JP2002148797A - Photosensitive resin composition, photosensitive element which uses the same, method for laminating photosensitive resin composition layer, photosensitive resin composition laminated substrate and method for hardening photosensitive resin composition layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition and a photosensitive element with little contamination of a plating liquid because elution of a photoinitiator into the plating liquid is hardly caused. SOLUTION: The photosensitive resin composition contains (A) a polymer having carboxyl groups, (B) a polymerizable compound having at least one unsaturated bond, and (C) a photopolymerization initiator. The composition contains bisphenol-A polyoxyethylene di(meth)acrylate as the component (B) and contains hexaaryl biimidazole as the component (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition, a photosensitive element using the same, a method for laminating a photosensitive resin composition layer, a photosensitive resin composition layer laminated substrate, and a photosensitive resin composition layer. A curing method.

[0002]

2. Description of the Related Art Conventionally, in the fields of manufacturing printed wiring boards and precision metal processing, photosensitive resin compositions and photosensitive films have been widely used as resist materials used for etching, plating and the like. Further, as a method of manufacturing a printed wiring board, a plating method is becoming mainstream in recent years because the density of printed wiring boards has been increased and patterns have become thinner.

In this plating method, a resist is covered except for a through hole and an electric circuit for mounting a chip, a through hole and an electric circuit are formed by electroplating, and thereafter, an electric circuit is formed by removing and etching the resist. How to do it. As a plating solution in the plating method, copper pyrophosphate, copper sulfate, solder, nickel, palladium, gold, etc. are used, but it is common to use copper sulfate for the production of an electric circuit and use a solder for the protection. is there.

[0004] In these platings, depending on the type of the photoinitiator that dissolves into the plating solution from the photosensitive resin composition and the photosensitive element, the deposition of copper sulfate plating is not sufficient, and the solder plating of the protective layer is not performed. It is known that the tin / lead ratio greatly deviates from the target ratio. Due to the deviation of the alloy ratio, problems such as melting of the solder at the time of stripping the resist and thinning of the underlying copper at the time of etching occur.

The photosensitive resin composition and the photosensitive element used in the conventional plating method include a photoinitiator contained in the photosensitive resin composition in order to reduce the amount of the photoinitiator eluted into the plating solution. And the photosensitivity was low.

In order to improve these problems, Japanese Patent Publication No.
No. 29285 discloses a hexaarylimidazole and a compound represented by the following general formula (II):

Embedded image (Wherein R ² and R ³ represent an alkyl group, n is 1, 2 or 3, and ring A represents a nitrogen-containing aromatic ring). A problem arises in that the pattern width of the subsequent resist is increased, and the circuit width formed by plating is reduced. Also, if you lower the exposure,
Although the line width is reduced, the curing is insufficient, and the problem of plating undermining occurs.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and has high photosensitivity and almost no elution of the photoinitiator into the plating solution. An object of the present invention is to provide a small amount of a photosensitive resin composition, a photosensitive element using the same, a method for laminating a photosensitive resin composition layer, a substrate for laminating a photosensitive resin composition layer, and a method for curing a photosensitive resin composition layer.

[0008]

The present invention comprises (A) a polymer having a carboxyl group, (B) a polymerizable compound having at least one unsaturated bond, and (C) a photopolymerization initiator. The present invention relates to a photosensitive resin composition comprising bisphenol A polyoxyethylene di (meth) acrylate as a component (B) and hexaarylbiimidazole as a component (C). The present invention also relates to the photosensitive resin composition, wherein the bisphenol A polyoxyethylene di (meth) acrylate is a compound represented by the following general formula (i).

Embedded image (Where n and m are positive integers such that n + m = 10)

The present invention also provides the photosensitive resin composition, wherein the component (A) contains a copolymer of an alkyl (meth) acrylate, a (meth) acrylic acid and a vinyl monomer copolymerizable therewith. About. Further, the present invention relates to the photosensitive resin composition wherein the vinyl monomer is styrene. The present invention also relates to the photosensitive resin composition, wherein the component (A) comprises two or more polymers having a carboxyl group. Further, the present invention provides, as the component (B),
Further, the present invention relates to the photosensitive resin composition containing a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol. The present invention also relates to a photosensitive element obtained by laminating the photosensitive resin composition on a support film. The present invention also relates to a method for laminating a photosensitive resin composition layer, comprising laminating the photosensitive element on a substrate such that the layer of the photosensitive resin composition adheres to the substrate. The present invention also relates to a photosensitive resin composition layer laminated substrate on which a photosensitive resin layer is laminated by the laminating method. Further, the present invention relates to a method for curing a photosensitive resin composition layer, which comprises exposing the photosensitive resin composition layer laminated substrate to light.

