JP2005292289A - Photoresist film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoresist film having high sensitivity and high resolution, superior also in storage stability under a yellow safe light, and suitable for exposure, particularly with an exposure machine using a blue-violet laser as a light source. <P>SOLUTION: The photoresist film is obtained by stacking a layer [I] comprising a photosensitive resin composition, containing a carboxylic polymer (A), an ethylenically unsaturated compound (B) and a photopolymerization initiator (C) having absorption at a main wavelength of ≤390 nm and a support film [II], wherein the light transmittance of the layer [I] comprising the photosensitive resin composition before curing to light of 405 nm wavelength is 15-50%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photosensitive resin composition suitable for an etching resist and a plating resist used for the manufacture of printed wiring boards and metal precision processing, and a photoresist film using the same, and more specifically, with high sensitivity and high resolution. In addition, the present invention relates to a photoresist film having excellent storage stability with a yellow safety light, and is particularly suitable for exposure with a blue-violet laser exposure machine.

  Conventionally, in a manufacturing process for precision processing of printed wiring boards and metals, first, a photosensitive resin composition is directly applied to a substrate, or a photoresist film is produced from the photosensitive resin composition, and the photoresist film is used. After lamination to the substrate, exposure is performed. In the exposure of such a photosensitive resin composition, a laser is used in addition to ultraviolet rays. Since exposure using such a laser can form an image of a desired shape without using a pattern mask, a small amount is used. It has advantages such as multi-product production and shortening of production time. However, since such a laser usually has an oscillation frequency in the near-ultraviolet region, an apparatus is expensive to secure a light source having a sufficient output, and therefore, a light source with a low output is usually forced to be used. Since the exposure amount of the light source is low, there is a demand for a photosensitive resin composition having sufficient sensitivity even at such a low exposure amount.

As a photosensitive resin composition having high sensitivity even at a low exposure amount as described above, the present applicant contains a binder resin, an ethylenically unsaturated compound, a lophine dimer, N-arylglycine, and an alkylaminobenzophenone. The photosensitive resin composition (for example, refer patent document 1 and 2) containing the photoinitiator and the compound of a specific structure was proposed.
Japanese Patent Laid-Open No. 2003-167338 Japanese Patent Laid-Open No. 2003-177524

However, in the disclosed techniques of Patent Documents 1 and 2, although the photosensitive resin composition has a low exposure and a high sensitivity, both are intended for ultraviolet irradiation, and are expected to reduce the cost of the light source. Exposure using a violet laser (h line: 390 to 420 nm) as a light source is not taken into consideration, and further improvements in this respect are required.
In addition, when a sensitizing dye having an absorption dominant wavelength from h-line to a long wavelength is used in combination with blue-violet laser exposure, it is exposed to a yellow safety light, which is a general working environment, and development is impossible. As a result, work in a dark room or under a red safety light is forced to cause problems in workability.

  Therefore, in the present invention, under such a background, high sensitivity, high resolution, and excellent storage stability with a yellow safety light, particularly for exposure with an exposure machine using a blue-violet laser as a light source. The object is to provide a suitable photoresist film.

However, as a result of intensive studies in view of such circumstances, the present inventors have obtained a carboxyl group-containing polymer (A), an ethylenically unsaturated compound (B), and a photopolymerization initiator (C) having an absorption main wavelength of 390 nm or less. A photoresist film formed by laminating a layer [I] composed of a photosensitive resin composition and a support film [II], and having a wavelength of 405 nm before curing of the layer [I] composed of the photosensitive resin composition The present inventors have found that a photoresist film having a light transmittance of 15 to 50% in the light beam meets the above purpose, and completed the present invention.
The absorption main wavelength is a wavelength having the maximum absorption intensity in the wavelength range of 320 to 700 nm. Specifically, a photopolymerization initiator is dissolved in methanol, and a “U-3000 type spectrophotometer” (1 cm cell) manufactured by Hitachi, Ltd. is used as a methanol solution having a concentration of 0.02 g / l, and a wavelength of 320 to 700 nm. The absorbance in the above range was measured every 5 nm, and the wavelength having the maximum absorption intensity was defined as the absorption main wavelength.

  In the present invention, as a photopolymerization initiator (C), it is possible to contain an alkylaminobenzophenone (C1) and a hexaarylbiimidazole derivative (C2) represented by the following general formula (1) in order to increase the resolution of a resin image. It is preferable that N-arylglycine (C3) and / or acridine derivative (C4) is further contained from the viewpoint of improving sensitivity.

（１）

Ｘは塩素原子を表し、ｉおよびｊは、それぞれ独立に０〜４の整数、Ｙはそれぞれ独立に水素原子あるいは塩素原子を表す。Ｒは炭素数１〜３のアルコキシ基を表し、ｋ、ｌ、ｍ、ｎは１２≧ｋ＋ｌ＋ｍ＋ｎ≧２を満たす０〜３の整数である。

(1)

X represents a chlorine atom, i and j each independently represent an integer of 0 to 4, and Y each independently represents a hydrogen atom or a chlorine atom. R represents an alkoxy group having 1 to 3 carbon atoms, and k, l, m, and n are integers of 0 to 3 that satisfy 12 ≧ k + 1 + m + n ≧ 2.

