JP2020056844A - Photosensitive resin composition, dry film, cured product, and electronic component - Google Patents

Abstract

To provide a photosensitive resin composition from which a cured film, which has excellent chemical resistance, excellent flexibility, and low CTE even when cured at a low-temperature around 220°C, can be obtained, the photosensitive resin composition being suitably used for an insulating film for rewiring, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and an electronic component having the cured product.SOLUTION: The photosensitive resin composition or the like is characterized by including a polybenzoxazole precursor (A), a photosensitizer (B), and a bifunctional or higher functional epoxy compound having a naphthalene skeleton (C).SELECTED DRAWING: None

Description

  The present invention relates to a photosensitive resin composition, a dry film, a cured product, and an electronic component.

  Conventionally, as an insulating material for rewiring in a semiconductor element, a resin composition containing a polybenzoxazole precursor (hereinafter, also referred to as a “PBO precursor”) as a main component has been used. The PBO precursor is heated at a high temperature (> 350 ° C.) to undergo a cyclization reaction to form a benzoxazole ring, which results in a rigid structure and an increase in packing density between molecules. According to the contained resin composition, a cured film having excellent mechanical properties such as chemical resistance, thermal properties and flexibility can be obtained.

  On the other hand, in recent years, a so-called molding-first type fan-out wafer-level package method has been developed in which a chip is sealed with a sealant and then rewiring is formed. Therefore, as an insulating material for rewiring used in such a method, a material that can be cured at a low temperature of about 220 ° C. is required from the viewpoint of heat resistance of a sealing material containing an epoxy resin as a main component.

  However, at such a low temperature, the resin composition containing the PBO precursor does not sufficiently advance the cyclization of the PBO precursor, and has various properties such as chemical resistance, thermal properties, and mechanical properties such as flexibility. There was a problem that it would decrease.

  On the other hand, conventionally, in order to solve these problems, various approaches for adding a crosslinking agent to a resin composition containing a PBO precursor have been proposed. For example, Patent Document 1 proposes a resin composition containing an alkali-soluble resin selected from a polyimide precursor and a PBO precursor and an epoxy compound having a specific structure.

JP 2014-111718 A

According to the technology described in Patent Document 1, it is true that an epoxy compound having a specific structure is blended into a resin composition as a cross-linking agent, so that such a resin composition has excellent chemical resistance even when cured at low temperatures. This gives a cured product of the nature.
However, in a wafer provided with an insulating film using a resin composition as described in Patent Document 1, there still remain problems such as warpage and cracks in the insulating film. The inventors of the present invention have conducted intensive studies on such a problem. As a result, when the compound described in Patent Document 1 is used as a cross-linking agent, the CTE (linear thermal expansion coefficient) of the insulating film is increased. The inventors have noticed that warpage occurs due to the difference in CTE from the above and that the stress due to this warp is applied to the insulating film, thereby causing cracks in the insulating film.

  In addition, the inventors have noticed that there is a trade-off problem that imparting mechanical properties such as flexibility to the low-temperature cured insulating film for rewiring leads to an increase in CTE and a decrease in chemical resistance. That is, it was found that it is important for the resin composition suitable for the insulating film for rewiring to achieve both low CTE and flexibility.

Accordingly, a main object of the present invention is to provide a low-CTE insulating film having excellent chemical resistance and excellent flexibility even when curing is performed at a low temperature of about 220 ° C. It is to provide a photosensitive resin composition suitable for use in an insulating film.
Another object of the present invention is to provide a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and an electronic component having the cured product. .

  The present inventors have intensively studied to achieve the above object. As a result, it has been found that the photosensitive resin composition containing a PBO precursor can solve the above-mentioned problem by including a bifunctional or more functional epoxy compound having a naphthalene skeleton as a crosslinking agent, thereby completing the present invention. Was.

  That is, the photosensitive resin composition of the present invention comprises (A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) a bifunctional or higher functional epoxy compound having a naphthalene skeleton. It is.

  It is preferable that the photosensitive resin composition of the present invention further contains a crosslinking agent having a triazine ring structure.

  The dry film of the present invention is characterized by having a resin layer obtained by applying and drying the photosensitive resin composition on a film.

  The cured product of the present invention is obtained by curing the photosensitive resin composition or the resin layer of the dry film.

  An electronic component according to the present invention includes the cured product.

  According to the present invention, even when curing is performed at a low temperature of about 220 ° C., a low CTE cured film having excellent chemical resistance and excellent flexibility can be obtained, and an insulating film for rewiring. To provide a suitable photosensitive resin composition. Further, according to the present invention, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and an electronic component having the cured product can be provided.

  Hereinafter, the components contained in the photosensitive resin composition of the present invention will be described in detail.

[(A) Polybenzoxazole precursor]
The photosensitive resin composition of the present invention contains (A) a polybenzoxazole precursor. (A) The method for synthesizing the polybenzoxazole precursor is not particularly limited, and may be a known method. For example, it can be obtained by reacting a dihydroxydiamine as an amine component with a dicarboxylic acid component such as dicarboxylic acid dichloride, dicarboxylic acid, or dicarboxylic acid ester as an acid component.

（式中、Ｘは４価の有機基を示し、Ｙは２価の有機基を示す。ｎは２以上の整数であり、好ましくは１０〜２００、より好ましくは２０〜７０である。） (A) The polybenzoxazole precursor is preferably a polyhydroxyamide, and more preferably a polyhydroxyamide having a repeating structure represented by the following general formula (1).

