JPH0635190A - Photosensitive resin composition and laminate using the same - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a photosensitive resin composition having high photosensitivity, excellent adhesiveness, resolution, and storage stability of a resist image and forming a resist image having a short skirt length. To do. [Constitution] (A) carboxyl group-containing polymer, (B)
A compound having at least one ethylenically unsaturated group,
(C) Photoinitiator represented by general formula (I) A photosensitive resin composition soluble or swellable in an alkaline aqueous solution containing (R ₁ is a hexylene group or the like), and a laminate in which the photosensitive resin composition is applied on a support and dried.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive resin composition and a laminate using the same.

[0002]

2. Description of the Related Art A photosensitive resin composition is widely used as a resist used in the production of printed circuit boards, and a photosensitive laminate (hereinafter referred to as a photosensitive film) in which the photosensitive resin composition is laminated on a support layer. Is also widely used.

The mainstream of these photosensitive films is an alkali developing type in which the uncured portion is removed with an alkaline aqueous solution. A photosensitive layer of the photosensitive film is laminated on a substrate for a printed circuit board which has been polished or treated with a chemical, and then a photo film is formed. After exposure through a tool, the support is removed, and development is performed using an alkaline aqueous solution such as a 0.5 to 2.0 wt% sodium carbonate aqueous solution to form a resist image on the substrate.

Conventionally, there are two methods of manufacturing a printed circuit board, a tenting method and a plating method. In the tenting method, the exposed copper surface of the resist image is etched with an acidic or alkaline etching solution, and then the resist is peeled off using an alkaline aqueous solution such as sodium hydroxide to produce a printed circuit board. In addition, the plating method is to perform copper plating and solder plating on the exposed copper surface, peel off the resist using an alkaline aqueous solution such as sodium hydroxide, and then etch the exposed copper surface with an alkaline etching solution to form a printed circuit board. To manufacture.

In recent years, there has been an increasing trend toward higher density of printed circuit boards, and the distance between two through holes (center-to-center distance: 2.54 m).
It is common to form 3 to 5 lines in m). To satisfy this requirement, 50 to 50
A resist image having a line width of 80 μm must be formed.

However, when the conventional photosensitive resin composition or photosensitive film is used, the ultraviolet rays transmitted through the photosensitive layer at the time of exposure are diffusely reflected on the copper metal surface to cure the photosensitive layer on the copper metal surface. Often observed, the resist will typically have a skirt of 10-20 μm. In particular, when the space between lines is narrow, this skirt causes insufficient resolution of the resist image, and eventually causes short circuit of the printed circuit or disconnection in the case of plating process. .

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and is a photosensitive resin which has a high photosensitivity and which forms a resist image in the shape of no shies after development and is excellent in resolution. The present invention provides a composition and a laminate using the same.

[0008]

The present invention provides (A) 40 to 80 parts by weight of a carboxyl group-containing polymer and (B) compounds 20 to 6 having at least one ethylenically unsaturated group.
0 parts by weight (so that the total amount of (A) and (B) becomes 100 parts by weight), (C) the photoinitiator represented by the general formula (I) is added to the above (A) and (B). 0.05 to 1.0 parts by weight based on 100 parts by weight of

[Chemical 4] (In the formula, R ₁ represents an alkylene group having 6 to 12 carbon atoms.) (D) The photoinitiator represented by the general formula (II) is added to 100 parts by weight of the total amount of (A) and (B). 1.0-1
0.0 parts by weight

[Chemical 5] (In the formula, Ar ₁ and Ar ₂ each independently represent an unsubstituted phenyl group or a phenyl group substituted with an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and R ₂ and R _3's each independently represent an alkyl group having 1 to 9 carbon atoms) and (E) the general formula (II
Photosensitizer soluble or swellable in an alkaline aqueous solution containing 0.01 to 3.0 parts by weight of the photoinitiator represented by I) based on 100 parts by weight of the total amount of (A) and (B). Resin composition

[Chemical 6] (Wherein R ₄ , R ₅ , R ₆ and R ₇ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) and the support is coated with the photosensitive resin composition and dried. The present invention relates to a laminated body.

