JPWO2010116868A1 - Photosensitive resin composition and laminate thereof - Google Patents

Abstract

(A) a first monomer which is a carboxylic acid or carboxylic acid anhydride having one polymerizable unsaturated group in the molecule and a non-acidic first monomer having one polymerizable unsaturated group in the molecule; Binder polymer which is a copolymer having a weight average molecular weight of 5,000 to 100,000 obtained by copolymerizing at least two monomers: 20 to 90% by weight, (B) at least one in the molecule A photopolymerizable compound which is an addition polymerizable monomer having two terminal ethylenically unsaturated groups: 5 to 75% by weight, and (C) a photopolymerization initiator: 0.01 to 30% by weight, under predetermined conditions A photosensitive resin composition, wherein a water contact angle of the photosensitive resin layer obtained after the development in step 1 is 60 ° or more and a Young's modulus is 4 GPa or more.

Description

The present invention relates to a photosensitive resin composition that can be developed with an alkaline aqueous solution, a photosensitive resin composition laminate in which the photosensitive resin composition is laminated on a support, and a substrate using the photosensitive resin composition laminate. The present invention relates to a method for forming a resist pattern and a use of the resist pattern.
More specifically, the present invention relates to the manufacture of printed wiring boards, the manufacture of flexible printed wiring boards, the manufacture of lead frames for IC chip mounting (hereinafter referred to as lead frames), the precision processing of metal foils such as the manufacture of metal masks, BGA (ball Tape substrate represented by semiconductor package manufacturing such as grid array) and CSP (chip size package), TAB (Tape Automated Bonding) and COF (Chip On Film: semiconductor IC mounted on a film-like fine wiring board) Resist pattern suitable for manufacturing of semiconductor bumps, suitable for the production of members such as ITO electrodes, address electrodes, electromagnetic wave shields in the field of flat panel displays, or as a protective mask member when processing a substrate by sandblasting give The present invention relates to a photosensitive resin composition.

  Conventionally, printed wiring boards are manufactured by a photolithography method. The photolithographic method is a method in which a photosensitive resin composition is applied onto a substrate, pattern exposure is performed to polymerize and cure the exposed portion of the photosensitive resin composition, and an unexposed portion is removed with a developer to form a resist on the substrate. A method of forming a conductor pattern on a substrate by forming a pattern, forming a conductor pattern by etching or plating, and then peeling and removing the resist pattern from the substrate.

  In the photolithography method described above, in applying the photosensitive resin composition onto the substrate, a method of applying a photoresist solution to the substrate and drying, or a support, a layer made of the photosensitive resin composition (hereinafter, “ Or a method of laminating a photosensitive resin laminate (hereinafter referred to as “dry film resist”) in which protective layers are sequentially laminated on a substrate, if necessary. In the production of printed wiring boards, the latter dry film resist is often used.

A method for producing a printed wiring board using the dry film resist will be described below.
First, when the dry film resist has a protective layer such as a polyethylene film, it is peeled off from the photosensitive resin layer. Next, the photosensitive resin layer and the support are laminated on a substrate such as a copper-clad laminate using a laminator so that the substrate, the photosensitive resin layer, and the support are in this order. Next, the exposed portion is polymerized and cured by exposing the photosensitive resin layer to ultraviolet rays containing i-line (365 nm) emitted from an ultra-high pressure mercury lamp through a photomask having a wiring pattern. Next, the support made of polyethylene terephthalate or the like is peeled off. Next, a non-exposed portion of the photosensitive resin layer is dissolved or dispersed and removed by a developing solution such as an aqueous solution having weak alkalinity to form a resist pattern on the substrate. Next, a known etching process or pattern plating process is performed using the formed resist pattern as a protective mask. Finally, the resist pattern is peeled from the substrate to produce a substrate having a conductor pattern, that is, a printed wiring board.

  On the other hand, a semi-additive construction method is used to produce a high-density wiring with a uniform conductor shape. In the semi-additive method, first, a resist pattern is formed on the seed copper thin film by the method described above. Next, plating is performed between the resist patterns to form a plated copper wiring, the resist is peeled off, and the plated copper wiring and the seed copper thin film are simultaneously etched by a technique called flash etching. Unlike the pattern plating method, the semi-additive method has a thin seed copper thin film. For this reason, there is almost no influence by etching, and a rectangular and high-density wiring can be manufactured.

Conventionally, the semi-additive construction method is a construction method aiming at high-density wiring, and high resolution has been an important characteristic.
Patent Document 1 below discloses the resolution of a photosensitive resin composition containing a quaternary copolymer of methacrylic acid / methyl methacrylate / butyl acrylate / 2-ethylhexyl acrylate and tricyclodecane dimethanol dimethacrylate. However, the resolution was not fully compatible with the current situation.

JP 2001-154348 A

  An object of the present invention is to provide a photosensitive resin composition having a particularly high resolution as a resist material such as an etching resist or a plating resist, and a photosensitive resin laminate using the same.

  As a result of various studies, the present inventor has achieved high resolution by controlling the water contact angle and Young's modulus of the cured product obtained by exposing and developing the photosensitive resin composition to predetermined values. Unexpectedly, it has been discovered that the sex can be achieved, and the present invention has been completed. That is, the present invention is as follows:

  [1] Photosensitivity containing (A) binder polymer: 20 to 90% by weight, (B) photopolymerizable compound: 5 to 75% by weight, and (C) photopolymerization initiator: 0.01 to 30% by weight. A resin composition, wherein the (A) binder polymer comprises a first monomer that is a carboxylic acid or carboxylic acid anhydride having one polymerizable unsaturated group in the molecule and a polymerizable unsaturated group in the molecule. A copolymer having a weight average molecular weight of 5,000 to 100,000, obtained by copolymerizing at least one second monomer that is non-acidic and has a weight average molecular weight of (B) The polymerizable compound is an addition polymerizable monomer having at least one terminal ethylenically unsaturated group in the molecule, and the photosensitive resin composition is exposed at an exposure amount of 5 steps of a 21-step Stouffer step tablet. Followed by 1% sodium carbonate The water contact angle of the photosensitive resin layer obtained after development with a solution (30 ° C.) over a period of time twice the minimum development time is 60 ° or more, and the Young modulus is 4 GPa or more. A photosensitive resin composition.