(In the formula, X represents a tetravalent organic group, and Y represents a divalent organic group. N is an integer of 2 or more, preferably 10 to 200, and more preferably 20 to 70.)

  (A) When synthesizing the polybenzoxazole precursor by the above synthesis method, in the above general formula (1), X is a residue of the above dihydroxydiamine, and Y is a residue of the above dicarboxylic acid component. is there.

  Examples of the dihydroxydiamine having the above-mentioned repeating structure include 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, and bis (3-amino-4-hydroxy Phenyl) propane, bis (4-amino-3-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone, 2,2-bis (3 -Amino-4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-amino-3-hydroxyphenyl) -1,1,1,3,3 , 3-hexafluoropropane and the like. Among them, 2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane is preferred.

  Examples of the dicarboxylic acid component having the above repeating structure include isophthalic acid, terephthalic acid, 5-tert-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, and 2,6-naphthalenedicarboxylic acid. 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis (4-carboxyphenyl) sulfone, 2,2-bis (p-carboxyphenyl) Dicarboxylic acid having an aromatic ring such as propane, 2,2-bis (4-carboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, oxalic acid, malonic acid, succinic acid, 1,2 -Cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclopentanedica It includes aliphatic dicarboxylic acids such as carbon acid. Among them, 4,4'-dicarboxydiphenyl ether is preferred.

  In the general formula (1), the tetravalent organic group represented by X may be either an aliphatic group or an aromatic group, but is preferably an aromatic group, and two hydroxy groups and two amino groups are located at ortho positions. More preferably, it is located on an aromatic ring. The tetravalent aromatic group preferably has 6 to 30 carbon atoms, more preferably 6 to 24 carbon atoms. Specific examples of the tetravalent aromatic group include, but are not limited to, the following groups.A known aromatic group that can be included in the polybenzoxazole precursor is selected according to the application. do it.

The tetravalent aromatic group is preferably a group shown below among the above aromatic groups.

  In the general formula (1), the divalent organic group represented by Y may be either an aliphatic group or an aromatic group, but is preferably an aromatic group. More preferably, it is bonded to The divalent aromatic group preferably has 6 to 30 carbon atoms, more preferably 6 to 24 carbon atoms. Specific examples of the divalent aromatic group include the following groups, but are not limited thereto, and any known aromatic group contained in the polybenzoxazole precursor may be selected according to the application. I just need.

（式中、Ａは単結合、−ＣＨ_２−、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ_２−、−ＮＨＣＯ−、−Ｃ（ＣＦ_３）_２−、−Ｃ（ＣＨ_３）_２−からなる群から選択される２価の基を表す。）

(In the formula, A is a single _{bond, -CH 2 -, - O -} , - CO -, - S -, - SO 2 -, - NHCO -, - C (CF 3) 2 -, - C (CH 3) ₂ - represents a divalent radical selected from the group consisting of).

The divalent organic group is preferably a group shown below among the aromatic groups.

  (A) The polybenzoxazole precursor may contain two or more kinds of the above-mentioned polyhydroxyamide repeating structures. Further, (A) the polybenzoxazole precursor may include a structure other than the above-described polyhydroxyamide repeating structure, and may include, for example, a polyamic acid repeating structure or a benzoxazole structure.

  (A) The number average molecular weight (Mn) of the polybenzoxazole precursor is preferably from 1,000 to 100,000, and more preferably from 5,000 to 50,000. Here, the number average molecular weight is a value measured by gel permeation chromatography (GPC) and converted into standard polystyrene. The weight average molecular weight (Mw) of (A) the polybenzoxazole precursor is preferably from 5,000 to 200,000, and more preferably from 10,000 to 100,000. Here, the weight average molecular weight is a value measured by GPC and converted into standard polystyrene. Mw / Mn is preferably from 1 to 5, more preferably from 1 to 3.

  As the polybenzoxazole precursor (A), one type may be used alone, or two or more types may be used in combination.

[(B) Photosensitizer]
The photosensitive resin composition of the present invention contains (B) a photosensitive agent. (B) The photosensitive agent is not particularly limited, and a photoacid generator or a photobase generator can be used. The photoacid generator is a compound that generates an acid by irradiation with light such as ultraviolet light or visible light, and the photobase generator changes the molecular structure or cleaves the molecule by the same light irradiation. A compound that produces more than one basic substance. In the present invention, a photoacid generator can be suitably used as the photosensitive agent (B).

  Examples of the photoacid generator include naphthoquinonediazide compounds, diarylsulfonium salts, triarylsulfonium salts, dialkylphenacylsulfonium salts, diaryliodonium salts, aryldiazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, and nitrobenzyl esters , Aromatic N-oxyimide sulfonate, aromatic sulfamide, benzoquinonediazosulfonic acid ester and the like. The photoacid generator is preferably a dissolution inhibitor. Among them, a naphthoquinonediazide compound is preferred.

  As the naphthoquinonediazide compound, specifically, for example, a naphthoquinonediazide adduct of tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (for example, TS533, TS567, TS583, and TS593 manufactured by Sanbo Chemical Laboratory Co., Ltd.) ), A naphthoquinonediazide adduct of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sanpo Chemical Laboratory), or 4- {4- [1,1-bis (4-hydroxyphenyl) ethyl] -α , Α-dimethylbenzyl} phenol naphthoquinonediazide adduct (for example, TKF-428 and TKF-528 manufactured by Sanbo Chemical Laboratory Co., Ltd.) and the like can be used.