（２）

Ｚはアルキルアミノ基を表す。Ｒ′は置換、非置換のアルキル基、フェニル基を表す。 Moreover, in this invention, it is preferable from the point of the visualization of an image to contain the compound (D1) and / or leuco dye (D2) shown by General formula (2) as dye (D).

(2)

Z represents an alkylamino group. R ′ represents a substituted or unsubstituted alkyl group or a phenyl group.

  The photoresist film of the present invention has high sensitivity and high resolution, and has an excellent effect on storage stability with a yellow safety light, and is exposed with an exposure machine using a blue-violet laser as a light source. It is a suitable photoresist film.

Hereinafter, the present invention will be described in detail.
The photosensitive resin composition used in the present invention contains a carboxyl group-containing polymer (A), an ethylenically unsaturated compound (B), and a photopolymerization initiator (C) having an absorption main wavelength of 390 nm or less. Examples of the carboxyl group-containing polymer (A) include acrylic polymers, polyester polymers, polyamide polymers, epoxy polymers, and the like. Among them, (meth) acrylic acid ester is the main component. It is preferable to use an acrylic polymer obtained by copolymerizing an ethylenically unsaturated carboxylic acid and, if necessary, other copolymerizable monomers. The acrylic polymer will be described below. However, it is not limited to this.

  Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, 2,2 , 2-trifluoroethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and the like.

  Examples of the ethylenically unsaturated carboxylic acid include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and anhydrides thereof. Half esters can also be used. Of these, acrylic acid and methacrylic acid are particularly preferable.

  Examples of the other copolymerizable monomers include (meth) acrylamide, 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, vinyl naphthalene, vinyl cyclohexane, vinyl toluene, Examples include vinyl acetate, alkyl vinyl ether, (meth) acrylonitrile and the like.

  The acrylic polymer preferably has a weight average molecular weight of 50,000 to 100,000, more preferably 30,000 to 80,000, an acid value of 100 to 300 mgKOH / g, and more preferably 120 to 220 mgKOH / g. preferable.

  If the weight average molecular weight is less than 50,000, the cured photosensitive resin composition may become brittle. Conversely, if the weight average molecular weight exceeds 100,000, the resolution and resist peelability tend to decrease. On the other hand, when the acid value is less than 100 mgKOH / g, the resolution and resist peelability are lowered, and when it exceeds 300 mgKOH / g, the fine wire adhesion tends to be lowered.

  Furthermore, the glass transition temperature (Tg) of the acrylic polymer is preferably in the range of 30 to 130 ° C, more preferably in the range of 60 to 100 ° C. When the glass transition temperature is less than 30 ° C., the photosensitive resin composition tends to flow and may cause edge fusion when it is rolled into a photoresist film. This is not preferable because the ability to follow the unevenness of the substrate surface may be reduced.

  As the ethylenically unsaturated compound (B) used in the present invention, a monofunctional monomer or a polyfunctional monomer is used. Examples of the monofunctional monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl (meth) acrylate, Glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, phthalic acid derivative half (meth) acrylate, N-methylol (meth) acrylamide, diethylaminoethyl methacrylate, polypropylene glyco Le (meth) acrylate, alkyl phenol polyethoxy (meth) acrylate, nonylphenol tetraethoxy acrylate, caprolactone-modified hydroxy (meth) acrylate.

  Polyfunctional monomers include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, 1,6-hexane glycol di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, β-hydroxyethyl-β'-acryloyloxyethyl-o-phthalate, phthalic acid Diglycidyl ester di (meth) acrylate, hydroxyhyvalic acid-modified neopentyl glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylo Propane ethylene oxide adduct triacrylate, trimethylolpropane propylene oxide adduct triacrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2'-bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2'-bis (4- (meth) acryloxypentaethoxy Phenyl) propane, 2,2'-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl acrylate and the following general formula (3) They include polyfunctional monomers containing a urethane bond represented by (6).

（３）

(3)

（４）

(4)

（５）

(5)

（６）

(6)

In the above general formulas (3) to (6), R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ₂ , R ₃ , R ₄ and R ₅ are each independently an alkylene group having 2 to 5 carbon atoms. , X and Y are divalent hydrocarbon groups having 2 to 20 carbon atoms, and l, m and n each independently represents an integer of 0 to 30.

  The mixing ratio (weight ratio) of the carboxyl group-containing polymer (A) and the ethylenically unsaturated compound (B) is preferably in the range of (A) / (B) = 40/60 to 70/30, particularly ( A) / (B) = 45/55 to 60/40 is preferable. If the mixing ratio is less than 40/60, the cured photosensitive resin composition may become brittle. On the other hand, if it exceeds 70/30, the resist shape may be deteriorated and the sensitivity may be lowered.

