JP2009109833A - Photosensitive resin composition, and photosensitive film and photosensitive permanent resist using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkali developable photosensitive resin composition capable of forming a dry film type solder resist excellent in plating resistance and resistance to the heat of soldering and also having adequate cracking resistance and HAST resistance. <P>SOLUTION: The photosensitive resin composition comprises (a) a binder polymer, (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups, (c) a polyurethane compound, (d) a photopolymerization initiator and (e) an inorganic filler, wherein the polyurethane compound (c) is obtained by reacting an epoxy acrylate compound having an ethylenically unsaturated group and two or more hydroxyl groups with a diisocyanate compound and a diol compound having a carboxyl group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, and a photosensitive film and a photosensitive permanent resist using the same.

With the reduction in size and weight of various electronic devices, photosensitive solder resists capable of forming fine opening patterns are used for printed wiring boards, semiconductor package boards, flexible wiring boards, and the like.
The solder resist generally requires characteristics such as developability, high resolution, insulation, solder heat resistance, and plating resistance. Particularly for solder resists for package substrates, for example, crack resistance against a temperature cycle test (TCT) of −55 ° C. to 125 ° C., and between fine wirings for a super accelerated high temperature high humidity life test (HAST) HAST resistance is required.
By the way, as the photosensitive resin composition for the solder resist, a liquid photosensitive resin composition is usually used in the field of printed wiring boards. As a liquid solder resist, a two-component type photosensitive resin composition in which an epoxy resin as a curable component and a photosensitive prepolymer containing a carboxylic acid group for imparting alkali developability are separately provided. It is common to consist of As the photosensitive prepolymer, an alkali-developable photosensitive prepolymer obtained by adding acrylic acid to a cresol novolac type epoxy resin and then acid-modifying is widely used (for example, see Patent Document 1).
In recent years, as a solder resist, a dry film type is attracting attention from the viewpoint of improving film thickness uniformity, surface smoothness, and thin film formability. According to such a dry film type solder resist, in addition to the above characteristics, effects such as simplification of the process for resist formation and reduction of the amount of solvent discharged during resist formation can be obtained. As a dry film type solder resist, a photosensitive resin composition having excellent storage stability, which is difficult to achieve with the conventional two-component type photosensitive resin composition, capable of alkali development, and excellent in chemical resistance, heat resistance, etc. Products have been developed (see, for example, Patent Document 2).
JP-A 61-243869 JP 2005-316431 A

However, among conventional photosensitive resin compositions, among the properties required for solder resists, many of them have excellent resistance to soldering heat but have insufficient resistance to plating solutions. In recent years, solder resists have been required to further improve plating resistance as well as solder heat resistance, and it has been difficult for conventional photosensitive resin compositions to sufficiently satisfy such requirements.
Therefore, the present invention has been made in view of such circumstances, and is capable of forming a dry film type solder resist excellent in plating resistance and solder heat resistance, and a photosensitive resin composition capable of alkali development, and the same. It aims at providing the photosensitive film and photosensitive permanent resist which used this.

In order to solve the above problems, the present invention provides (a) a binder polymer, (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups, (c) a polyurethane compound, and (d) initiation of photopolymerization. (E) containing an inorganic filler, and the (c) polyurethane compound reacts an epoxy acrylate compound having an ethylenically unsaturated group and two or more hydroxyl groups, a diisocyanate compound, and a diol compound having a carboxyl group. The photosensitive resin composition which is obtained by making it provide is provided.
Since the photosensitive resin composition of the present invention contains the component (e), a cured film having excellent chemical resistance can be formed. Therefore, a solder resist having excellent plating resistance and solder heat resistance can be formed. Can do. Moreover, since this photosensitive resin composition contains the said (c) component, it can form the toughness and the cured film excellent in elongation after hardening, and the soldering resist excellent in crack resistance is obtained. Furthermore, since the solder resist obtained from the photosensitive resin composition of the present invention is hardly contaminated even under high temperature and high humidity conditions, it has excellent HAST resistance.

The present invention also provides a photosensitive resin composition in which the content of the (e) inorganic filler is 10 to 200 parts by weight with respect to 100 parts by weight of the total of the components (a), (b), and (c). provide.
The present invention also provides a photosensitive resin composition in which (a) the binder polymer is a vinyl copolymer compound obtained by using (meth) acrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component. By including such a binder polymer, the developability of the photosensitive resin composition is further improved.
Moreover, this invention provides the photosensitive resin composition which further contains (f) block type isocyanate in the said photosensitive resin composition. By including the component (f), the photosensitive resin composition can form a cured film having further excellent adhesion to the substrate after curing.
Moreover, this invention provides a photosensitive film provided with a support body and the layer which consists of the said photosensitive resin composition of this invention formed on this support body. According to such a photosensitive film, a dry film type solder resist made of the photosensitive resin composition of the present invention can be easily formed.
Furthermore, this invention provides the photosensitive permanent resist which consists of a photocured material of the said photosensitive resin composition of this invention apply | coated on the board | substrate for printed wiring boards. Since this permanent resist is formed from the photosensitive resin composition of the present invention, it is excellent in plating resistance and solder heat resistance, and has sufficient crack resistance and HAST resistance.