  The photobase generator may be an ionic photobase generator or a non-ionic photobase generator, but the ionic photobase generator has higher sensitivity of the composition and is suitable for forming a pattern film. It is preferable because it becomes advantageous. Examples of the basic substance include a secondary amine and a tertiary amine.

  Examples of the ionic photobase generator include salts of aromatic component-containing carboxylic acids and tertiary amines, and ionic PBGs WPBG-082, WPBG-167, WPBG-168, and WPBG- manufactured by Wako Pure Chemical Industries, Ltd. 266, WPBG-300 or the like can be used.

  Non-ionic photobase generators include, for example, α-aminoacetophenone compounds, oxime ester compounds, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzyl carbamate groups, and alkoxyoxybenzyl groups. Compounds having a substituent such as a carbamate group are exemplified. As other photobase generators, WPBG-018 (trade name: 9-anthrylmethyl N, N'-diethylcarbamate) and WPBG-027 (trade name: (E) -1- [3- (2) manufactured by Wako Pure Chemical Industries, Ltd.] -Hydroxyphenyl) -2-propenoyl] piperidine), WPBG-140 (trade name: 1- (anthraquinon-2-yl) ethyl imidazolecarboxylate), WPBG-165 and the like can also be used.

  As the photosensitive agent (B), one type may be used alone, or two or more types may be used in combination. The amount of the photosensitive agent (B) is preferably 3 to 30 parts by mass with respect to 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (A).

[(C) Bifunctional or higher functional epoxy compound having naphthalene skeleton]
The photosensitive resin composition of the present invention contains (C) a bifunctional or higher functional epoxy compound having a naphthalene skeleton (hereinafter, also simply referred to as “(C) naphthalene-type epoxy compound”). (C) The naphthalene type epoxy compound thermally reacts with the hydroxyl group of the polybenzoxazole precursor to form a crosslinked structure, thereby not only improving the chemical resistance of the cured product, but also surprisingly, And contribute to lower CTE.

  (C) The naphthalene-type epoxy compound is not particularly limited as long as it has a naphthalene skeleton and has two or more epoxy groups. For example, 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 6-diglycidyl naphthalene, 1,7-diglycidyl naphthalene, 2,7-diglycidyl naphthalene, triglycidyl naphthalene, 1,2,5,6-tetraglycidyl naphthalene, naphthol aralkyl type epoxy resin, naphthalene skeleton modified cresol novolak And modified naphthalene-type epoxy resins such as methoxynaphthalene-modified cresol novolak-type epoxy resin, naphthylene ether-type epoxy resin, and methoxynaphthalene-di-methylene-type epoxy resin. As the (C) naphthalene type epoxy compound, one type may be used alone, or two or more types may be used in combination.

  Commercially available products include DIC Corporation's HP-4032D, HP-4700, HP-4770, HP-5000, HP-6000, HP-4710, Nippon Kayaku's NC-7000L, NC-7300L, and the like.

  (C) The naphthalene-type epoxy compound may or may not have a flexible chain in the structure, but improves the flexibility of the cured product of the photosensitive resin composition of the present invention without having the flexible chain. Therefore, for example, the epoxy group may not have a linear structure having 5 to 10 atoms, and more preferably 3 to 5 atoms, between the epoxy groups.

  (C) The epoxy equivalent of the naphthalene type epoxy compound is preferably from 100 to 300 g / eq.

  (C) The compounding amount of the naphthalene-type epoxy compound is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (A). I do. By setting the content in such a range, it is possible to maintain an appropriate crosslinking density for the (A) polybenzoxazole precursor.

(Other crosslinking agents)
The photosensitive resin composition of the present invention may contain (C) a crosslinking agent other than a bifunctional or higher epoxy compound having a naphthalene skeleton. In the present specification, the other crosslinking agent is preferably a compound that reacts with the phenolic hydroxyl group of the polybenzoxazole precursor and forms a crosslinked structure, other than the naphthalene-type epoxy compound. Here, the functional group that reacts with the phenolic hydroxyl group of the polybenzoxazole precursor includes a cyclic ether group such as an epoxy group, a cyclic thioether group such as an episulfide group, an alkylene group having 1 to 12 carbon atoms such as a methylol group, and a hydroxyl group. An alcoholic hydroxyl group to which a group is bonded is exemplified.

（式中、Ｒ^２１Ａ、Ｒ^２２Ａ、Ｒ^２３Ａ、Ｒ^２４Ａ、Ｒ^２５ＡおよびＲ^２６Ａはそれぞれ独立に炭素数１〜３のアルキレン基であることが好ましい。Ｒ^２１Ｂ、Ｒ^２２Ｂ、Ｒ^２３Ｂ、Ｒ^２４Ｂ、Ｒ^２５ＢおよびＲ^２６Ｂはそれぞれ独立に水素原子、または、炭素数１〜３のアルキル基であることが好ましい。） As other crosslinking agents, among others, a crosslinking agent having a triazine ring structure is preferable, and in the present invention, the elongation of the cured product can be further improved. The crosslinking agent having a triazine ring structure is not particularly limited, but is preferably a crosslinking agent represented by the following general formula (2).

(In the formula, R ^21A , R ^22A , R ^23A , R ^24A , R ^25A and R ^26A are each independently preferably an alkylene group having 1 to 3 carbon atoms. R ^21B , R ^22B , R ^23B , R ^24B , R ^25B and R ^26B are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

In the general formula (C), each of R ^21A , R ^22A , R ^23A , R ^24A , R ^25A and R ^26A is more preferably a methylene group. More preferably, R ^21B , R ^22B , R ^23B , R ^24B , R ^25B and R ^26B are each independently a methyl group or a hydrogen atom.

