JP4614858B2 - Photosensitive resin composition and laminate thereof - Google Patents

Description

  The present invention relates to a photosensitive resin composition and use thereof, and more specifically, a photosensitive resin laminate suitable for manufacturing a conductive pattern such as a printed wiring board, a flexible substrate, and a lead frame, and a method of forming a resist pattern using the same. The present invention relates to a conductor pattern manufacturing method, a printed wiring board manufacturing method, a lead frame manufacturing method, and a semiconductor package manufacturing method.

For electronic devices such as personal computers and mobile phones, printed wiring boards and the like are used for mounting components and semiconductors. A so-called dry film resist (hereinafter abbreviated as DFR) composed of a support, a photosensitive resin layer, and a protective layer has been conventionally used as a resist for manufacturing printed wiring boards and the like. The DFR is generally prepared by laminating a photosensitive resin layer on a support and further laminating a protective layer on the photosensitive resin layer.
As the photosensitive resin layer used here, an alkali developing type using a weak alkaline aqueous solution as a developing solution is generally used.
To create a printed wiring board using DFR, first peel off the protective layer, and then laminate the DFR on a permanent circuit creation board such as a copper-clad laminate or flexible board using a laminator, etc. Exposure is performed through a film or the like. Next, if necessary, the support is peeled off, and the photosensitive resin layer in the unexposed portion is dissolved or dispersed and removed with a developing solution to form a resist pattern on the substrate.

  After forming the resist pattern, the process for forming a circuit is roughly divided into two methods. The first method is a method in which after removing a copper surface such as a copper-clad laminate not covered with a resist pattern by etching, the resist pattern portion is removed with an alkaline aqueous solution stronger than the developer. In this case, for simplicity of the process, a method (tenting method) in which a through hole (through hole) is covered with a cured film and then etched is frequently used. The second method is to remove the resist pattern portion after performing plating treatment of copper, solder, nickel, tin, etc. on the above copper surface, and further etch the copper surface of the copper-clad laminate, etc. that appeared ( Plating method). In any case, cupric chloride, ferric chloride, a copper ammonia complex solution or the like is used for etching.

Responding to the recent miniaturization of printed wiring boards mounted on personal computers and the like, high resolution and adhesion of resists are required. High resolution is generally achieved by improving the crosslinking density of the photosensitive resin composition. However, when the crosslinking density is increased, the cured resist film becomes hard and brittle. When using the tenting method, it is required that the cured film does not break through the tenting process (tenting property), but the problem is that the tenting property deteriorates due to the hardened film. To do. In addition, if the cured film is broken by pressure such as spraying in the development or etching process, the copper line is broken, causing a defect. Therefore, a resist having high resolution and good cured film flexibility and tenting properties is required.
In addition, if the etchant resistance is weak in the etching process, the etchant may permeate from the bottom surface of the resist, which may cause defects such as rattling of the copper circuit or flow of the resist line.

The step of dissolving or dispersing and removing the photosensitive resin layer in the unexposed portion with a developer after exposure is called a development step. Not all of the DFR components dissolve in the developer, and each time the development process is repeated, insoluble components with poor developer dispersibility increase and aggregates (scum) are generated. Aggregates re-adhere on the substrate, causing a short circuit failure in the tenting and etching methods, and may clog the developing tank piping. Therefore, for the purpose of reducing aggregates, (b) Attempts to use an alkylphenol type monofunctional monomer having good developer dispersibility as a photopolymerizable unsaturated compound (Patent Document 1), or a phenoxy type monofunctional monomer is used. Although there was an attempt (Patent Document 2), none of them was satisfactory.
Further, Patent Document 3 discloses a photosensitive resin composition using a pyrazoline compound, but there is no disclosure about a photosensitive resin composition having good tenting properties.
In addition, Patent Document 4 discloses a photosensitive resin composition using a binder resin containing benzyl methacrylate as a copolymer component, but an example using a pyrazoline compound as a photopolymerization initiator is disclosed. There was no.
Therefore, a photosensitive resin composition having excellent developer dispersion stability in the development process, generating no agglomerates, expressing high resolution, good cured film flexibility, tenting properties, and good etching solution resistance. It has been sought.

JP 2001-174986 A JP 2001-305730 A JP-A-2005-215142 JP 2005-121790 A

  The present invention is a photosensitive resin composition having good post-development resolution, excellent developer dispersion stability, not generating aggregates, excellent cured film flexibility, tenting properties, and good etchant resistance, An object of the present invention is to provide a photosensitive resin laminate having a photosensitive resin layer composed of the composition, and to provide a resist pattern forming method and a conductor pattern manufacturing method using the laminate. .

（式中Ａ、Ｂ及びＣは、それぞれ独立に、アリール基、複素環基、炭素数３以上の直鎖または分枝鎖のアルキル基、およびＮＲ_２（Ｒは水素原子、またはアルキル基）からなる群から選ばれる置換基を表す。ａ,ｂ及びｃの夫々は０〜２の整数であるが、ａ＋ｂ＋ｃの値は１以上である。） As a result of studying to solve the above problems, by using a specific photosensitive resin composition, the developer dispersion stability is excellent, no aggregates are generated, resolution and adhesion are good, tenting properties, and good. It has been found that it has a good etching solution resistance and can form a good conductor pattern, and has led to the present invention.
That is, this invention is invention of the manufacturing method of the following photosensitive resin compositions, photosensitive resin laminated bodies, a resist pattern formation method, and a conductor pattern.
(1) (a) Resin for binders having a carboxyl group content of 100 to 600 in terms of acid equivalent, containing benzyl (meth) acrylate as a copolymerization component, and having a weight average molecular weight of 5,000 to 500,000: 10 90% by mass, (b) photopolymerizable unsaturated compound: 3-70% by mass, (c) photopolymerization initiator: 0.1-20% by mass, and (d) represented by the following general formula (I) Compound: 0.1-20 mass% of photosensitive resin composition characterized by including.

