JPS63132233A - Photoresist composition - Google Patents

Abstract

PURPOSE:To obtain a compsn. with which developing time is short and which has an excellent electroplating bath resistant characteristic by incorporating a photosensitive component and binder component consisting of one kind of a specific Br modified bisphenol A type epoxy acrylate formed by modifying both terminals of a specific bisphenol a type epoxy resin with acrylate or methacrylate into said compsn. CONSTITUTION:This compsn. contains the photosensitive component and the binder component consisting of at least one kind of the Br modified bisphenol A type epoxy acrylate which is expressed by the formula and is formed by modifying both terminals of the Br modified bisphenol A type epoxy resin having >=350 epoxy equiv. and Br content of >=30% of the entire part with the acrylate or methacrylate. In the formula, R is CH3 or H, n is 0-5 integer. the photoresist compsn. with which the developing time is short and which is applicable to a solder resist for a printed circuit board having small-diameter through-holes is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a photolithographic photoresist composition.

[Conventional technology]

For example, the magazine “Nikkei New Materials J 1986 2
As shown in the May 24th issue, pages 25-39, as the density of printed circuit boards becomes higher, solder resists can also be used to form more precise patterns than the conventional method of printing patterns using screen printing. There is a transition to photo solder resist using photolithography technology. The types of photo solder resists are roughly classified into three types: dry film type, liquid non-solvent type (non-contact exposure type), and liquid solvent type (contact exposure type). The dry film type is a type in which a photosensitive film is laminated between a base film and a protective film. Just before use, the protective film is peeled off, the photosensitive film and substrate are bonded under heat, and a mask is placed on top of the base film for exposure. A pattern is obtained by developing with an organic solvent or an alkaline aqueous solution. The liquid solvent-free type is applied to a substrate using a roll coater, bar coater, curtain coater, screen solid coating, etc., and exposed with a gap between the resist layer and the mask to prevent the resist from adhering to the mask. A pattern is obtained by developing in the same way. In addition, the liquid solvent type is applied to the substrate using the same method as the liquid non-solvent type, and the solvent in the resist is evaporated by heating to make the resist surface tack-free, and then a mask is placed on top of the resist. A pattern is obtained by exposing and developing in the same manner. All of these types of photo solder resists undergo post-heat treatment and post-exposure treatment after pattern formation to improve the durability of the pattern.

[Problem that the invention seeks to solve]

Among these, the dry film type has a simple process,
It is expensive and its adhesion is slightly inferior. The liquid solvent-free type uses parallel light for exposure, which creates a hole in the exposure machine, and since it is non-contact, the resolution is inferior. Liquid solvent type requires evaporation of the coating machine solvent, resulting in poor throughput and long development time.Also, with liquid photo solder resist, the resist gets into the hole or through hole of a single component during coating, so it is difficult to use when coating with small diameter holes. It cannot be used for substrates, or even if it can be used, it must be developed for a long time.

Recently, a part-additive method has been introduced in which all plating inside small-diameter through holes is done by electrolytic plating, but conventional photo solder resists, with the exception of some dry film types, are resistant to strong alkaline electroless plating baths. There were problems such as the lack of a liquid photo solder resist that could not be applied to the part-additive method, and the fact that there was no liquid photo solder resist that could be applied to the part-additive method.

This invention was made to solve the above-mentioned problems, and it can be applied to a substrate as a liquid solvent type or dry film type and exposed by contact exposure, has a short development time, and is electroless resistant. The purpose is to obtain a photoresist composition with excellent plating bath properties.

Means for Solving Problem C] The photoresist composition according to the present invention comprises (A) a photosensitive component, and (8) an epoxy equivalent of 350 or more and a total Br content of 3.
0% or more of Br-modified bisphenol A-type epoxy resin (where n is an integer from O to 5) Br-modified bisphenol A-type epoxy acrylate H (wherein R is CHl or H, n is an integer from 0 to 5).

The photoresist composition of the present invention uses the above n-type Br-modified bisphenol A epoxy acrylate as a binder, and these may be used alone or in combination of two or more.

