JPH1048830A - Photosensitive resin composition and photosensitive film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin compsn. having improved adhesiveness to a base metal, suppressing undercutting by etching and useful for precision working of a metal and to obtain a photosensitive film. SOLUTION: This photosensitive resin compsn. contains a polymer binder contg. acrylic acid, methacrylic acid, acrylic ester or methacrylic ester as a constituent monomer (A), monomer having a polymerizable ethylenic unsatd. bond in each molecule (B), a photopolymn. initiator and an isocyanurate compd. represented by the formula (D) (where each of R<1> -R<3> is trialkoxysilyl bonded by alkylene or arylene). A layer of this photosensitive resin compsn. is laminated on a substrate film to obtain the objective photosensitive film.

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 suitable for precision metal processing such as production of a lead frame (hereinafter abbreviated as "lead frame") for mounting an IC chip and production of a metal mask, and a photosensitive film using the same. About.

[0002]

2. Description of the Related Art There are two methods of precision metal processing of lead frames, metal masks, and the like, a stamping method of punching using a mold and an etching method of forming an image by a photographic method using a photosensitive resin and then etching. It is roughly divided into two. Under the recent trend of light, thin, short and multi-product small quantity, the stamping method cannot manufacture narrow products due to miniaturization. In order to increase the variety of products, an etching method that can manufacture narrow products and does not require a mold is advantageous.

As the photosensitive resin used in such an etching method, there are three types: a water-soluble liquid photosensitive resin, a solvent-containing liquid photosensitive resin, and a photosensitive film. When a liquid photosensitive resin is used, enormous investment is required for a coating apparatus, and the coating takes considerable time. The photosensitive resin itself and the working life after coating the photosensitive resin are short. Has the common drawback of low. Further, as an individual disadvantage, the water-soluble liquid photosensitive resin is made of casein or PV.
Since A (polyvinyl alcohol) is cured using a chromate, a waste liquid treatment step of treating a harmful heavy metal salt after use is complicated. In solvent-containing liquid photosensitive resin,
Since the organic solvent is discharged during coating, there is a possibility that the environment is adversely affected.

On the other hand, in the photosensitive film method, since an image is formed after the photosensitive film is heated and pressed on a base metal and used, the equipment investment is lower than that of a liquid photosensitive resin, the sensitivity is high, and the working life is long. Has a long feature, and is attracting attention as a method suitable for precision metal processing. However, the conventional photosensitive film has poor adhesion to 42 alloy (Fe / Ni = 58/42) or SUS used as a base metal, and the etching solution easily permeates the resist-metal interface during etching, and There is a problem that the surface layer portion is easily eroded (referred to as etching etching).

[0005]

The object of the present invention is to provide a photosensitive resin composition which has improved adhesion to an underlying metal, has less etching undercut, and is useful for precision metal processing. The invention according to claim 2 provides a photosensitive film having a photosensitive resin composition which improves adhesion to a base metal, has less etching undercut, and is useful for precision metal processing.

[0006]

The present invention provides (A) a binder polymer containing acrylic acid, methacrylic acid, acrylate or methacrylate as a constituent monomer, and (B) an ethylenic polymerizable in a molecule. A monomer having an unsaturated bond, (C) a photopolymerization initiator, and (D) a general formula (I)

Embedded image (Wherein, R ¹ , R ² and R ³ each independently represent a trialkoxysilyl group bonded by an alkylene group or an arylene group), and relates to a photosensitive resin composition containing an isocyanurate compound represented by the formula:

[0007] The present invention also relates to a photosensitive film obtained by laminating a layer of the photosensitive resin composition on a support film.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive resin composition of the present invention comprises
(A) a binder polymer containing acrylic acid, methacrylic acid, acrylate or methacrylate as a constituent monomer, (B) a monomer having a polymerizable ethylenically unsaturated bond in a molecule, (C) photopolymerization initiation And (D) an isocyanurate compound represented by the general formula (I).

In the present invention, the binder polymer (A) containing acrylic acid, methacrylic acid, acrylic ester or methacrylic ester as a constituent monomer includes, for example, acrylic acid, methacrylic acid, acrylic ester or methacrylic ester. And copolymers thereof with a vinyl monomer copolymerizable therewith. These copolymers are used alone or in combination of two or more.