  [2] The photosensitive resin composition according to [1], wherein the (A) binder polymer is a phenyl group-containing copolymer or a cyclohexyl group-containing copolymer.

  [3] The photosensitive resin composition according to the above [1] or [2], wherein the ethylenically unsaturated bond concentration of the photosensitive resin composition is 0.1 mol / 100 g or more.

  [4] The photosensitive resin composition according to any one of [1] to [3], wherein a Young's modulus of the obtained photosensitive resin layer is 5 GPa or more.

  [5] The photosensitive resin composition according to [4], wherein the obtained photosensitive resin layer has a Young modulus of 6 GPa or more.

  [6] The photosensitive resin composition according to any one of [1] to [5], wherein the (C) photopolymerizable initiator contains a 2,4,5-triarylimidazole dimer.

  [7] A photosensitive resin laminate comprising the photosensitive resin composition according to any one of [1] to [6] laminated on a support.

  [8] A resist pattern comprising a laminating step, an exposing step, and a developing step for forming a layer of the photosensitive resin composition according to any one of [1] to [6] on a substrate. Forming method.

  [9] The resist pattern forming method according to [8], wherein in the exposure step, the layer of the photosensitive resin composition is directly drawn and exposed.

  [10] A method for manufacturing a printed wiring board, comprising etching or plating a substrate on which a resist pattern is formed by the method for forming a resist pattern according to [8] or [9].

  [11] A method for producing a substrate having a concavo-convex pattern, comprising processing a substrate on which a resist pattern is formed by the method for forming a resist pattern according to [8] or [9], by sandblasting.

  [12] A method for manufacturing a semiconductor package or bump, comprising etching or plating a substrate on which a resist pattern is formed by the method for forming a resist pattern according to [8] or [9].

  [13] A method for manufacturing a lead frame, comprising etching or plating a substrate on which a resist pattern is formed by the method for forming a resist pattern according to [8] or [9].

  [14] A cured resin product obtained by curing the photosensitive resin composition according to [1] to [6].

  [15] A cured resin laminate having the cured resin according to [14] on a support.

  The photosensitive resin composition of the present invention, the photosensitive resin laminate, and the resist pattern obtained by the method of forming a resist pattern using these have predetermined characteristics such as a water contact angle of 60 ° or more and a Young modulus of 4 GPa or more. In particular, it has excellent high resolution.

Hereinafter, the present invention will be specifically described.
The water contact angle of the cured product obtained by exposing and developing the photosensitive resin composition of the present invention is 60 ° or more, and its Young modulus is 4 GPa or more, preferably 5 GPa or more, more preferably 6 GPa or more. It is necessary to obtain a resist pattern having a high resolution.

  When the water contact angle is 60 ° or more, the cured portion after exposure does not swell, the washout property during development is excellent, the resolution is good, and the Young modulus is 4 GPa or more. The resist pattern at the time of development is excellent in standing property, and if it is 5 GPa or more, the standing property becomes better, and if it is 6 GPa or more, it becomes even better.

  The Young's modulus of the cured product obtained by exposing and developing the photosensitive resin composition of the prior art was less than 4 GPa. This is because it was thought that when the Young's modulus was high, the resulting resist pattern became brittle and handling became difficult. Moreover, the water contact angle of the hardened | cured material obtained by exposing and developing the photosensitive resin composition of this invention must be 60 degrees or more. On the other hand, the concept of controlling the water contact angle to a predetermined value does not exist in the prior art from the viewpoint of preventing swelling of the cured portion after exposure, improving washout performance during development, and improving resolution. It was. The present invention is based on the discovery that the resolution of a cured product obtained by exposing and developing a photosensitive resin composition is significantly improved by controlling both the water contact angle and Young's modulus to predetermined values. It was completed after confirming the effect.

  In the present specification, the “water contact angle” is specifically 1.5 μl from the needle tip using an optical mirror (automatic) contact angle meter DropMaster DM500 manufactured by Kyowa Interface Science Co., Ltd. according to JIS R3257. The measurement target resin composition is laminated on a substrate, exposed to light, contacted with the surface of the photosensitive resin composition on the developed substrate, and measured 60 seconds after the contact of the water droplet.

  In the present specification, “Young Modulus” can be measured by a nanoindentation method using Nanoindenter DCM manufactured by Toyo Technica Co., Ltd. Specifically, “Young Modulus” is a method of laminating a resin composition to be measured on a substrate, exposing and developing the surface of the photosensitive resin composition on the substrate using Nano Indenter DCM manufactured by Toyo Technica Co., Ltd. taking measurement. As a measurement method, DCM Basic Hardness, Modulus, Tip Cal, Load Control.msm (MultiLoad Method) is used. The parameters of the indentation test are Percent To Unload = 90%, Maximum Load = 1 gf, Load Rate Multiple For Unload Rate = 1, Number Of Times to Load = 5, Peak Hold time = 10 s, Time To Load = 15 s, Posson Ratio = 0.25. The Young modulus is the value of “Modulas At Max Load”.

(A) Binder polymer

The resin for (A) binder polymer used in the present invention can be obtained by copolymerizing one or more monomers from the following two types of monomers.
The first monomer is a carboxylic acid or acid anhydride having one polymerizable unsaturated group in the molecule. Examples include (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, and maleic acid half ester.