Wherein A, B and C are each independently an aryl group, a heterocyclic group, a linear or branched alkyl group having 3 or more carbon atoms, and NR ₂ (R is a hydrogen atom or an alkyl group). And each of a, b and c is an integer of 0 to 2, but the value of a + b + c is 1 or more.

（式中、Ｄ、Ｅ、及びＦはそれぞれ独立に水素、アルキル基、アルコキシ基及びハロゲン基のいずれかを表し、ｄ、ｅ、及びｆはそれぞれ独立に１〜５の整数である。） (2) (c) 0.1-20 mass% of compounds represented by the following general formula (II) are contained as a photopolymerization initiator, The photosensitive resin composition according to (1).

(In the formula, D, E, and F each independently represent hydrogen, an alkyl group, an alkoxy group, or a halogen group, and d, e, and f are each independently an integer of 1 to 5).

（式中、Ｒ_１及びＲ_２は、ＨまたはＣＨ_３であり、これらは同一であっても相違してもよい。また、Ｒ_３及びＲ_４は、エチレン基又はプロピレン基であり、それぞれ同一であっても異なっていてもよく、異なっている場合、−(Ｒ_３−Ｏ)−及び−(Ｒ_４−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い。ｍ５、ｍ６、ｎ５、及びｎ６は、０又は正の整数であり、これらの合計は、２〜４０である。） (3) (b) The photopolymerizable unsaturated compound contains at least one compound represented by the following general formulas (III) and (IV): (1) or (2) Photosensitive resin composition.

(In the formula, R ₁ and R ₂ are H or CH ₃ , and these may be the same or different. R ₃ and R ₄ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating unit of — (R ₃ —O) — and — (R ₄ —O) — may be a block structure or a random structure, m5, m6, n5 , And n6 are 0 or a positive integer, and the sum of these is 2 to 40.)

（式中、Ｒ_５及びＲ_６は、ＨまたはＣＨ_３であり、これらは同一であっても相違してもよい。また、Ｒ_７及びＲ_８は、エチレン基又はプロピレン基であり、それぞれ同一であっても異なっていてもよく、異なっている場合、−(Ｒ_７−Ｏ)−及び−(Ｒ_８−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い。ｍ７、ｍ８、ｎ７、及びｎ８は、０又は正の整数であり、これらの合計は、２〜４０である。）

(In the formula, R ₅ and R ₆ are H or CH ₃ , which may be the same or different. R ₇ and R ₈ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating units of — (R ₇ —O) — and — (R ₈ —O) — may have a block structure or a random structure.m7, m8, n7 , And n8 are 0 or a positive integer, and the sum of these is 2 to 40.)

(4) A photosensitive resin laminate comprising the photosensitive resin composition according to any one of (1) to (3) laminated on a support and a photosensitive resin composition layer.
(5) Formation of a resist pattern characterized in that the photosensitive resin laminate according to (4) is laminated on the surface of a metal plate or metal-coated insulating plate, exposed to ultraviolet light, and then unexposed portions are removed by development. Method.
(6) The resist pattern forming method as described in (5), wherein the exposure is performed without using a photomask in the exposure step.
(7) A method for producing a conductor pattern, comprising etching or plating a substrate on which a resist pattern is formed by the method according to (5) or (6).
(8) A method for producing a printed wiring board, comprising etching or plating a substrate on which a resist pattern is formed by the method according to (5) or (6).
(9) A lead frame manufacturing method including a step of etching a substrate on which a resist pattern is formed by the method according to (5) or (6).
(10) A method for manufacturing a semiconductor package, including a step of etching or plating a substrate on which a resist pattern is formed by the method according to (5) or (6).

  According to the present invention, the developer dispersion stability is excellent in the development process, no aggregates are generated, the resolution and adhesion are good, and the cured film flexibility, tenting property, and good etchant resistance are possessed. Therefore, it is possible to provide a photosensitive resin composition suitable for forming a good conductor pattern and a photosensitive resin laminate having a photosensitive resin layer made of the composition. Moreover, the formation method of the resist pattern using this laminated body and the manufacturing method of conductor patterns, such as a printed wiring board which has fine wiring, can be provided.

Hereinafter, the present invention will be specifically described.
The photosensitive resin laminate used in the present invention is a laminated film in which a photosensitive resin layer is sandwiched between a support and a protective layer, or a protective layer is peeled from the laminated film. Sometimes called film, dry film (resist) or DFR.
As for content of the carboxyl group contained in (a) resin for binders used for this invention, 100-600 are preferable at an acid equivalent, More preferably, it is 300-450. An acid equivalent means the mass of the linear polymer which has a 1 equivalent carboxyl group in it.
The carboxyl group in the binder resin is necessary to give the photosensitive resin layer developability and releasability with respect to an aqueous alkali solution. The acid equivalent is preferably 100 or more from the viewpoint of development resistance, resolution, and adhesion, and is preferably 600 or less from the viewpoint of developability and peelability.
The weight average molecular weight of the (a) binder resin used in the present invention is preferably 5,000 to 500,000. The weight average molecular weight of the binder resin is preferably 500000 or less from the viewpoint of resolution, and 5000 or more is preferable from the viewpoint of edge fuse. The edge fuse refers to a phenomenon in which when a resist roll is stored, the resist oozes out from the end of the roll, causing a chip and causing a defect.