The acrylate or methacrylate includes, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-methyl acrylate
Alkyl acrylates or methacrylic acid alkyl esters such as ethylhexyl ester and methacrylic acid 2-ethylhexyl ester, and acrylate or methacrylic acid in which these alkyl groups are substituted with a hydroxyl group, an epoxy group, a halogen group, an amino group, or an alkylamino group Esters and the like. Examples of the acrylic acid ester or methacrylic acid ester and vinyl monomers copolymerizable with acrylic acid or methacrylic acid include acrylamide, acrylonitrile, diacetone acrylamide, styrene, and vinyl toluene. These constituent monomers are used alone or in combination of two or more.

In the present invention, the monomer (B) having a polymerizable ethylenically unsaturated bond in the molecule includes a monofunctional vinyl monomer and a polyfunctional vinyl monomer.
Examples of the monofunctional vinyl monomer include a vinyl monomer which is a copolymer component exemplified as the component (A).

Examples of the polyfunctional vinyl monomer include, for example,
Compounds obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol (polyethylene glycol diacrylate, polyethylene glycol dimethacrylate (having 2 to 14 ethylene groups), trimethylolpropane diacrylate, trimethylol Propane dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropaneethoxytriacrylate, trimethylolpropaneethoxytrimethacrylate, trimethylolpropanepropoxytriacrylate, trimethylolpropanepropoxytrimethacrylate, tetramethylolmethanetriacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetraacrylate, tet Lamethylol methane tetramethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate (having 2 to 14 propylene groups), dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexaacrylate Methacrylate, glycerol propoxy triacrylate, etc.), bisphenol A polyoxyethylene diacrylates or bisphenol A polyoxyethylene dimethacrylates (bisphenol A dioxyethylene diacrylate,
Bisphenol A dioxyethylene dimethacrylate,
Bisphenol A trioxyethylene diacrylate,
Bisphenol A trioxyethylene dimethacrylate, bisphenol A decaoxyethylene diacrylate, bisphenol A decaoxyethylene dimethacrylate, etc.), a compound obtained by adding an α, β-unsaturated carboxylic acid to a glycidyl group-containing compound (trimethylolpropane Triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc.), polycarboxylic acid (phthalic anhydride, etc.) and a substance having a hydroxyl group and an ethylenically unsaturated group (β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, etc.) ), Alkyl acrylate or alkyl methacrylate (methyl acrylate, methyl methacrylate, ethyl acrylate, methacrylic acid) Chiruesuteru, acrylic acid butyl ester, methacrylic acid butyl ester, 2-ethylhexyl esters of acrylic acid, 2-ethylhexyl methacrylate ester, a urethane acrylate or urethane methacrylate (tolylene diisocyanate 2-
Reaction product of hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, reaction product of trimethylhexamethylene diisocyanate, cyclohexanedimethanol and 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, hexamethylene diisocyanate And a reaction product of polyethylene glycol or polypropylene glycol with 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate). These are used alone or in combination of two or more.

Of these, at least one of them is a compound having at least two polymerizable ethylenically unsaturated bonds in one molecule from the viewpoint of improving chemical resistance, adhesion, etc. and reducing etching undermining. It is preferably used, and more preferably contains urethane acrylate or urethane methacrylate having at least two polymerizable ethylenically unsaturated bonds in one molecule.

As the photopolymerization initiator (C) in the present invention, for example, aromatic ketones (benzophenone, N, N ')
-Tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N-tetraethyl-4,4 '
-Diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone, etc., benzoin ether (benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, etc.), benzoin (methyl benzoin, ethyl benzoin, etc.) ), Acridine compounds (benzyldimethyl ketal, β- (acridine-
9-yl) acrylic acid diester compound, 9-phenylacridine, 9-pyridylacridine, 1,7-diacridinoheptane and the like, 2,4,5-triarylimidazole dimer (2- (o-chlorophenyl) ) -4,5
-Diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5
-Diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer,
2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) 5-phenylimidazole dimer, 2- (2,4-
Dimethoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl)-
4,5-diphenylimidazole dimer and the like). Also, 2-benzyl- which is an α-aminoketone
2-Dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Irgacure-369, trade name of Nippon Ciba Geigy) may be used in combination, and these may be used alone or in combination of two or more. Is done.

In the present invention, (D) the general formula (I)

Embedded image In the isocyanurate compound represented by the general formula (I), R ¹ , R ² and R ³ in the general formula (I) are each independently a trialkoxysilyl group bonded by an alkylene group or an arylene group, and the alkylene group or the arylene The group may have a substituent, and examples of such a substituent include an amino group, a hydroxyl group, an alkoxyl group, and a halogen atom.

Examples of the alkylene group include alkylene groups having 1 to 10 carbon atoms such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, and decylene. Groups. As the above arylene group,
For example, a phenylene group, a naphthylene group and the like can be mentioned.