  According to the present invention, an alkali-developable photosensitive resin composition capable of forming a dry film type solder resist having excellent plating resistance and solder heat resistance, and having sufficient crack resistance and HAST resistance, and The used photosensitive film and photosensitive permanent resist can be provided.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as the case may be. However, the present invention is not limited to the following embodiments.
[Photosensitive resin composition]
First, the photosensitive resin composition which concerns on suitable embodiment is demonstrated. In the present embodiment, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding to it, (meth) acrylate means acrylate or methacrylate corresponding to it, and (meth) acryloyl group means acryloyl group. Or the methacryloyl group corresponding to it is meant.
The photosensitive resin composition of the present invention comprises (a) a binder polymer, (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups, (c) a polyurethane compound, and (d) a photopolymerization initiator, (E) It contains at least an inorganic filler. Hereinafter, each of these components will be described in detail.
(A) Binder polymer The binder polymer which is the component (a) of the present invention is a polymer having a carboxyl group in the molecule. The binder polymer may further have an ethylenically unsaturated group, and may be a polymer that functions as a so-called photosensitive prepolymer.
Examples of the binder polymer include known resins such as acrylic resin, polyurethane, epoxy resin, phenoxy resin, polyester, polyamide, polyimide, polyamideimide, polyesterimide, polycarbonate, melamine resin, polyphenylene sulfide, and polyoxybenzoyl, and acids thereof. Examples of the modified resin include those having a carboxyl group in the molecule. Among them, it is preferable to be obtained by polymerizing a monomer (polymerizable monomer) having an ethylenically unsaturated double bond (such as radical polymerization).

  Examples of such a monomer having an ethylenically unsaturated double bond include acrylamide such as diacetone acrylamide, vinyl alcohol esters such as acrylonitrile and vinyl-n-butyl ether, and (meth) acrylic acid alkyl esters. , (Meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) Acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid , And β-styryl (meth) acrylic acid, etc. (Meth) acrylic acid monomers, maleic acid, maleic anhydride, maleic acid monomers such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanosilicic acid Cinnamic acid, itaconic acid, crotonic acid, propiolic acid and the like. These can be used alone or in combination of two or more.

As a binder polymer of this embodiment, an acrylic resin is preferable from a viewpoint of making photosensitivity and the resist shape after photocuring favorable. The acrylic resin can be obtained by radical polymerization using, for example, (meth) acrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component. In particular, a vinyl copolymer compound obtained by using methacrylic acid and (meth) acrylic acid alkyl ester as a copolymerization component is preferable.
Examples of (meth) acrylic acid alkyl esters include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid pentyl ester. Examples include esters, (meth) acrylic acid hexyl esters, (meth) acrylic acid heptyl esters, (meth) acrylic acid octyl esters, and (meth) acrylic acid 2-ethylhexyl esters.
As said vinyl type copolymer compound, you may use what is obtained by copolymerizing the vinyl monomer which can be copolymerized with these with (meth) acrylic-acid alkylester and (meth) acrylic acid. Examples of such vinyl monomers include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, methacrylic acid glycidyl ester, 2,2,2- Examples include trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, and vinyl toluene.

Moreover, what contains the acrylic acrylate which has an ethylenically unsaturated group as a copolymerization component as a vinyl-type copolymer compound which is an acrylic resin is applicable.
As the binder polymer, an acid-modified polyester resin is also preferable. Examples of the acid-modified polyester resin include a chain structure including an ester bond formed by a polymerization reaction between a diglycidyl ether type epoxy compound and a dibasic acid using a tertiary amine having a pKa of 9.0 or less as a catalyst. And a resin having a carboxyl group formed by adding an acid anhydride to this chain structure.
Diglycidyl ether type epoxy compounds for forming this acid-modified polyester resin include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F type epoxy resins such as bisphenol F diglycidyl ether, and bisphenol S diester. Bisphenol S type epoxy resins such as glycidyl ether, biphenol type epoxy resins such as biphenol diglycidyl ether, bixylenol type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A type epoxy resins such as hydrogenated bisphenol A glycidyl ether, These dibasic acid-modified diglycidyl ether type epoxy resins and the like can be mentioned. Among these, bisphenol A type epoxy resins are preferred because they are excellent in heat resistance and chemical resistance and do not relatively shrink due to curing. These can be used alone or in combination of two or more.

From the viewpoint of improving alkali developability, the acid value of the binder polymer according to the present embodiment is preferably 50 to 170 mgKOH / g, for example, in the case of an acrylic or acid-modified polyester binder polymer. It is more preferable that it is 150 mgKOH / g, and it is further more preferable that it is 90-130 mgKOH / g.
Here, the acid value can be measured as follows. That is, first, about 1 g of a resin solution whose acid value is to be measured is precisely weighed, and then 30 g of acetone is added to this resin solution to dissolve it uniformly. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N aqueous KOH solution. And an acid value is computed by following Formula.
A = 10 × Vf × 56.1 / (Wp × I)
In the formula, A represents the acid value (mgKOH / g), Vf represents the titration amount (mL) of 0.1N KOH aqueous solution, Wp represents the weight (g) of the measured resin solution, and I was measured. The ratio (mass%) of the non volatile matter in a resin solution is shown. Such an acid value measuring method can be applied to the following (c) polyurethane compound and the like.

  In addition, the weight average molecular weight (Mw) of the binder polymer is preferably 20000 to 150,000 and more preferably 40000 to 130,000 from the viewpoint of improving the coating properties and alkali developability of the photosensitive resin composition. Preferably, it is 60000-120,000. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) (in terms of standard polystyrene).

(B) Photopolymerizable monomer having one or more ethylenically unsaturated groups The photopolymerizable monomer as component (b) of the present invention is a compound having one or more ethylenically unsaturated groups in the molecule. . Examples of such photopolymerizable monomers include bisphenol A (meth) acrylate compounds, compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, and glycidyl group-containing compounds with α, β- Examples thereof include a compound obtained by reacting an unsaturated carboxylic acid, a urethane monomer such as a (meth) acrylate compound having a urethane bond in the molecule, or a urethane oligomer. Besides these, nonylphenoxy polyoxyethylene acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxy Examples thereof include phthalic acid compounds such as alkyl-o-phthalate, (meth) acrylic acid alkyl esters, and EO-modified nonylphenyl (meth) acrylate. These may be used alone or in combination of two or more.