Next, the components contained in the photosensitive resin composition of the present invention will be described in detail. As the carboxyl group-containing polymer used as the component (A) in the present invention, for example, (meth) acrylic acid alkyl ester [(meth) acrylic acid means methacrylic acid and acrylic acid.
The same shall apply hereinafter] and a copolymer of (meth) acrylic acid and a vinyl monomer copolymerizable therewith, and the like. These copolymers can be used alone or in combination of two or more kinds.

Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester,
(Meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester and the like can be mentioned. Examples of vinyl monomers copolymerizable with (meth) acrylic acid alkyl ester and (meth) acrylic acid include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) 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.

As the compound having at least one ethylenically unsaturated group used as the component (B) in the present invention, known compounds can be used without any particular limitation. Examples of such a compound include polyethylene glycol di (meth) acrylate (having 2 to 14 ethylene groups), trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane. Ethoxytri (meth) acrylate, trimethylolpropane propoxytri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (the number of propylene groups is 2 to 2). 14), dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. and an α, β-unsaturated carboxylic acid Compounds, bisphenol A tetraoxyethylene di (meth) acrylate, bisphenol A hexaoxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate, and other bisphenol A polyoxyethylene di (meth) acrylates
Compounds obtained by adding α, β-unsaturated carboxylic acids to glycidyl group-containing compounds such as acrylates, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether acrylate, and polyvalent carboxylic acids such as phthalic anhydride And an esterification product of a substance having a hydroxyl group and an ethylenically unsaturated group such as β-hydroxyethyl (meth) acrylate, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, Alkyl ester of (meth) acrylic acid such as (meth) acrylic acid 2-ethylhexyl ester, reaction product of tolylene diisocyanate and 2-hydroxyethyl (meth) acrylic acid ester, trimethylhexamethylene diisocyanate and cyclohexane diester Urethane (meth) acrylate of a reaction product of pentanol and 2-hydroxyethyl (meth) acrylate esters.

The compounding amount of the component (A) in the present invention is 40.
It is necessary to adjust the amount to 80 parts by weight, and 55 to 65 parts by weight is particularly preferable. If the blending amount is less than 40 parts by weight, the photocured product tends to be brittle, and when used as a photosensitive film, the coating property is poor. If the blending amount exceeds 80 parts by weight, sufficient sensitivity cannot be obtained.

The amount of the component (B) to be blended must be 20 to 60 parts by weight, and 35 to 45 parts by weight is particularly preferable. If the amount is less than 20 parts by weight, sufficient sensitivity cannot be obtained, and if it exceeds 60 parts by weight, the photocured product tends to become brittle.

Further, as the component (B), it is preferable to use a compound having two or more ethylenically unsaturated groups from the viewpoint of improving the sensitivity.

Examples of the component (C) in the present invention include 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- Examples thereof include bis (9-acridinyl) undecane and 1,12-bis (9-acridinyl) dodecane. These can be used alone or in combination of two or more.

The photoinitiator (acridine compound) represented by the general formula (I), which is the component (C), can be easily produced by reacting diphenylamine with a divalent carboxylic acid in the presence of a metal oxide. can do.

The component (C) is 0.05 to 1.0 with respect to 100 parts by weight of the total amount of the components (A) and (B).
It is used in parts by weight, preferably 0.1 to 0.5 parts by weight. If it is less than 0.05 part by weight, sufficient photosensitivity cannot be obtained and the resolution is lowered. Further, when it is used in an amount of more than 1.0 part by weight, further improvement in sensitivity cannot be expected and the ultraviolet transmittance of the photosensitive layer is lowered, so that a normal resist image cannot be obtained.

The photoinitiator represented by the general formula (II) used as the component (D) of the present invention is, for example, 1- (4-methoxyphenyl) -2,2-dimethoxy-2-phenyl-. 1-ethanone, 1- (4-methoxyphenyl) -2-methoxy-2-ethoxy-2-phenyl-1-ethanone, 1- (4-methoxyphenyl) -2
-Methoxy-2-propoxy-2-phenyl-1-ethanone, the formula

[Chemical 7] 2,2-dimethoxy-1,2-diphenyl-
1-ethanone (commonly called benzyl dimethyl ketal) and the like can be mentioned. These can be used alone or in combination of two or more. Of these, benzyl dimethyl ketal is preferable.

