JPS6238449A - Photopolymerizable composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having an excellent adhesive property against a substrate composed of copper and a less tendency for separating it from the substrate in a solder bath and a good sensitivity by incorporating a specific binder polymer to the titled composition. CONSTITUTION:The titled composition is composed of a high polymer compd. A having a polymerizable double bond in a side chain of a molecule, a (meth) acrylate compd. B having a phosphoric acid ester proup and a photopolymerization initiator C. The high polymer A has >=5,000 a weight average molecular weight with regard to a film formation, a heat resistance and a chemical resistance, more preferably, 10,000-200,000 the weight average molecular weight considering coating, developing and laminating properties in addition to the prescribed characteristics. The photopolymerizable composition B comprises the (meth)acrylate having the phosphoric acid ester group, more preferably, tris(meth)acryloxyethyl phosphate. The compounding ratio of each components is preferably (A):(B):(C)=100:(0.5-50):(0.5-10).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel photopolymerizable composition, and particularly to a photopolymerizable composition suitable for use in a permanent protective mask. More specifically, the present invention relates to a photopolymerizable composition that is suitable for use as a permanent protective mask because it has excellent properties as a solder resist in the production of printed wiring boards and as an electroless metal resist.

[Conventional technology]

Among the resists used in the manufacture of printed wiring boards, etching resists and electrolytic plating resists are usually used as temporary protective masks and therefore do not remain on the final printed wiring board. On the other hand, solder resists and fully additive electroless metal resists are usually used as permanent protective masks as final components of printed wiring boards without peeling, so they require various characteristics different from those of temporary protective masks. Ru.

In the case of a solder resist, one of these various performances is adhesion to copper. That is, it is important that the resist does not peel off from the copper when immersed in a solvent such as trichlorethylene or in a solder bath at about 0°C.

Conventionally, many additives have been proposed for improving the adhesion of resist to copper. For example, Tokko Akira! No. 0-9/77 states that certain nitrogen-containing heterocyclic compounds are effective. Tokko Akira again! Certain sulfur compounds have been proposed for goo. However, although these are effective to some extent mainly for temporary protective masks, they are extremely inadequate for permanent protective masks that require resistance under the harsh conditions mentioned above. Subsequently, techniques disclosed □ include the use of a specific nitrogen-containing compound and a phosphoric acid compound in combination (Japanese Patent Publication No. 5tr-19033, Japanese Patent Publication No. Sho S Ku/1113 Octopus, No. RG-QTJt, No. !R Za 19/3E issue, S9-da 6 & dar issue, same l
The combination of organic peroxides and phosphoric acid compounds (Japanese Unexamined Patent Application Publication No. 1973-1977, specification of No. 7 J) has been proposed as a permanent protective mask. . All of these reports state that the addition of a phosphoric acid compound alone has almost no effect. Also, Tokko Akira!
3-Da 41.7 Da No. 6 describes phosphorus-containing acrylate as an example of a photopolymerizable compound, but there is no mention of improving adhesion, and JP-A-Sho! Gu 6-0'17 discloses that a specific phosphoric acid compound is effective as an additive component in a peeling and developing composition for temporary masks, but it is not sufficient for use in permanent masks. Furthermore, even when adhesive performance is improved by adding multiple compounds to the temporary adhesive, it often has a negative effect on other properties, such as sensitivity and storage stability. desirable.

[Structure of the invention]

As a result of intensive investigation into the relationship between the constituent components of photopolymerizable compositions and the effect of adding a phosphoric acid compound, we found that the phosphoric acid compound alone exhibits extremely effective adhesive properties only when a specific binder polymer is included. The inventors have discovered the following and arrived at the present invention.

In other words, the gist of the present invention is (A> a polymer compound having a polymerizable double bond in the side chain and having a weight average molecular weight of s, o o o or more, (B) a (meth) phosphate group-containing A photopolymerizable composition comprising an acrylate compound and (C) a photopolymerization initiator.

Next, the present invention will be explained in detail.

As the first component of the composition of the present invention, (A) a linear polymer compound having a polymerizable double bond in its side chain can be used. In addition to its role as a binder polymer, this material exhibits a specific synergistic effect with the phosphoric acid compound of the first component, resulting in excellent heat resistance and solvent resistance.