This Br-modified bisphenol A type epoxy acrylate is, for example, Br-modified bisphenol A represented by the above formula 1.
It is obtained by dissolving a type epoxy resin in a solvent such as cellosolve acetate and reacting it with acrylic acid or methacrylic acid at 120° C. for 3 to 8 hours using 2-ethyl-4-methylimidazole or the like as a catalyst. Obtained B
R-modified bisphenol A type epoxy acrylates differ depending on the molecular weight of the epoxy resin charged, but they are all sticky semi-solids or solids, and when applied in liquid form, mainly solid acrylate is used, and when used as a dry film, It is preferable to use mainly sticky semi-solid acrylate.

These Br-modified bisphenol A-type epoxy acrylates have a lower dissolution rate in 1,1,1-trichloroethane, which is the main component of the photoresist developer, compared to those not modified with Br, considering their respective molecular weights and melting points. Photoresists using these Br-modified bisphenol A type epoxy acrylates as binder components have good properties.
Compared to a photoresist using bisphenol A type epoxy acrylate that is not modified with Br, the development time is reduced. Furthermore, since the unexposed area has good solubility in the developing solution, resist clogged in small holes of, for example, 0.4 mm or 0.3 mm in diameter can be removed by development. Furthermore, Br-modified bisphenol A type epoxy acrylate has excellent chemical resistance, heat resistance, and flame retardancy, and by applying it to photoresists, it has excellent acid resistance, alkali resistance, soldering heat resistance, flame retardance, etc. A pattern is obtained.

Examples of the photosensitive component include photopolymerizable monomers and photopolymerizable oligomers. In particular, in order to improve developability and flame resistance, it is preferable to add a photopolymerizable monomer having a Br content of 35% or more based on the total weight of the resin fraction of the photoresist composition. An example is 5R-
803, 5R-804, 5R-314, 5R-414,
GX-6099, GX-6045, GX-6043, G
X-6094, GX-6092, D-5001 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., bred), BPS-DAE, TB
S-2EO-DA (manufactured by NICCA CHEMICAL CO., LTD., commercial a)
)and so on.

The photoresist composition of the present invention preferably contains 5 to 70% by weight of a photosensitive component and 15 to 90% by weight of Br-modified bisphenol A epoxy acrylate. A photopolymerization initiator, an organic solvent, an antifoaming agent, a leveling agent, etc. can be added depending on the purpose to impart flammability, sensitivity, coating properties, etc. To improve flexibility and adhesion, use aliphatic urethane diacrylate, dimer acid diacrylate, neopentyl glycol-modified trimethylolpropane diacrylate, caprolactone-modified dipentaerythritol hexaacrylate, long-chain aliphatic acrylate with 10 or more carbon atoms. It is preferable to add the like, and it is preferable to add these in an amount of 5 to 70% by weight of the entire resin content of the resist. Examples of these include R-604, DP
CA-20%DPC^-30, DPCA-60, DPC
A-120 (manufactured by Nippon Kayaku Co., Ltd., trade number) Chemilink 9503, Chemilink 9504. Chemilink 9505,
Chemilink 2000 (manufactured by Satmar Co., Ltd., Commercial 11
), 5p-5003 (manufactured by Showa Kobunshi Co., Ltd., Commercial W), etc.

Examples of the photopolymerization initiator include 2,2 diethoxyacetophenone, anthraquinone, 2-methylanthraquinone, 2-t-butylanthraquinone, benzyl methyl ketal, benzyl-β-methoxyethyl acetal, and 1-
Phenol 1,2-propanedione-2-(〇-ethoxycarbonyl)oxime, benzophenone, O-benzoin methyl benzoate, Michler's ketone, 4-4'-bisdiethylaminobenzophenone.

4-4'-dichlorobenzophenone, benzyl, 2-phenyl-2-hydroxyacetophenone, benzoin methyl ether, benzoin isopropyl ether, P-
Dimethylaminobenzoic acid, ethyl p-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, isoamyl p-dimethylbenzoate, benzoin-
n-butyl ether, benzoin isobutyl ether,
Benzoin alkyl ether, 4'-isopropyl-2
-Hydroxy-2-methyl-propiophenone, p-dimethylaminoacetophenone.

pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, chlorothioxanthone, 2-isopropylthioxanthone, dibenzosuberone, 2,5-
Bis-(4'-diethylaminobenzal)cyclopentanone, 1-acetylamino-4-nitronaphthalene, 5
-Nitroacenaphthene, l-nitropyrene, α,α-dichloro-4-phenoxyacetophenone, 1-can be present.