The component (D) is used in an amount of 1.0 to 10.0 parts by weight, preferably 2.0 to 5.0 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). To be
If it is less than 1.0 part by weight, sufficient photosensitivity cannot be obtained and the resolution is lowered. Further, when it is used in an amount exceeding 10.0 parts by weight, the storage stability of the photosensitive resin composition is lowered and it cannot be put to practical use.

The photoinitiator represented by the general formula (III) of the component (E) in the present invention is, for example, p,
Examples thereof include p-dimethylaminobenzophenone, p, p-diethylaminobenzophenone and p, p-dipropylaminobenzophenone.

The component (E) is used in an amount of 0.01 to 3.0 parts by weight, preferably 0.03 to 1.0 part by weight, based on 100 parts by weight of the total of the components (A) and (B). To be
If it is less than 0.01 part by weight, the resolution will be lowered. Also 3.0
When it is used in an amount exceeding the range of weight, the ultraviolet transmittance of the photosensitive layer is lowered and a normal resist image cannot be obtained.

The photosensitive resin composition of the present invention includes, for example,
A thermal polymerization inhibitor such as p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, phenothiazine and t-butylcatechol can be contained.

Further, the photosensitive resin composition of the present invention may contain a coloring agent such as a dye or a pigment. As the colorant, for example, fuchsin, auramine base, crystal violet, Victoria pier blue, malachite green, methyl orange, acid violet RRH and the like are used.

Further, the photosensitive resin composition of the present invention comprises
Known additives such as a plasticizer, an adhesion promoter, and talc may be added, or a combination of a halogen compound such as carbon tetrabromide and a leuco dye may be added so that the exposed portion is discolored. .

The photosensitive resin composition of the present invention can be used as a laminate (photosensitive film) by coating it on a support and drying it. As the support, a polymer film, for example, a film made of polyethylene terephthalate, polypropylene, polyethylene or the like is used, and a polyethylene terephthalate film is preferable. Since these polymer films must be removable from the photosensitive layer later, they are materials that cannot be removed or have been subjected to a surface treatment that makes them impossible to remove. must not. The thickness of these polymer films is usually 5 to 100 μm, preferably 10 to 30 μm. One of these polymer films may be laminated on both sides of the photosensitive layer as a support film for the photosensitive layer and the other as a protective film for the photosensitive layer.

In producing the photosensitive film, first, the photosensitive resin composition containing the components (A) to (E) is uniformly dissolved in a solvent. The solvent may be a solvent that dissolves the photosensitive resin composition, for example, acetone, methyl ethylmerketone, a ketone solvent such as methyl isobutyl ketone,
An ether solvent such as methyl cellosolve and ethyl cellosolve, a chlorinated hydrocarbon solvent such as dichloromethane and chloroform, and an alcohol solvent such as methyl alcohol and ethyl alcohol are used. These solvents may be used alone or in combination of two or more.

Then, the photosensitive resin composition in the form of a solution is uniformly applied on the polymer film as the supporting film layer, and then the solvent is removed by heating and / or blowing with hot air to form a dry film. The thickness of the dry film is not particularly limited and is usually 10 to 100 μm, preferably 20 to 6
It is set to 0 μm. The photosensitive film of the present invention comprising the two layers of the photosensitive layer and the polymer film thus obtained is stored as it is or on the other surface of the photosensitive layer, and the protective film is further wound into a roll and stored. To be done.

In producing a photoresist image using the photosensitive film of the present invention, when the protective film is present, the protective film is removed and then the photosensitive layer is pressed against the substrate while heating. To stack.
The surface to be laminated is usually a metal surface, but is not particularly limited. Heating and pressure bonding of the photosensitive layer are usually 90 to 130 ° C.,
The pressure is 3 kgf / cm ² , but these conditions are not particularly limited.

When the photosensitive film of the present invention is used, it is not always necessary to preheat the substrate beforehand if the photosensitive layer is heated as described above. Needless to say, the substrate may be preheated to further improve the stackability.

The photosensitive layer thus laminated is
It is then imagewise exposed to actinic light using a negative or positive film. As the active light, light generated from a known active light source such as carbon arc, mercury vapor arc, xenon arc, or the like is used.