The (D) isocyanurate compound represented by the general formula (I) includes, for example,
No. 1 to No. 9 compounds and the like.

[0018]

Embedded image

[0019]

Embedded image

[0020]

Embedded image

Of these, the No. 1 compound (1, 3,
5-N-tris (trimethoxysilylpropyl) isocyanurate) is commercially available from Nippon Unicar Co., Ltd.

The amount of the component (A) in the present invention is as follows:
The total amount of the component (A) and the component (B) is preferably 10 to 80 parts by weight based on 100 parts by weight, and 30 to 7 parts by weight.
More preferably, it is 0 parts by weight. If the blending amount is 10
If the amount is less than the weight part, there is a tendency that sufficient sensitivity cannot be obtained,
If it exceeds 80 parts by weight, the photocured product tends to be brittle. The weight average molecular weight of the component (A) (measured by a gel permeation chromatography method and converted using a standard polystyrene calibration curve) is 10,000 from the viewpoint of coating properties, film strength, developability, and the like. It is preferably set to ~ 200,000.

In the present invention, the compounding amount of the component (B) is as follows:
The total amount of the component (A) and the component (B) is preferably from 20 to 90 parts by weight based on 100 parts by weight, and 30 to 7 parts by weight.
More preferably, it is 0 parts by weight. When the blending amount is 20
If the amount is less than part by weight, the photocured product tends to be brittle and sufficient physical properties cannot be obtained. If the amount exceeds 90 parts by weight, sufficient sensitivity tends not to be obtained.

The amount of the component (C) in the present invention is as follows:
The amount is preferably 0.03 to 20 parts by weight based on 100 parts by weight of the total of the component (A) and the component (B).
More preferably, the amount is from 0.05 to 10 parts by weight. If the amount is less than 0.03 parts by weight, sufficient sensitivity tends not to be obtained. If the amount exceeds 20 parts by weight, light absorption on the surface of the composition at the time of exposure increases, and light curing inside the composition increases. Tends to be insufficient.

The amount of the component (D) in the present invention is as follows:
Preferably, the amount is 0.05 to 5 parts by weight based on 100 parts by weight of the total of the components (A) and (B).
More preferably, it is set to 1 part by weight. If the amount is less than 0.05 part by weight, sufficient adhesion to the substrate tends not to be obtained, and if it exceeds 5 parts by weight, the stability tends to decrease and the development residue tends to be easily caused. ,Also,
The cost tends to increase.

The photosensitive resin composition of the present invention may optionally contain a plasticizer, a thermal polymerization inhibitor, a dye, a pigment, a filler, an adhesion promoter, a fragrance, an imaging agent, and the like. . Among these, the use of the blocked isocyanate can further improve the adhesion to the substrate.

The photosensitive resin composition of the present invention can be used, for example, as a liquid resist on a metal surface (copper, copper-based alloy, nickel,
Chromium, iron, iron-based alloys such as stainless steel, etc.), and then dried and coated with a protective film. The photosensitive resin composition of the present invention, if necessary, acetone, methyl ethyl ketone, methylene chloride, toluene, methanol, ethanol, propanol, butanol, methyl glycol, ethyl glycol, propylene glycol, monomethyl ether, dimethylformamide and other solvents and It can be mixed with these mixed solvents and applied as a solution.

The photosensitive film of the present invention is obtained by laminating a layer of the photosensitive resin composition of the present invention on a support film. The photosensitive film of the present invention, on a support film such as polyester, the photosensitive resin composition of the present invention,
It can be obtained by coating and drying, then laminating, and, if necessary, laminating a protective film such as polyolefin by a conventional method. Examples of the coating method include a roll coating method and a knife coating method, and the drying temperature is usually 70 to 150 ° C., and the drying time is usually 1 to 6
0 minutes. 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. As the protective film, a transparent and inert film such as a polyolefin film such as polyethylene and polypropylene, and a polyester film such as polyethylene terephthalate can be used.

The layer of the photosensitive resin composition obtained above comprises
After being irradiated with actinic rays through a negative or positive max pattern called an artwork, it is developed with a developing solution to form a resist pattern. As 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 that is safe and stable and has good operability is used, and a dilute solution of sodium carbonate or the like is used for an alkali developing type photoresist as in the present invention. Examples of the developing method include a dip method, a paddle method, and a spray method.
The high-pressure spray method is preferable for improving the resolution.