Specific examples of this polymer compound include (meth)acrylic polymers containing hydroxyethyl (meth)acrylate or hydroxyglobil (meth)acrylate alone or as a comer; Polymers with esterified acrylic acid, polymers with esterified (meth)acrylic acid introduced into the hydroxyl groups of phenoxy resin, polymers with etherified (meth)allyl groups introduced into the same hydroxyl groups, and polymers with glycidyl (meth)acrylate introduced into the same hydroxyl groups. Addition-modified polymers, (co)polymerized polymers of diallyl(yne)phthalate and/or triallyl isocyanurate, (co)polymerized polymers of glycidyl (meth)acrylate, polymers in which (meth)acrylic acid is esterified and introduced, carboxyl groups Glycidyl (
Polymers in which meth)acrylate has been added, polymers in which a copolymer of maleic anhydride is subjected to an addition reaction with a compound containing both hydroxyl groups and (meth)acrylic groups, and (meth)acrylic acid in partially hydrolyzed vinyl acetate polymers. Examples include polymers in which esterification has been introduced. Among these,
A polymer having a (meth)acrylic group in a side chain is advantageous, and a polymer obtained by esterifying (meth)acrylic acid into a glycidyl (meth)acrylate copolymer is most preferred.

These polymer compounds should have a weight average molecular weight of 5,000 or more in terms of film-forming properties, heat resistance, and chemical resistance, and should also have a weight average molecular weight of io, ooθ~2 when coating properties, developability, and lamination properties are also taken into consideration.
A range of 00,000 is most preferred.

The third component of the photopolymerizable composition of the present invention is (B) a (meth)acrylate compound having a phosphate group.

Specific examples of these include compounds having free acid protons such as (meth)acryloxy ether phosphate, (meth)acryloxypropyl phosphate, bis(meth)acryloxyethyl phosphate; ) Acryloxyethyl and sphenyl phosphate, (meth)acryloxypropyl bisphenyl phosphate, bis(acryloxyethyl) phenyl phosphate, bis(methacryloxyethyl) butyl phosphate, tris(acryloxyethyl) phosphate , tris(methacryloxyethyl) phosphate, and other compounds that do not contain free acid protons.

It has been confirmed that all of these provide a high degree of adhesiveness when combined with the above-mentioned polymer compound. However, among these compounds, when a large amount of compounds with free phosphate protons are incorporated into a composition, there is a slight decrease in storage stability and electrical insulation properties, which is presumed to be caused by the phosphate protons. Admitted. Therefore, a highly preferred phosphoric acid compound is a (meth)acrylate compound having no free phosphoric acid group represented by the following general formula (I).

R' ■ [In the formula, R1 is a hydrogen atom or a methyl group, R2 is an alkylene group, Rs is an alkyl group or a phenyl group that may have a substituent, and n is l, co or J.] Furthermore, Particularly preferred is tris(meth)acryloxyethyl phosphate.

The third component used in the composition of the present invention is (C) a photopolymerization initiator. Specifically, benzoin, benzoin alkyl ethers, ethylanthraquinone, co-, eudimethoxycophenylacetophenone, benzyl, benzophenone, tei, hiro'-bis-dimethylaminobenzophenone, xanthone, thioxanthone, biimidazole/dye, trichloromethyl-8 -) Any known lyazine/dye may be suitably used.

(A), (B) of the photopolymerizable composition of the present invention described above,
(C) The component ratio of each component can be changed arbitrarily depending on the purpose of use, but usually the weight ratio is (A):(B)
: (C) −/00 : 0. /~/ 00: 0
．． /~ Yu O1, preferably (A): (B):
(C) −/o o: o, s-g.

:o, used in the range s''-io.

The present composition may further contain (D) a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups, if necessary.

Specific examples of these include diols, such as ethylene glycol, polyethylene glycol, propylene gelylcol, butanediol, hexamethylene glycol, dihydroxyethyl ether of bisphenol, tetrabrominated bisphenol, and dihydroxyethyl ether thereof. , acrylic acid diester or methacrylic acid diester such as cyclohexane dimetatool; acrylic acid or methacrylic acid polyhydric ester of divalent or higher polyols such as trimethylolpropane, pentaerythritol, dipentaerythritol or its derivatives, glycerol; the above-mentioned polyols Itaconic acid, crotonic acid, and maleic acid esters of compounds; polyvalent allyl ethers or esters; reaction products of polyvalent epoxy compounds and acrylic acid or methacrylic acid; diincyanates, such as tolylene diisocyanate, isophorone diisocyanate A reaction product of trimethyl hexamethylene diisocyanate, etc., and monohydroxy (meth) acrylates, such as ethylene glycol mono (meth) acrylate, glycerol di (meth) acrylate, or pentaerythritol tri (meth) acrylate;
The diisocyanates, the monohydroxy (meth)
Reaction products with acrylates and diols, such as hexamethylene glycol, diethylene glycol or cyclohexane dimetatool, patent application! 9-/
A: 4#29 Any of the compounds described in the specification can be used. Among these, monomers of polyfunctional esters of acrylic acid or methacrylic acid are preferred.