After the exposure, the polymer film on the photosensitive layer is removed, and then the unexposed portion is removed using an alkaline aqueous solution by a known method such as spraying, rocking dipping, brushing and scraping. develop. Examples of the base of the alkaline aqueous solution include alkali hydroxides of hydroxides such as lithium, sodium and potassium, alkali carbonates of carbonates or bicarbonates of lithium, sodium and potassium, alkali metals such as potassium phosphate and sodium phosphate. Phosphates, alkali metal pyrophosphates such as sodium pyrophosphate, potassium pyrophosphate and the like are used, and an aqueous solution of sodium carbonate is particularly preferable.

The pH of the alkaline aqueous solution used for development is preferably between 9 and 11, and the development temperature is adjusted according to the developability of the photosensitive layer. A surface active agent, a defoaming agent, and a small amount of an organic solvent for accelerating the development may be mixed in the alkaline aqueous solution.

Further, when manufacturing a printed wiring board, the exposed surface of the substrate is treated by a known method such as etching or plating using the developed photoresist image as a mask. Next, the photoresist image is usually stripped with a stronger alkaline aqueous solution than the alkaline aqueous solution used for development. As this strongly alkaline aqueous solution,
For example, a 1 to 5 wt% sodium hydroxide aqueous solution or the like is used.

[0034]

EXAMPLES The present invention will be described in more detail with reference to examples. Examples 1 to 8 and Comparative Examples 1 to 9 Photosensitive resin compositions having the compositions shown in Table 1 and Table 2 described below were prepared, and the photosensitive resin composition 4 was prepared using the apparatus shown in FIG.
Is evenly coated on a polyethylene terephthalate film 12 having a thickness of 20 μm as a support, dried for about 5 minutes in a hot air convection dryer 6 at 100 ° C. to remove the solvent, and the thickness of the photosensitive layer after drying. Was 50 μm. 1 in FIG.
Is a polyethylene terephthalate film feeding roll, 2 and 3 are film feeding rolls, 5 is a coating thickness adjusting roll, 7 and 8 are polyethylene film laminating rolls, 9 is a polyethylene film feeding roll, and 10 is a photosensitive film winding roll. The coating speed at this time is 1m
/ Min, the hot air temperature was 90 ° C. Then, a polyethylene film 11 having a thickness of 30 μm was laminated on the photosensitive layer as a protective film and wound into a length of 125 m. While peeling off the protective film from the photosensitive film obtained by the above method, the photosensitive layer was hot-rolled by a Hitachi Chemical Co., Ltd. hot roll laminator (model HLM-1500), the copper surface was polished with a cleanser, washed with water, and dried. Substrate for printed wiring board (Hitachi Chemical Co., Ltd., trade name MCL-E-61)
Lamination temperature of 110 ° C and lamination pressure of 3.0 kgf / cm ²
It was laminated with.

When the temperature of the printed wiring board substrate laminated with the photosensitive film reached 23 ° C., a photo tool (21-step step tablet of Stuffer and line / space = 30 / 30-) was formed on the polyethylene terephthalate surface.
250/250 (resolution), line / space = 30 /
A phototool having a wiring pattern of 400 to 250/400 (adhesion) is brought into close contact, and an exposure machine (model HMW-201B, 3 kW ultrahigh pressure mercury lamp) manufactured by Oak Manufacturing Co., Ltd. is used to develop a 21-step step tablet of a stofer. Exposure was performed with an energy amount such that the number of remaining step steps afterward was 8.0.

After 15 minutes of exposure, the polyethylene terephthalate film was peeled off, and development was carried out by spraying a 1.0 wt% sodium carbonate aqueous solution at 30 ° C.
At this time, the development was performed by setting the speed so that the development was completed at a position of 2/3 from the entrance in the conveyor type developing tank. The exposure amount at which the number of remaining steps after development at this time is 8.0, the resolution at that time, the adhesiveness, the skirt length of the shape of the resist image, and the storage stability are shown in Tables 1 and 2.