In order to better exhibit the effects of the present invention, the weight average molecular weight of the binder resin is more preferably 5,000 to 200,000, still more preferably 5,000 to 100,000. The degree of dispersion (sometimes referred to as molecular weight distribution) is represented by the ratio of the weight average molecular weight to the number average molecular weight of the following formula.
(Dispersity) = (weight average molecular weight) / (number average molecular weight)
The degree of dispersion is about 1 to 6, preferably 1 to 4.
The acid equivalent is measured by a potentiometric titration method using a Hiranuma automatic titration apparatus (COM-555) manufactured by Hiranuma Sangyo Co., Ltd., and using a 0.1 mol / L sodium hydroxide aqueous solution.
The molecular weight is 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) It is calculated | required as a weight average molecular weight (polystyrene conversion) by 4 in-line, moving bed solvent: Tetrahydrofuran, using a calibration curve by a polystyrene standard sample).

The (a) binder resin used in the present invention contains benzyl (meth) acrylate as an essential component from the viewpoint of resolution and aggregation. In addition, a compound in which an aromatic group of benzyl (meth) acrylate such as methoxybenzyl (meth) acrylate or chlorobenzyl (meth) acrylate is substituted with an alkoxy group, a halogen, an alkyl group, or the like can also be used. The content of benzyl (meth) acrylate in the binder resin is preferably 10 to 90% by mass. 90% or less is preferable from the viewpoint of developability, and 10% or more is preferable from the viewpoint of aggregation. More preferably, it is 20-85 mass%, More preferably, it is 30-80 mass%.
The resin for binder (a) used in the present invention is obtained by copolymerizing at least one monomer from the following two types of monomers in addition to benzyl (meth) acrylate.

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, maleic acid half ester, and the like.
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. Examples of the compound include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2 -Hydroxypropyl (meth) acrylate, (meth) acrylonitrile, furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, cresyl (meth) acrylate, naphthyl (meth) Aryl (meth) acrylates such as acrylate, vinyl compounds having a phenyl group (for example, styrene), benzene such as methoxybenzyl (meth) acrylate and chlorobenzyl (meth) acrylate Le (meth) aromatic ring alkoxy group acrylate, halogen, alkyl group can be used compounds obtained by substituting.

(A) Binder resin used in the present invention is a mixture of benzyl (meth) acrylate and the first monomer and the second monomer diluted 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 a radical polymerization initiator such as benzoyl peroxide or azoisobutyronitrile to the resulting solution 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 ratio of the resin for binder (a) used in the present invention to the total of the photosensitive resin composition is in the range of 10 to 90% by mass, preferably 30 to 70% by mass. The resist pattern formed by exposure and development is preferably 10% by mass or more and 90% by mass or less from the viewpoint that the resist pattern has sufficient resistance as a resist, for example, tenting, etching, and various plating processes. Moreover, you may contain resin for binders other than the resin for binders which contains the said benzyl (meth) acrylate as a copolymerization component in the photosensitive resin composition of this invention.

（式中、Ｒ_１及びＲ_２は、ＨまたはＣＨ_３であり、これらは同一であっても相違してもよい。また、Ｒ_３及びＲ_４は、エチレン基又はプロピレン基であり、それぞれ同一であっても異なっていてもよく、異なっている場合、−(Ｒ_３−Ｏ)−及び−(Ｒ_４−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い。ｍ５、ｍ６、ｎ５、及びｎ６は、０又は正の整数であり、これらの合計は、２〜４０である。） Among the photopolymerizable unsaturated compounds (b) used in the present invention, the photopolymerizable unsaturated compounds represented by the following general formulas (III) and (IV) will be described.

(In the formula, R ₁ and R ₂ are H or CH ₃ , and these may be the same or different. R ₃ and R ₄ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating unit of — (R ₃ —O) — and — (R ₄ —O) — may be a block structure or a random structure, m5, m6, n5 , And n6 are 0 or a positive integer, and the sum of these is 2 to 40.)

（式中、Ｒ_５及びＲ_６は、ＨまたはＣＨ_３であり、これらは同一であっても相違してもよい。また、Ｒ_７及びＲ_８は、エチレン基又はプロピレン基であり、それぞれ同一であっても異なっていてもよく、異なっている場合、−(Ｒ_７−Ｏ)−及び−(Ｒ_８−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い。ｍ７、ｍ８、ｎ７、及びｎ８は、０又は正の整数であり、これらの合計は、２〜４０である。）

(In the formula, R ₅ and R ₆ are H or CH ₃ , which may be the same or different. R ₇ and R ₈ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating units of — (R ₇ —O) — and — (R ₈ —O) — may have a block structure or a random structure.m7, m8, n7 , And n8 are 0 or a positive integer, and the sum of these is 2 to 40.)

