JPH08314140A - Resin composition, resist ink composition and its cured body - Google Patents

Abstract

PURPOSE: To provide a resist ink compsn. which can be developed with water and gives a cured body having superior resistance to electroless gold plating when a soldering resist pattern is formed by removing a UV-unexposed part by development and to provide a cured body of the resist ink compsn. CONSTITUTION: This resist ink compsn. contains an onium salt (A) as a reaction product of an epoxy compd. having two or more epoxy groups in one molecule with a thio-ether compd. and an acid compd., an epoxy compd. (B) having two or more epoxy groups in one molecule and a cationic photopolymn. initiator (C).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is capable of developing with a dilute alkaline aqueous solution which can be used as a solder resist or an electroless plating resist in the production of printed wiring boards, and its cured product is
The present invention relates to a resist ink composition having excellent adhesion, solder heat resistance, resistance to electroless gold plating, and the like, and a cured product thereof.

[0002]

2. Description of the Related Art In recent years, ultraviolet ray curable compositions have been widely used in various fields for reasons such as resource saving, energy saving, workability improvement and productivity improvement. In the field of printed wiring board processing, for the same reason, various inks such as solder resist inks and marking inks have been transferred from conventional thermosetting compositions to ultraviolet curable compositions.

[0003]

Although a screen printing method has been widely used as a method for forming a resist pattern on a printed wiring board, when such a screen printing method is used, in many cases, bleeding, bleeding, or bleeding during printing, or Causes a phenomenon such as sagging, which makes it impossible to cope with the recent high density of printed wiring boards and surface mounting of components.

To solve these problems, dry film type photoresists and liquid photo solder resists have been developed. In the case of a dry film type photoresist, there are problems that bubbles are easily generated during thermocompression bonding, heat resistance and adhesiveness are uncertain, and the price is high. On the other hand, examples of the liquid photo solder resist include, for example, JP-A-60-208337 and JP-A-61-59.
In Japanese Patent No. 447, etc., a solder resist ink composition mainly composed of a partial reaction product of a novolac type epoxy resin with acrylic acid is proposed. However, any of these ink compositions must use an organic solvent such as 1,1,1-trichloroethane, trichloroethylene, toluene, and cyclohexanone during development, which is problematic in terms of working environment and economy. was there. Further, in order to solve the problems caused by these organic solvents, there has been proposed one which can be developed with a dilute alkaline aqueous solution. For example
54390 discloses a resist ink composition mainly composed of a reaction product of a novolac type epoxy resin, acrylic acid and a polybasic acid anhydride. However, in order to carry out development in a dilute alkaline aqueous solution without problems, this resist ink composition makes the reaction product of a novolac type epoxy resin and allyl acid a relatively high acid value of the reaction product of a polybasic anhydride. This is a problem in terms of properties and that the drying time of the solvent must be shortened.If the substrate is coated with the ink composition and the solvent is dried and left for a long time, the unexposed area is developed with a dilute alkaline aqueous solution. In that case, development cannot be performed at all, which is a problem from the viewpoint of the process. Further, the cured product has a problem that resistance to electroless gold plating is insufficient.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the inventors of the present invention can develop with water even if there is no carboxylic acid in the structure of the main resin, and It has succeeded in providing a resin composition suitable for a resist ink and a cured product thereof which can be developed even if the drying time is long and have excellent adhesion of a cured film, solder heat resistance, resistance to electroless gold plating and the like.

That is, the present invention is: 1) An onium salt (A) which is a reaction product of an epoxy compound (a) having at least two epoxy groups in one molecule, a thioether compound (b) and an acid compound (c). ) And an epoxy compound (B) having at least two epoxy groups in one molecule and a photocationic polymerization initiator (c), 2) at least two in one molecule. An onium salt (A) which is a reaction product of the above epoxy compound (a) having an epoxy group, a thioether compound (b) and an acid compound (c), and an epoxy compound having at least two epoxy groups in one molecule ( B) and a cationic photopolymerization initiator (C) are contained in the resist ink composition, 3) a cured product of the composition according to the items 1) and 2).