The photopolymerization initiator (C) used in the present invention is required to be a photopolymerization initiator having an absorption main wavelength of 390 nm or less, preferably 320 to 390 nm, and the photopolymerization initiator having an absorption main wavelength exceeding 390 nm. When the is used, a light fog is generated in the working environment of a yellow safety light, a good pattern shape cannot be obtained, and a good resolution cannot be obtained.
Specific examples of the photopolymerization initiator (C) are not particularly limited as long as the absorption main wavelength is 390 nm or less, preferably 320 to 390 nm. In the alkylaminobenzophenone (C1), the general formula (1) Hexaarylbiimidazole derivatives (C2), N-arylglycines (C3), acridine derivatives (C4), benzophenone, benzyldimethyl ketal, thioxanthone derivatives, alkylaminobenzoic acid alkyl esters, triazine derivatives, coumarin derivatives, etc. Among them, alkylaminobenzophenone (C1), hexaarylbiimidazole derivative (C2) represented by the above general formula (1), N-arylglycine (C3), and acridine derivative (C4) are particularly suitable, Used in combination of two or more

  Examples of the alkylaminobenzophenone (C1) include 4,4′-bis (diethylamino) benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4,4′-bis (dimethylamino) benzophenone, Among these, 4,4′-bis (diethylamino) benzophenone is particularly preferable, and these are used alone or in combination of two or more.

  The hexaarylbiimidazole derivative (C2) represented by the general formula (1) may be of the structure represented by the general formula (1), but in the general formula (1), X represents a chlorine atom. I and j are each independently an integer of 0 to 4, Y is independently a hydrogen atom or a chlorine atom, R is an alkoxy group having 1 to 3 carbon atoms, k, l, m, and n are 12 It is an integer of 0 to 3 that satisfies ≧ k + 1 + m + n ≧ 2.

  Specific examples of the hexaarylbiimidazole derivative (C2) represented by the general formula (1) include, for example, 2,2′-bis (2,3-dichlorophenyl) -4,4 ′, 5,5′-tetrakis. (3-methoxyphenyl) bisimidazole, 2,2′-bis (2,3-dichlorophenyl) -4,4 ′, 5,5′-tetrakis (4-methoxyphenyl) bisimidazole, 2,2′-bis ( 2,4-dichlorophenyl) -4,4 ', 5,5'-tetrakis (3-methoxyphenyl) phenylbisimidazole, 2,2'-bis (2,5-dichlorophenyl) -4,4', 5,5 '-Tetrakis (3-methoxyphenyl) bisimidazole, 2,2'-bis (2,6-dichlorophenyl) -4,4', 5,5'-tetrakis (3-methoxyphenyl) bi Imidazole, 2,2 ', 4,4'-tetrakis (2-chlorophenyl) -5,5'-bis (3-methoxyphenyl) bisimidazole, 2,2', 4,4'-tetrakis (2-chlorophenyl) -5,5'-bis (4-methoxyphenyl) bisimidazole, 2,2 ', 4,4'-tetrakis (2-chlorophenyl) -5,5'-bis (2,3-dimethoxyphenyl) bisimidazole, 2,2 ', 4,4'-tetrakis (2-chlorophenyl) -5,5'-bis (3,4-dimethoxyphenyl) bisimidazole, 2,2'-bis (2-chlorophenyl) -4,4' 5,5'-tetrakis (4-methoxyphenyl) bisimidazole, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetrakis (3,4-dimethoxyphenyl) Nyl) bisimidazole, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetrakis (3,4,5-trimethoxyphenyl) bisimidazole, 2,2'-bis (2 -Chlorophenyl) -4,5-bis (3-methoxyphenyl) -4 ', 5'-diphenylbisimidazole, 2,2'-bis (2-chlorophenyl) -4,5-bis (3,4-dimethoxyphenyl) ) -4 ', 5'-diphenylbisimidazole, 2,2'-bis (2-chlorophenyl) -4- (3,4-dimethoxyphenyl) -4', 5,5'-triphenylbisimidazole, etc. Among them, 2,2 ', 4,4'-tetrakis (2-chlorophenyl) -5,5'-bis (3-methoxyphenyl) bisimidazole, 2,2', 4,4'-tetrakis 2-chlorophenyl) -5,5'-bis (2,3-dimethoxyphenyl) bisimidazole, 2,2'-bis (2-chlorophenyl) -4- (3,4-dimethoxyphenyl) -4 ', 5 5'-triphenylbisimidazole is preferred, and these are used alone or in combination of two or more.

  Examples of N-arylglycine (C3) include N-phenylglycine, N-phenylglycine butyl ester, Np-methylphenylglycine ethyl ester, and N-methoxyphenylglycine. These are preferably used alone or in combination of two or more.

  Examples of the acridine derivative (C4) include 9-phenylacridine, 9- (p-methylphenyl) acridine, 9- (p-ethylphenyl) acridine, 9- (pn-propylphenyl) acridine, 9- ( p-iso-propylphenyl) acridine, 9- (pn-butylphenyl) acridine, 9- (p-tert-butylphenyl) acridine, 9- (p-methoxyphenyl) acridine, 9- (p-ethoxy) Phenyl) acridine, 9- (p-acetylphenyl) acridine, 9- (p-dimethylaminophenyl) acridine, 9- (p-cyanophenyl) acridine, 9- (p-chlorophenyl) acridine, 9- (p- Bromophenyl) acridine, 9- (m-methylphenyl) acridine, 9- (mn-propyl) Nyl) acridine, 9- (m-iso-propylphenyl) acridine, 9- (mn-butylphenyl) acridine, 9- (m-tert-butylphenyl) acridine, 9- (m-methoxyphenyl) acridine , 9- (m-ethoxyphenyl) acridine, 9- (m-acetylphenyl) acridine, 9- (m-dimethylaminophenyl) acridine, 9- (m-diethylaminophenyl) acridine, 9- (m-cyanophenyl) Acridine, 9- (m-chlorophenyl) acridine, 9- (m-bromophenyl) acridine, 9-methylacridine, 9-ethylacridine, 9-n-propylacridine, 9-iso-propylacridine, 9-cyanoethylacridine , 9-hydroxyethyl acridine, 9-chloroethyl acetate Examples include lysine, 9-methoxyacridine, 9-ethoxyacridine, 9-n-propoxyacridine, 9-iso-propoxyacridine, 1,7-bis (9-acridinyl) heptane, phenylbenzoacridine, 9-chloroethoxyacridine and the like. Among them, 9-phenylacridine and 1,7-bis (9-acridinyl) heptane are preferable, and these are used alone or in combination of two or more.

