as cyclohexanone, aromatics such as toluene, xylene and tetramethylbenzene, hydrocarbons, glycol ethers such as dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether,
Esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic hydrocarbons such as octane and decane, organic solvents such as petroleum ethers such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha. Or carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, 2-
It is preferable to use reactive monomers such as hydroxyethyl (meth) acrylate, polyethylene glycol di (meth) acrylate and glycerin polypropoxytri (meth) acrylate. Further, in order to accelerate the reaction, it is preferable to use a catalyst (eg, triethylamine, benzyldimethylamine, triphenylphosphine, triphenylstibine, etc.), and the amount of the catalyst used is
Preferably 0.1 to 10% by weight with respect to the reaction raw material mixture
It is. In order to prevent polymerization during the reaction, it is preferable to use a polymerization inhibitor (eg, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc.), and the amount thereof is, relative to the reaction raw material mixture, Preferably 0.01 to 1% by weight
It is. The reaction temperature is preferably 60 to 150 ° C. The reaction time is preferably 5 to 30 hours. In this way, the reaction product (A) can be obtained. (B)
Specific examples of the component include, for example, ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxy (meth) acrylate, 2-hydroxypropyl (meth) acrylate, styrene, α-alkylstyrene,
Carbitol (meth) acrylate, mono (meth) acrylates such as (meth) acrylic acid, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polypropoxy Tri (meth) acrylate, trimethylolpropane triethoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol polypropoxytetra (meth) ) Reactive diluents (B-1) such as polyfunctional (meth) acrylates such as acrylates, ethylene glycol monoalkyl ethers, diethylene glycol Monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates, diethylene glycol monoalkyl ether acetates, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, etc. Of the above, aromatic hydrocarbons such as toluene and xylene, organic solvents (B-2) such as solvent naphtha, and the like.

Specific examples of the component (C) include, for example:
2,4-diethylthioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methyl-1
-[4- (Methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1
-(4-morpholinophenyl-1-butanone, 4-benzoyl 4'-methyldiphenyl sulfide, 2,4
Mention may be made of 6-trimethylbenzoyldiphenylphosphine oxide, Michler's ketone and benzyl dimethyl ketal. Further, these photopolymerization initiator (C) and a photopolymerization accelerator such as amines may be used in combination.
Examples of the photopolymerization accelerator such as amines include 2-dimethylaminoethylbenzoate, dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, p-
Examples thereof include isoamyl dimethylaminobenzoate.

Specific examples of the component (D) are preferably copper powder having a particle size of 10 μm or less, silver powder, palladium powder, mixed powder of silver and palladium, surface-treated gold powder, silver powder,
Examples thereof include ruthenium oxide and others.

The conductor paste composition of the present invention comprises (A)
(B: B-1, B-2) (C) and (D) components can be prepared by dissolving, mixing and kneading.
In the conductor paste composition of the present invention, the use ratio of each component can be as follows (% is weight%). The total amount of the component (A) + the component (B-1) + the component (C) is preferably 5 to 25% of the composition, particularly preferably 8 to 30%, and the component (D) is 50-95%
Is preferable, and particularly preferably 70 to 92%.
Further, the preferable and used amount of each component in the total amount of (A) + (B-1) + (C) is as follows. That is, the amount of the component (A) used is 50 to 90%, (B-1)
The amount of the component used is 6 to 45%, and the amount of the component (C) used is
5 to 30%. The amount of the organic solvent (B-2) used may be any ratio for the purpose of adjusting the viscosity suitable for using the composition of the present description.

The conductor paste composition of the present invention contains a leveling agent, a defoaming agent, a polymerization inhibitor, waxes, a non-reactive polymer, an epoxy (meth) acrylate, a urethane (meth) as long as its performance is not impaired. ) Acrylate, polyester (meth) acrylate, a reaction product of epoxy (meth) acrylate and polybasic acid anhydride, and the like can also be used. The conductor paste composition of the present invention is printed and applied on the entire surface of a substrate such as a glass or ceramic substrate by a method such as screen printing, roll coating, curtain flow coating, spray coating and the like. After printing and coating, if necessary, the organic solvent is removed by prebaking at 50-80 ° C with far infrared rays or warm air to remove the organic solvent, and exposure with ultraviolet rays is performed using a negative mask that allows ultraviolet rays to pass through only the circuit portion. The amount of UV exposure is 500-
5000 mJ / cm ² is preferred. Next, it is developed by means of a spray or the like with a developing solution of a dilute alkaline aqueous solution such as an aqueous solution of sodium carbonate or an aqueous solution of caustic soda, and then 400 to 1
A circuit board is obtained by firing at 000 ° C.

[0009]

The present invention will be described below with reference to examples. In the examples, “parts” means “parts by weight” and “%” means “% by weight”. (Synthesis Example of Reactant (A)) Synthesis Example 1 SMA-1000 (manufactured by EIf Atochen North America, Inc., copolymer of styrene and maleic anhydride, acid value 480) 50
0 part, 2-hydroxyethyl acrylate 272.9
Parts, 0.6 parts of methylhydroquinone, 519.9 parts of carbitol acetate, and heated to 90 ° C. and stirred,
The reaction mixture was dissolved. Then, the reaction solution was cooled, charged with 6.4 parts of triethylamine, and heated to 90 ° C. to about 1
The reaction was carried out for 0 hours to obtain a reaction product (A-1) having an acid value (mg / KOH / g) of 154 mgKOH / g and a solid content of 60%.