  As the other crosslinking agents, one type may be used alone, or two or more types may be used in combination. The amount of the other crosslinking agent is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the non-volatile component of the polybenzoxazole precursor so that the developability is not impaired by the crosslinking. Moreover, 0.1-20 mass parts is more preferable.

(Plasticizer)
The photosensitive resin composition of the present invention preferably contains a plasticizer. The plasticizer is not particularly limited as long as it is a compound that improves plasticity. In the present invention, by blending a plasticizer, (A) the cyclization reaction of the polybenzoxazole precursor is promoted, and a low-temperature curability is further improved, and a cured product having excellent chemical resistance can be obtained. . Originally, when cured at a low temperature of about 220 ° C., the cyclization rate of (A) the polybenzoxazole precursor is low, and when a crosslinking agent is added, the curability at a low temperature can be improved. And the crosslinking agent react, the cyclization rate can be further reduced. Although the detailed mechanism is not clear, in the present invention, the plasticizing action of the plasticizer, that is, the aggregation action between polymer molecular chains is reduced, and the mobility and flexibility between the molecular chains are improved. It is considered that the thermal molecular motion of the polybenzoxazole precursor was improved, and the cyclization reaction was promoted. Further, in the present invention, by blending a plasticizer, a cured product having more excellent flexibility can be obtained. Furthermore, in the present invention, although the development resistance of the unexposed area is excellent by blending the (C) naphthalene-type epoxy compound, the development property of the exposed area is improved by blending a plasticizer. Pattern formation becomes possible. One type of plasticizer may be used alone, or two or more types may be used in combination. The plasticizer is preferably a plasticizer that does not undergo a cross-linking reaction with other components in the composition. Further, the plasticizer preferably does not have a function of generating thermal acid.

  The plasticizer may be a plasticizer having a self-polymerizable group or a plasticizer having no self-polymerizable group. Examples of the self-polymerizable group include a (meth) acryloyl group, a vinyl group and an allyl group. In this specification, the term “(meth) acryloyl group” is a general term for an acryloyl group, a methacryloyl group, and a mixture thereof, and the same applies to other similar expressions.

  The photosensitive resin composition of the present invention can further improve the flexibility of a cured product by containing a plasticizer having a self-polymerizable group. The plasticizer having a self-polymerizable group is preferably a bifunctional (meth) acrylic compound. The bifunctional (meth) acrylic compound is preferably a compound that does not form a crosslinked structure with other components in the composition. Further, the bifunctional (meth) acrylic compound is preferably a compound that forms a linear structure by self-polymerization.

  The bifunctional (meth) acrylic compound is not particularly limited as long as it has two (meth) acryloyl groups. Specific examples thereof include 1,4-butanediol diacrylate and 1,6-hexanediol diacrylate. Diols such as 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate , Dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, neopentyl glycol Diacrylate of diol obtained by adding at least one of ethylene oxide and propylene oxide to diene, diacrylate of glycol such as caprolactone-modified neopentyl glycol dihydroxypivalate diacrylate, bisphenol A EO (ethylene oxide) adduct Acrylate, bisphenol A PO (propylene oxide) adduct diacrylate, bisphenol A diglycidyl ether acrylic acid adduct, tricyclodecane dimethanol diacrylate, tris (2-hydroxyethyl) isocyanurate bisphenol A to ethylene oxide and propylene oxide Diacrylates of diols obtained by adding at least one of them, hydrogenated dicyclopentadienyl diacrylate, Diacrylates having a cyclic structure such as Russia hexyl diacrylate, diacrylates of isocyanuric acid, such as isocyanuric acid ethylene oxide modified diacrylate, difunctional polyester acrylate, and the like methacrylates corresponding to these.

  Commercially available products include light acrylate 1,6HX-A, 1,9ND-A, 3EG-A, 4EG-A (trade name of Kyoeisha Chemical Co., Ltd.), HDDA, 1,9-NDA, DPGDA, TPGDA (Daicel. ORNEX Co., Ltd.), VISCOAT # 195, # 230, # 230D, # 260, # 310HP, # 335HP, # 700HV, # 540 (Osaka Organic Chemical Industry Co., Ltd.), ARONIX M-208, M -21B, M-215, M-220, M-225, M-240, M-270, M-6200, M-6250, M-6500 (trade name of Toagosei Co., Ltd.), NK ester BPE-200, BPE-500, BPE-900 (trade name of Shin-Nakamura Chemical Co., Ltd.) and the like.

  Among the bifunctional (meth) acrylic compounds, di (meth) acrylate or bifunctional polyester (meth) acrylate of an alkylene oxide adduct of diol (such as ethylene oxide or propylene oxide) is preferable, and bifunctional polyester (meth) acrylate is preferable. ) Acrylates are more preferred.

  As the di (meth) acrylate of the alkylene oxide adduct of the diol, specifically, one obtained by modifying the diol with an alkylene oxide and then adding a (meth) acrylate to the terminal is preferable, and one having an aromatic ring in the diol is more preferable. . For example, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate and the like can be mentioned. The specific structure of the di (meth) acrylate of the diol alkylene oxide adduct is shown below, but is not limited thereto.

（式中、ｍ＋ｎは２以上であり、２〜４０であることが好ましく、３．５〜２５であることがより好ましい。）

(In the formula, m + n is 2 or more, preferably 2 to 40, and more preferably 3.5 to 25.)