  In the present invention, it is particularly possible to use a combination of alkylaminobenzophenone (C1) and hexaarylbiimidazole derivative (C2) represented by the above general formula (1) as the photopolymerization initiator (C). Further, in addition to the alkylaminobenzophenone (C1) and the hexaarylbiimidazole derivative (C2) represented by the general formula (1), an N-arylglycine (C3) and / or acridine derivative (C4) is further added. Use in combination is preferable in terms of sensitivity.

  In this invention, content of the photoinitiator (C) whole is 0.5-10.0 weight with respect to a total of 100 weight part of a carboxyl group-containing polymer (A) and an ethylenically unsaturated compound (B). Part, preferably 1.0 to 6.0 parts by weight, more preferably 1.5 to 4.0 parts by weight, and less than 0.5 part by weight cannot provide the required sensitivity. Exceeding 10.0 parts by weight is not preferable because an insoluble material is generated in the photosensitive resin.

  When the alkylaminobenzophenone (C1) and the hexaarylbiimidazole derivative (C2) represented by the general formula (1) are used in combination, the total of the carboxyl group-containing polymer (A) and the ethylenically unsaturated compound (B) is 100. The alkylaminobenzophenone (C1) is preferably 0.05 to 2.0 parts by weight, particularly 0.1 to 1.5 parts by weight, more preferably 0.2 to 1.0 parts by weight with respect to parts by weight. The hexaarylbiimidazole derivative (C2) represented by the general formula (1) is preferably 0.5 to 8.0 parts by weight, particularly 1.0 to 6.0 parts by weight. Furthermore, it is preferable that it is 1.5-4.0 weight part. If the alkylaminobenzophenone (C1) is less than 0.05 parts by weight, the required sensitivity cannot be obtained and the resolution is deteriorated. If the alkylaminobenzophenone (C1) exceeds 2.0 parts by weight, the light transmittance at 405 nm may be 15 to 50%. It is difficult, and a favorable pattern shape cannot be obtained, which is not preferable.

  Further, in addition to the alkylaminobenzophenone (C1) and the hexaarylbiimidazole derivative (C2) represented by the general formula (1), when N-arylglycine (C3) and / or acridine derivative (C4) is used in combination, The content of N-aryl glycine (C3) is 0.01 to 2.0 parts by weight, particularly 0. 0 parts by weight based on 100 parts by weight of the total of the carboxyl group-containing polymer (A) and the ethylenically unsaturated compound (B). It is preferable that it is 03-1.0 weight part, Furthermore, it is 0.05-0.7 weight part, Content of an acridine derivative (C4) is 0.01-5.0 weight part, Especially 0.05- It is preferably 3.0 parts by weight, more preferably 0.1 to 2.0 parts by weight.

  If the content of N-aryl glycine (C3) is less than 0.01 parts by weight, the sensitivity will be low, and if it exceeds 2.0 parts by weight, the resolution and adhesion will be reduced, which is not preferred. If the content is less than 0.01 parts by weight, the sensitivity is low, and if it exceeds 5.0 parts by weight, the resolution is lowered, which is not preferable.

  In the present invention, in addition to the above photopolymerization initiator (C), a photopolymerization initiator having an absorption main wavelength exceeding 390 nm, for example, an anthraquinone derivative such as riboflavin triacetate or diaminoanthraquinone, a coumarin derivative such as coumarin 6 and the like. In the range that does not impair the effects of the present invention, it is preferable to use all of the photopolymerization initiator as a photopolymerization initiator (C) having an absorption main wavelength of 390 nm or less under a yellow safety light. It is preferable in terms of storage stability.

  Thus, a photosensitive resin composition containing a carboxyl group-containing polymer (A), an ethylenically unsaturated compound (B) and a photopolymerization initiator (C) is obtained. In the present invention, the dye (D) It is preferable from the viewpoint of the visibility of an image to contain the compound (D1) shown by the said General formula (2) and / or a leuco dye (D2).

  The compound (D1) represented by the general formula (2) is not particularly limited as long as it has a structure represented by the general formula (2). In the general formula (2), Z represents an alkylamino group, such as a dimethylamino group or a diethylamino group, and R ′ represents a substituted or unsubstituted alkyl group or a phenyl group, such as a methyl group or an ethyl group. N-propyl group, iso-propyl group, n-butyl group, sec-butyl group, tert-butyl group, alkyl group such as 1,3-dimethylbutyl group, phenyl group, dimethylaminophenyl group, diethylaminophenyl group, Substituted phenyl groups such as ethoxyphenyl group and hydroxyphenyl group, preferably ethyl group and ethoxyphenyl group.