The component (b) according to this embodiment preferably contains a bisphenol A (meth) acrylate compound from the viewpoint of improving alkali developability. Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). ) Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, etc. Is mentioned.
More preferably, the component (b) according to the present embodiment includes 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane. Examples of 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy nonaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl), 2,2- Bis (4-((meth) acryloxydodecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl), 2,2-bis (4-((meth) acrylic) Loxytetradecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl), and 2,2-bis (4-((meth) acryloxyhexadecaethoxy) phenyl) Etc. You may use these individually or in combination of 2 or more types.
Among the above compounds, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is FA-321M (trade name, manufactured by Hitachi Chemical Co., Ltd.) or BPE-500 (Shin Nakamura Chemical Co., Ltd.). ), Commercially available as trade name), and 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) is BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) It is commercially available.

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-(( (Meth) acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) phenyl ) Propane, 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxynonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl), 2,2-bis (4- ( (Meth) acryloxytetradecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl), and 2,2-bis (4-((meth) acryloxyhexadeca) Propoxy) phenyl) and the like. These may be used alone or in combination of two or more.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane, Examples include 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane. . These can be used alone or in combination of two or more.

Examples of the compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. Polypropylene glycol di (meth) acrylate, polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, tri Methylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO / PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meth) A Examples thereof include acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more.
“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. Further, “EO modified” means having a block structure of ethylene oxide units (—CH ₂ —CH ₂ —O—), and “PO modified” means propylene oxide units (—CH ₂ —CH ₂ —CH _{2). -O -, - CH 2 (CH} 3) means having a block structure of _CH 2 -O-).

Examples of the compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth) acryloxy- 2-hydroxy-propyloxy) phenyl and the like. Examples of the α, β-unsaturated carboxylic acid for obtaining the above compound include (meth) acrylic acid.
Examples of urethane monomers include (meth) acrylic monomers having an OH group at the β-position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Examples include addition reaction products with diisocyanate compounds, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, and EO or PO-modified urethane di (meth) acrylate.
Furthermore, examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester. Can be mentioned. These (b) components can be used individually by 1 type or in combination of 2 or more types.

(C) Polyurethane Compound The polyurethane compound as the component (c) of the present invention reacts with an epoxy acrylate compound having two or more hydroxyl groups and an ethylenically unsaturated group, a diisocyanate compound, and a diol compound having a carboxyl group. It was obtained.
As a polyurethane compound concerning this embodiment, what has a bisphenol A type structure as a hard segment part formed from an epoxy acrylate compound which has two or more hydroxyl groups and ethylenically unsaturated groups is preferred. Preferred polyurethane compounds include UXE-3011 and UXE-3012 (Nippon Kayaku Co., Ltd., sample name).
As described above, the polyurethane compound includes an epoxy acrylate compound having two or more hydroxyl groups and an ethylenically unsaturated group (hereinafter referred to as “raw material epoxy acrylate”), a diisocyanate compound (hereinafter referred to as “raw material diisocyanate”), and a carboxyl. It is a compound obtained using a diol compound having a group (hereinafter referred to as “raw diol”) as a raw material component. First, these raw material components will be described.
Examples of the raw material epoxy acrylate include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, novolac type epoxy compounds, and compounds obtained by reacting (meth) acrylic acid with epoxy compounds having a fluorene skeleton.

  As the raw material diisocyanate, any compound having two isocyanato groups can be used without particular limitation. For example, phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolden diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, arylene sulfone ether diisocyanate, allyl cyanide diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, norbornane-diisocyanate methyl and the like can be mentioned. As a diisocyanate compound, it can apply individually by 1 type or in combination of 2 or more types.

  The raw material diol is a compound having two hydroxyl groups such as an alcoholic hydroxyl group and / or a phenolic hydroxyl group in the molecule and a carboxyl group. The hydroxyl group preferably has an alcoholic hydroxyl group from the viewpoint of improving the developability of the photosensitive resin composition with an alkaline aqueous solution. Examples of such diol compounds include dimethylolpropionic acid and dimethylolbutanoic acid.

Next, an example of a process for producing a polyurethane compound using the above-described raw material components will be described.
That is, in the production process of the polyurethane compound, first, the raw material epoxy acrylate and the raw material diol are reacted with the raw material diisocyanate. In this reaction, a so-called urethanization reaction occurs mainly between the hydroxyl group in the raw material acrylate and the isocyanate group in the raw material diisocyanate and between the hydroxyl group in the raw material diol and the isocyanate group in the raw material diisocyanate. By this reaction, for example, an intermediate in which a structural unit derived from a raw material epoxy acrylate and a structural unit derived from a raw material diol are alternately or block-polymerized via a structural unit derived from a raw material diisocyanate. Arise.
Next, such an intermediate and raw material epoxy are reacted to obtain a polyurethane compound. In this reaction, a so-called epoxycarboxylation reaction occurs mainly between the carboxyl group derived from the diol compound in the intermediate and the epoxy group of the raw material epoxy. The polyurethane compound thus obtained has, for example, a main chain formed from the above-described intermediate and a side chain containing an ethylenically unsaturated group derived from the raw material epoxy acrylate or the raw material epoxy.

In the process for producing the polyurethane compound described above, in the step of obtaining the intermediate, in addition to the raw material epoxy acrylate, the raw material diol and the raw material diisocyanate, a diol compound different from these may be further added. Thereby, it becomes possible to change the main chain structure of the obtained polyurethane compound, and the characteristics such as the acid value described later can be adjusted to a desired range. Moreover, in each process mentioned above, you may use a catalyst etc. suitably.
As such a polyurethane compound, the compound represented by following General formula (1) can be illustrated, for example.