The second monomer is a non-acidic compound having one polymerizable unsaturated group in the molecule. The compound is selected so as to maintain various properties such as developability of the photosensitive resin layer, resistance in etching and plating processes, and flexibility of the cured film.
Resin for (A) binder polymer used for this invention is styrene and a styrene derivative, for example, alpha-methyl styrene, p-hydroxy styrene, p-methyl styrene, p-methoxy styrene, p-chloro styrene, benzyl, for example. (Meth) acrylate, 4-hydroxybenzyl (meth) acrylate, 4-methoxybenzyl (meth) acrylate, 4-methylbenzyl (meth) acrylate, 4-chlorobenzyl (meth) acrylate, methyl (meth) acrylate, ethyl (meta ) Acrylate, n-propyl (meth) acrylate, cyclohexyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) ) Acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, (meth) acrylamide, N-methylolacrylamide, N-butoxymethylacrylamide, (meth) acrylonitrile, ( Examples include glycidyl acrylate and the like, and each may be used alone or in combination of two or more.

  The resin for binder polymer (A) used in the present invention is a radical polymerization in a solution obtained by mixing the first monomer and the second monomer and diluting with a solvent such as acetone, methyl ethyl ketone or isopropanol. It is preferable to carry out the synthesis by adding an appropriate amount of an initiator such as benzoyl peroxide or azoisobutyronitrile and stirring with heating. In some cases, the synthesis is performed while a part of the mixture is dropped into the reaction solution. After completion of the reaction, a solvent may be further added to adjust to a desired concentration. As synthesis means, bulk polymerization, suspension polymerization, or emulsion polymerization may be used in addition to solution polymerization.

  The amount of the carboxyl group contained in the resin for the binder polymer (A) of the present invention is preferably from 100 to 600 in terms of acid equivalent, and more preferably from 250 to 450. An acid equivalent means the mass of resin for binders which has 1 equivalent of carboxyl groups in it.

  The carboxyl group in the binder resin is necessary for giving the photopolymerizable resin layer developability and releasability with respect to an alkaline aqueous solution. It is 100 or more from the viewpoint of improving development resistance, resolution and adhesion, and 600 or less from the viewpoint of improving developability and peelability. The acid equivalent is measured by a potentiometric titration method using Hiranuma automatic titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd. and 0.1 mol / L sodium hydroxide.

  As for the weight average molecular weight of (A) resin for binder polymers used for this invention, 5,000-500,000 are preferable. It is 500,000 or less from the viewpoint of improving developability and resolution, and when the photosensitive resin laminate is wound into a roll, a phenomenon that the photosensitive resin composition oozes out from the roll end surface, that is, edge fuse From the point of being suppressed, it is 5,000 or more. In order to exhibit the effect of the present invention better, the weight average molecular weight of the binder resin is more preferably 5,000 to 100,000, and further preferably 5,000 to 60,000.

  The weight average molecular weight was measured by Gel Permeation Chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 type, column: Shodex (registered trademark) manufactured by Showa Denko KK (KF-807, KF-806M). , KF-806M, KF-802.5) in series, moving bed solvent: tetrahydrofuran, polystyrene standard sample (use of calibration curve by Shodex STANDARD SM-105 manufactured by Showa Denko KK) as polystyrene conversion.

  The ratio of the resin for (A) binder polymer used in the present invention to the total of the photosensitive resin composition (solid content, hereinafter the same) is in the range of 20 to 90% by mass, preferably 30 to 70% by mass. It is. From the viewpoint that the resist pattern formed by exposure and development has sufficient characteristics as a resist, for example, sufficient resistance in tenting, etching, and various plating processes, it is preferably 20% by mass or more and 90% by mass or less.

The monomer constituting the resin for the (A) binder polymer used in the present invention can be selected from a phenyl group-containing monomer or a cyclohexyl group-containing monomer. Preferred is a phenyl group-containing monomer. In order to make the water contact angle of the cured photosensitive resin composition 60 ° or more, it is an effective means to use a phenyl group-containing monomer or a cyclohexyl group-containing monomer-containing binder polymer. The content ratio of the phenyl group-containing monomer or the cyclohexyl group-containing monomer of the binder polymer in the photosensitive resin composition is preferably 5 to 95%, more preferably 10 to 85%.
Examples of the resin for the binder polymer (A) used in the present invention include α-methylstyrene, p-hydroxystyrene, p-methylstyrene, p-methoxystyrene, p-chlorostyrene, benzyl (meth) acrylate, 4 -Hydroxybenzyl (meth) acrylate, 4-methoxybenzyl (meth) acrylate, 4-methylbenzyl (meth) acrylate, 4-chlorobenzyl (meth) acrylate, and cyclohexyl (meth) acrylate are preferred.

(B) Photopolymerizable compound

  The photopolymerizable compound (B) used in the present invention is an addition polymerizable monomer having at least one terminal ethylenically unsaturated group. Examples of the addition polymerizable monomer (B) that is a photopolymerizable compound used in the photosensitive resin composition of the present invention include 4-nonylphenylheptaethylene glycol dipropylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and phenoxy. Hexaethylene glycol acrylate, reaction product of half ester compound of phthalic anhydride and 2-hydroxypropyl acrylate and propylene oxide (product name OE-A 200, manufactured by Nippon Shokubai Kagaku), 4-normal octylphenoxypentapropylene glycol acrylate, 2,2-bis [{4- (meth) acryloxypolyethoxy} phenyl] propane, 2,2-bis {(4-acryloxypolyethoxy) cyclohexyl} propane or 2,2-bis {(4-methacryloxy) Polyethoxy) cyclohexyl} propane, 1,6-hexanediol (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polyoxyethylene polyoxy Polyfunctional group containing polyoxyalkylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate, 2-di (p-hydroxyphenyl) propane di (meth) acrylate, glycerol tri (meth) acrylate, urethane group ( (Meth) acrylate, for example, urethane compound of hexamethylene diisocyanate and pentapropylene glycol monomethacrylate, polyfunctional (meth) acrylate of isocyanuric acid ester compound Examples include relate, tricyclodecane dimethanol diacrylate and tricyclodecane dimethanol dimethacrylate.