More specifically, as the compound (D1) represented by the general formula (2), compounds represented by Z = diethylamino group, R ′ = ethyl group (solvent blue 5), Z = dimethylamino group, R ′ = ethoxy Examples include a compound represented by a phenyl group (solvent blue 81), a compound represented by Z = dimethylamino group, R ′ = phenyl group (solvent blue 4), and the like.
Examples of the leuco dye (D2) include leuco crystal violet, leucomalachite green, and leuco berlin blue 1.

  In the present invention, when the compound (D1) represented by the general formula (2) is used as the dye (D), the content thereof is a total of 100 of the carboxyl group-containing polymer (A) and the ethylenically unsaturated compound (B). 0.001 to 1.0 part by weight, particularly 0.005 to 0.5 part by weight, more preferably 0.01 to 0.1 part by weight, and 0.001 part by weight with respect to part by weight. If it is less than 1.0, it becomes difficult to visually recognize the image after development, and if it exceeds 1.0 part by weight, it becomes difficult to adjust the light transmittance at a wavelength of 405 nm to 15 to 50%, and the pattern shape after development becomes a remarkably inverted trapezoid. . Moreover, when using leuco dye (D2), the content is 0.01-2.0 weight part with respect to a total of 100 weight part of a carboxyl group-containing polymer (A) and an ethylenically unsaturated compound (B). In particular, it is preferably 0.05 to 1.5 parts by weight, more preferably 0.1 to 1.0 parts by weight, and if it is less than 0.01 parts by weight, the image visibility is inferior and the sensitivity is lowered. If it exceeds 0 part by weight, the adhesion is deteriorated, which is not preferable.

  In the present invention, for the purpose of adjusting the light transmittance at a wavelength of 405 nm to 15 to 50%, a compound having no photopolymerization action and having absorption at a wavelength of 405 nm can be used.

  The photosensitive resin composition of the present invention includes a saturable absorbing dye, a plasticizer, an antioxidant, a solvent, a surface tension modifier, a stabilizer, a chain transfer agent, an antifoaming agent, an interface, if necessary. A known additive such as an activator may be blended.

As such an additive, for the purpose of preventing discoloration of the substrate surface, triarylphosphine (E) is preferably blended. Examples of the triarylphosphine include triphenylphosphine, tolylphosphine, trixylphosphine, tribiphenyl. Examples include phosphine, trinaphthylphosphine, trianthrylphosphine, triphenanthrylphosphine and the like, and triphenylphosphine is particularly preferable.
The triarylphosphine content is 0.001 to 2.0 parts by weight, especially 0.005 to 100 parts by weight in total of the carboxyl group-containing polymer (A) and the ethylenically unsaturated compound (B). 0.5 part by weight, more preferably 0.01 to 0.1 part by weight. If it is less than 0.01 part by weight, the effect of preventing discoloration will be insufficient. The resin becomes brittle, which is not preferable.

  Thus, a photosensitive resin composition can be obtained. In the present invention, the light transmittance of a light beam having a wavelength of 405 nm before curing of the layer [I] made of the photosensitive resin composition must be 15 to 50%. And preferably 20 to 45%, particularly preferably 30 to 40%. If the light transmittance is less than 15%, not only the pattern shape after development becomes a remarkable inverted trapezoid but also the sensitivity becomes low, and if it exceeds 50%, sufficient resolution cannot be obtained and the effect of the present invention cannot be obtained.

  In adjusting the light transmittance to 15 to 50%, it is not particularly limited. For example, when selecting the type of photopolymerization initiator (C) to be used, the content thereof, or a photoresist film as described later. The thickness of the photosensitive resin composition layer [I], the selection of the type of the dye (D1) and their content, the selection of the types of compounds other than the above that do not act as a photoinitiator, the content thereof, etc. can do.

Thus, the photosensitive resin composition used in the present invention is obtained, and the photosensitive resin composition has high sensitivity, high resolution, good pattern formation, and storage stability in a yellow safety light. Therefore, it is very useful as a photosensitive resin composition used for exposure with a blue-violet laser exposure machine.
Next, a photoresist film using such a photosensitive resin composition will be described.

The photoresist film of the present invention is obtained by laminating the support film [II] and the layer [I] made of the photosensitive resin composition obtained above, or the support film [II] obtained above. A layer [I] made of a photosensitive resin composition and a protective film [III] are laminated.
Specifically, it is obtained by coating the photosensitive resin composition on the support film [II] and drying it, and then, if necessary, further laminating the protective film [III] on the upper surface thereof.

There is no limitation in particular as said support film [II], For example, a polyethylene terephthalate (PET) film, a polypropylene film, a polyethylene naphthalate film etc. are mentioned, Especially PET film is preferable.
In the present invention, it is preferable in terms of pattern quality to use a film having a haze of 2.0% or less for the support film [II], particularly 1.5% or less, more preferably 1.0% or less. Are preferred. Such a film having a haze exceeding 2.0% is not preferable because the pattern side wall is wrinkled.

  As the protective film [III], when the photoresist film is kept in a roll shape, the photosensitive resin composition layer [I] having adhesiveness is prevented from being transferred to the support film [II]. For example, a polyethylene film, a PET film, a polypropylene film, a polyvinyl alcohol film, a polytetrafluoroethylene film, a nylon film and the like can be mentioned, and among them, a polyethylene film and a polypropylene film are preferable.