ここで、一般式（１）中、Ｒ^１１はエポキシアクリレートの残基、Ｒ^１２はジイソシアネートの残基、Ｒ^１３は炭素数１〜５のアルキル基、Ｒ^１４は水素原子又はメチル基を示す。なお、残基とは、原料成分から結合に供された官能基を除いた部分の構造をいう。また、式中に複数ある基は、それぞれ同一でも異なっていてもよい。

Here, in the general formula (1), R ¹¹ is an epoxy acrylate residue, R ¹² is a diisocyanate residue, R ¹³ is an alkyl group having 1 to 5 carbon atoms, and R ¹⁴ is a hydrogen atom or a methyl group. In addition, a residue means the structure of the part remove | excluding the functional group used for the coupling | bonding from the raw material component. In addition, a plurality of groups in the formula may be the same or different.

The acid value of the polyurethane compound is preferably 20 to 130 mgKOH / g, more preferably 40 to 110 mgKOH / g, and still more preferably 50 to 100 mgKOH / g. Thereby, the developability with the alkaline aqueous solution of the photosensitive resin composition becomes good, and an excellent resolution can be obtained.
Moreover, the weight average molecular weight of the polyurethane compound is preferably 3000 to 30000 from the viewpoint of obtaining good coating properties with the photosensitive resin composition and good crack resistance and HAST resistance of the cured film, and preferably 5000 to 20000. It is more preferable that it is 7000-15000.
Since such a polyurethane compound has good compatibility with the binder polymer (a), a uniform photosensitive resin composition is easily obtained. Moreover, since the photosensitive resin composition containing this polyurethane compound can form the toughness and the cured film excellent in elongation, it can improve the crack resistance after hardening and HAST tolerance. When it is contained together with (f) block type isocyanate which will be described later, such characteristics can be exhibited particularly well.

(D) Photopolymerization initiator Examples of the photopolymerization initiator that is the component (d) of this embodiment include benzophenone, N, N′-tetraalkyl-4,4′-diaminobenzophenone, and 2-benzyl-2- Aromatic ketones such as dimethylamino-1- (4-morpholinophenyl) -butanone-1 and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, 4,4′- Bis (dimethylamino) benzophenone (Mihera ketone), 4,4′-bis (diethylamino) benzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-morpholinophenone) -butanone-1 , 2-ethylanthraquinone, aromatic ketones such as phenanthrenequinone, benzoin methyl ether, benzoy Benzoin ether such as ethyl ether and benzoin phenyl ether, benzoin such as methyl benzoin and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- ( o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4 , 5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, and 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer 2,4,5-triarylimidazole dimer such as 9-phenylacridine Beauty 1,7-bis (9,9'-acridinyl) acridine derivatives such as heptane, N- phenylglycine, N- phenylglycine derivatives, coumarin-based compounds. These can be used singly or in combination of two or more.
The component (d) according to this embodiment preferably contains an acridine derivative, and more preferably contains 1,7-bis (9,9′-acridinyl) heptane from the viewpoint of improving sensitivity and resolution. . 1,7-bis (9,9′-acridinyl) heptane is commercially available as N-1717 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.).

(E) Inorganic filler The inorganic filler which is (e) component is, for example, barium sulfate, barium titanate, powdered silicon oxide, amorphous silica, talc, clay, calcined kaolin, magnesium carbonate, calcium carbonate, aluminum oxide, water Examples thereof include aluminum oxide and mica powder. Of these, barium sulfate is preferable. These inorganic fillers may be mixed directly in the resin, or may be dispersed in a solvent or the like and added to the resin.
The average particle size of the inorganic filler is preferably 0.01 μm to 5 μm, more preferably 0.05 μm to 3 μm, and further preferably 0.1 μm to 2 μm. When the average particle diameter is less than 0.01 μm, the plating resistance tends to be lowered, and when it exceeds 5 μm, the resist surface has irregularities and the resist shape tends to deteriorate.

(F) Block-type isocyanate It is preferable that the photosensitive resin composition of this embodiment further contains (f) block-type isocyanate. The block type isocyanate is inactive at room temperature (20 to 30 ° C.), but is a compound that regenerates isocyanate groups by reversibly dissociating the blocking agent when heated. The dissociation temperature of the blocking agent is preferably 120 to 200 ° C.
Examples of such isocyanate compounds include isocyanurate type, biuret type, and adduct type. Among these, the isocyanurate type is preferable from the viewpoint of improving the adhesion by the photosensitive resin composition. These can be used alone or in combination of two or more.
In the block type isocyanate compound, examples of the blocking agent bonded to the isocyanate include at least one selected from diketones, oximes, phenols, alkanols and caprolactams. Specific examples include methyl ethyl ketone oxime and ε-caprolactam.

As such a block type isocyanate, for example, Sumidur BL-3175, Death Module TPLS-2957, TPLS-2062, TPLS-2957, TPLS-2078, BL4165, TPLS2117, BL1100, BL1265, Desmotherm 2170, Desmotherm 2265 (and above) , Sumitomo Bayer Urethane Co., Ltd., trade name), Coronate 2512, Coronate 2513, Coronate 2520 (above, Nippon Polyurethane Industry Co., Ltd., trade name), B-830, B-815, B-846, B- 870, B-874, and B-882 (Mitsui Takeda Chemical Co., Ltd., trade name). These can be used alone or in combination of two or more.
When the insulating property excellent in the photosensitive resin composition is calculated | required, as above-mentioned, as a block type isocyanate, what contains aromatic rings, such as an isocyanuric skeleton and a benzene ring, is preferable in the structure. Examples of such block-type isocyanates include Sumidur BL-3175, Sumidur BL-4265, and B-870.