The photoresist composition of the present invention is applied onto a substrate used for manufacturing printed circuit boards, such as a glass epoxy laminate or a glass polyimide laminate, and after drying with a negative mask tightly attached and irradiated with ultraviolet light, the photoresist composition is applied to a predetermined area. By irradiating ultraviolet light through a negative mask, developing with an organic solvent, and then baking, a mesh resist pattern having electroless plating bath resistance is formed.

That is, the photoresist composition obtained as described above is coated with a glass epoxy laminate, glass polyimide, etc. by spin cording, dip coating, roller coating, curtain coating, screen printing, etc., or by forming it into a dry film and thermocompression bonding. Coating onto various substrates such as laminates. In order to improve the adhesion between the substrate and the oil film, it is desirable to roughen the substrate using a solvent or mechanical polishing.

The substrate coated with the above-mentioned photoresist composition is pre-baked at a predetermined temperature and time for the resist coated in liquid form to volatilize most of the solvent and bring the negative mask into close contact with the substrate to create a favorable condition for exposure. , a negative mask is placed over the cover film for exposure, but as the solvent has already been removed from the dry film, the film is left at room temperature for about 30 minutes after being crimped, and then exposed with a negative mask placed over the cover film. . Next, after leaving it for about 10 to 60 minutes at a temperature of room temperature to about 80°C to promote polymerization, use 1,1,1-trichloroethane or a resist developer containing this as a main component, such as Eterna VG, Eterna The film is developed by spraying with IR (manufactured by Asahi Kasei Kogyo Co., Ltd.), chlorocene NU (manufactured by Dow Chemical Company), or by using ultrasonic waves.

After that, it is washed with water, dried, and completely cured by exposing it to a predetermined temperature for 30 minutes to 3 hours.

The formed mesh resist pattern has a resolution of up to 50μ, and no change was observed even after being immersed in an electroless copper plating bath at pH 12, 5, and 70 to 80°C for more than 24 hours. It has electroless plating bath resistance.

Also 0,3nim, 0.4+++m, 0.5mm,
A dry film thickness of 30μ is coated with a roll coater on a 1.6t glass epoxy steel laminate with a 0.9+++m drilled hole.
Even if it is applied and buttered so that it becomes 0.
．． The resist in the 9@m and 0.5 mm holes can be developed in approximately the same time as the unexposed area on the plate surface, and at 0.4 am, it is 3 to 5 times that of the plate surface, and at O,: 3 mm, it is about 5 to 6 times that of the plate surface. Furthermore, the pattern shape on the plate surface does not change at all, and no film loss occurs in the exposed areas.

Since the photoresist composition of the present invention uses Br-modified bisphenol A type epoxy acrylate as a binder, a non-tacky solid film or a slightly tacky semi-solid film can be obtained by evaporating the solvent. It can be used as a liquid solvent type resist or a dry film type resist on the substrate, and B
The development time using a halogenated solvent is shortened due to the action of R.

〔Example〕

Examples of the present invention will be described below.

Production Example 1 200 g of Epicote 5051H (Br-modified bisphenol A epoxy resin, epoxy equivalent 1214 g/5 qiv, manufactured by Yuka Shell Co., Ltd., commercial a) and 100 g of cellosolve acetate were heated at 120°C in a 300 m 12 four-way flask.
to completely dissolve Epicote 5051) 1,
Next, 2-ethyl-4-methylimidazole 2g, methoquinone 0.35g, methacrylic acid 13.5g. and stir for 5 hours. The acid value of this system was measured and 0.1 mg KO
Continue heating and stirring until the temperature becomes less than H/g. After the acid value reaches the target value, it is left to cool at room temperature and the Br-modified bisphenol A
Type epoxy acrylate sample 1 was obtained.

Production example 2 Epicoat 5051 (Br modified bisphenol A type epoxy resin, epoxy equivalent 616 g/eqiv) 200
g and 70 g of cellosolve acetate were heated to 120°C in a 300 mQ four-way flask to completely dissolve Epicote 5051, and then 2-ethyl-4-methylimidazole 2&, 0.35 g of methoquinone, and 26.6 g of methacrylic acid
Br-modified bisphenol A type epoxy acrylate sample 2 was obtained by similarly reacting until the acid value reached 0.1 mg KOH/g.