  As the bifunctional polyester (meth) acrylate, M-6200, M-6250, and M-6500 (trade names manufactured by Toagosei Co., Ltd.) are preferable.

  The blending amount of the plasticizer having a self-polymerizable group is preferably 3 to 40 parts by mass with respect to 100 parts by mass of the non-volatile component of the polybenzoxazole precursor. Can be.

The photosensitive resin composition of the present invention can further improve the chemical resistance of the cured product by containing a plasticizer having no self-polymerizable group. Examples of the plasticizer having no self-polymerizable group include sulfonamide compounds such as N-butylbenzenesulfonamide and N-ethyl-p-toluenesulfonamide, dimethyl phthalate, diethyl phthalate, and di (2-ethylhexyl phthalate). ), Maleic acid ester compounds such as di (2-ethylhexyl) maleate, trimellitic acid esters such as tris (2-ethylhexyl) trimellitate, aliphatic dibases such as dimethyl adipate and dibutyl adipate Phosphate esters such as acid esters, trimethyl phosphate, and tris (butoxyethyl) phosphate; (C ₆ H ₅ O) ₂ P (O) OC ₆ H ₄ C (CH ₃ ) ₂ C ₆ H ₄ OP (O) (OC ₆ H ₅₎ aromatic condensed phosphoric acid esters such as represented by _2, class N'eteru like ether compounds such as. Among them, a sulfonamide compound, a phthalate compound and a maleate compound are preferred.

  The sulfonamide compound is preferably a benzenesulfonamide compound represented by the following general formula (3).

（一般式（３）中、Ｒ^３１は、有機基、ニトロ基、ハロゲン原子、スルホ基、スルホニル基、アミノ基またはアミド基であり、Ｒ^３２は、水素原子または有機基であり、ｎは０〜５の整数である。ｎが２以上の場合、Ｒ^３１はそれぞれ同じであっても異なっていてもよい。）

(In the general formula (3), R ³¹ is an organic group, a nitro group, a halogen atom, a sulfo group, a sulfonyl group, an amino group, or an amide group; R ³² is a hydrogen atom or an organic group; An integer of from 5 to 5. When n is 2 or more, R ³¹ may be the same or different.)

  The maleic ester compound is preferably a compound represented by the following general formula (4).

（一般式（４）中、Ｒ^４１およびＲ^４２は、それぞれ独立に水素原子、有機基、ニトロ基、ハロゲン原子、スルホ基、スルホニル基、アミノ基またはアミド基であり、Ｒ^４１とＲ^４２は、結合して環を形成してもよい。Ｒ^４３は水素原子または有機基であり、Ｒ^４４は、水素原子または有機基である。）

(In the general formula (4), R ⁴¹ and R ⁴² are each independently a hydrogen atom, an organic group, a nitro group, a halogen atom, a sulfo group, a sulfonyl group, an amino group or an amide group, and R ⁴¹ and R ⁴² are And R ⁴³ may be a hydrogen atom or an organic group, and R ⁴⁴ may be a hydrogen atom or an organic group.)

  In the general formulas (3) and (4) and the general formulas (5) and (6) described later, the organic group is a group containing a carbon atom. Examples of the organic group include an alkyl group having 1 to 12 carbon atoms, which may be linear or branched.

  The compounding amount of the plasticizer having no self-polymerizable group is preferably 1 to 50 parts by mass, more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor. preferable. When the amount is 1 part by mass or more, a plasticizing effect is easily exhibited, and when the amount is 50 parts by mass or less, the characteristics of the obtained cured film are not impaired.

  In the present invention, it is preferable to use a plasticizer having a self-polymerizable group and a plasticizer not having a self-polymerizable group in combination, and a cured product excellent in flexibility and chemical resistance can be obtained.

(Thermal acid generator)
The photosensitive resin composition of the present invention preferably contains a thermal acid generator. In the present invention, it is considered that the phenolic hydroxyl group of the (A) polybenzoxazole precursor reacts with the epoxy group of the (C) naphthalene-type epoxy compound to form a crosslinked structure. Since the dielectric properties are deteriorated due to the generation of hydroxyl groups in the structure, there is room for improvement as an insulating material. Although the detailed mechanism is not clear, when the thermal acid generator is blended in the present invention, the cyclization reaction at a low temperature is promoted by acting as a catalyst for the cyclization reaction of the polybenzoxazole precursor (A). Dielectric properties are improved by reducing the number of hydroxyl groups in the crosslinked structure, and a cured product having more excellent chemical resistance and heat resistance can be obtained by promoting the cyclization reaction. One kind of the thermal acid generator may be used alone, or two or more kinds may be used in combination.

  The thermal acid generator is not particularly limited as long as an acid is generated by heat. Examples of the generated acid include, for example, sulfonic acid, carboxylic acid, acetic acid, hydrochloric acid, nitric acid, bromic acid, and iodic acid.From the viewpoint of cyclization efficiency, strong acids are preferable, and benzenesulfonic acid and p-toluene are preferable. Sulfonic acids such as arylsulfonic acids such as sulfonic acid, perfluoroalkylsulfonic acids such as trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid and camphorsulfonic acid, and alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid and butanesulfonic acid. Is preferred. These acids are added to the photosensitive resin composition as a thermal acid generator, for example, a salt as an onium salt or a compound latentified by a covalent bond such as imidosulfonate.