In addition to the components (a) to (f) described above, the photosensitive resin composition may further include other components according to desired properties.
As other components, first, a diluent may be mentioned. By including a diluent, the viscosity of the photosensitive resin composition is adjusted, and application on a predetermined substrate becomes easy. Examples of the diluent include aliphatic alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, n-pentanol and hexanol, hydrocarbons such as benzyl alcohol and cyclohexane, diacetone alcohol, Aliphatic ketones such as 3-methoxy-1-butanol, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, ethylene glycol, diethylene glycol, tri Ethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, Ethylene glycol alkyl ethers such as pyrene glycol diacetate, propylene glycol monoethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate And acetate thereof, diethylene glycol monoalkyl ethers and acetate thereof, diethylene glycol dialkyl ethers, triethylene glycol alkyl ethers, propylene glycol alkyl ethers and acetate thereof, and dipropylene glycol alkyl ethers.
Also, petroleum solvents such as toluene, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha, ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate Carboxylic acid esters such as ethyl propionate, methyl butyrate, and ethyl butyrate, amines, amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone, dimethyl sulfoxide Examples of the diluent include dioxane, tetrahydrofuran, cyclohexanone, γ-butyrolactone, 3-hydroxy-2-butanone, 4-hydroxy-2-pentanone, and 6-hydroxy-2-hexanone. These can be used alone or in combination of two or more.

In addition, the photosensitive resin composition may further contain an adhesion improver for the purpose of improving the adhesion to a metal such as copper used in a circuit such as a printed wiring board. Examples of the adhesion improver include additives such as benzoguanamine, melamine, dicyandiamide, triazine compounds and derivatives thereof, imidazole, thiazole, triazole, and silane coupling agents.
More specifically, examples of the adhesion improver include melamine, acetoguanamine, benzoguanamine, melamine-phenol-formalin resin, and dicyandiamide. These are commercially available as 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZINE, 2MA-OK (above, Shikoku Kasei Kogyo Co., Ltd., trade name). Also, triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, and 2,4-diamino-6-xylyl-S-triazine can be exemplified. These adhesion improvers can improve the adhesion to a circuit made of copper or the like, and can also improve the PCT resistance and the electric corrosion resistance of the layer made of the photosensitive resin composition. The adhesion improver according to this embodiment preferably contains dicyandiamide from the viewpoint of achieving chemical resistance and plating resistance at a higher level.

Furthermore, the photosensitive resin composition can be used as required, such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, malachite green, crystal violet, titanium oxide, carbon black, naphthalene black, azo organic pigments, etc. A colorant or dye may be contained. In addition, polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol, phenothiazine, thixotropic agents such as benton, montmorillonite, aerosil, amide wax, defoaming such as silicone, fluorine and polymer An agent, a leveling agent, and the like may be included within a range that does not affect the desired characteristics of the photosensitive resin composition.
Furthermore, the photosensitive resin composition may contain a flame retardant as necessary. From the viewpoint of recent environmental problems, a flame retardant containing no halogen is preferred.

Next, the suitable content rate of each component in the photosensitive resin composition which concerns on this embodiment is demonstrated.
First, the content of the component (a) is preferably 20 to 60 parts by weight, and preferably 25 to 55 parts by weight with respect to 100 parts by weight as a total of the components (a), (b) and (c). It is more preferable that the amount is 30 to 50 parts by weight. When the content of the component (a) is in such a range, the coating properties and the photosensitivity become better.
The content of the component (b) is preferably 10 to 50 parts by weight, and preferably 15 to 45 parts by weight with respect to 100 parts by weight as a total of the components (a), (b) and (c). More preferred is 20 to 40 parts by weight. When the content of the component (b) is in such a range, the photosensitivity and the cured film strength become better.
The content of the component (c) is preferably 10 to 50 parts by weight, and preferably 15 to 45 parts by weight with respect to 100 parts by weight as a total of the components (a), (b) and (c). More preferred is 20 to 40 parts by weight. When the content of the component (c) is in such a range, the HAST resistance and crack resistance of the cured film become better.
Moreover, it is preferable that content of (d) component is 0.1-20 weight part with respect to a total of 100 weight part of (a), (b) and (c) component, 0.5-10 More preferably, it is 1 part by weight, even more preferably 1 part by weight. When the content of the component (d) is in such a range, the photosensitivity and the solder heat resistance of the cured film become better.
Furthermore, it is preferable that content of (e) component is 10-200 weight part with respect to a total of 100 weight part of (a), (b) and (c) component, and is 20-100 weight part. More preferably, the amount is 30 to 70 parts by weight. (E) When content of a component is such a range, the plating tolerance of a cured film will become more favorable.
When the photosensitive resin composition contains the component (f), the content is preferably 5 to 40 parts by weight with respect to 100 parts by weight of the total of the components (a), (b) and (c). 10 to 30 parts by weight, more preferably 15 to 25 parts by weight. When the content of the component (f) is in such a range, the cured film has better crack resistance and HAST resistance.

When the photosensitive resin composition is applied as a liquid composition, the content of the diluent is preferably 5 to 40% by mass in the total weight. On the other hand, when forming a photosensitive resin composition layer on a support like a photosensitive film described later, from the viewpoint of improving the coating properties, the content of the diluent is before application to the support. It is preferable that it is 30-70 mass% in a varnish state, and it is preferable to set it as 3 weight% or less after application | coating.
Moreover, when the photosensitive resin composition contains an adhesion improver, the content is 0.1 to 10 parts by weight with respect to 100 parts by weight of the total amount of the components (a), (b) and (c). It is preferable that it is 0.3 to 2 parts by weight, and preferably 0.5 to 1.5 parts by weight. When the content is in such a range, the plating resistance and the chemical resistance become better.
Furthermore, when the photosensitive resin composition contains an adhesion improver, the content thereof is 10 to 200 parts by weight with respect to 100 parts by weight of the total amount of the components (a), (b) and (c). It is preferably 20 to 150 parts by weight, more preferably 30 to 100 parts by weight. When the flame retardant is in such a range, good flame retardancy can be obtained.