Production Example 3 200 g of AER-755 (Br-modified bisphenol A epoxy resin, epoxy equivalent 460 g/eqiv, M Kasei Kogyo Co., Ltd. 11, trademark) and 50 g of cellosolve acetate were heated to 120°C in a 300-Yoturo flask to produce AER. -755 completely dissolved, then 2-ethyl-
4-methylimidazole 2g, methoquinone 0.35g,
35.6 g of methacrylic acid was added and reacted in the same manner to obtain Br-modified bisphenol A type epoxy acrylate sample 3.

Example I V section A) Br-modified bisphenol A-type epoxy acrylate sample 125 B) Br-modified bisphenol A-type epoxy acrylate sample 225 C) Chemilink 9503 (manufactured by Satoma Co., Ltd.) 10D
) R-604 (manufactured by Nippon Kayaku Co., Ltd.)
4E) GX-6094 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
4F) 5P-5003 (manufactured by Showa Kobunshi Co., Ltd.) 4G) Benzophenone
3H) Michler's Ketone
2) Silicone antifoaming agent
0.3J) Talc
O, S) Phthalocyanine green
0.2L) Cellosolve Acetate
Photoresist sample 1 was obtained by uniformly kneading 22A) to 22L) using three rolls.

Example 2 Part by weight A) Br-modified bisphenol A epoxy acrylate sample 210 B) Br-modified bisphenol A epoxy acrylate sample 340 C) Chemilink 9503 5
D) DPCA-60 (Nippon Kayaku Co., Ltd. It)
5E) R-6045 F) GX-60945 G) 5P-50033 H) Benzophenone 3)
Michler's Ketone 2J) Silicone antifoaming agent 0.5K) Phthalocyanine Green 0.2L) Toluene
21.3 A) to L) are uniformly kneaded using three rolls, and coated to a thickness of 2 using a roll coater.
It was coated on a 5 μm polyethylene terephthalate film to a dry film thickness of 30 μm, dried with hot air at 80° C. for 5 minutes, and then covered with a 50 μm thick polyethylene film to obtain photoresist sample 2. .

Example 3 Part by weight A) Br modified bisphenol A type epoxy acrylate sample 110 B) Br modified bisphenol A type epoxy acrylate sample 2 40C) Chemilink 9503 5D) DPCA
-603 E) GX-60944 F) 5P-50033 G) Benzophenone 3H)
Michler's Ketone 2) Silicone antifoaming agent 0.3J) Talc 0.5K) Phthalocyanine Green 0.2L) Cellosolve Acetate 29 A) to L) were uniformly kneaded using a Miki roll to obtain photoresist sample 3.

Comparative Example I V holder A) VR-60 (bisphenol A type epoxy acrylate, manufactured by Showa Kobunshi Co., Ltd.) 68.5% cellosolve acetate solution 25B) VR-90 (bisphenol A type epoxy acrylate, manufactured by Showa Kobunshi Co., Ltd.) ) 76.6% cellosolve acetate solution 2
5C) Chemilink 9503 1
0D) R-6044 E) GX-60944 F) 5P-50034 G) Benzophenone 3 days)
Michler's Ketone 2) Silicone antifoaming agent 0.35) Talc
0.5K) Phthalocyanine Green 0.2L) Cellosolve Acetate 22A) to L) were uniformly kneaded using three rolls to obtain Photoresist Comparative Sample 1.

Comparative Example 2 Part by weight A) VR-6068, 5% cellosolve acetate solution 20B) V
R-9076, 6% f=o so#f7cetate solution
10C) Cresolborac epoxy acrylate 50% cellosolve acetate solution 40D) Trimethylolpropane triacrylate 5E)
Benzophenone 3F) Michler's Ketone 2G) Silicone antifoaming agent Q, 314) Talc o, 5X) Phthalocyanine Green 0.2J) Cellosolve Acetate 19 A) to J) were uniformly kneaded with a Miki roll to obtain photoresist comparison sample 2. .

The photoresists in the above test examples and comparative examples are as follows:
Photoresist sample 2 was coated with a dry film laminator, and the others were coated with a roll coater so that the dry film thickness was 30 μm1.
The photoresist sample 2 was coated on a 1.6t glass poxy copper clad laminate and a 1.6t glass poxy copper clad laminate with through holes drilled with a 9+A+A drill, and photoresist sample 2 was heated at room temperature for 30 minutes.
Others were left under warm air at 80°C for 40 minutes and had a thickness of 30 to 200 μm.
line and space pattern, diameter 0.1~1,
A negative film mask containing a 4 mm round cutout pattern was brought into close contact with the resist, and a 200 a.
Exposure was performed at a light intensity of J/aj. Remove the exposure mask,
After leaving it at room temperature for 30 minutes, Eterna IR (main ingredient 1.1
．． After spray development was performed using 1-trichloroethane (manufactured by Asahi Kasei Industries, Ltd.) at a pressure of 1.5 kg/cnf,
Wash with water, drain well, and dry at 80°C for 20 minutes.