  Specific examples of the thermal acid generator include sulfonic ester compounds, sulfonimide compounds, sulfonium salts, 2-sulfobenzoic anhydride, p-toluenesulfonic anhydride, benzothiazolium salts, ammonium salts, phosphonium salts, Sulfonates and the like. Among these, a sulfonic acid ester compound and a sulfonic acid salt are preferable. The thermal acid generator is preferably a compound that generates a strong acid (having an acid dissociation constant pKa in water of 0 or less) by heat.

  Examples of the sulfonic acid ester compound include ethyl methanesulfonate, methyl methanesulfonate, 2-methoxyethyl methanesulfonate, 2-isopropoxyethyl methanesulfonate, cyclohexyl 4-methylbenzenesulfonate, (1R, 2S, 5R)- 5-methyl-2- (propan-2-yl) cyclohexyl 4-methylbenzenesulfonic acid, phenyl p-toluenesulfonate, ethyl p-toluenesulfonate, methyl p-toluenesulfonate, 2-phenyl p-toluenesulfonate Ethyl, n-propyl p-toluenesulfonate, n-butyl p-toluenesulfonate, t-butyl p-toluenesulfonate, n-hexyl p-toluenesulfonate, n-heptyl p-toluenesulfonate, p-toluene N-octyl sulfonate, p-tolue 2-methoxyethyl sulfonate, propargyl p-toluenesulfonate, 3-butynyl p-toluenesulfonate, ethyl trifluoromethanesulfonate, n-butyl trifluoromethanesulfonate, ethyl perfluorobutanesulfonate, methyl perfluorobutanesulfonate Benzyl (4-hydroxyphenyl) methylsulfonium hexafluoroantimonate, benzyl (4-hydroxyphenyl) methylsulfonium hexafluorophosphate, trimethylsulfonium methylsulfate, tri-p-sulfonium trifluoromethanesulfonate, trimethylsulfonium trifluoromethanesulfonate, Pyridinium-p-toluenesulfonate, ethyl perfluorooctanesulfonate, 1,4-butanesultone, 2 , 4-butane sultone, 1,3-propane sultone, phenol red, bromocresol green, bromocresol purple and the like.

  As the sulfonic acid ester compound, a compound represented by the following general formula (5) is preferable.

（一般式（５）中、Ｒ^５１は、水素原子またはアルキル基を表し、Ｒ^５２は、水素原子または有機基を表す。）

(In the general formula (5), R ⁵¹ represents a hydrogen atom or an alkyl group, and R ⁵² represents a hydrogen atom or an organic group.)

The alkyl group which R ⁵¹ can have may be straight-chain or branched. Further, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 6.

The organic group which R ⁵² can take may be linear or branched, and may have a cyclic structure. The number of carbon atoms is preferably from 1 to 16, more preferably from 1 to 11.

  As the sulfonate, a compound represented by the following general formula (6) is preferable.

（一般式（６）中、Ｒ^６１は水素原子またはアルキル基を表し、Ｒ^６２、Ｒ^６３はそれぞれ独立に水素原子または有機基を表す。Ｒ^６２とＲ^６３は結合して環を形成してもよい。）

(In the general formula (6), R ⁶¹ represents a hydrogen atom or an alkyl group, and R ⁶² and R ⁶³ each independently represent a hydrogen atom or an organic group. R ⁶² and R ⁶³ are bonded to form a ring. May be.)

The alkyl group which R ⁶¹ can take may be straight-chain or branched. Further, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 6.

The organic group that can be taken by R ⁶² and R ⁶³ may be linear or branched.

  Among the thermal acid generators, a thermal acid generator that generates an acid at 120 to 220 ° C is preferable. In the case of a thermal acid generator that generates an acid at a temperature of 120 ° C. or higher, the reaction hardly proceeds during prebaking, and a development residue hardly occurs. Further, a thermal acid generator that generates an acid at 150 to 220 ° C. is preferable. The generation of acid can be confirmed at the temperature at which the weight is reduced by TG-DTA.

  The amount of the thermal acid generator is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor. More preferably, it is 1 to 3 parts by mass.

(Sensitizers, adhesives, and other components)
The photosensitive resin composition of the present invention includes, within a range not impairing the effects of the present invention, a known sensitizer for further improving the photosensitivity, and a silane coupling agent for improving the adhesion to the substrate. Can also be blended. Further, in order to impart processing characteristics and various functions to the photosensitive resin composition of the present invention, various other organic or inorganic low-molecular or high-molecular compounds may be blended. For example, a surfactant, a leveling agent, fine particles, and the like can be used. The fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as silica, carbon, and layered silicate. Further, various colorants, fibers and the like may be blended in the photosensitive resin composition of the present invention.

(solvent)
The solvent used in the photosensitive resin composition of the present invention includes (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a bifunctional or more functional epoxy compound having a naphthalene skeleton, and other additives. There is no particular limitation as long as it dissolves. Examples include N, N′-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N, N′-dimethylacetamide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ- Examples include butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoramide, pyridine, γ-butyrolactone, and diethylene glycol monomethyl ether. These may be used alone or in combination of two or more. The amount of the solvent to be used can be appropriately determined according to the coating film thickness and the viscosity. For example, it can be used in the range of 50 to 9000 parts by mass based on 100 parts by mass of the polybenzoxazole precursor (A).

  The photosensitive resin composition of the present invention is preferably of a positive type.

[Dry film]
The dry film of the present invention has a resin layer obtained by applying the photosensitive resin composition of the present invention to a film (for example, a support (carrier) film) and then drying. This resin layer is used after being laminated so as to be in contact with the base material.