  The amount of the (B) addition polymerizable monomer contained in the photosensitive resin composition of the present invention is in the range of 5 to 75% by mass with respect to the entire photosensitive resin composition, and a more preferable range is 15 to 70. % By mass. This amount is 5% by mass or more from the viewpoint of suppressing poor curing and a delay in development time, and is 75% by mass or less from the viewpoint of suppressing cold flow and delayed peeling of the cured resist.

  The photopolymerizable compound (B) used in the present invention preferably has an ethylenically unsaturated bond concentration of the photosensitive resin composition of 0.1 mol / 100 g or more in order to make the Young's modulus 4 GPa or more.

The ethylenically unsaturated bond concentration D in the photosensitive resin can be obtained from the following equation.
_{D = (E 1 × F 1} × 100) / (Mw 1 × G) + (E 2 × F 2 × 100) / (Mw 2 × G) + ··· + (E n × F n × 100) / (Mw _n × G)

D: Concentration of ethylenically unsaturated group (mol / 100 g) with respect to 100 g of photosensitive resin composition
E: Blending amount F: Number of polymerization terminals Mw: Weight average molecular weight of photopolymerizable compound n: Number of photopolymerizable compound to be blended G: Total weight of photosensitive resin composition

  In order to make the Young's modulus of the photosensitive resin composition 4 GPa or more, it is an effective means to select a photopolymerizable compound having 3 or more double bonds or a photopolymerizable compound having a molecular weight of 600 or less.

  Specifically, a 7: 3 mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (Toagosei M-306, product name), triacrylate obtained by adding an average of 3 moles of ethylene oxide to trimethylolpropane (Shin Nakamura Chemical) A-TMPT-3EO (product name), urethanized product of hexamethylene diisocyanate and polypropylene glycol monomethacrylate, tricyclodecanedimethanol dimethacrylate (NK ester DCP, product name, manufactured by Shin-Nakamura Chemical Co., Ltd.), bisphenol A Polyethylene glycol dimethacrylate (BPE-200, manufactured by Shin-Nakamura Chemical Co., Ltd., product name) in which an average of 2 moles of ethylene oxide is added to both ends of each.

｛式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子又はメチル基であり、Ａ及びＢは炭素数２〜６のアルキレン基を示し、これらは同一であっても相違していてもよく、異なっている場合、−（Ａ−Ｏ）−及び−（Ｂ−Ｏ）−の繰り返し単位は、ブロック構造でもランダム構造でもよく、ｍ１、ｍ２、ｍ３及びｍ４は、０又は正の整数であり、これらの合計は２〜４０である。｝及び／又は下記一般式（ＩＩＩ）：

｛式中、Ｒ^３及びＲ^４は、それぞれ独立に、水素原子又はメチル基を表し、Ａ及びＢは炭素数２〜６のアルキレン基を示し、これらは同一であっても相違していてもよく、異なっている場合、−（Ａ−Ｏ）−及び−（Ｂ−Ｏ）−の繰り返し単位は、ブロック構造でもランダム構造でもよく、ｍ５、ｍ６、ｍ７及びｍ８は、０又は正の整数であり、これらの合計は０〜４０であり、Ｒ^５は、ハロゲン原子又は炭素数１〜３のアルキル基であり、ｎは０〜１４である。｝で表される光重合性化合物を含有することは有効な手段である。一般式（ＩＩ）または（ＩＩＩ）の含有量はバインダーポリマーと重合性化合物の合計質量部の１０質量％以上が好ましく、２０質量％以上がより好ましい。The photopolymerizable compound (B) used in the present invention contains a photopolymerizable compound having one double bond in order to make the water contact angle of the cured photosensitive resin composition 60 ° or more. It is an effective means to make the amount 10% by mass or less of the total mass part of the binder polymer and the polymerizable compound.
Further, (B) the photopolymerizable compound has the following general formula (II) in order to set the water contact angle of the cured photosensitive resin composition to 60 ° or more:

{In the formula, R ₁ and R ₂ are each independently a hydrogen atom or a methyl group, and A and B represent an alkylene group having 2 to 6 carbon atoms, which may be the same or different. If different,-(A-O)-and-(B-O)-may have a block structure or a random structure, and m1, m2, m3 and m4 are 0 or a positive integer. Yes, the sum of these is 2-40. } And / or the following general formula (III):

{Wherein R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and A and B represent an alkylene group having 2 to 6 carbon atoms, which may be the same or different. If different,-(AO)-and-(BO)-may have a block structure or a random structure, and m5, m6, m7 and m8 are 0 or a positive integer. And the sum of these is 0 to 40, R ⁵ is a halogen atom or an alkyl group having 1 to 3 carbon atoms, and n is 0 to 14. } It is an effective means to contain the photopolymerizable compound represented by these. The content of the general formula (II) or (III) is preferably 10% by mass or more, more preferably 20% by mass or more, based on the total mass part of the binder polymer and the polymerizable compound.

(C) Photopolymerization initiator As the (C) photopolymerization initiator used in the present invention, the following general formula (I):
{In the formula, X, Y and Z each independently represent a group selected from the group consisting of hydrogen, an alkyl group having 1 to 5 carbon atoms and an alkoxy group, and a halogen group, and p, q and r Are each independently an integer of 1 to 5. } It is preferable from a viewpoint of high resolution to include at least one 2,4,5-triarylimidazole dimer represented by:

  In the compound represented by the above general formula (I), the covalent bond connecting two lophine groups is 1,1′-, 1,2′-, 1,4′-, 2,2′-, Although it is in the 2,4′- or 4,4′-position, a compound in the 1,2′-position is preferred. Examples of the 2,4,5-triarylimidazole dimer include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis- ( m-methoxyphenyl) imidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, etc., and in particular, 2- (o-chlorophenyl) -4,5-diphenylimidazole. Dimers are preferred.