The onium salt (A) used in the present invention is
It can be obtained by reacting the epoxy compound (a) having at least two epoxy groups in one molecule with the thioether compound (b) and the acid compound (c). Specific examples of the epoxy compound (a) include novolak type epoxy resins (for example, novolaks obtained by reacting phenols such as phenol, cresol, halogenated phenols and alkylphenols with formaldehyde under an acidic catalyst, epichlorohydrin and Examples of the commercially available product include EOCN-103 and EOCN-103 manufactured by Nippon Kayaku Co., Ltd.
104S, EOCN-1020, EOCN-1027,
EPPN-201, BREN-S; manufactured by Dow Chemical Co., DEN-431, DEN-439; manufactured by Dainippon Ink and Chemicals, Inc., N-730, N-770, N-86.
5, N-665, N-673, VH-4150, etc.), a bisphenol type epoxy resin (for example, bisphenol A, bisphenol F, bisphenol S, and tetrabromobisphenol A, and the like, and epichlorohydrin and / or methylepichlorohydrin are reacted. And bisphenol A,
Examples thereof include condensates of diglycidyl ether and the above bisphenols. Specific examples of the thioether compound (b) include, for example,

[0008]

Embedded image

[0009]

Embedded image

[0010]

Embedded image

[0011]

[Chemical 4]

[0012]

Embedded image

And the like.

Specific examples of the acid compound (C) include organic carboxylic acids such as acetic acid, propionic acid, acrylic acid and methacrylic acid. The thioether compound (b) and the acid compound (c) are neutralized, and then the epoxy compound (a) is reacted at a reaction temperature of 40 to 100 ° C., preferably 50 to 70 ° C. to produce an onium salt ( A) can be obtained. The proportion of each component used is preferably 0.5 to 2 equivalents, and particularly preferably 0.7 to 1.5 equivalents of the component (b) to 1 equivalent of the component (a). The component (c) is
Preferably 0.5 to 1.5 with respect to 1 equivalent of the component (a).
It is an equivalent, and particularly preferably 0.7 to 1.1 equivalents. Examples of the reaction solvent include ethyl methyl ketone, cyclohexanone, toluene, xylene, tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol, monoethyl ether, butyl cellosolve acetate, carbitol. It is preferable to use acetate, butyrolactone, petroleum ether, petroleum naphtha, solvent naphtha and the like.

Specific examples of the epoxy compound (B) having at least two epoxy groups in one molecule include the same compounds as the epoxy compound (a).

Specific examples of the cationic photopolymerization initiator (C) used in the present invention include, for example, triphenylsulfonium, hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate and diphenyl-4. -Thiophenoxyphenylsulfonium hexafluoroantimonate, 4,4'-bis [bis (p-2
-Hydroxyethoxyphenyl) sulfonio] phenyl sulfide bishexafluoroantimonate, and the like.

The composition of the present invention can be prepared by heating, mixing and dissolving the components (A), (B) and (C).

The proportion of each component used in the composition of the present invention is
The component (A) is preferably 20 to 80% by weight, particularly preferably 30 to 70% by weight. (B) component is 20
Is preferably 80 to 80% by weight, particularly preferably 30 to 70%.
% By weight. The component (C) is preferably 0.5 to 10% by weight, particularly preferably 1 to 7% by weight.

The composition of the present invention further contains barium sulfate, barium titanate, silicon oxide powder, finely powdered silicon oxide, amorphous silica, talc, if necessary for the purpose of improving properties such as adhesion and hardness. Known inorganic fillers such as clay, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide and mica powder can be used. The amount used is 0 to 60% by weight in the composition of the present invention.
Is preferable, and particularly preferably 5 to 40% by weight.

Furthermore, if necessary, a known and commonly used coloring agent such as phthalocyanine blue, phthalocyanine, green, iodin clean, disazo yellow, crystal violet, titanium oxide, carbon black and naphthalene black, hydroquinone, hydroquinone monomethyl ether, Known and commonly used thickeners such as t-butylcatechol, pyrogallol, phenothiazine, defoaming agents such as silicone-based, fluorine-based, polymer-based and / or leveling agents, imidazole-based, thiazole-based, triazole-based, silane coupling Well-known and commonly used additives such as adhesion promoters such as agents can be used.

Further, photopolymerizable oligomers such as phenol / novolac type epoxy (meth) acrylate, polyester (meth) acrylate and polyurethane (meth) acrylate, and photopolymerizable monomers such as dipentaerythritol hexa and penta (meth) acrylate. Also, a radical photoinitiator can be used within a range that does not affect various properties as a solder resist.

The composition of the present invention can be obtained by blending the blending components preferably in the above proportions and uniformly mixing them with a roll mill or the like.