[Photosensitive film]
Next, the photosensitive film of suitable embodiment is demonstrated. FIG. 1 is a diagram schematically showing a cross-sectional configuration of a photosensitive film according to a preferred embodiment. As shown in FIG. 1, the photosensitive film 1 includes a support 10 and a photosensitive resin composition layer 20 made of a photosensitive resin composition formed on the support 10. Moreover, as shown in the figure, a protective film 30 that covers the layer may be further provided on the photosensitive resin composition layer 20.
The photosensitive resin composition layer 20 is a layer made of the photosensitive resin composition of the preferred embodiment described above. The photosensitive resin composition layer 20 is prepared by dissolving the photosensitive resin composition in a solvent such as a diluent as described above to obtain a solution having a solid content of about 30 to 80% by weight. It is preferable to form by coating.
Although the thickness of the photosensitive resin composition layer 20 varies depending on the use, it is preferably 10 to 100 μm and more preferably 15 to 60 μm in thickness after drying after removing the solvent by heating and / or hot air blowing. Preferably, it is 20-50 micrometers. If this thickness is less than 10 μm, coating tends to be difficult industrially, and if it exceeds 100 μm, the sensitivity and resolution inside the photosensitive resin composition layer tend to be lowered.
Moreover, as the support body 10 with which the photosensitive film 1 is provided, the polymer film etc. which have heat resistance and solvent resistance, such as a polyethylene terephthalate, a polypropylene, polyethylene, polyester, etc. are mentioned, for example.
The thickness of the support 10 is preferably 5 to 100 μm, more preferably 10 to 30 μm, and still more preferably 12 to 25 μm. When the thickness is less than 5 μm, the support 10 tends to be broken when the support 10 is peeled off before development, and when it exceeds 100 μm, it tends to be difficult to wind up the roll. Moreover, there exists a tendency for the sensitivity and resolution of the photosensitive resin composition layer at the time of exposure to fall.
The photosensitive film 1 composed of two layers of the support 10 and the photosensitive resin composition layer 20 as described above, or the photosensitive property composed of three layers of the support 10, the photosensitive resin composition layer 20 and the protective film 30. The film 1 may be stored as it is, for example, or may be stored in a roll shape around a winding core with a protective film interposed.

[Method of forming resist pattern]
Next, a preferred embodiment of a method for forming a resist pattern using the above-described photosensitive resin composition will be described.
First, the photosensitive resin composition layer which consists of the photosensitive resin composition of embodiment mentioned above is formed on the board | substrate which should form a resist. The photosensitive resin composition layer is formed by a method of applying the varnish of the photosensitive resin composition by a known method such as a screen printing method or a method of applying by a roll coater, or by using the above-described photosensitive film 1 and laminating. It can be formed by a method of attaching the photosensitive resin composition layer 20 or the like. When using the photosensitive film 1, you may perform the removal process which removes the protective film 30 before affixing. Examples of the substrate on which the resist is to be formed include a printed wiring board, a semiconductor package substrate, and a flexible wiring board.
Next, an exposure process is performed in which the photosensitive resin composition layer is irradiated with actinic rays through a mask pattern having a predetermined pattern shape, and a predetermined region of the photosensitive resin composition layer is photocured. Depending on the type of photoinitiator, exposure by a direct drawing method having no mask pattern such as a laser direct drawing exposure method or a DLP (Digital Light Processing) exposure method is also possible.

As the active light source, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, an Ar ion laser, a semiconductor laser, or the like that effectively emits ultraviolet rays is used. it can. Moreover, what can radiate | emit visible light effectively, such as a flood bulb for photography, a solar lamp, can be used.
After the exposure step, a development step is performed in which the region (uncured portion) that has not been cured without being irradiated with actinic rays in the photosensitive resin composition layer is dissolved in a developer. Thereby, a resist pattern having a predetermined pattern shape is formed. As the developer, an alkali developer is used, and for example, a dilute solution (1 to 5 wt% aqueous solution) of sodium carbonate at 20 to 50 ° C. is suitable. Development can be performed by a known method such as spraying, rocking dipping, brushing, scraping or the like.
After the development process is completed, it is preferable to further irradiate the resist pattern with ultraviolet rays or heat with a high-pressure mercury lamp for the purpose of further improving the solder heat resistance and chemical resistance of the resist pattern. When irradiating with ultraviolet rays, it is preferable to adjust the irradiation amount as necessary. For example, irradiation can be performed at an irradiation amount of about 0.2 to 10 J / cm ² . Moreover, when heating a resist pattern, it is preferable to carry out on the conditions for about 15 to 90 minutes in the range of about 100-170 degreeC.
Both ultraviolet irradiation and heating may be performed. In this case, both may be performed at the same time, and after either one is performed, the other may be performed. When performing ultraviolet irradiation and a heating simultaneously, it is more preferable to heat to 60-150 degreeC from a viewpoint of providing solder heat resistance, chemical resistance, etc. more favorably.
The solder resist thus formed is used, for example, as a plating resist or etching resist when plating or etching is performed on the substrate, and is left on the substrate as it is to protect wiring and the like. Used as a protective film (photosensitive permanent resist).
Since the resist pattern has excellent plating resistance and HAST resistance by being formed from the photosensitive resin composition of the above-described embodiment, it is a solder resist for printed wiring boards, semiconductor package substrates, and flexible wiring boards. It is effective as
The substrate on which the solder resist is formed is then mounted with a component such as an LSI (for example, wire bonding or solder connection), and further mounted on an electronic device such as a personal computer.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples.
(Examples 1-3, Comparative Examples 1-2)
[Preparation of photosensitive film]
First, the solution of the photosensitive resin composition was obtained by mixing the component (1) -component (6) shown in Table 1 and other components with the compounding quantity (part by weight) of the solid content shown in the table. In the table, the resin (1) in the component (1) is an acrylic resin, and is a copolymer of methacrylic acid, methyl methacrylate and butyl acrylate (methacrylic acid: methyl methacrylate: butyl acrylate = 17 wt. %: 62% by weight: 21% by weight) and a weight average molecular weight of 100,000 and an acid value of 110 mg KOH / g. These components (1) correspond to the component (a) in the above-described embodiment.
In addition, FA-321M in component (2) is bisphenol A polyoxyethylene dimethacrylate (manufactured by Hitachi Chemical Co., Ltd., trade name FA-321M). These correspond to the component (b) in the above-described embodiment.
Furthermore, UXE-3011 in component (3) is a polyurethane compound (manufactured by Nippon Kayaku Co., Ltd., sample name UXE-3011, weight average molecular weight: 10,000), and corresponds to component (c) in the above-described embodiment. To do.
Further, N-1717 in component (4) is 1,7-bis (9-acridinyl) heptane (trade name N-1717, manufactured by Asahi Denka Kogyo Co., Ltd.). Applicable.
Furthermore, B-30 in the component (5) is barium sulfate (trade name Variace B-30, manufactured by Sakai Chemical Industry Co., Ltd.) and corresponds to the component (e) in the above-described embodiment.
Furthermore, BL-3175 in the component (6) is a block type isocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., trade name BL-3175), and corresponds to the component (f) of the above-described embodiment.
In addition, methyl ethyl ketone was added to these photosensitive resin compositions as a diluent.