In the compounds represented by the general formulas (III) and (IV), the lower limit of m5 + m6 + n5 + n6 or m7 + m8 + n7 + n8 is preferably 2 or more, and the upper limit is preferably 40 or less. When these values are less than 2, the flexibility and tenting properties of the cured film deteriorate, and when it exceeds 40, the effect on resolution is not sufficient.
As a specific example represented by the above general formula (III), polyethylene glycol dimethacrylate (NK ester BPE-200 manufactured by Shin-Nakamura Chemical Co., Ltd.) in which an average of 2 moles of ethylene oxide is added to both ends of bisphenol A, respectively. Polyethylene glycol dimethacrylate (NK ester BPE-500 manufactured by Shin-Nakamura Chemical Co., Ltd.) with an average of 5 moles of ethylene oxide added to both ends of bisphenol A, and an average of 6 moles of ethylene oxide to both ends of bisphenol A Polyalkylene glycol dimethacrylate with an average of 2 moles of propylene oxide and dimethylphenol of polyalkylene glycol with an average of 15 moles of ethylene oxide and an average of 2 moles of propylene oxide added to both ends of bisphenol A, respectively. There is an acrylate. As a specific example represented by the general formula (IV), there is polyethylene glycol dimethacrylate in which an average of 5 moles of ethylene oxide is added to both ends of hydrogenated bisphenol A.

  (B) In addition to the compound groups represented by the general formulas (III) and (IV), the photopolymerizable unsaturated compounds shown below can be used in combination. For example, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 2-di (p-hydroxyphenyl) ) Propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyoxypropyltrimethylolpropane tri (meth) acrylate, polyoxyethyltrimethylolpropane triacrylate, pentaerythritol tetra (meth) Acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane triglycidyl ether tri (meth) acrylate, bisphenol A diglycol Dil ether di (meth) acrylate, β-hydroxypropyl-β ′-(acryloyloxy) propyl phthalate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyalkylene glycol (meth) acrylate, polypropylene glycol Examples include poly (alkylene glycol) dimethacrylates in which ethylene oxide is further added at both ends to polypropylene glycol to which mono (meth) acrylate and propylene oxide are added.

Moreover, a urethane compound is also mentioned. Examples of the urethane compound include a diisocyanate compound such as hexamethylene diisocyanate, tolylene diisocyanate, or 2,2,4-trimethylhexamethylene diisocyanate, and a compound having a hydroxyl group and a (meth) acryl group in one molecule (2- And urethane compounds obtained by reaction with hydroxypropyl acrylate, oligopropylene glycol monomethacrylate, etc.). Specifically, there is a reaction product of hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (Nippon Yushi Co., Ltd., Blenmer PP1000).
(B) The ratio of the photopolymerizable unsaturated compound to the total of the photosensitive resin composition is preferably 3% by mass or more from the viewpoint of sensitivity, and preferably 70% by mass or less from the viewpoint of edge fuse. More preferably, it is 10-60 mass%, More preferably, it is 15-55 mass%.
(B) Even when the compound represented by the general formula (III) and / or (IV) is contained as the photopolymerizable unsaturated compound, the ratio of the sum of these to the sum of the photosensitive resin composition is: It is the range of 3-70 mass%. From the viewpoint of resolution, it is 3% by mass or more, and from the viewpoint of flexibility of the resist pattern, it is 70% by mass or less. More preferably, it is 3-30 mass% or less.

（式中、Ｄ、Ｅ、及びＦはそれぞれ独立に水素、アルキル基、アルコキシ基及びハロゲン基のいずれかを表し、ｄ、ｅ、及びｆはそれぞれ独立に１〜５の整数である。）
上記一般式（ＩＩ）で表される化合物においては、２個のロフィン基を結合する共有結合は、１，１’−、１，２’−、１，４’−、２，２’−、２，４’−又は４，４’−位についているが、１，２’−位についている化合物が好ましい。２，４，５−トリアリールイミダゾール二量体には、例えば、２−（ｏ−クロロフェニル）−４，５−ジフェニルイミダゾール二量体、２−（ｏ−クロロフェニル）−４，５−ビス−（ｍ−メトキシフェニル）イミダゾール二量体、２−（ｐ−メトシキフェニル）−４，５−ジフェニルイミダゾール二量体等があるが、特に、２−（ｏ−クロロフェニル）−４，５−ジフェニルイミダゾール二量体が好ましい。 Of the photopolymerization initiator (c) used in the present invention, a 2,4,5-triarylimidazole dimer represented by the following general formula (II) will be described.

(In the formula, D, E, and F each independently represent hydrogen, an alkyl group, an alkoxy group, or a halogen group, and d, e, and f are each independently an integer of 1 to 5).
In the compound represented by the above general formula (II), the covalent bond for bonding 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 present invention, the ratio of the photopolymerization initiator (c) to the total of the photosensitive resin composition is 0.1 to 20% by mass. If this ratio is less than 0.1% by mass, sufficient sensitivity cannot be obtained. On the other hand, when the ratio exceeds 20% by mass, fogging due to diffraction of light passing through the photomask at the time of exposure tends to occur, and as a result, resolution is deteriorated.
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, for example, quinones such as 2-ethylanthraquinone and 2-tert-butylanthraquinone, aromatic ketones such as benzophenone, benzoin ethers such as benzoin, benzoin methyl ether and benzoin ethyl ether, Examples include benzyl dimethyl ketal and benzyl diethyl ketal.
Further, for example, there are combinations of thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and tertiary amine compounds such as dimethylaminobenzoic acid alkyl ester compounds.
Further, there are oxime esters such as 1-phenyl-1,2-propanedione-2-O-benzoyloxime and 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.

（式中Ａ、Ｂ及びＣは、それぞれ独立に、アリール基、複素環基、炭素数３以上の直鎖または分枝鎖のアルキル基、およびＮＲ_２（Ｒは水素原子、またはアルキル基）からなる群から選ばれる置換基を表す。ａ,ｂ及びｃの夫々は０〜２の整数であるが、ａ＋ｂ＋ｃの値は１以上である。） The (d) pyrazoline compound represented by the following general formula (I) used in the present invention will be described.