  In the photosensitive resin composition of the present invention, the proportion in the case of containing at least one 2,4,5-triarylimidazole dimer represented by the general formula (I) is 0.1 to 20% by mass. Is preferred. From the viewpoint of resolution and adhesiveness, it is 0.1% by mass or more, and from the viewpoint of development aggregation, it is 20% by mass or less. A more preferable range is 0.5 to 15% by mass, and a further preferable range is 1 to 10% by mass.

  As the (C) photopolymerization initiator used in the present invention, a system in which the 2,4,5-triarylimidazole dimer represented by the general formula (I) and p-aminophenyl ketone are used in combination is preferable. . Examples of p-aminophenyl ketone include p-aminobenzophenone, p-butylaminoacetophenone, p-dimethylaminoacetophenone, p-dimethylaminobenzophenone, p, p'-bis (ethylamino) benzophenone, p, p'- Bis (dimethylamino) benzophenone [Michler's ketone], p, p′-bis (diethylamino) benzophenone, and p, p′-bis (dibutylamino) benzophenone.

Also, a combination with a pyrazoline compound such as 1-phenyl-3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline is a preferred embodiment.
In addition to the compounds shown above, other photopolymerization initiators can be used in combination. Here, the photopolymerization initiator is a compound that is activated by various actinic rays such as ultraviolet rays and starts polymerization.

  Other photopolymerization initiators include quinones such as 2-ethylanthraquinone, 2-tert-butylanthraquinone, aromatic ketones such as benzophenone, benzoin and benzoin ethers such as benzoin methyl ether and benzoin ethyl ether. , Acridine compounds such as 9-phenylacridine, benzyldimethyl ketal, benzyldiethyl ketal.

There are also combinations of thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and tertiary amine compounds such as dimethylaminobenzoic acid alkyl ester compounds.
There are also oxime esters such as 1-phenyl-1,2-propanedione-2-O-benzoyloxime, 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime. Further, N-aryl-α-amino acid compounds can also be used, and among these, N-phenylglycine is particularly preferable.

  The ratio of the preferable (C) photoinitiator in this invention is 0.01-30 mass%. If this ratio is less than 0.01% by mass, sufficient sensitivity cannot be obtained. On the other hand, when the ratio exceeds 30% by mass, “fogging” due to diffraction of light passing through a photomask is likely to occur during exposure, and as a result, resolution is deteriorated. As for content, 0.1-15 mass% is more preferable, and 0.1-10 mass% is further more preferable.

(D) Other components In the photosensitive resin composition of this invention, a leuco dye can be contained in order to express the contrast after exposure (discrimination between an exposed part and an unexposed part). As for content in the case of containing a leuco dye, 0.1-10 mass% is preferable. Examples of such leuco dyes include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green], and fluorane dye. It is done. Among these, when leuco crystal violet is used, the contrast is good and preferable.

It is a preferred embodiment of the present invention from the viewpoint of adhesion and contrast that the leuco dye and the halogen compound are used in combination in the photosensitive resin composition.
Examples of the halogen compound include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris (2 , 3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane, and halogenated triazine compounds. Examples of the halogenated triazine compound include 2,4,6-tris (trichloromethyl) -s-triazine and 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine.

When the halogen compound is contained, the content of the halogen compound in the photosensitive resin composition is preferably 0.01 to 10% by mass.
In order to improve the handleability of the photosensitive resin composition, it is possible to add the following coloring substances in addition to the above-mentioned leuco dye. Examples of such coloring substances include fuchsin, phthalocyanine green, auramine base, paramadienta, crystal violet, methyl orange, Nile Blue 2B, Victoria Blue, Malachite Green (Eisen (registered trademark) MALACHITE GREEN manufactured by Hodogaya Chemical Co., Ltd.), Basic Blue 20 and Diamond Green (Eizen (registered trademark) DIAMOND GREEN GH manufactured by Hodogaya Chemical Co., Ltd.) can be used.

It is preferable that the addition amount in the case of containing the said coloring substance contains 0.001-1 mass% in the photosensitive resin composition. A content of 0.001% by mass or more has an effect of improving handleability, and a content of 1% by mass or less has an effect of maintaining storage stability.
Of these, a combination of tribromomethylphenylsulfone and a leuco dye or a combination of a triazine compound and a leuco dye is useful.
Furthermore, in order to improve the thermal stability and storage stability of the photosensitive resin composition of the present invention, the photosensitive resin composition is selected from the group consisting of radical polymerization inhibitors, benzotriazoles, and carboxybenzotriazoles. It is preferable to contain at least one compound.

  Examples of such radical polymerization inhibitors include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2 Examples include '-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), nitrosophenylhydroxyamine aluminum salt, and diphenylnitrosamine.

  Examples of benzotriazoles include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, and bis (N-2-ethylhexyl) aminomethylene-1,2,3-benzo. Examples include triazole, bis (N-2-ethylhexyl) aminomethylene-1,2,3-tolyltriazole, and bis (N-2-hydroxyethyl) aminomethylene-1,2,3-benzotriazole.

  Examples of carboxybenzotriazoles include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, and N- (N, N-di-2-ethylhexyl). Examples include aminomethylenecarboxybenzotriazole, N- (N, N-di-2-hydroxyethyl) aminomethylenecarboxybenzotriazole, and N- (N, N-di-2-ethylhexyl) aminoethylenecarboxybenzotriazole.