In the present invention, the maximum roughness (Ry) of the surface on the photosensitive resin composition layer [I] side of the protective film [III] is 0.2 μm or less, and the content of fish eyes having a major axis of 80 μm or more is included. It is preferable to use a film of 8 pieces / m ² or less from the viewpoint of preventing microvoids, and the preferable range of the maximum roughness (Ry) is 5.0 μm or less, particularly 2.0 μm or less, and the content of fish eye Is preferably 8 pieces / m ² or less, particularly 4 pieces / m ² or less. When the maximum roughness (Ry) exceeds 5.0 μm, microvoids are likely to occur, and when the fisheye content exceeds 8 / m ² , the effect on yield when the microvoids are generated is preferably increased. Absent.

  In producing the photoresist film, for example, the photosensitive resin composition of the present invention is uniformly applied to one side of the support film [II], and the temperature is increased from 2 to 10 in an oven at 50 to 120 ° C. or sequentially increasing in temperature. It can be manufactured by drying for a minute to form a photosensitive resin composition layer [I], and then pressure laminating the protective film [III] on the upper surface of the layer [I].

  In the photoresist film, the thickness of the photosensitive resin composition layer [I] is preferably 60 μm or less, particularly 10 to 50 μm, more preferably 15 to 30 μm. When the thickness exceeds 60 μm, it is difficult to obtain sufficient sensitivity. Moreover, the thickness of the said support film [II] is 5-25 micrometers normally, Preferably it is 12-20 micrometers. If the thickness is less than 5 μm, the film is too soft and inconvenient to handle. Conversely, if the thickness exceeds 25 μm, the followability to uneven portions on the substrate surface is reduced and the cost is increased. The thickness of the protective film [III] is usually 10 to 50 μm, preferably 10 to 30 μm.

  The photoresist film thus obtained is useful for, for example, printed wiring boards, etching resists and plating resists used in the manufacturing process of precision metal processing. In particular, the photoresist film of the present invention exhibits high sensitivity and high resolution, and exhibits sufficient sensitivity even with laser exposure, particularly exposure with a blue-violet laser, and a good pattern shape can be obtained.

Next, the manufacturing method of the printed wiring board using this photoresist film is demonstrated in order of a process.
As the substrate of the printed wiring board, a copper-clad substrate, 42 alloy, SUS or the like is used. In order to increase the adhesion between the substrate and the photosensitive resin composition, the surface of the substrate is mechanically polished or an acid-based chemical is used. The metal surface may be soft etched.

〔exposure〕
In order to form an image on the above substrate with a photoresist film, the protective film [III] of the photoresist film is peeled off, and the photosensitive resin composition layer [I] side is attached to the metal surface of the substrate. Next, a desired pattern image is directly printed by a direct drawing exposure machine or the like. As the light source of the direct drawing exposure machine, an argon laser, a third harmonic of a YAG laser, a third harmonic of a YVO ₄ laser, a semiconductor laser, or the like is used. In recent years, a direct-drawing exposure machine that uses a blue-violet semiconductor laser light source to form a pattern image with a two-dimensional micromirror array has been developed and is attracting attention because it is expected to reduce the cost of the apparatus. In particular, in the present invention, it is suitable for an exposure oscillation wavelength of 390 to 420 nm (h line) with a blue-violet laser.

  In the present invention, a conventional exposure apparatus using a pattern mask can also be used. In the case of contact exposure, a pattern mask is placed on the support film [II] for exposure. In the case of projection exposure, since the laminated base material and the pattern mask are arranged with the projection optical body interposed therebetween, it is possible to prevent deterioration of the pattern mask due to contact with the support film [II]. At the time of projection exposure, the distance between the support film [II] and the pattern mask is adjusted so that the pattern is focused on the support film [II] or the substrate surface.

〔developing〕
After the exposure, the support film [II] is peeled off and developed. Since the photosensitive resin composition is a dilute alkali development type, development is performed using an aqueous solution of 0.3 to 3% by weight of an alkali such as sodium carbonate, potassium carbonate, tetramethylammonium hydroxide. In addition, a small amount of an organic solvent or the like may be mixed in the alkaline aqueous solution in order to promote a surfactant, an antifoaming agent or development.

[Etching, plating]
Etching is usually performed according to a conventional method using an acidic etching solution such as a cupric chloride-hydrochloric acid aqueous solution or a ferric chloride-hydrochloric acid aqueous solution. Rarely, an ammonia-based alkaline etching solution is also used. In the plating method, pretreatment is performed using a plating pretreatment agent such as a degreasing agent or a soft etching agent, and then plating is performed using a plating solution.

Hereinafter, the present invention will be specifically described with reference to examples.
Hereinafter, “parts” and “%” are based on weight unless otherwise specified.

-The following were prepared as a carboxyl group-containing polymer (A).
[Carboxyl group-containing polymer (A1)]
Acrylic polymer obtained by polymerization at a ratio of methyl methacrylate / n-butyl acrylate / hydroxyethyl methacrylate / methacrylic acid = 61/11/5/23 (weight ratio) (weight average molecular weight: 75,000, acid (Value: 150 mg KOH / g, Tg: 94 ° C.)
[Carboxyl group-containing polymer (A2)]
Acrylic polymer obtained by polymerization at a ratio of methyl methacrylate / styrene / 2-ethylhexyl carbitol methacrylate / methacrylic acid = 32/30/10/28 (weight ratio) (weight average molecular weight: 70,000, acid (Value: 203 mg KOH / g, Tg: 99 ° C.)