Wherein A, B and C are each independently an aryl group, a heterocyclic group, a linear or branched alkyl group having 3 or more carbon atoms, and NR ₂ (R is a hydrogen atom or an alkyl group). And each of a, b and c is an integer of 0 to 2, but the value of a + b + c is 1 or more.

  Examples of the compound represented by the general formula (I) include 1- (4-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-tert-butyl). -Styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1,5-bis- (4-tert-butyl-phenyl) -3- (4-tert-butyl-styryl) -pyrazoline, 1- (4-tert-octyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1,5-bis- (4-tert-octyl-phenyl) -3- (4-tert-octyl-styryl) -pyrazoline, 1- (4-dodecyl-phenyl) -3-styryl -5-phenyl-pyrazoline, 1-phenyl-3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-dodecyl- Stynyl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-tert-octyl-phenyl) -3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -Pyrazoline, 1- (4-tert-butyl-phenyl) -3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1- (4-tert-butyl-phenyl) -3- (4-dodecyl) Styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline 1- (4-tert-octyl-phenyl) -3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (2,4-dibutyl-phenyl) -3- ( 4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1-phenyl-3- (3,5-di-tert-butyl-styryl) -5- (3,5-di-tert- 1-phenyl-3- (2,6-di-tert-butyl-styryl) -5- (2,6-di-tert-butyl-phenyl) -pyrazoline, 1-phenyl-3 (2,5-di-tert-butyl-styryl) -5- (2,5-di-tert-butyl-phenyl) -pyrazoline, 1-phenyl-3- (2,6-di-n-butyl-styryl) ) -5- (2,6-di-n-butyl-phenyl) -pyrazoline, 1- (3,4-di-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1- (3 , 5-Di-tert-butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1- (4-tert-butyl-phenyl) -3- (3,5-di-tert-butyl-phenyl)- Pyrazoline, 1- (3,5-di-tert-butyl-phenyl) -3- (3,5-di-tert-butyl-styryl) -5- (3,5-di-tert-butyl-phenyl)- Pyrazoline.

Among the pyrazoline compounds represented by the above general formula (I), B and C are each independently a linear or branched alkyl group having 3 or more carbon atoms, or NR ₂ (R is a hydrogen atom or an alkyl group). A is a substituent selected from the group consisting of an aryl group, a heterocyclic group, and a linear or branched alkyl group having 3 or more carbon atoms, a is 0 or 1, and b = C = 1 is more preferable, and a pyrazoline compound having a tert-butyl group in both B or C and B and C is more preferable, and among them, 1-phenyl-3- (4-tert -Butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline is particularly preferred. In particular, for an exposure light source having a wavelength of 400 nm or more that is preferably used in maskless exposure, a pyrazoline compound having a benzoxazole group is preferable, and in particular, 1- (4- (benzoxazol-2-yl) phenyl) -3. -(4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline is preferred. Furthermore, the combination of the 2,4,5-triarylimidazole dimer and the compound of the above general formula (I) is particularly preferable from the viewpoint of resolution.
When the compound represented by the general formula (I) is contained, the proportion of the compound represented by the general formula (I) is 0.1 to 20% by mass with respect to the total of the photosensitive resin composition. Is preferred. If this ratio is less than 0.1% by mass, sufficient sensitivity cannot be obtained. On the other hand, when the ratio exceeds 20% by mass, fogging due to diffraction of light passing through the photomask at the time of exposure tends to occur, and as a result, resolution is deteriorated. Since the compound represented by the general formula (I) is particularly sensitive to h-line having a wavelength of 405 nm, in the photosensitive resin composition containing the general formula (I), a pattern by a direct drawing method corresponding to h-line. Also preferred for formation.

The photosensitive resin composition of the present invention may contain a coloring substance such as a dye or a pigment, or a coloring dye that develops color when irradiated with light. Examples of the coloring substance used include fuchsin, phthalocyanine green, auramine base, chalcoxide green S, paramadienta, crystal violet, methyl orange, nile blue 2B, malachite green (Eizen (registered trademark) MALACHITE GREEN manufactured by Hodogaya Chemical Co., Ltd.). ), Victoria Blue (Eizen (registered trademark) VICTORIA PURE BLUE manufactured by Hodogaya Chemical Co., Ltd.), Basic Blue 20, Diamond Green (Eisen (registered trademark) DIAMOND GREEN GH manufactured by Hodogaya Chemical Co., Ltd.), and the like.
Examples of the coloring dye include a combination of a leuco dye or a fluorane dye and a halogen compound. Examples of the leuco dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green], and the like.

Halogen compounds 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, triazine compounds and the like. Examples of the triazine compound include 2,4,6-tris (trichloromethyl) -s-triazine and 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine.
Among such coloring dyes, a combination of tribromomethylphenylsulfone and a leuco dye or a combination of a triazine compound and a leuco dye is useful.
The amount of the coloring substance and the color former is preferably 0.01 to 10% by mass in the photosensitive resin composition. It is preferably 0.01% by mass or more from the viewpoint of recognizing sufficient colorability (coloring property), 10% by mass or less from the viewpoint of maintaining the contrast between the exposed part and the unexposed part and maintaining storage stability.