Next, the components contained in the photosensitive resin composition of the present invention will be described in detail. The polymer having a carboxyl group used as the component (A) in the present invention includes, for example, alkyl (meth) acrylate [(meth) acrylic acid means methacrylic acid and acrylic acid.
The same applies hereinafter), and copolymers of (meth) acrylic acid and a vinyl monomer copolymerizable therewith. These copolymers are used alone or in combination of two or more.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate,
Examples include ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Examples of the vinyl monomer copolymerizable with the alkyl (meth) acrylate or the (meth) acrylic acid include, for example, tetrahydrofurfuryl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and (meth) acrylate. Acrylic acid diethylaminoethyl ester, methacrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth)
Acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, vinyltoluene and the like can be mentioned.

The compound having at least one unsaturated bond and being polymerizable, which is used as the component (B) in the present invention, includes bisphenol A dioxyethylene di (meth) acrylate and bisphenol A trioxyethylene di (meth) acrylate. A) acrylate, bisphenol A polyoxyethylene di (meth) acrylate such as bisphenol A decaoxyethylene di (meth) acrylate, and other compounds obtained by, for example, reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid ( Polyethylene glycol di (meth) acrylate (having 2 to 14 ethylene groups), trimethylolpropanedi (meth) acrylate, trimethylolpropanetri (meth) acrylate, trimethylolpropaneethoxytri (meth) acrylate, trimethylol Propa Propoxytri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, polypropylene glycol di (meth) acrylate (having 2 to 14 propylene groups), dipentaerythritol penta (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc.), compounds obtained by adding an α, β-unsaturated carboxylic acid to a glycidyl group-containing compound (trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl) Ether acrylate, etc.),
Esterified product of polycarboxylic acid (such as phthalic anhydride) and a substance having a hydroxyl group and an ethylenically unsaturated group (such as β-hydroxyethyl (meth) acrylate), and alkyl ester of (meth) acrylic acid ((meth) acrylic) Acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2
-Ethylhexyl ester, etc.), urethane (meth) acrylate (reacted product of tolylene diisocyanate and 2-hydroxyethyl (meth) acrylate, trimethylhexamethylene diisocyanate, cyclohexanedimethanol, and 2-hydroxyethyl (meth) acrylate And the like).

The compounding amount of the component (A) in the present invention is 4
0 to 80 parts by weight (the total amount of component (A) and component (B) is 100
Parts by weight), and more preferably 55 to 65 parts by weight. If the amount is less than 40 parts by weight, the photocured product becomes brittle, and when used as a photosensitive film, the coating properties tend to be poor. If the amount exceeds 80 parts by weight, sufficient sensitivity tends not to be obtained.

The compounding amount of the component (B) in the present invention is preferably 20 to 60 parts by weight (so that the total amount of the components (A) and (B) is 100 parts by weight). 4
More preferably, it is 5 parts by weight. When the blending amount is 20
If the amount is less than parts by weight, sufficient sensitivity tends not to be obtained,
If it exceeds 60 parts by weight, the photocured product tends to become brittle.

It is preferable to use a compound having two or more unsaturated bonds as the component (B) from the viewpoint of improving sensitivity.

The hexaarylbiimidazole used as the component (C) in the present invention includes, for example,
2,2'-bis (o-chlorophenyl) -4,4 ',
5,5'-tetraphenylbiimidazole, 2,2'-
Bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p
-Dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole , 2,2'-bis (o, o '
-Dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2 '-Bis (o-methylphenyl)-
4,4 ', 5,5'-tetraphenylbiimidazole and the like. These hexaarylbiimidazoles, for example, Bull.Chem.Soc.Japan, 33, 565 (1960 ), J.or
g. Chem., 36 [16] 2262 (1971).

The amount of the component (C) in the present invention is as follows:
0.1 to 3.0 parts by weight (based on 100 parts by weight of the total of the components (A) and (B)) is preferred, and 0.5 to 2.5 parts by weight.
It is more preferred to be parts by weight. This compounding amount is 0.1
If the amount is less than 30 parts by weight, sufficient photosensitivity tends not to be obtained. If the amount exceeds 3.0 parts by weight, the line width of the resist tends to be large.