Next, these photosensitive resin composition solutions were uniformly applied onto a 16 μm polyethylene terephthalate film (product name: G2-16, manufactured by Teijin Limited) as a support, and a hot air convection dryer was used. The photosensitive resin composition layer was formed on the support by using and drying at 100 ° C. for 10 minutes. The film thickness after drying of the photosensitive resin composition layer was 30 μm.
Subsequently, on the surface of the photosensitive resin composition layer opposite to the side in contact with the support layer, a polyethylene film (manufactured by Tamapoly Co., Ltd., trade name NF-15) is bonded as a protective film, and the photosensitive film Got.

[Characteristic evaluation]
Using the photosensitive films prepared in Examples 1 to 3 and Comparative Examples 1 and 2, the following tests were performed, respectively, and the plating resistance, solder heat resistance, crack resistance when each photosensitive film was used, HAST resistance, laminating properties and resolution were evaluated. The results are summarized in Table 2.

(Plating resistance)
First, an evaluation substrate was prepared as follows using each photosensitive film. That is, first, the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a glass epoxy substrate is polished with an abrasive brush and washed with water. And then dried. Using a continuous press type vacuum laminator (trade name: MVLP-500, manufactured by Meiki Seisakusho) on this printed wiring board substrate, the press hot plate temperature is 70 ° C., the evacuation time is 20 seconds, the lamination press time is 30 seconds, and the atmospheric pressure is 4 kPa. Hereinafter, the polyethylene film of the photosensitive film was peeled and laminated under the condition of a pressure bonding pressure of 0.4 MPa to obtain a laminate for evaluation.
The laminate for evaluation after laminating was allowed to stand at room temperature (25 ° C.) for 1 hour, and then a direct-drawing exposure machine (manufactured by Hitachi Via Mechanics Co., Ltd., product name “DE-” 1AH "), and using the drawing data having a grid pattern from above the evaluation laminate, the stowage 21-step tablet is exposed with an energy amount of 14 after development. went.
After the exposure, the polyethylene terephthalate film on the evaluation laminate is peeled off and sprayed with a 1% by mass aqueous sodium carbonate solution at 30 ° C. for 1.5 times the minimum development time (minimum time during which the unexposed area is developed). Development was performed. Thereby, the pattern formed by hardening the photosensitive resin composition layer was formed.
Subsequently, ultraviolet irradiation is performed with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and further heat treatment is performed at 160 ° C. for 60 minutes on the printed wiring board substrate. An evaluation substrate on which a solder resist was formed was obtained.
The substrate for evaluation is subjected to electroless nickel plating (trade name Nimden NPR-4, manufactured by Uemura Kogyo Co., Ltd.) (treatment for 15 minutes), and further electroless gold plating (trade name, Goblite, manufactured by Uemura Kogyo Co., Ltd.). TAM-54) was applied (10 minutes treatment).
For the evaluation substrate thus plated, the plating solution soaks into the bottom of the solder resist, and the solder resist floats and peels from the substrate is observed with a 100-fold metal microscope. evaluated. That is, the case where no penetration into the bottom of the solder resist was observed and the solder resist was not lifted or peeled off was indicated as “◯”, and the case where any of them was recognized as “X”.

(Solder heat resistance)
Using the evaluation substrate having a solder resist obtained in the same manner as in the “plating resistance” test, the solder heat resistance was evaluated as follows. That is, after applying a rosin flux (product name: MH-820V, manufactured by Tamura Kaken Co., Ltd.) to the substrate for evaluation, a soldering treatment was performed in which the substrate was immersed in a 260 ° C. solder bath for 30 seconds.
The state of occurrence of cracks in the solder resist on the evaluation substrate subjected to solder plating in this way, and the degree to which the solder resist floated from the substrate and peeling were observed with a 100-fold metal microscope. The results were evaluated according to the following criteria. In other words, “O” indicates that no cracking of the solder resist was observed and no solder resist was lifted or peeled off, and “X” indicates that any of them was recognized.