  The dry film of the present invention is formed by uniformly applying the photosensitive resin composition of the present invention to the film by an appropriate method such as a blade coater, a lip coater, a comma coater, a film coater, and the like, and drying to form the above-described resin layer. Preferably, it can be manufactured by laminating a film (a so-called protective (cover) film) thereon. The same film material may be used for the protective film and the support film, or different films may be used.

In the dry film of the present invention, as the film material of the support film and the protective film, any of those known as materials used for dry films can be used.
As the support film, for example, a thermoplastic film such as a polyester film such as polyethylene terephthalate having a thickness of 2 to 150 μm is used.
As the protective film, a polyethylene film, a polypropylene film, or the like can be used, but a film having lower adhesive strength to the resin layer than the supporting film is preferable.

  The thickness of the resin layer on the dry film of the present invention is preferably 100 μm or less, more preferably 5 to 50 μm.

[Cured product]
The cured product of the present invention is obtained by curing the photosensitive resin composition of the present invention in a predetermined step. The pattern film as the cured product may be manufactured by a known and commonly used manufacturing method. For example, in the case of (B) a positive photosensitive resin composition containing a photoacid generator as a photosensitive agent, the following steps are performed. To manufacture.

First, as step 1, a coating film is obtained by applying and drying a photosensitive resin composition on a substrate, or by transferring a resin layer from a dry film onto a substrate. As a method of applying the photosensitive resin composition on the substrate, a method conventionally used for applying the photosensitive resin composition, for example, a spin coater, a bar coater, a blade coater, a curtain coater, a screen printing machine, and the like , A spray coating method using a spray coater, and an ink jet method. As a method for drying the coating film, methods such as air drying, heating drying using an oven or a hot plate, and vacuum drying are used. It is desirable that the drying of the coating film is performed under such conditions that the cyclization of the polybenzoxazole precursor in the photosensitive resin composition does not occur. Specifically, natural drying, blast drying, or heat drying can be performed at 70 to 140 ° C. for 1 to 30 minutes. Preferably, drying is performed on a hot plate for 1 to 20 minutes. Vacuum drying is also possible. In this case, the drying can be performed at room temperature for 20 minutes to 1 hour.
The substrate on which the coating film of the photosensitive resin composition is formed is not particularly limited, and can be widely applied to semiconductor substrates such as silicon wafers, wiring substrates, various resins, metals, and the like.

  Next, as step 2, the coating film is exposed through a photomask having a pattern or directly. An exposure light having a wavelength capable of activating a photoacid generator (B) as a photosensitive agent is used. Specifically, the exposure light preferably has a maximum wavelength in the range of 350 to 440 nm. As described above, the photosensitivity can be adjusted by appropriately adding a sensitizer. As the exposure device, a contact aligner, a mirror projection, a stepper, a laser direct exposure device, or the like can be used.

  Next, as step 3, the coating film is treated with a developer. This makes it possible to form a pattern film of the photosensitive resin composition of the present invention by removing the exposed portions in the coating film.

  As a method used for development, any method can be selected from conventionally known methods for developing a photoresist, for example, a rotary spray method, a paddle method, an immersion method involving ultrasonic treatment, and the like. Examples of the developer include inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate, and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine; tetramethylammonium hydroxide; and tetrabutylammonium hydroxide. And aqueous solutions of quaternary ammonium salts. If necessary, an appropriate amount of a water-soluble organic solvent such as methanol, ethanol, or isopropyl alcohol or a surfactant may be added to these. Thereafter, if necessary, the coating film is washed with a rinsing liquid to obtain a pattern film. As the rinsing liquid, distilled water, methanol, ethanol, isopropyl alcohol and the like can be used alone or in combination. Further, the above-mentioned solvent may be used as a developer.

  Then, as a step 4, the pattern film is heated to obtain a cured coating film (cured product). By this heating, the polybenzoxazole precursor is cyclized to obtain polybenzoxazole. The heating temperature is appropriately set so that the pattern film of the photosensitive resin composition can be cured. For example, heating is performed at 150 ° C. or more and less than 350 ° C. for about 5 to 120 minutes in an inert gas. A more preferable range of the heating temperature is 180 to 250 ° C. Since the photosensitive resin composition of the present invention contains the (C) naphthalene-type epoxy compound, cyclization is promoted, and the heating temperature can be lower than 250 ° C., and further, 220 ° C. or lower. The heating is performed by using, for example, a hot plate, an oven, and a temperature rising oven in which a temperature program can be set. As the atmosphere (gas) at this time, air may be used, or an inert gas such as nitrogen or argon may be used.

  The use of the photosensitive resin composition of the present invention is not particularly limited. For example, it is suitable as a coating material, a printing ink, or an adhesive, or a display device, a semiconductor device, an electronic component, an optical component, or a building material. Used. Specifically, as a material for forming a display device, a color filter, a film for a flexible display, a resist material, an alignment film, or the like can be used as a layer forming material or an image forming material. In addition, as a material for forming a semiconductor device, a resist material, a layer forming material such as a buffer coat film, or the like can be used. Furthermore, as a material for forming an electronic component, a sealing material or a layer forming material can be used for a printed wiring board, an interlayer insulating film, a wiring coating film, or the like. Furthermore, as a material for forming an optical component, a hologram, an optical waveguide, an optical circuit, an optical circuit component, an antireflection film, or the like can be used as an optical material or a layer forming material. Furthermore, as a building material, it can be used for a paint, a coating agent and the like.