  The total addition amount of radical polymerization inhibitors, benzotriazoles, or carboxybenzotriazoles is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass. This amount is preferably 0.01% by mass or more from the viewpoint of imparting storage stability to the photosensitive resin composition, and more preferably 3% by mass or less from the viewpoint of maintaining sensitivity.

  You may make the photosensitive resin composition of this invention contain a plasticizer as needed. Examples of such plasticizers include polyethylene glycol, polypropylene glycol, polyoxypropylene polyoxyethylene ether, polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monomethyl ether, and polyoxyethylene monoethyl. Ethers, polyoxypropylene monoethyl ether, glycol esters such as polyoxyethylene polyoxypropylene monoethyl ether, phthalic acid esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, citric acid Tributyl, triethyl citrate, triethyl acetylcitrate, tri-n-propyl acetylcitrate, tri-n-acetylcitrate Chill, and the like.

  As a quantity in the case of containing a plasticizer, it is preferable to contain 5-50 mass% in the photosensitive resin composition, More preferably, it is 5-30 mass%. 5 mass% or more is preferable from the viewpoint of suppressing delay in development time and imparting flexibility to the cured film, and 50 mass% or less is preferable from the viewpoint of suppressing insufficient curing and cold flow.

<Photosensitive resin composition preparation solution>
The photosensitive resin composition of the present invention may be a photosensitive resin composition preparation liquid to which a solvent is added. Suitable solvents include ketones represented by methyl ethyl ketone (MEK), or alcohols such as methanol, ethanol, isopropyl alcohol. It is preferable to add a solvent to the photosensitive resin composition so that the viscosity of the photosensitive resin composition preparation liquid is 500 to 4,000 mPa · sec at 25 ° C.

<Photosensitive resin laminate>
The photosensitive resin laminate of the present invention comprises a photosensitive resin layer and a support that supports the layer. If necessary, the photosensitive resin laminate may have a protective layer on the surface opposite to the support of the photosensitive resin layer. Good.
The support used here is preferably a transparent one that transmits light emitted from the exposure light source. Examples of such a support include polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film. , Polyacrylonitrile film, styrene copolymer film, polyamide film, cellulose derivative film and the like. These films can be stretched if necessary. The haze is preferably 5 or less. The thinner the film, the more advantageous in terms of image forming property and economic efficiency, but a film having a thickness of 10 to 30 μm is preferably used because of the necessity of maintaining the strength.

  Further, an important characteristic of the protective layer used in the photosensitive resin laminate is that the protective layer is sufficiently smaller than the support and can be easily peeled with respect to the adhesion with the photosensitive resin layer. For example, a polyethylene film or a polypropylene film can be preferably used as the protective layer. Also, a film having excellent peelability disclosed in JP-A-59-202457 can be used. The thickness of the protective layer is preferably 10 to 100 μm, and more preferably 10 to 50 μm.

  The thickness of the photosensitive resin layer in the photosensitive resin laminate of the present invention is preferably 5 to 100 μm, more preferably 5 to 50 μm. As the thickness is thinner, the resolution is improved, and as the thickness is increased, the film strength is improved. Therefore, the thickness can be appropriately selected according to the application.

  A conventionally known method can be adopted as a method for preparing the photosensitive resin laminate of the present invention by sequentially laminating a support, a photosensitive resin layer, and if necessary, a protective layer. For example, the photosensitive resin composition used for the photosensitive resin layer is made into the above-mentioned photosensitive resin composition preparation liquid, first applied onto a support using a bar coater or a roll coater, and dried, and then on the support. A photosensitive resin layer made of the photosensitive resin composition is laminated on the substrate. Then, if necessary, a photosensitive resin laminate can be produced by laminating a protective layer on the photosensitive resin layer.

<Resist pattern formation method>
A resist pattern using the photosensitive resin laminate of the present invention can be formed by a process including a laminating process, an exposing process, and a developing process. An example of a specific method is shown.
First, a laminating process is performed using a laminator. When the photosensitive resin laminate has a protective layer, the protective layer is peeled off, and then the photosensitive resin layer is heat-pressed and laminated on the substrate surface with a laminator. In this case, the photosensitive resin layer may be laminated on only one surface of the substrate surface, or may be laminated on both surfaces as necessary. The heating temperature at this time is generally 40 to 160 ° C. Moreover, the adhesiveness with respect to the board | substrate of the obtained resist pattern improves by performing this thermocompression bonding twice or more. At this time, a two-stage laminator provided with two rolls may be used for pressure bonding, or it may be repeatedly pressed through the roll several times.

Next, an exposure process is performed using an exposure machine. If necessary, the support is peeled off and exposed to active light through a photomask. The exposure amount is determined from the light source illuminance and the exposure time. You may measure using a photometer.
In the exposure step, a maskless exposure method may be used. In maskless exposure, exposure is performed directly on a substrate by a drawing apparatus without using a photomask. As the light source, a semiconductor laser having a wavelength of 350 to 410 nm, an ultrahigh pressure mercury lamp, or the like is used. The drawing pattern is controlled by a computer, and the exposure amount in this case is determined by the illuminance of the exposure light source and the moving speed of the substrate.

Next, a developing process is performed using a developing device. After exposure, if there is a support on the photosensitive resin layer, it is removed. Subsequently, the unexposed portion is developed and removed using a developer composed of an alkaline aqueous solution to obtain a resist image. As the alkaline aqueous solution, an aqueous solution of Na ₂ CO ₃ or K ₂ CO ₃ is preferable. These are selected according to the characteristics of the photosensitive resin layer, but an aqueous Na ₂ CO ₃ solution having a concentration of 0.2 to 2% by mass is generally used. A surface active agent, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution. In addition, it is preferable to maintain the temperature of this developing solution in a development process at the constant temperature in the range of 20-40 degreeC.
Although a resist pattern is obtained by the above-mentioned process, a heating process at 100 to 300 ° C. can be further performed depending on the case. By carrying out this heating step, chemical resistance can be further improved. For heating, a heating furnace of a hot air, infrared ray, far infrared ray, or the like can be used.