(Crack resistance)
For the evaluation substrate having a solder resist obtained in the same manner as in the above “plating resistance” test, after being exposed to the atmosphere of −55 ° C. for 15 minutes, the temperature was increased at a temperature increase rate of 180 ° C./min. Next, after being exposed to the atmosphere at 125 ° C. for 15 minutes, a test was performed in which a heat cycle in which the temperature was lowered at a rate of 180 ° C./min.
After the test, cracks and peeling of the solder resist (permanent resist film) on the evaluation substrate were observed with a 100-fold metal microscope and evaluated according to the following criteria. That is, those that could not observe cracks and peeling of the solder resist were marked with “◯”, and those that could confirm any of them were marked with “x”.

(HAST resistance)
First, a copper surface of a printed wiring board substrate (trade name E-679, manufactured by Hitachi Chemical Co., Ltd.) in which a 12 μm thick copper foil is laminated on a glass epoxy base material is etched to have a line / space of 50 μm / 50 μm. It was processed into a comb-type electrode. This was used as an evaluation wiring board.
A solder resist made of a cured product of a resist was formed on the comb-shaped electrode of this evaluation wiring board in the same manner as in the “plating resistance” test, and this was used as an evaluation substrate. This evaluation substrate was exposed to a super accelerated high temperature high humidity life test (HAST) bath for 100 hours under the conditions of 130 ° C./85%/5V. After the test, the degree of migration in each evaluation substrate was observed with a 100-fold metal microscope and evaluated according to the following criteria. That is, “◯” indicates that no significant migration occurred in the solder resist (permanent resist film), and “X” indicates that significant migration occurred. Migration is a phenomenon in which discoloration of the solder resist around the electrode and a decrease in insulation resistance occur when copper is eluted and deposited from the copper electrode to the solder resist.

(Laminate)
First, the copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) having a size of 25 cm in length and 20 cm in width obtained by laminating a 12 μm thick copper foil on a glass epoxy substrate. After polishing, washing with water and drying with an abrasive brush, a wiring pattern was formed by processing by etching, and this was used as a substrate for evaluation.
Using a continuous press type vacuum laminator (trade name: MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) on the wiring pattern of the evaluation substrate, the hot plate temperature is 70 ° C., the evacuation time is 20 seconds, the lamination press time is 30 seconds, and the atmospheric pressure. The polyethylene film of the photosensitive film was peeled off and laminated under conditions of 4 kPa or less and a pressure bonding pressure of 0.4 MPa.
After the lamination, bubbles between the substrate of the laminate and the photosensitive resin composition layer and between the wiring patterns were visually observed and evaluated according to the following criteria. That is, “O” indicates that no bubbles were observed between the substrate and the photosensitive resin composition layer and between the wiring patterns, and “X” indicates that bubbles were observed.

(Resolution)
The evaluation laminate obtained in the same manner as in the above “Plating Resistance” test was allowed to stand at room temperature for 1 hour, and then a direct drawing exposure machine using a 405 nm blue-violet laser diode as a light source (Hitachi Via Mechanics Co., Ltd.) Using product data “DE-1AH”), drawing data having a wiring pattern having a line width / space width of 6/6 to 47/47 (unit: μm) is used from above the evaluation laminate. Then, exposure was carried out with an energy amount at which the number of remaining step steps after development of the stove 21-step step tablet was 14.
The polyethylene terephthalate on the evaluation laminate after exposure is peeled off and spray-developed with a 1% by weight aqueous sodium carbonate solution at 30 ° C. for 1.7 times the minimum development time (minimum time for removing unexposed areas). Then, the unexposed part was removed and the resolution was evaluated. The value of the resolution is represented by the smallest value among the space widths (μm) in which the unexposed portions can be completely removed by the development processing, and the smaller the numerical value, the higher the resolution.

  As shown in Table 2, when the photosensitive resin composition of the present invention containing all of the components (a) to (e) was used (Examples 1 to 3), excellent plating resistance and solder heat resistance were obtained. In addition, it was confirmed that sufficient crack resistance, HAST resistance, laminating properties, and resolution were obtained. On the other hand, in Comparative Examples 1 and 2 not including any of the components (a) to (e), the plating resistance or solder heat resistance was insufficient.

It is a figure which shows typically the cross-sectional structure of the photosensitive film of suitable embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive film, 10 ... Support body, 20 ... Photosensitive resin composition layer, 30 ... Protective film.

Claims (6)

(A) a binder polymer, (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups, (c) a polyurethane compound, and (d) a photopolymerization initiator, (e) containing an inorganic filler, The photosensitive resin in which the polyurethane compound (c) is obtained by reacting an epoxy acrylate compound having an ethylenically unsaturated group and two or more hydroxyl groups, a diisocyanate compound, and a diol compound having a carboxyl group. Composition. 2. The photosensitive resin composition according to claim 1, wherein the content of the (e) inorganic filler is 10 to 200 parts by weight with respect to 100 parts by weight in total of the components (a), (b), and (c). . The photosensitive resin composition of Claim 1 or Claim 2 whose said (a) binder polymer is a vinyl-type copolymer compound obtained by making a (meth) acrylic acid and a (meth) acrylic-acid alkylester into a copolymerization component. object. (F) The photosensitive resin composition as described in any one of Claim 1 thru | or 3 which further contains block type isocyanate. A photosensitive film provided with a support body and the layer which consists of a photosensitive resin composition as described in any one of Claim 1 thru | or 4 formed on this support body. The photosensitive permanent resist which consists of a photocured material of the photosensitive resin composition as described in any one of Claim 1 thru | or 4 apply | coated on the board | substrate for printed wiring boards.

Images