The general formula (I) further used as the component (C) in the present invention

Embedded image (Wherein, R ¹ represents an alkylene group having 6 to 12 carbon atoms), for example, 1,6
-Bis (9-acridinyl) hexane, 1,7-bis (9-acridinyl) heptane, 1,8-bis (9-acridinyl) octane, 1,9-bis (9-acridinyl) nonane, 1,10-bis (9-acridinyl) decane, 1,11-bis (9-acridinyl) undecane,
1,12-bis (9-acridinyl) dodecane and the like.

The photopolymerization initiator (acridine compound) represented by the general formula (I) used as the component (C)
Can be easily produced, for example, by reacting diphenylamine and a divalent carboxylic acid in the presence of a metal oxide.

The compounding amount of the photopolymerization initiator represented by the general formula (I) in the present invention is 0.05 to 1 part by weight (the above (A)
(To 100 parts by weight of the total of the component and the component (B)), and more preferably 0.1 to 0.5 part by weight.

The photosensitive resin composition of the present invention may optionally contain a vinyl compound other than those described above, a photopolymerization initiator, a plasticizer, a dye, a pigment, an imaging agent, a filler, an adhesion promoter, and the like. Can be used.

The photosensitive resin composition of the present invention is applied on a metal surface, for example, a surface of copper, nickel, chromium or the like, preferably on a copper surface, as a liquid resist, dried and coated with a protective film. Or used as a photosensitive element. Although the thickness of the photosensitive resin composition layer varies depending on the use, it is preferably 10 to 100 μm in thickness after drying. In the case of a liquid resist, an inert polyolefin film such as polyethylene or polypropylene is used as a protective film.

The photosensitive element is obtained by coating and drying a photosensitive resin composition on a support film such as polyester and laminating a protective film such as polyolefin if necessary. If necessary, the photosensitive resin composition is mixed with a solvent such as acetone, methyl ethyl ketone, methylene chloride, toluene, methanol, ethanol, propanol, butanol, methyl glycol, ethyl glycol, propylene glycol, monomethyl ether, or a mixed solvent thereof. And apply as a solution.

The photosensitive resin composition layer is irradiated with actinic rays in a pattern through a negative or positive mask pattern called artwork, and then developed with a developing solution.
This is used as a resist pattern. As a light source of the actinic ray used at this time, for example, a carbon arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp or the like that effectively emits ultraviolet rays is used.

As the developing solution, one which is safe and stable and has good operability is used. For an alkali developing type photoresist, a dilute solution of sodium carbonate or the like is used. Development methods include a dip method and a spray method, and a high-pressure spray method is most suitable for improving resolution.

The electroplating performed after the development includes copper plating (copper sulfate plating, copper pyrophosphate plating, etc.), solder plating (high throw solder plating, etc.), watt bath (nickel sulfate-nickel chloride) plating, nickel plating (sulfamine Nickel plating, etc.), and gold plating (hard gold plating, soft gold plating, etc.).

[0027]

Next, the present invention will be described with reference to examples. Examples 1 to 3 and Comparative Examples 1 and 2 The materials shown in Tables 1 and 2 were blended to obtain solutions.

[Table 1]

[Table 2]

The solution of the photosensitive resin composition was obtained by dissolving the component (C) shown in Table 3 in this solution.

[Table 3]

Next, the solution of the photosensitive resin composition was added to 2
The photosensitive element was obtained by uniformly coating on a 5 μm-thick polyethylene terephthalate film and drying with a hot air convection dryer at 100 ° C. for 10 minutes. The dried film thickness of the photosensitive resin composition layer was 50 μm. On the other hand, a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E-6) which is a glass epoxy material in which copper foil (thickness: 35 μm) is laminated on both sides
The copper surface of 1) was polished using a polishing machine having a brush equivalent to # 600 (manufactured by Sankeisha), washed with water, dried in an air stream, and the obtained copper-clad laminate was heated to 80 ° C. Then, the photosensitive resin composition layer was laminated on the copper surface while being heated to 120 ° C.

Next, on the substrate thus obtained,
Using a negative film, exposure was performed at 60 mJ / cm ² with a 3 kW high-pressure mercury lamp (HMW-201B, manufactured by Oak Manufacturing Co., Ltd.). At this time, in order to evaluate the light sensitivity, a negative film (an optical density of 0.05 was set as the first step, and an optical density of 0.15 was set for each step so that the light transmission amount was reduced stepwise).
21-step tablet).