<Method for manufacturing printed wiring board>
The method for producing a printed wiring board of the present invention is performed by performing the following steps after forming a resist pattern on a copper-clad laminate or flexible substrate as a substrate by the above-described resist pattern forming method.
First, a step of forming a conductor pattern on the copper surface of the substrate exposed by development using a known method such as an etching method or a plating method is performed.
Thereafter, the resist pattern is peeled off from the substrate with an aqueous solution having alkalinity stronger than that of the developer to obtain a desired printed wiring board. The alkaline aqueous solution for peeling (hereinafter also referred to as “peeling solution”) is not particularly limited, but an aqueous solution of NaOH or KOH having a concentration of 2 to 5% by mass is generally used. It is possible to add a small amount of a water-soluble solvent to the stripping solution. In addition, it is preferable that the temperature of this peeling liquid in a peeling process is the range of 40-70 degreeC.

<Lead frame manufacturing method>
The lead frame manufacturing method of the present invention is performed by performing the following steps after forming a resist pattern on a metal plate such as copper, copper alloy, iron-based alloy or the like as a substrate by the above-described resist pattern forming method.
First, a step of etching the substrate exposed by development to form a conductor pattern is performed. Then, the peeling process which peels a resist pattern with the method similar to the manufacturing method of the above-mentioned printed wiring board is performed, and a desired lead frame is obtained.

<Semiconductor package manufacturing method>
In the semiconductor package manufacturing method of the present invention, a semiconductor package is manufactured by mounting a chip on which circuit formation as an LSI has been completed by the following steps.
First, copper sulfate plating is performed on the exposed portion of the base metal in the resist pattern-attached base material obtained by development to form a conductor pattern. Thereafter, a peeling process for peeling the resist pattern by the same method as the printed wiring board manufacturing method described above is performed, and further, etching is performed to remove a thin metal layer for portions other than the columnar plating, and the chip is formed. A desired semiconductor package is obtained by mounting.

<Bump manufacturing method>
The bump manufacturing method of the present invention is performed for mounting a chip on which circuit formation as an LSI has been completed, and bumps are manufactured by the following steps.
First, copper sulfate plating is performed on the exposed portion of the base metal in the resist pattern-attached base material obtained by development to form a conductor pattern. Thereafter, a peeling process for peeling the resist pattern by the same method as the above-described method for manufacturing a printed wiring board is performed, and further, a thin metal layer other than the columnar plating is removed by etching. Get a bump.

<Manufacturing method of substrate having concave / convex pattern>
The resist pattern can be used as a protective mask member when the substrate is processed by the sandblasting method by the resist pattern forming method described above.
Examples of the substrate include glass, silicon wafer, amorphous silicon, polycrystalline silicon, ceramic, sapphire, and metal material. A resist pattern is formed on the substrate such as glass by the same method as the resist pattern forming method described above. After that, a blasting material is sprayed from the formed resist pattern to be cut to a desired depth, and a resist pattern portion remaining on the substrate is removed from the substrate with an alkaline stripping solution or the like, and then the substrate is processed. The substrate can have a fine concavo-convex pattern. As the blasting material used in the above sandblasting process, known materials are used. For example, fine particles of about 2 to 100 μm such as SiC, SiO ₂ , Al ₂ O ₃ , CaCO ₃ , ZrO, glass, and stainless steel are used.

  The above-described method for producing a substrate having a concavo-convex pattern by the sandblasting method can be used for the production of flat panel display partition walls, organic EL glass cap processing, silicon wafer drilling processing, ceramic pinning processing, and the like. . Moreover, it can utilize for manufacture of the electrode of a metal material layer chosen from the group which consists of a ferroelectric film and a noble metal, a noble metal alloy, a refractory metal, and a refractory metal compound.

Hereinafter, examples of embodiments of the present invention will be specifically described.
(Examples 1-18, Comparative Examples 1-6)
First, a method for producing samples for evaluation of Examples and Comparative Examples will be described, and then an evaluation method and evaluation results for the obtained samples will be shown.

1. Production of Evaluation Samples Evaluation samples in Examples and Comparative Examples were produced as follows.
<Preparation of photosensitive resin laminate>
The photosensitive resin composition prepared by thoroughly stirring and mixing the photosensitive resin composition and the solvent having the composition shown in Table 1 below (however, the number of each component indicates the blending amount (part by mass) as a solid content). A liquid coating was applied uniformly on the surface of a polyethylene terephthalate film having a thickness of 16 μm as a support using a bar coater, followed by drying for 2.5 minutes in a dryer at 95 ° C. to form a photosensitive resin layer. The thickness of the photosensitive resin layer was 25 μm.
Next, a 21 μm thick polyethylene film was laminated as a protective layer on the surface of the photosensitive resin layer on which the polyethylene terephthalate film was not laminated to obtain a photosensitive resin laminate.

  Table 2 below shows the names of the material components B-1 to D-2 in the photosensitive resin composition preparation liquid represented by abbreviations in Table 1.

<Board surface preparation>
As a substrate for resolution evaluation, a substrate for contact angle evaluation, and a substrate for elastic modulus evaluation, the surface of a 0.4 mm thick copper clad laminate on which 35 μm rolled copper foil is laminated is (A) jet scrub polished at a spray pressure of 0.20 MPa. (Nippon Carlit Co., Ltd., Sac Random R (registered trademark) # 220) was prepared.