The above-mentioned component (D) has a weight ratio of component (A) t-1
When it is set to 00, 300 or less, preferably 100 or less can be added.

In addition, the composition of the present invention may also contain a thermal polymerization inhibitor, a coloring agent, a plasticizer, an exposure visualizing agent, a flame retardant, an organic solvent for dilution, etc., as necessary.

Next, modes of use using the composition of the present invention will be explained. The composition can be applied, laminated or printed onto the surface of the article to be coated, and then photocured by irradiation of the entire surface with actinic radiation.

Alternatively, imagewise exposure may be carried out using a one-image mask film during light irradiation, and then the unexposed areas may be washed away with a developer to form an imagewise permanent protective coating.

One of the most preferred embodiments is to apply the present composition in liquid or dry film form to the surface of a wiring board on which a copper circuit is formed,
A permanent protective mask for the solder is formed by the above procedure, and by further immersing the mask in a molten solder bath, desired portions can be soldered.

Other applications of the composition of the present invention include permanent protective coatings for electronic components and conductive wires, insulating protective films for integrated circuits, other permanent protective coatings, and precision image resists. It can also be applied to various resists, printing plates, etc.

〔Example〕

Next, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.

Example 1 Polymer with weight average molecular weight gr, o o o (hereinafter abbreviated as polymer A) tpry-1 Urethane acrylate/IIf, A-IP-B-, whose main component is a compound represented by the following structural formula IP-A Hs -OCH, sha CH, O- is shown. ] Tris (acryloxyethyl) phosphine thorn, Otsu?
, tetrabromobisphenol dimethacrylokydiethyl ether L, 7%, benzophenone 1. Run, Michler Ketone O, O gy, Victoria Pure Blue 0.0/J%, Phthalocyanine Green 0. /
A photoresist obtained by dissolving and dispersing 7 f and antimony trioxide θJ 9- in methyl ethyl ketone 4 toy was used to coat a 23 μm thick polyethylene terephthalate film to form a dry film photoresist with a photosensitive layer thickness of 50 μm. Obtained. Next, the above dry film was laminated on a copper circuit-forming printed wiring board at f/20°C.

Next, it was exposed to light for 70 seconds through an image mask film at a distance of 4QCm using a Kosakai ultra-high pressure mercury lamp, and then held at 75° C. for 70 minutes. After cooling to room temperature, the polyethylene terephthalate film was peeled off and chlorocene (i, i, t
-T! A resist image was obtained by spraying development using a developer (J chloroethane) for 1 minute at CoSC. Then light intensity 16o
After exposure using a high-pressure mercury lamp of vi/cm at a distance of 10 cm at a conveyor speed of 5 m/-, the film was heated at ljO℃ for 3
A sample for evaluation was prepared by heat treatment for 0 minutes. 7j on Nishikigami
A resist pattern portion having a width of .mu.m was immersed in Trichlene for 70 minutes at room temperature and then rubbed vigorously (hereinafter abbreviated as fine line Trichlene test), but no peeling of the resist was observed. The same pattern was also placed in a molten solder bath at 60°C for 3
Although the resist was immersed for 0 seconds (hereinafter abbreviated as solder heat resistance test), no peeling of the resist from the copper was observed. Further, when the resist on the brocade was cross-cut into 1Oθ pieces with a Kaminri and a cellophane tape peeling test (hereinafter abbreviated as cross-cut test) was performed, all 100 pieces were completely adhered.

Laminate polyethylene on the photosensitive layer in dry film state at 0°C and relative humidity of 0%.
Although it was stored for several days (hereinafter abbreviated as storage stability test), no changes were observed in both sensitivity and developability, and no fading of the dye was observed.

Furthermore, the film-forming properties of the photosensitive layer and the lamination properties on the substrate were good.

Example Copolymer Evaluation was carried out in the same manner as in Example 1, except that y- was used for the polymer l of the weight average molecules fki3o and ooo represented by the following instead of copolymer copolymer. The results are shown in Table/.