Synthesis Example 2 SMA-1000 (manufactured by EIf Atochen North America, Inc., copolymer of styrene and maleic anhydride, acid value 480) 50
0 parts, 1,4-butanediol monoacrylate 339
Parts, 0.7 parts of methylhydroquinone, 564.5 parts of carbitol acetate, and heated to 90 ° C. and stirred,
The reaction mixture was dissolved. Then, the reaction solution was cooled, charged with 7 parts of triethylamine, heated to 90 ° C., reacted for about 10 hours, and a reaction product (A- having a solid content of 60% with an acid value (mgKOH / g) of 142 mgKOH / g) (A- 2) was obtained.

Examples 1 to 4 Conductor paste compositions were prepared according to the compositions shown in Table 1. The obtained conductor paste composition was screen-printed on a gold surface of a ceramic substrate with a film thickness of 35 μm using a 150-mesh polyester screen plate, prebaked at 80 ° C. for 30 minutes, and then contacted with a negative film,
An ultrahigh pressure mercury lamp was used to irradiate an exposure dose of 3 J / cm ² , and then the unexposed area was exposed to a 1.0% aqueous sodium hydroxide solution (solution temperature 30
° C.) 1 minute at a spray pressure 3 kg / cm ² was used to developed.
The developability and the state of the pattern after development were evaluated. After development, it was baked in N ₂ gas at 900 ° C. for 10 minutes to form a circuit. The conductor resistance of the circuit and the adhesion of the circuit to the ceramic substrate were evaluated.

[0012]

Table 1 Table 1 Example 1 2 3 4 Reaction product (A-1) obtained in Synthesis Example 1 11.67 11.67 5.84 Reaction product (A-2) obtained in Synthesis Example 2 11.67 5.83 KAYARAD PEG400DA * 1 1.32 1.32 KAYARAD T-2040 * 2 1.32 KAYARAD GPO-303 * 3 1.32 carbitol acetate 30 30 30 30 Irgacure 969 * 4 1 1 1 1 1 KAYACURE DETX-S * 5 0.68 0.68 0.68 0.68 Copper powder with an average particle size of 2.0 μm 40 40 40 40 Developability ○ ○ ○ ○ Pattern condition after development ○ ○ ○ ○ Conductor resistance of circuit (mΩ / port) 0.9 1.5 1.0 0.9 Adhesion ○ ○ ○ ○

Note) * 1 KAYARAD PEG 400DA: polyethylene glycol diacrylate manufactured by Nippon Kayaku Co., Ltd. * 2 KAYARAD T-2040: ditrimethylol propane tetrapropoxy tetraacrylate manufactured by Nippon Kayaku Co., Ltd. * 3 KAYARAD GPO-303: Glycerin tripropoxy triacrylate manufactured by Nippon Kayaku Co., Ltd. * 4 Irgacure 369: manufactured by Ciba Geigy,
Photopolymerization initiator, 2-benzyl-2-dimethylamino-1
-(4-morpholino-phenyl) -1-butanone. * 5 KAYACURE DETX-S: manufactured by Nippon Kayaku Co., Ltd., photopolymerization initiator, 2,4-diethylthioxanthone.

Test Method and Evaluation Method (Developability) The following evaluation criteria were used. ○ ... ・ Completely developed during development. △ ... ・ Slight residue is left during development. X ...- Some areas are not developed during development.

(State of the pattern at the time of development) O ... The pattern is maintained accurately. Δ: The pattern width is narrow. X ...- Part or all of the pattern portion is peeled off.

(Circuit conductor resistance value) The resistance of the circuit portion is measured. (Unit: mΩ / unit)

(Adhesion) 100 pieces of 1 mm squares were made on the circuit portion, and a peeling test was conducted using a cellophane tape. The peeling state of the first eye was observed and evaluated according to the following criteria. ○ ・ ・ ・ ・ 100/100 that does not come off △ ・ ・ ・ ・ 50/100 to 30/100 × ・ ・ ・ ・ 0/100 to 50/100

As is clear from the evaluation results in Table 1, the conductor paste composition of the present invention and its cured product have excellent developability, good pattern accuracy after development, low resistance value, and excellent adhesion. ing.

[0019]

EFFECT OF THE INVENTION The conductor paste composition of the present invention is excellent in developability in the formation of a circuit pattern by selectively exposing it to ultraviolet rays through a film having a pattern formed thereon and developing an unexposed portion. The pattern accuracy is good, the resistance value of the formed circuit pattern is low, and the adhesion is excellent.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01B 1/22 H01B 1/22 A

Claims (2)

[Claims] 1. A reaction product (A) of a copolymer (a) of styrene and maleic anhydride and a hydroxyl group-containing mono (meth) acrylate (b), a diluent (B), a photopolymerization initiator (C) and a conductor. A conductor paste composition comprising powder (D). 2. A cured product of the composition according to claim 1.