<Laminate>
Using a hot roll laminator (Asahi Kasei Electronics Co., Ltd., AL-70) on a copper clad laminate that has been leveled and preheated to 60 ° C. while removing the polyethylene film of the photosensitive resin laminate. And laminated at a roll temperature of 105 ° C. The air pressure was 0.35 MPa, and the laminating speed was 1.5 m / min.

<Exposure>
The substrate for resolution evaluation was exposed with a super high pressure mercury lamp super high pressure mercury lamp (OMW Seisakusho, HMW-201KB) using a chromium glass photomask. The contact angle evaluation substrate and the elastic modulus evaluation substrate were exposed without using a mask.

<Development>
After the polyethylene terephthalate film was peeled off, a 1 mass% Na ₂ CO ₃ aqueous solution at 30 ° C. was sprayed for a predetermined time to dissolve and remove the unexposed portion of the photosensitive resin layer. At this time, the shortest time required for completely dissolving the photosensitive resin layer in the unexposed portion was defined as the minimum development time.

2. Evaluation method Each evaluation method was as follows.
(1) Resolution The substrate for resolution evaluation that had passed 15 minutes after the lamination was exposed through a line pattern mask (chrome glass photomask) in which the width of the exposed area and the unexposed area was 1: 1. Development was performed with a development time twice as long as the minimum development time, and the minimum mask line width in which a cured resist line was normally formed was ranked as a resolution value as follows:
A: Resolution value is 8 μm or less;
○: Resolution value exceeds 8 μm and 10 μm or less;
X: The value of resolution exceeds 10 μm.

(2) Contact angle The resolution evaluation substrate that had passed 15 minutes after lamination was exposed without a mask. The exposure was performed with the exposure amount of the minimum resolution at the time of resolution evaluation. Development was performed with a development time twice as long as the minimum development time to obtain a substrate for contact angle measurement, and the contact angle was measured.

(3) Young modulus The substrate for resolution evaluation that had passed 15 minutes after lamination was exposed without a mask. The exposure was performed with the exposure amount of the minimum resolution at the time of resolution evaluation. Development was performed with a development time twice the minimum development time to obtain a substrate for contact angle measurement, and the Young's modulus was measured.
The evaluation results of Examples 1 to 18 and Comparative Examples 1 to 6 are shown in Table 1 below.

From Table 1, in Examples 1-18, it turns out that the resolution is excellent when both the contact angle and the elastic modulus are within the range of the present invention.
In Comparative Examples 1 to 6, depending on the selection of the resin for the binder polymer and the photopolymerizable compound and the change in their blending ratio, the water contact angle and the Young modulus were outside the scope of the present invention. You can see that the resolution is not good.

  The present invention relates to the manufacture of printed wiring boards, the manufacture of lead frames for mounting IC chips, the precision processing of metal foils such as the manufacture of metal masks, the manufacture of packages such as BGA and CSP, the manufacture of tape substrates such as COF and TAB, the manufacture of semiconductor bumps In addition, it can be used for manufacturing a partition of a flat panel display such as an ITO electrode, an address electrode, and an electromagnetic wave shield, and a method for manufacturing a substrate having an uneven pattern by a sandblasting method.

Claims (15)

  Photosensitive resin composition containing (A) binder polymer: 20 to 90% by weight, (B) photopolymerizable compound: 5 to 75% by weight, and (C) photopolymerization initiator: 0.01 to 30% by weight The (A) binder polymer has one polymerizable unsaturated group in the molecule and a first monomer that is a carboxylic acid or carboxylic anhydride having one polymerizable unsaturated group in the molecule. And a copolymer having a weight average molecular weight of 5,000 to 100,000 obtained by copolymerizing at least a second monomer that is non-acidic and has (B) photopolymerizability. The compound is an addition-polymerizable monomer having at least one terminal ethylenically unsaturated group in the molecule, and the photosensitive resin composition is exposed at a 5-step exposure amount of a 21-step Stouffer step tablet. Then 1% sodium carbonate in water The water contact angle of the photosensitive resin layer obtained after development over a time period twice as long as the minimum development time using (30 ° C.) is 60 ° or more and the Young modulus is 4 GPa or more. A photosensitive resin composition.   The photosensitive resin composition according to claim 1, wherein the (A) binder polymer is a phenyl group-containing copolymer or a cyclohexyl group-containing copolymer.   The photosensitive resin composition of Claim 1 whose ethylenically unsaturated bond density | concentration of the said photosensitive resin composition is 0.1 mol / 100g or more.   The photosensitive resin composition of Claim 1 whose Young modulus of the said photosensitive resin layer is 5 GPa or more.   The photosensitive resin composition of Claim 4 whose Young modulus of the said photosensitive resin layer is 6 GPa or more.   (C) The photosensitive resin composition of Claim 1 in which a photopolymerizable initiator contains a 2,4,5-triaryl imidazole dimer.   A photosensitive resin laminate comprising the photosensitive resin composition according to any one of claims 1 to 6 laminated on a support.   A method for forming a resist pattern, comprising a laminating step, an exposing step, and a developing step of forming a layer of the photosensitive resin composition according to claim 1 on a substrate.   The resist pattern forming method according to claim 8, wherein in the exposure step, the photosensitive resin composition layer is directly drawn and exposed.   The manufacturing method of a printed wiring board including etching or plating the board | substrate with which the resist pattern was formed by the formation method of the resist pattern of Claim 8.   The manufacturing method of the base material which has an uneven | corrugated pattern including processing the board | substrate with which the resist pattern was formed by the formation method of the resist pattern of Claim 8 by sandblasting.   The manufacturing method of a semiconductor package or bump including etching or plating the board | substrate with which the resist pattern was formed by the formation method of the resist pattern of Claim 8.   A method for manufacturing a lead frame, comprising etching or plating a substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 8.   A cured resin obtained by curing the photosensitive resin composition according to claim 1.   A cured resin laminate having the cured resin according to claim 14 on a support.