In order to improve the thermal stability and storage stability of the photosensitive resin composition in the present invention, it is preferable that the photosensitive resin composition contains the following additives. Examples of such additives include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2′- Examples include methylene bis (4-ethyl-6-tert-butylphenol), 2,2′-methylene bis (4-methyl-6-tert-butylphenol), diphenylnitrosamine and the like. In addition, as stabilizers, a compound in which propylene oxide is further added to both sides of polypropylene glycol in which an average of 1 mol of propylene oxide is added to both sides of bisphenol A, benzotriazole, carboxybenzotriazole, 1- (2-dialkylamino) carboxybenzo There are triazole, pentaerythritol 3,5-di-t-butyl-4-hydroxyphenylpropionic acid tetraester.
The total amount of the additives is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass. From the viewpoint of imparting storage stability to the photosensitive resin composition, 0.01 mass% or more is preferable, and from the viewpoint of maintaining sensitivity, 3 mass% or less is more preferable.

Furthermore, you may make the photosensitive resin composition of this invention contain additives, such as a plasticizer, as needed. Examples of such additives include phthalates such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, acetyl triethyl citrate, acetyl citrate tri- Examples thereof include n-propyl, tri-n-butyl acetylcitrate, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ether, polypropylene glycol alkyl ether, and the like.
The amount of the additive such as a plasticizer is preferably 5 to 50% by mass, more preferably 5 to 30% by mass in the photosensitive resin composition. 5 mass% or more is preferable from a viewpoint of suppressing the delay of image development time or providing a softness | flexibility to a cured film, and 50 mass% or less is preferable from a viewpoint of suppressing insufficient hardening and cold flow.
The photosensitive resin laminate of the present invention is produced by laminating the photosensitive resin composition on a support to form a photosensitive resin layer.

As the support, a transparent base film that normally transmits actinic rays is used. Examples of such a base film include synthetic resin films such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate having a thickness of about 10 μm to 100 μm. However, polyethylene terephthalate having usually adequate flexibility and strength is preferably used. The film thickness is preferably 10 μm or more in order to make it difficult to generate wrinkles during lamination and to prevent damage to the support. In order to obtain sufficient resolution, the film thickness is preferably 30 μm or less. The haze is preferably 5 or less. Although the film thickness of the photosensitive resin layer of this invention changes with uses, it is 5 micrometers or more and 100 micrometers or less normally. More preferably, they are 5 micrometers or more and 50 micrometers or less.
In the photosensitive resin laminate of the present invention, a protective layer is formed on the surface of the photosensitive resin layer opposite to the support of the photosensitive resin layer as necessary. It is necessary for the protective layer that the adhesive strength between the photosensitive resin layer and the protective layer is smaller than the adhesive strength between the photosensitive resin layer and the support. The layer can be easily peeled off.
The protective layer is a film for protecting the photosensitive resin layer of the present invention. Examples of such a film include synthetic resin films such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate having a thickness of about 10 to 100 μm. A film or a polypropylene film is preferably used. The thickness of the protective layer is preferably 10 μm or more and 50 μm or less.

Next, the manufacturing method of the photosensitive resin laminated body of this invention is demonstrated.
A conventionally known method can be adopted as a method of forming a photosensitive resin laminate by sequentially laminating a support, a photosensitive resin layer, and a protective layer.
For example, the photosensitive resin composition used for the photosensitive resin layer is mixed with a solvent that dissolves them to make a uniform solution, and is first coated on a support using a bar coater or roll coater and dried. A photosensitive resin layer made of a photosensitive resin composition is laminated thereon.
Next, a photosensitive resin laminate can be produced by laminating a protective layer on the photosensitive resin layer.
Next, an example of a method for producing a printed wiring board using the photosensitive resin laminate of the present invention will be described.
A printed wiring board is manufactured through the following steps.
(1) Lamination process The process of making it adhere | attach using hot roll laminators on board | substrates, such as a copper clad laminated board and a flexible substrate, peeling off the protective layer of the photosensitive resin laminated body.

(2) Exposure process The process of sticking the mask film which has a desired wiring pattern on a support body, and performing exposure using an actinic light source.
Or the process of drawing and exposing a wiring pattern directly on a resist without a mask film.
(3) Development process The process which melt | dissolves or disperses the unexposed part of the photosensitive resin layer using an alkali developing solution after peeling a support body, and forms a resist pattern on a substrate.
(4) Etching process or plating process An etching solution is sprayed on the formed resist pattern to etch a copper surface not covered with the resist pattern, or copper, solder, nickel, and copper are not covered with the resist pattern. A step of performing a plating process such as tin.
(5) Stripping step The step of removing the resist pattern from the substrate using an alkaline stripping solution.

Examples of the active light source used in the (2) exposure step include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, and a xenon lamp. In order to obtain a finer resist pattern, it is more preferable to use a parallel light source. When it is desired to reduce the influence of dust and foreign matter as much as possible, exposure (proximity exposure) may be performed in a state where the photomask is floated by several tens of μm to several hundreds of μm from the support (A).
Examples of the alkaline developer used in the above (3) development step include aqueous solutions of sodium carbonate, potassium carbonate and the like. These alkaline aqueous solutions are selected in accordance with the characteristics of the photosensitive resin layer (B), but an aqueous sodium carbonate solution of 0.5% to 3% is generally used.
The (4) etching step is performed by a method suitable for the DFR used, such as acidic etching or alkaline etching.
As the alkaline stripping solution used in the above (5) stripping step, generally an alkaline aqueous solution that is stronger than the alkaline aqueous solution used in the development, for example, an aqueous solution of 1% or more and 5% or less of sodium hydroxide or potassium hydroxide. Can be mentioned.
When a plating process such as a semi-additive method is provided, the copper surface that appears under the resist pattern may be etched after the resist pattern is removed.
Hereinafter, examples of embodiments of the present invention will be described in more detail by way of examples.