[0037]

[Table 1]

[0038]

[Table 2]

* 1 P _M -800 Hitachi Chemical Co., Ltd.
Prototype Methacrylic acid / Methyl methacrylate / Ethyl acrylate = 20/50/30 (wt%) methyl cellosolve solution (solid content = 40.0 wt%) Weight average molecular weight = 100,000 * 2 1,7- Bis (9-acridinyl) heptane
Asahi Denka Kogyo Co., Ltd. Prototype * 3 Benzyl dimethyl ketal Nippon Ciba Geigy Co., Ltd. * 4 BPE-500: 2,2-bis [4- (methacryloxy-polyethoxy) phenyl] propane Shin-Nakamura Chemical Co., Ltd. * 5 APG-400: Heptapropylene glycol diacrylate Shin Nakamura Chemical Co., Ltd. * 6 SR-454: Trimethylolpropane triacrylate EO adduct SARTOMER COMPANY * 7 14G: Polyethylene glycol # 600 dimethacrylate Shin Nakamura Chemical ( * 8 APG-200: Tripropylene glycol diacrylate Shin-Nakamura Chemical Co., Ltd. * 9 Time required for the unexposed photosensitive film to be completely dissolved and removed by the developer * 10 Residue after development The number of steps is 8.0 (stoper Exposure energy required to obtain a 21-step step tablet) * 11 Adhesion when the number of remaining step steps after development is 8.0 (line / space = n / 400 μm) * 12 The number of remaining step steps after development Resolution at 8.0 (line / space = n / nμm)

[0040]

As is clear from the above examples, the photosensitive resin composition of the present invention and the photosensitive film using the same have high photosensitivity, excellent resolution and storage stability, and thereby excellent adhesion. A resist image having an excellent shape and a short skirt length can be obtained.

[0041]

[Brief description of drawings]

FIG. 1 is a systematic diagram of a manufacturing apparatus diagram of a photosensitive film used in Examples.

[Explanation of symbols]

1 Polyethylene terephthalate film feeding roll 2, 3 Film feeding roll 4 Photosensitive resin composition 5 Coating thickness adjusting roll 6 Dryer 7, 8 Polyethylene film laminating roll 9 Polyethylene film feeding roll 10 Photosensitive film winding roll 11 Polyethylene film 12 Polyethylene Terephthalate film

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[Procedure amendment]

[Submission date] February 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016] (C) a photoinitiator represented by the general formula is a component (I) (acridine compound), for example, readily prepared by reacting diphenylamine with divalent carboxylic acid in the presence of a metal salt compound can do.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyohito Tanno 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant (72) Inventor Hajime Kakumaru 4-13, Higashimachi, Hitachi City, Ibaraki Prefecture No. 1 In the Yamazaki Plant of Hitachi Chemical Co., Ltd. (72) Inventor Naohiro Kubota 7-35 Higashiohisa, Arakawa-ku, Tokyo Inside Asahi Denka Kogyo Co., Ltd. (72) Nobuhide Tominaga 7 Hisashi Higashio, Arakawa-ku, Tokyo 2-35 Asahi Denka Kogyo Co., Ltd. (72) Inventor Koji Ishizaki 7-35 Higashiohisa Arakawa-ku Tokyo Tokyo Asahi Denka Kogyo Co., Ltd.

Claims (2)

[Claims] 1. A polymer 40 containing a carboxyl group (A)
-80 parts by weight, (B) 20-60 parts by weight of a compound having at least one ethylenically unsaturated group ((A) and (B)
The total amount of the photoinitiator is 100 parts by weight), and (C) the photoinitiator represented by the general formula (I) is added to the above (A) and (B).
0.05 to 1.0 parts by weight based on 100 parts by weight of (In the formula, R ₁ represents an alkylene group having 6 to 12 carbon atoms.) (D) The photoinitiator represented by the general formula (II) is added to 100 parts by weight of the total amount of (A) and (B). 1.0-1
0.0 parts by weight (In the formula, Ar ₁ and Ar ₂ each independently represent an unsubstituted phenyl group or a phenyl group substituted with an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and R ₂ and R _3's each independently represent an alkyl group having 1 to 9 carbon atoms) and (E) the general formula (II
Photosensitizer soluble or swellable in an alkaline aqueous solution containing 0.01 to 3.0 parts by weight of the photoinitiator represented by I) based on 100 parts by weight of the total amount of (A) and (B). Resin composition. [Chemical 3] (In the formula, R ₄ , R ₅ , R ₆ and R ₇ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) 2. A laminate obtained by applying the photosensitive resin composition according to claim 1 on a support and drying the support.