Example 3 In place of Polymer A, triallyl in cyanurate and diallyl isophthalate 3/7 had a weight average molecular weight of 6! , θ0
Copolymer of 0/9f, tris(acryloxyethyl)phosphnitoco? , tetrabromo bisphenol dimethacrylokydiethyl ether co, 1ly-1 Example 1
Except for using a photosensitive solution obtained by dissolving urethane acrylate) 4(, j51-, benzophenone/f, Michler's ketone 0.0 j9- and Victoria Pure Blue〇, 0/ff methyl ethyl ketone/f) was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4 In Example 1, urethane acrylate-1m was replaced with acrylate monomer DPCA-1rθ (Nippon Kayaku Co., Ltd.) l? Evaluation was performed in the same manner except that . The results are shown in Table 1K.

Example S In Example 1, tris(acryloxyethyl)phosphate was replaced with acryloxyethylbisphenylphosphny) L! Evaluation was performed in the same manner except that ff was used. The results are shown in Table/.

Example 6 Evaluation was carried out in the same manner as in Example 1 except that 0.11 f of methacryloxyethyl phosphate was used in place of tris(acryloxyethyl) phosphate. As shown in Table 1, the results showed excellent properties, except for some thermal fading of the dye in the storage stability test.

Comparative Example 1 In place of the polymer of Example 1, a weight average molecule z denoted by OHO ! :, r o o o The evaluation was carried out in the same manner as in Example 1, except that a polymer ttp having no unsaturated double bonds was used. By immersing the sample in Triclean for 70 minutes, all of the 75μ fine wires were peeled off. Further, when the resist was immersed in a molten solder bath at 240° C. for 30 seconds, peeling of the resist from the copper was observed. Even in the cross-cut test, all 100 pieces peeled off.

Comparative Example: Instead of polymer A in Example 1, methyl methacrylate/methyl acrylate containing no unsaturated double bonds (g
Evaluations were conducted in the same manner as in Example 1, except that copolymer BR-75 (weight average molecular weight 1ooooo, manufactured by Mitsubishi Rayon ■) of (r/ts) was used. The results were poor as shown in Table/.

Comparative Example 3 Evaluation was carried out in the same manner as in Example 1 except that trimethylolpropane triacrylate, which is a trifunctional acrylate, was used instead of tris(acryloxyethyl)phosphate.

As shown in Table 1, the results were poor as in the previous example.

Comparative Example In Example 1, an acrylic-modified epoxidized novolac resin (weight average molecular weight, lIo) was used instead of Boria-A.
The evaluation was performed in the same manner except that 3.o) was used. As shown in Table 1, the results were particularly poor in solder heat resistance and lamination properties.

In Comparative Example and Example B, Polymer Aft Acrylic Copolymer B
R-ri! Evaluation was performed in the same manner as in the same example except that . As a result, as shown in Table 1K, fairly good results were obtained.

Table 1 [Effects of the Invention] The composition of the present invention has excellent adhesion to substrates such as copper, does not peel off even in solder baths, and has excellent sensitivity, so it can be used as a photoresist for semiconductor processing, It is particularly suitable for use as a photoresist for permanent protection masks.

Applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent Attorney Hase - (1 other person)

Claims (6)

[Claims] (1) (A) A polymer compound having a polymerizable double bond in its side chain and having a weight average molecular weight of 5,000 or more, (B) a (meth)acrylate compound containing a phosphate group, and (C
) A photopolymerizable composition comprising a photopolymerization initiator. (2) A (meth)acrylate compound containing a phosphate ester group has the general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [In the formula, R^1 is a hydrogen atom or a methyl group. , R^2 represents an alkylene group, R^3 represents an alkyl group or phenyl group which may have a substituent, and n represents 1, 2 or 3. ] The composition according to claim 1, which is a (meth)acrylate compound represented by the following. (3) The (meth)acrylate compound represented by the general formula (I) has a mathematical formula, a chemical formula, a table, etc. [wherein R^1 has the same meaning as above] Composition. (4) The composition according to claim 1, characterized in that the composition contains (D) a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups. (5) The composition according to claim 1, wherein the polymer compound is a (meth)acrylic polymer having a (meth)acrylic group in a side chain. (6) The composition according to claim 1, wherein the composition is used as a solder resist for manufacturing printed wiring boards.