Next, the polyethylene terephthalate film is removed, and an unexposed portion is developed by spraying a 1% by weight aqueous solution of sodium carbonate at 30 ° C. for 50 to 150 seconds to form a photocured film formed on the copper-clad laminate. The photosensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet. The results are shown in Table 4. The light sensitivity is indicated by the number of steps of the step tablet. The higher the number of steps of the step tablet, the higher the light sensitivity.

Next, using a separately prepared photosensitive element, each element was exposed to an exposure amount showing a value of 8 steps using a 21-step tablet, and then the polyethylene film and the polyethylene terephthalate film were removed. A cured photosensitive resin composition layer (cured film) was obtained. Subsequently, the cured film was soldered with a plating solution [45% by weight.
Tin borofluoride 64 ml / liter, 45 wt% lead borofluoride 22 ml / liter, 42 wt% borofluoric acid 20
0 ml / liter, Plutein LA Conductivity Salt (Meltex, trade name) 20 g / l, Plutein LA Starter (Meltex trade name) 4
0 ml / liter] at a rate of 0.1 m ² / liter. After leaving the cured film for 7 days at room temperature while immersing the cured film, the solder plating solution from which the cured film was removed was removed.
It was charged into a Hull cell plating apparatus and plated at 1 A for 5 minutes with the same apparatus.

After plating, a current density of 3 was measured using a fluorescent X-ray film thickness meter (trade name: STF-158V, manufactured by Seiko Instruments Inc.).
The tin / lead ratio (A ₁ ) of the plating film of A / dm ² was measured. At that time, the tin / lead ratio (A ₂ ) of the one in which the cured film was not immersed was used as a blank, and A ₁ / A ₂ was used as the alloy ratio. The closer this value is to 1, the lower the plating bath contamination.

[0034]

[Table 4]

From Table 4, it was confirmed that in Examples 1 to 3, the photosensitivity was high and there was almost no plating bath contamination.

[0036]

The photosensitive resin composition of the present invention, a photosensitive element using the same, a method for laminating a photosensitive resin composition layer,
The photosensitive resin composition layer laminated substrate and the method for curing the photosensitive resin composition layer are excellent in that there is almost no plating bath contamination and high photosensitivity.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08F 291/06 C08F 291/06 G03F 7/004 512 G03F 7/004 512 7/029 7/029 7/031 7/031 7/033 7/033 (72) Inventor Riki Ishikawa 4-3-1-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd.Yamazaki Office (72) Inventor Yuichi Kamakura 4-3-1 Higashicho, Hitachi City, Ibaraki Prefecture No. Hitachi Chemical Co., Ltd. Yamazaki Works F-term (reference) 2H025 AA01 AB01 AB15 AB17 AC01 AD01 BC14 BC32 BC42 CA14 CA28 CB13 CB14 CB16 CB43 EA08 FA03 FA17 4J011 PA69 PB38 PC02 QA13 QB16 RA03 SA78 UA01 VA01 WA01 4J20 CA03 CB10 CC05 CD10 4J100 AL66P BA08P BC45P CA01 JA37

Claims (10)

[Claims] 1. A photosensitive resin composition comprising (A) a polymer having a carboxyl group, (B) a polymerizable compound having at least one unsaturated bond, and (C) a photopolymerization initiator. Yes, a photosensitive resin composition containing bisphenol A polyoxyethylene di (meth) acrylate as the component (B) and hexaarylbiimidazole as the component (C). 2. The photosensitive resin composition according to claim 1, wherein the bisphenol A polyoxyethylene di (meth) acrylate is a compound represented by the following general formula (i). Embedded image (Where n and m are positive integers such that n + m = 10) 3. The photosensitive composition according to claim 1, wherein the component (A) contains a copolymer of an alkyl (meth) acrylate, a (meth) acrylic acid and a vinyl monomer copolymerizable therewith. Resin composition. 4. The photosensitive resin composition according to claim 3, wherein the vinyl monomer is styrene. 5. The photosensitive resin composition according to claim 1, wherein the component (A) comprises two or more kinds of polymers having a carboxyl group. 6. The photosensitive resin according to claim 1, which further comprises, as a component (B), a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol. Composition. 7. A photosensitive element obtained by laminating the photosensitive resin composition according to claim 1, on a support film. 8. A method for laminating a photosensitive resin composition layer, comprising laminating the photosensitive element according to claim 7 on a substrate such that the layer of the photosensitive resin composition is in close contact with the substrate. 9. A photosensitive resin composition layer laminated substrate on which a photosensitive resin layer is laminated by the lamination method according to claim 8. 10. A method for curing a photosensitive resin composition layer, which comprises exposing the photosensitive resin composition layer laminated substrate according to claim 9.