Next, after performing post-exposure at 2J/ai with a high-pressure mercury lamp,
The photoresist was heated for 1 hour at a temperature of 0.degree. C. to completely cure the photoresist, and the following evaluations were performed.

Development time> For the perforated substrate, the development time was the time until the resist in the holes of each diameter was completely removed, and for the others, the time until the 100 μm line and space pattern was developed.

<Resolution> The minimum width of a line and space pattern that can be patterned using an optical microscope without being deformed or undeveloped is defined as the resolution.

Adhesion> Resist film cross-cut cellophane peeling tape test (JIS-00202) was followed.

hardness Pencil hardness test (IPC-SM-840A) was followed.

<Electrical properties> Comb-shaped electrode (,]l5-Z3197 by etching method
) was formed, and the insulation resistance value was measured by applying a voltage for 5 ovi minutes.

<Solder heat resistance> The samples were immersed in a solder bath at 260°C±5°C for 60 seconds to evaluate changes in appearance and adhesion.

Electroless plating bath resistance> a) Cu5O4r5H, 010gb) Ethylenediaminetetraacetic acid 30gC) Formalin (37
%) 3mjld) Polyethylene glycol: 2-# (Mw=600) 20ge) 2,
2'-dipyridyl 0.03gf)
1 g of NaOHl g) Water An electroless plating bath consisting of an amount that makes the total 1000 d or more is kept at 80'C, and a resist is coated on a substrate with plating nuclei attached in advance, patterned, and then cured. After being immersed for 24 hours, it was taken out and washed with water, and changes in the appearance and adhesion of the resist were evaluated.

These results are shown in Table 1.

As is clear from Table 1, photoresist samples No. 3 require a shorter development time than Comparative Samples 1 and 2, and are also capable of developing substrates with small diameter holes. Comparative sample 2 uses materials with large curing shrinkage such as cresol novolac type epoxy acrylate and trimethylolpropane triacrylate, so it lacks flexibility, tends to crack and peel, and has poor adhesion to the copper surface. bad.

Comparative sample 1 cannot be patterned with a thickness smaller than 100 μm because the resist has poor solubility in the developer. Both the photoresist sample and the comparative sample show sufficient electrical properties and hardness values for a solder resist.

From the above results, the photoresist using Br-modified bisphenol A type epoxy acrylate is effective as a solder resist for small-diameter through-hole boards, and has electroless plating bath resistance, so it can be used as a solder resist for part-additive printed circuit boards. is also clearly effective.

〔Effect of the invention〕

As described above, according to the present invention, since Br-modified bisphenol A type epoxy acrylate is used as a binder component, a photoresist composition that has a short development time and is applicable to solder resists for printed circuit boards having small diameter through holes can be obtained. effective.

Claims (4)

[Claims] (1) (A) a photosensitive component; (B) an epoxy equivalent of 350 or more and a total Br content of 3
Br-modified bisphenol A type epoxy resin with a content of 0% or more ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ... (I) (where n is an integer from 0 to 5) Br modified with acrylate or methacrylate at both ends. Modified bisphenol A type epoxy acrylate▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (R is CH_3 or H, n is an integer from 0 to 5) A binder component consisting of at least one of the following: A photoengravable photoresist composition comprising: (2) The photoresist composition according to claim 1, wherein the photoresist composition contains 15 to 90% by weight of the total resin content of Br-modified bisphenol A type epoxy acrylate. (3) Aliphatic urethane diacrylate, dimer acid diacrylate, neopentyl glycol-modified trimethylolpropane diacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and carbon number 10
3. The photoresist composition according to claim 1, wherein the photoresist composition contains at least one of the above long-chain aliphatic acrylates in an amount of 5 to 70% by weight based on the total resin content. (4) Claims 1 to 3 characterized in that the photopolymerizable monomer having a Br content of 35% or more of the total resin content is contained as a photosensitive component in an amount of 5 to 70% by weight of the total resin content. The photoresist composition according to any one of the above.