Below, the preparation method of the sample for evaluation of an Example and a comparative example, the evaluation method about the obtained sample, and an evaluation result are shown.
1. Production of Evaluation Sample The photosensitive resin laminates in Examples and Comparative Examples were produced as follows.
<Preparation of photosensitive resin laminate>
Prepare the compounds shown in Table 1, thoroughly stir and mix the photosensitive resin composition of the composition ratio shown in Table 2, and apply uniformly to the surface of a 20 μm thick polyethylene terephthalate film as a support using a bar coater, The photosensitive resin layer was formed by drying for 4 minutes in a dryer at 95 ° C. The thickness of the photosensitive resin layer was 40 μm.
In the composition shown in Table 1, MEK represents methyl ethyl ketone, and the mass parts of P-1 to P-2 in Table 2 are values including MEK.
Next, a 25 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.

<Board surface preparation>
Etching solution resistance, resolution, adhesion, and tenting property evaluation use a 1.6 mm thick copper clad laminate with 35 μm rolled copper foil laminated on the surface, wet buffol polishing (manufactured by 3M Co., Ltd., Scotch Bright) (Registered trademark) HD # 600, twice).
<Laminate>
While peeling the polyethylene film of the photosensitive resin laminate, it was laminated at a roll temperature of 105 ° C. with a hot roll laminator (Asahi Kasei Co., Ltd., AL-70) on a copper clad laminate that had been leveled and preheated to 60 ° C. The air pressure was 0.35 MPa, and the laminating speed was 1.5 m / min.
<Exposure>
A mask film necessary for evaluation is placed on a polyethylene terephthalate film, which is a support, on a photosensitive resin layer, and a 21-step tablet made by Stöffer is 7 steps by an ultra-high pressure mercury lamp (OMW Seisakusho, HMW-201KB). The exposure amount was as follows. When this exposure method is selected, it is shown in Table 2 as a “photomask”.
Or, using a direct drawing type exposure apparatus (manufactured by Hitachi Via Mechanics Co., Ltd., DI exposure machine DE-1AH, light source: GaN blue-violet diode, main wavelength 407 ± 3 nm) without using a mask film, a 21-step tablet made by Stöffer Was exposed at an exposure amount of 7 steps. When this exposure method is selected, it is shown in Table 2 as “direct drawing”.

<Development>
After the polyethylene terephthalate film is peeled off, a 1 mass% Na ₂ CO ₃ aqueous solution at 30 ° C. is sprayed for a predetermined time using an alkali developing machine (manufactured by Fuji Kiko Co., Ltd., a dry film developing machine). Was dissolved and removed in a time twice the minimum image time. At this time, the minimum time required for completely dissolving the photosensitive resin layer in the unexposed portion was defined as the minimum development time.
<Etching>
The developed substrate was etched with a salt copper etching apparatus (manufactured by Tokyo Chemical Industry Co., Ltd.) at 3 mol / l hydrochloric acid, 250 g / l cupric chloride at 50 ° C. for 1.3 times the minimum etching time. At this time, the time when the copper foil on the substrate was completely dissolved and removed was defined as the minimum etching time.
<Resist stripping>
The cured resist was peeled off by spraying a 3% by mass aqueous sodium hydroxide solution heated to 50 ° C. on the evaluation substrate after development.

2. Evaluation method (1) Resolution evaluation A substrate for resolution evaluation that has passed 15 minutes after lamination is a line pattern in which the width of the exposed portion and the unexposed portion is 1: 1, using a mask film or a direct drawing method. Exposed. Development was performed with a development time twice as long as the minimum development time, and the minimum mask width in which a cured resist line was normally formed was defined as a resolution value, and the resolution was ranked as follows.
A: The resolution value is 30 μm or less.
○: The resolution value exceeds 30 μm and is 35 μm or less.
(Triangle | delta): The value of resolution exceeds 35 micrometers and is 40 micrometers or less.
X: The resolution value exceeds 40 μm.

(2) Evaluation of cohesion A photosensitive layer (resist layer) having a thickness of 40 μm and an area of 0.16 m ^{2 in} the photosensitive resin laminate is dissolved in 200 ml of a 1% by mass Na ₂ CO ₃ aqueous solution, and a circulation spray device is used. The spray pressure was 0.1 MPa for 3 hours. Thereafter, the developer was allowed to stand for 1 day, and the generation of aggregates was observed. When a large amount of agglomerates are generated, powdery or oily substances are observed at the bottom and side surfaces of the spray device. In addition, aggregates may float in the developer. The composition having good developer cohesiveness does not generate these aggregates at all, or even if they are generated, they can be easily washed away from the spray device by washing with water. The state of occurrence of aggregates was ranked by visual observation as follows.
A: No aggregate is generated.
○: Although there is no aggregate on the bottom or side of the spray device, a very small amount of aggregate that can be visually confirmed is observed floating in the developer, but it is easily washed away when washed with water.
(Triangle | delta): The aggregate is floating in the bottom part or side surface part of a spray apparatus, and a developing solution.
Even if it is washed with water, everything cannot be washed away.
X: Aggregates are observed in the entire spray apparatus and the aggregates are floating in the developer.
It is impossible to wash everything away with water, and most of it remains.