The resist ink composition of the present invention is cured, for example, as follows to obtain a cured product. That is, 1 is applied to a printed wiring board by screen printing, spraying, roll coating, electrostatic coating, curtain coating, or the like.
The composition of the present invention is applied in a film thickness of 0 to 160 μm, the coating film is dried at 60 to 110 ° C., and then the negative film is brought into direct contact with the coating film (or on the coating film without contacting the film). Then, the unexposed portion is dissolved and removed (developed) with water or a dilute alkaline aqueous solution (for example, 0.5 to 2% sodium carbonate aqueous solution or 0.5 to 2% caustic soda aqueous solution). After that, in order to further improve various physical properties, irradiation with ultraviolet rays and / or heating (for example, 100 to 200 ° C.)
Then, sufficient curing is performed for 0.5 to 1.0 hour to obtain a cured film.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to examples. (Synthesis Example of Onium Salt (A)) Synthesis Example 1 2100 parts of cresol / novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104, epoxy equivalent 210, softening point 94 ° C.), carbitol acetate 18
85 parts were charged, mixed and dissolved, and heated to 70 ° C. Then, a mixture of thiodiglycol 880 and 600 parts of acetic acid was added dropwise thereto over 30 minutes, and the acid value (mgK
The reaction was carried out until the OH / g) became 1 or less to obtain an onium salt (A-1). The viscosity of the product is 150 poise (25
℃).

Synthesis Example 2 Trisphenol type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.,
EPPN-502, epoxy equivalent 168, softening point 70
(° C) 1680 parts and carbitol acetate 1453 parts were charged, mixed and dissolved, and heated to 70 ° C. Then add 30 parts of a mixture of 518 parts of thiodiglycol and 500 parts of acetic acid.
The reaction mixture was added dropwise over a period of 70 minutes at 70 ° C. (mgKOH /
g) The reaction is carried out until it becomes 1 or less, and the onium salt (A-
2) was obtained. The viscosity of the product was 105 poise (25 ° C). Examples 1 to 4 A resist ink composition was blended according to the blending composition (numerical values are parts by weight) shown in Table 1 below, and each was kneaded separately with a three-roll mill to prepare. This is screen-printed using a 100-mesh polyester screen to a thickness of 20 to 30 μm, and is applied over the entire surface to a patterned copper through-hole printed wiring board, and the coating film is dried at 80 ° C. in a hot air drier. After drying for 1 hour, a negative film having a resist pattern is brought into close contact with the coating film, and an ultraviolet exposure device (Oak Manufacturing Co., Ltd., model HMW-680) is used.
It was irradiated with ultraviolet rays using GW (exposure amount: 1000 m
J / cm ² ) and then with water for 60 seconds, 2.0 kg / cm
Development was performed with a spray pressure of ² , and the unexposed portion was dissolved and removed.
The obtained product was evaluated as described below.

Thereafter, the sample was irradiated with ultraviolet rays at 1000 mJ / cm ² and then cured by heating in a hot air dryer at 150 ° C. for 40 minutes. The test piece having the cured film obtained was as described below (adhesion, solder heat resistance). , Resistance to electroless gold plating)
Was tested. Each test method is shown below.

(Adhesion) According to the test method of JIS D 0202, a cross-cut was put on the cured film in a grid pattern, and then the state of peeling after a peeling test with cellophane tape was visually judged.

Double circle: 100/100 with no peeling at all ○: 100/100 with slightly peeled cross-cut portion Δ: 50/100 to 90/100 × ... 0/100 to 50/100 (Solder heat resistance) According to the test method of JIS C 6481, the test piece was immersed in a solder bath at 260 ° C for 10 seconds three or two times to change the appearance. evaluated.

(Post-flux resistance) Soaking for 10 seconds 3
The test was repeated and the change in appearance was evaluated.

○ ・ ・ ・ ・ No change in appearance △ ・ ・ ・ ・ ・ ・ Discoloration of the cured film is observed × ・ ・ ・ ・ Floating, peeling, and solder dip in the cured film Note) Post flux used (rosin type) : JIS
Use flack according to C 6481.

(Flux resistance for levelers) After dipping for 10 seconds twice and dipping in boiling water for 10 minutes, changes in appearance were evaluated.

○ ・ ・ ・ ・ No change in appearance △ ・ ・ ・ ・ Discoloration of cured film is observed × ・ ・ ・ ・ Floating, peeling, and solder latent of cured film Note) Flux for leveler used: (stock ) Made by MEC
W-121 (resistance to electroless gold plating) The copper surface of a copper through-hole printed wiring board on which a pattern is formed is subjected to surface treatment (surface polishing (Ishii Inscription Co., Ltd., jet scrub polishing using abrasive grain No. 270)) or (Ishii Notation Co., Ltd., N
o. 1200 roll buffed), washed with water and dried. ), And in the same manner as described above, coating → drying → exposure →
Development → heating was performed to obtain a test piece. Using this test piece, electroless gold plating was performed as in the following steps, and the peeling state of the resist was determined by performing a change in appearance and a peeling test using cellophane tape on the test piece.

Good: No change in appearance and no peeling of the resist.

Δ: No change in appearance, but slight peeling of the resist.