但し、ｌ＝ｎ＝１〜２の整数、ｍ＝７〜１０の整数である。
〔エチレン性不飽和化合物（Ｂ３）〕
テトラエチレングリコールジメタクリレート
〔エチレン性不飽和化合物（Ｂ４）〕
２−アクリロイルオキシエチル−２−ヒドロキシエチルフタル酸 -The following were used as an ethylenically unsaturated compound (B).
[Ethylenically unsaturated compound (B1)]
2,2'-bis [4- (methacryloxy polyethoxy) phenyl] propane (the number of repeating units of ethylene oxide = 10)
[Ethylenically unsaturated compound (B2)]
Compound represented by the following formula (Nippon Yushi Co., Ltd., “30PDC800B”)

However, l = n = 1 to 2 and m = 7 to 10.
[Ethylenically unsaturated compound (B3)]
Tetraethylene glycol dimethacrylate [ethylenically unsaturated compound (B4)]
2-acryloyloxyethyl-2-hydroxyethylphthalic acid

-The following were used as a photoinitiator (C).
[Photopolymerization initiator (C1-1)]
4,4'-bis (diethylamino) ethylbenzophenone (absorption main wavelength: 375 nm)
[Photopolymerization initiator (C2-1)]
In general formula (1), i = j = 0, Y = Cl, R = methoxy group, k = n = 0, l = n = 2 (substituted at the 2,3-position of the phenyl group) (Wavelength: 350nm)
[Photopolymerization initiator (C2-2)]
In general formula (1), i = j = 0, Y = H, R = methoxy group, k = l = m = n = 3 compound (substituted at 2, 3, and 4 positions of phenyl group) Wavelength: 335nm)
[Photopolymerization initiator (C2-3)]
In general formula (1), i = j = 1 (substituted at the 3-position of the phenyl group), Y = H, R = methoxy group, k = l = m = n = 1 (substituted at the 4-position of the phenyl group) A certain compound (absorption main wavelength: 330 nm)
[Photopolymerization initiator (C2-4)]
2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole (absorption main wavelength: 320 nm)
[Photopolymerization initiator (C3-1)]
N-phenylglycine (absorption main wavelength: 320 nm)
[Photopolymerization initiator (C4-1)]
9-phenylacridine (absorption main wavelength: 355 nm)
[Photopolymerization initiator (C ′)]
Coumarin 6 (absorption main wavelength: 460 nm)
Each absorption dominant wavelength was measured by the method as described above.

-The following were used as dye (D).
[Dye (D1-1)]
In the general formula (2), a compound in which Z = diethylamino group and R ′ = ethyl group (solvent blue 5)
[Dye (D2-1)]
Leuco crystal violet

-The following were used as support film [II].
Polyethylene terephthalate film manufactured by Toray Industries, Inc. (thickness: 16 μm, haze 1.6%)

-The following were used as protective film [III].
Low-density polyethylene film (thickness: 21 μm) manufactured by Tamapoly

[Examples 1-5, Comparative Examples 1-3]
Using a carboxyl group-containing polymer (A), an ethylenically unsaturated compound (B), a photopolymerization initiator (C), and a dye (D) as shown in Table 1, a dope (methyl ethyl ketone / isopropyl alcohol) of the photosensitive resin composition = Resin solution with a solid content of 51% prepared at 80/20 (weight ratio).
Next, the dope of the obtained photosensitive resin composition was uniformly applied onto the support film [II] using a 3 mil applicator, and then dried in an oven at 90 ° C. for 3 minutes to give a photosensitive film having a thickness of 20 μm. Resin composition layer [I] was formed. Further, a protective film [III] was laminated on the photosensitive resin composition layer [I] using a manual thermocompression laminator (40 ° C., 1 m / min) to prepare a photoresist film.

The light transmittance of the layer [I] made of the photosensitive resin composition with respect to light having a wavelength of 405 nm was measured using a “U-3000 type spectrophotometer” manufactured by Hitachi, Ltd. ] Was sandwiched between film holders and measured at a wavelength of 405 nm without placing anything on the reference side.
The following evaluation was performed using the photoresist film obtained above.
As a copper-clad laminate, a copper-clad laminate (copper foil 35 μm) having a thickness of 1.6 mm and a size of 200 mm × 125 mm was passed through a buff (# 1000) polishing machine, and this was adjusted in an oven at 60 ° C. A preheated one was used.