As a treatment after development, the resist may be further cured by heating (80 to 250 ° C.) or exposure (0.2 to 5 J / cm ² ), if necessary. For the etching performed after the development, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, a hydrogen peroxide-based etching solution, or the like can be used, but from the viewpoint of a good etch factor, ferric chloride is used. Preferably, a solution is used.

[0030]

The present invention will be described below with reference to examples. Example 1 A photosensitive resin composition solution was obtained by blending the materials shown in Tables 1 and 2.

[0031]

[Table 1]

Embedded image

[0032]

[Table 2]

Next, this photosensitive resin composition solution was added to 16
A photosensitive film was obtained by uniformly coating the film on a polyethylene terephthalate film having a thickness of μm by a roll coating method and drying the film with a hot air convection dryer at 100 ° C. for 5 minutes. The film thickness of the photosensitive resin composition layer after drying was 20 μm. on the other hand,
0.15mmt42 alloy (manufactured by Yamaha) in 10% by weight N
The photosensitive film was immersed in an aOH solution at 50 ° C. for 2 minutes, then washed with water and dried.
While laminating.

Next, the substrate thus obtained is
Using a negative film, exposure was performed at 70 mJ / cm ² using a 3 kW high-pressure mercury lamp (HMW-590, manufactured by Oak Manufacturing Co., Ltd.).
At this time, in order to evaluate the light sensitivity, a negative film (optical density of 0.05 was set as the first stage, and optical density of 0.15 was set for each stage, so that the light transmission amount was reduced stepwise. Increasing step tablets) were used. Next, the polyethylene terephthalate film was removed, and an unexposed portion was removed by spraying a 1% by weight aqueous solution of sodium carbonate at 30 ° C. for 20 seconds. By measuring the number of steps of the step tablet of the photocurable film formed on the 42 alloy substrate, the light sensitivity of the photosensitive resin composition was evaluated. As a result, 8.0 steps were shown. The light sensitivity is indicated by the number of steps of the step tablet, and the higher the number of steps of the step tablet, the higher the light sensitivity.

Next, the developed product is sprayed with a 45 Baume ferric chloride solution (Bome indicates the specific gravity of the solution. The larger the numerical value, the larger the specific gravity) is sprayed at 50 ° C., 2 kg · f / cm ² for 8 minutes. The etching is completed by
It was immersed in an OH solution at 50 ° C. for 2 minutes, the resist was peeled off, washed with water and dried to obtain an etched 42 alloy base material. By observing the line of the obtained 42 alloy base material and examining the etching hole, no etching hole was found. Similarly, the prepared photosensitive film is
After lamination on the alloy base material, it was left under a condition of 30 ° C.-90% RH for 1 day, and then exposed and developed in the same manner as above to evaluate the stability. Insufficient stability can be easily found visually because undeveloped resist adheres to the substrate. Example 1 had good stability.

Examples 2-3 and Comparative Example 1 In Example 1, the components (B) and (C) shown in Table 1 were replaced with the components shown in Table 3 except that
After obtaining a photosensitive resin composition solution in the same manner as in Example 1,
A photosensitive film was obtained in the same manner as in Example 1 using this photosensitive resin composition solution. Hereinafter, an evaluation test was performed in the same manner as in Example 1, and the results are also shown in Table 3.

[0037]

[Table 3]

As is clear from Table 3, the photosensitive resin compositions of the present invention containing the component (D) of the present invention (Examples 1 to 3) have less etching undercuts than the comparative examples, and have improved properties. You can see that it is done. Further, in Examples 1 and 2 containing urethane acrylate monomer (UA-11) as the component (B) in the present invention, the etching migration was further improved compared to Example 3 in which urethane acrylate monomer was not used. Recognize.

[0039]

According to the present invention, the photosensitive resin composition of the present invention has improved adhesiveness to an underlying metal, has less etching recession, and is useful for precision metal processing. The photosensitive film according to the second aspect has a photosensitive resin composition which improves adhesion to a base metal, has little etching, and is useful for precision metal processing.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G03F 7/033 G03F 7/033 // H01L 23/50 H01L 23/50 A

Claims (2)

[Claims] 1. A binder polymer containing acrylic acid, methacrylic acid, an acrylate ester or a methacrylic ester as a constituent monomer, (B) a monomer having a polymerizable ethylenically unsaturated bond in a molecule, C) a photopolymerization initiator and (D) a general formula (I) (Wherein, R ¹ , R ² and R ³ each independently represent a trialkoxysilyl group linked by an alkylene group or an arylene group). 2. A photosensitive film obtained by laminating a layer of the photosensitive resin composition according to claim 1 on a support film.