X: ・ The resist floated, the plating diving was recognized, and the peeling of the resist was large in the peeling test.

The acidic degreasing solution of the electroless gold plating process degreasing, specimen 30 ° C. ((Corporation) Japan MacDermid made, 20% Vol aqueous Metex L-5B)
Soak for 3 minutes.

Immersion of the test piece in water washed with running water for 3 minutes.

Soft etch : A test piece was dipped in an ammonium persulfate aqueous solution of 14.3% wt for 3 minutes at room temperature.

Immersion of the test piece in water washed and running water for 3 minutes.

Acid immersion , 10% Vol. Test piece in sulfuric acid solution at room temperature for 1 minute,
Immersion.

Washing / immersing the test piece in running water for 30 seconds to 1 minute.

Immersion of catalyst -Test piece was immersed in a catalyst solution at 30 ° C. (10% Vol. Aqueous solution of METAL BREAT ACTIVATOR 350 manufactured by Meltex Co., Ltd.) for 7 minutes.

Immersion of the test piece in water washed with running water for 3 minutes.

Electroless nickel plating・ Test pieces were plated at 85 ° C. and pH = 4.6 with a nickel plating solution (Melplate Ni-865 manufactured by Meltex Co., Ltd.).
M, 20% Vol. Soak for 20 minutes.

Acid immersion , 10% Vol. Test piece in sulfuric acid solution at room temperature for 1 minute,
Immersion.

Washing / immersing the test piece in running water for 30 seconds to 1 minute.

Electroless gold plating・ Test pieces were gold plated at 95 ° C. and pH = 6 (manufactured by Meltex Co., Ltd., Ourolectroles UP 15% Vo)
l. Immersion in potassium gold cyanide 3% Vol aqueous solution) for 10 minutes.

Immerse the test piece in water rinse / running water for 3 minutes.

Rinsing with hot water・ Dip the test piece in warm water at 60 ° C. for 3 minutes, thoroughly wash it with water, dry well and obtain an electroless gold-plated test piece.

[0050]

[Table 1] Table 1 Example 1 2 3 4 (A) component Onium salt (A-1) 92.3 76.9 100 obtained in Synthesis Example 1 Onium salt (A-2) 92.3 15.4 (B obtained in Synthesis Example 2) ) Component EOCN-104S * 1 40 40 EPPN-201 * 2 40 35 (C) Component SP-170 * 3 5 5 5 5 Others Carbitol acetate 30 30 30 30 Fused silica 35 35 35 35 Aerosil 380 * 4 2 2 2 2 2 Cyanine Green 2 2 2 2 Adhesion ○ ◎ ○ ◎ Solder heat resistance Post flux resistance ○ ○ ○ ○ Leveler flux resistance ○ ○ ○ △ Electroless gold plating resistance Jet scrub polishing ○ ○ ○ ○ Buff polishing ○ ○ ○ ○

Note) * 1 EOCN-104S: Nippon Kayaku Co., Ltd., o-cresol / novolak type epoxy resin * 2 EPPN-201: Nippon Kayaku Co., Ltd., phenol / novolak type epoxy resin * 3 SP -170: Asahi Denka Kogyo Co., Ltd., photocationic polymerization initiator, propylene carbonate 50% diluted product * 4 Aerosil 380: Nippon Aerosil Co., Ltd.
Anhydrous silica

As is clear from the evaluation results in Table 1, the resist ink composition of the present invention and the cured product thereof have excellent developability in water, and the cured product has excellent resistance to electroless gold plating. Is.

[0053]

INDUSTRIAL APPLICABILITY The resist ink composition of the present invention can be exposed to ultraviolet rays selectively through a film on which a pattern is formed, and by developing an unexposed portion, a solder resist pattern can be formed without a carboxylic acid. It has excellent developability with water, and its cured product has excellent resistance to electroless gold plating and also sufficiently satisfies adhesion, solder heat resistance, etc., and is particularly suitable for a liquid solder resist ink composition.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05K 3/06 H05K 3/06 H 3/28 3/28 D

Claims (3)

[Claims] 1. An onium salt (A) which is a reaction product of an epoxy compound (a) having at least two epoxy groups in one molecule, a thioether compound (b) and an acid compound (c), and one molecule. A resin composition comprising an epoxy compound (B) having at least two epoxy groups and a photocationic polymerization initiator (C). 2. An onium salt (A) which is a reaction product of an epoxy compound (a) having at least two epoxy groups in one molecule, a thioether compound (b) and an acid compound (c), and one molecule. A resist ink composition comprising an epoxy compound (B) having at least two epoxy groups and a photocationic polymerization initiator (C). 3. A cured product of the composition according to claim 1.