(3) Cured film flexibility evaluation DFR having a thickness of 40 μm was laminated on a copper-clad laminate, and the entire surface was exposed with HMW-201KB with a 7-step exposure of a 21-step tablet made by Stöffer. After the polyethylene terephthalate as a support was peeled off, a 1 mass% Na ₂ CO ₃ aqueous solution at 30 ° C. was sprayed at twice the minimum development time to obtain a cured image. Eleven cuts with a width of 1 mm were made at right angles to the obtained cured image, and cellotape (registered trademark) was peeled off. At this time, the following ranking was performed according to the degree of peeling of the cured resist by peeling of cellophane (registered trademark). That the resist is easily peeled means that the cured film has poor flexibility.
A: The cured resist is not peeled off at all.
○: A part of the cured resist is peeled off.
Δ: The cured resist is almost peeled off.
X: The cured resist peels off when the cut is made.

(4) Tenting property A through-hole with a radius of 6 mm exists at equal intervals (1008 holes). A photosensitive resin is laminated on a tenting evaluation substrate, and a 21-step tablet made by Stöffer becomes 7 steps by HMW-201KB. The entire film was exposed with an exposure amount, developed with a development time twice as long as the minimum development time, and further washed with water at a spray pressure of 0.3 MPa in a water-washing tank, and the film tear rate was measured.
The following ranking was performed according to the film tear rate.
○: Film tear rate is less than 1%.
(Triangle | delta): The film tear rate is less than 1 to 5%.
X: Film tear rate is 5% or more.

(5) Etching property evaluation The substrate for resolution evaluation which has passed 15 minutes after laminating is subjected to 7-step tablet made by Stofer using HMW-201KB through a line pattern mask in which the width of the exposed part and the unexposed part is 1: 1. It exposed with the exposure amount used as a step. Developed with a development time twice as long as the minimum development time, etched at 1.3 mol of hydrochloric acid 3 mol / l, cupric chloride 250 g / l, 1.3 times the minimum etching time at 50 ° C, and then stripped the resist to remove the copper line A substrate with a formed thereon was obtained. The copper line top width of the portion having a mask line width of 100 μm was measured. At this time, the closer the copper line top width is to 100 μm, the more the etching solution does not penetrate under the resist, and the etching solution resistance is considered to be stronger. The following ranking was performed according to the width of the copper line.
○: 80 μm or more.
Δ: 70 μm or more and less than 80 μm.
X: Less than 70 micrometers.
3. The evaluation results of Examples and Comparative Examples are shown in Table 2.

According to the present invention, it is suitable as an etching resist or a plating resist in the fields of production of printed wiring boards, flexible wiring boards, lead frames, semiconductor packages and the like, and precision metal processing.

Claims (10)

(A) Resin for binders having a carboxyl group content of 100 to 600 in terms of acid equivalent, containing benzyl (meth) acrylate as a copolymerization component, and having a weight average molecular weight of 5,000 to 500,000: 10 to 90% by mass (B) Photopolymerizable unsaturated compound: 3 to 70% by mass, (c) Photopolymerization initiator: 0.1 to 20% by mass, and (d) Compound represented by the following general formula (I): 0 A photosensitive resin composition containing 1 to 20% by mass.

Wherein A, B and C are each independently an aryl group, a heterocyclic group, a linear or branched alkyl group having 3 or more carbon atoms, and NR ₂ (R is a hydrogen atom or an alkyl group). And each of a, b and c is an integer of 0 to 2, but the value of a + b + c is 1 or more. (C) 0.1-20 mass% of compounds represented by the following general formula (II) are contained as a photoinitiator, The photosensitive resin composition of Claim 1 characterized by the above-mentioned.

(In the formula, D, E, and F each independently represent hydrogen, an alkyl group, an alkoxy group, or a halogen group, and d, e, and f are each independently an integer of 1 to 5). (B) The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerizable unsaturated compound contains at least one compound represented by the following general formulas (III) and (IV).

(In the formula, R ₁ and R ₂ are H or CH ₃ , and these may be the same or different. R ₃ and R ₄ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating unit of — (R ₃ —O) — and — (R ₄ —O) — may be a block structure or a random structure, m5, m6, n5 , And n6 are 0 or a positive integer, and the sum of these is 2 to 40.)

(In the formula, R ₅ and R ₆ are H or CH ₃ , which may be the same or different. R ₇ and R ₈ are an ethylene group or a propylene group, and are the same respectively. In this case, the repeating units of — (R ₇ —O) — and — (R ₈ —O) — may have a block structure or a random structure.m7, m8, n7 , And n8 are 0 or a positive integer, and the sum of these is 2 to 40.)   A photosensitive resin laminate comprising the photosensitive resin composition according to any one of claims 1 to 3 laminated on a support and a photosensitive resin composition layer. A method for forming a resist pattern, comprising: laminating the photosensitive resin laminate according to claim 4 on a surface of a metal plate or a metal-coated insulating plate, exposing to ultraviolet rays, and then removing an unexposed portion by development.   6. The resist pattern forming method according to claim 5, wherein in the exposure step, exposure is performed without using a photomask.   A method for producing a conductor pattern, comprising etching or plating a substrate on which a resist pattern is formed by the method according to claim 5.   A method for producing a printed wiring board, comprising etching or plating a substrate on which a resist pattern is formed by the method according to claim 5.   A method for manufacturing a lead frame, comprising a step of etching a substrate on which a resist pattern is formed by the method according to claim 5.   A method for manufacturing a semiconductor package, comprising a step of etching or plating a substrate on which a resist pattern is formed by the method according to claim 5.