(sensitivity)
While peeling off the protective film [III] of the photoresist film, lamination was performed using a manual thermocompression roll laminator so that the photosensitive resin composition layer [I] was in close contact with the copper-clad laminate (lamination conditions: (Hot roll temperature 100 ° C., roll pressure 0.3 MPa, laminating speed 1.2 m / min). Then, after leaving still at room temperature for 15 minutes, a parallel light exposure machine (ORC company make, "EXM-1201-J-01 type") using a 5 kW super-high pressure mercury lamp is used to place a stove on the support film [II]. The 21-step step tablet was brought into vacuum contact, and then an optical glass filter L-40 made by HOYA was placed so as to overlap the stove 21-step step tablet, and exposure was performed by removing 365 nm (i-line) (exposure) Method (a)), when the support film [II] was peeled off after 15 minutes and developed with a 1% sodium carbonate aqueous solution at 30 ° C. with a spray pressure of 0.15 MPa and a development time twice the breakpoint, The exposure amount (mJ / cm ² ) at which the number of steps of a 21-step stopher tablet was 7 was measured.
Here, the exposure amount is not the numerical value of the i-line integrating actinometer built in the exposure machine, but the UV illuminance meter (ORC, “UV-MO2” type “UV-42” manufactured by ORC) according to the exposure method (a). It is a numerical value calculated by the following equation based on the illuminance and the exposure time measured using a combination of “type receiver”.
Exposure amount (mJ / cm ² ) = Illuminance (mW / cm ² ) × Exposure time (s)
That is, the UV illuminometer indicated value when light is irradiated from the upper surface using an exposure machine in a state where an illuminometer light receiver is installed under the mylar film and the optical glass filter L-40 is placed on the mylar film. Was the illuminance, and the exposure amount was calculated using the exposure time count displayed on the exposure machine during exposure of the substrate as the exposure time.
In addition, the exposure amount that the number of steps of the 21 step step tablet is 7 layers, and the exposure step (a) is 8, 10, 12, 14, 16 mJ / cm ² exposure amount, and the 21 step step tablet is laminated. This is the minimum exposure amount at which the seven-step resist can remain on the entire surface after printing on the substrate and development under the above development conditions.

(Resolution (a))
With the exposure method (a), the exposure part / unexposed part is 10/10 μm, 15/15 μm, 20/20 μm, 25/25 μm, at an exposure amount at which the number of steps of the stove 21-step tablet is 7 steps. Contact exposure is performed using a pattern mask (glass chrome dry plate) having a parallel line pattern of 30/30 μm, 35/35 μm, 40/40 μm, 45/45 μm, and 50/50 μm and an optical glass filter L-40. Then, development similar to the above was performed, and the minimum line width (μm) that could be formed was measured using a metal microscope.

(Resolution (b))
According to the exposure method (a), the exposure part / unexposed part is 15/15 μm, 17.5 / 17.5 μm, 20/20 μm, in the exposure amount at which the number of steps of the stove 21-step tablet is 7 steps. A parallel line pattern of 25/25 μm, 30/30 μm, 40/40 μm, 50/50 μm, and 60/60 μm can be obtained with 405 nm light (h line) using a “DI-2080 type exposure machine” manufactured by Pentax. After exposure (exposure method (b)), development similar to the above was performed, and the minimum line width (μm) that could be formed was measured using a metal microscope.

(Storage stability with yellow safety light)
After laminating the photoresist film on a copper-clad laminate in the same manner as above, under a yellow safety light (Matsushita Electric Industrial Co., Ltd., “FLR40S • Y • F / M” 3 lights) at a distance of 50 cm The surface on which the photoresist film was laminated was directed upward, irradiated with yellow light for 1 hour, developed in the same manner as described above, and the presence or absence of a residue of the photosensitive resin composition on the copper-clad laminate was visually confirmed. In addition, it was 650 lux when the illumination intensity of the yellow safety light in the copper clad laminated board position was measured.
Table 2 shows the evaluation results of Examples and Comparative Examples.

  The photoresist film of the present invention has high sensitivity and high resolution, and has an excellent effect on storage stability with a yellow safety light, and is exposed with an exposure machine using a blue-violet laser as a light source. It is very useful as a suitable photoresist film.

Claims (6)

  A layer [I] and a support film comprising a photosensitive resin composition containing a carboxyl group-containing polymer (A), an ethylenically unsaturated compound (B), and a photopolymerization initiator (C) having an absorption main wavelength of 390 nm or less. II], wherein the layer [I] made of the photosensitive resin composition has a light transmittance of 15 to 50% in a light beam having a wavelength of 405 nm before curing. Photo resist film. 2. The photoresist film according to claim 1, comprising an alkylaminobenzophenone (C1) and a hexaarylbiimidazole derivative (C2) represented by the following general formula (1) as the photopolymerization initiator (C).

(1)

X represents a chlorine atom, i and j each independently represent an integer of 0 to 4, and Y each independently represents a hydrogen atom or a chlorine atom. R represents an alkoxy group having 1 to 3 carbon atoms, and k, l, m, and n are integers of 0 to 3 that satisfy 12 ≧ k + 1 + m + n ≧ 2.   The photoresist film according to claim 1 or 2, further comprising N-arylglycine (C3) and / or an acridine derivative (C4) as the photopolymerization initiator (C). Furthermore, the compound (D1) and / or leuco dye (D2) shown by General formula (2) are contained as dye (D), The photoresist film in any one of Claims 1-3 characterized by the above-mentioned.

(2)

Z represents an alkylamino group. R ′ represents a substituted or unsubstituted alkyl group or a phenyl group.   Furthermore, protective film [III] is laminated | stacked on the layer [I] side which consists of photosensitive resin compositions, The photoresist film in any one of Claims 1-4 characterized by the above-mentioned.   The photoresist film according to claim 1, wherein the photoresist film is used for exposure with a blue-violet laser exposure machine.