  The photosensitive resin composition of the present invention is mainly used as a pattern forming material, and the pattern film formed thereby functions as a component that imparts heat resistance and insulation as a permanent film made of, for example, polybenzoxazole. In particular, surface protection films for semiconductor devices, display devices and light emitting devices, interlayer insulation films, insulation films for rewiring, protection films for flip-chip devices, protection films for devices having a bump structure, interlayer insulation for multilayer circuits It can be suitably used as a film, an insulating material for passive components, a protective film for a printed wiring board such as a solder resist or a coverlay film, and a liquid crystal alignment film. In particular, the photosensitive resin composition of the present invention is suitable as a material for forming a layer to be laminated, for example, an interlayer insulating film or an insulating film for rewiring, since the cured product has excellent chemical resistance.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, “parts” and “%” are all based on mass unless otherwise specified.

(Synthesis of polybenzoxazole precursor (A1))
2,2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3,3 was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a nitrogen gas inlet. After dissolving 40.3 g (0.11 mol) of hexafluoropropane in 1500 g of N-methyl-2-pyrrolidone, 35.4 g (0.12 mol) of diphenyl ether-4,4′-dicarboxylic acid dichloride was added to the reaction system. The solution was added dropwise while cooling the temperature to 0 to 5 ° C.
After completion of the dropwise addition, the temperature of the reaction system was returned to room temperature, and the mixture was stirred for 6 hours. Thereafter, 1.8 g (0.1 mol) of pure water was added, and the mixture was further reacted at 40 ° C. for 1 hour. After the completion of the reaction, the reaction solution was dropped into 2000 g of pure water. The precipitate was collected by filtration, washed, and dried under vacuum to obtain an alkali-soluble polyhydroxyamide (A1) which is a polybenzoxazole precursor having a repeating structure shown below. The weight average molecular weight was 32,000, the number average molecular weight was 12,500, and the PDI was 2.56.

(Preparation of positive photosensitive resin composition)
The photoacid generator (B1), the epoxy compound (C1, C2, * 1), and the respective components in the ratios shown in Table 1 below are based on 100 parts by mass of the polybenzoxazole precursor (A1) synthesized above. After blending the components, γ-butyrolactone was added so that the content of the polymer was 30% by mass, to give a varnish.

(Preparation of cured film)
A varnish was applied on the wafer using a spin coater MS-A150 manufactured by Mikasa Corporation. After drying on a hot plate at 120 ° C. for 10 minutes, curing was carried out by heating at 150 ° C. for 30 minutes and then at 220 ° C. for 1 hour (heating rate: 4 ° C./min) to obtain a cured film for a physical property test. Thereafter, the wafer was exposed to 121 ° C./100% RH for 1 hour using a pressure cooker test (PCT) apparatus, and peeled from the silicon wafer.

(CTE)
The linear thermal expansion coefficient (CTE) of the cured film was measured using TMAQ400 manufactured by TA Instruments Japan under the following conditions, and evaluated according to the following evaluation criteria.
-TMA measurement conditions Test piece: 15 mm x 3 mm, distance between chucks: 16 mm
Force: 0.03N, nitrogen flow rate: 100mL / min Temperature program: 30 ° C → 350 ° C (10 ° C / min)
A: CTE is less than 45 ppm / ° C B: CTE is 45 ppm / ° C or more and less than 50 ppm / ° C C: CTE is 50 ppm / ° C or more

(chemical resistance)
A wafer having a cured film having a thickness of 10 to 12 μm is cut into a square of 2 cm, immersed in GBL (γ-butyrolactone), washed with water, and dried. The evaluation was based on the evaluation criteria.
A +: Film loss less than 1% A: Film loss 1% or more and less than 3% B: Film loss 3% or more and less than 5% C: Film loss 5% or more

(Elongation)
The elongation percentage of the cured film was measured under the following conditions using EZ-SX manufactured by Shimadzu.
[Tensile test conditions]
Sample size: 50mm x 5mm, distance between grips: 30mm
Speed: 3 mm / min, number of measurements: 6 times A +: elongation at break 40% or more A: elongation at break 30% or more and less than 40% B: elongation at break 10% or more and less than 30% C: elongation at break less than 10%

<(B) Photosensitizer>
(B1) Naphthoquinonediazide compound (TKF-428 manufactured by Sanbo Chemical Laboratory)

（Ｃ２）ＨＰ４７００（ＤＩＣ社製）

<(C) Bifunctional or higher functional epoxy compound having naphthalene skeleton>
(C1) HP4032D (manufactured by DIC)

(C2) HP4700 (manufactured by DIC)

＊２：トリアジン環構造を有する架橋剤（三和ケミカル社製ＭＷ３９０）

＊３：２官能ポリエステルアクリレート（東亜合成社製Ｍ６２５０）
＊４：Ｎ−ブチルベンゼンスルホンアミド（第八化学工業社製ＢＭ−４）

＊５：熱酸発生剤（富士フィルム和光純薬工業社製ＷＰＡＧ６１８）

＊６：ＧＢＬ（γ−ブチロラクトン） * 1: Epoxy compound (EX-214P manufactured by Nagase ChemteX Corporation)

* 2: Crosslinking agent having a triazine ring structure (MW390 manufactured by Sanwa Chemical Co., Ltd.)

* 3: Bifunctional polyester acrylate (M6250 manufactured by Toa Gosei Co., Ltd.)
* 4: N-butylbenzenesulfonamide (BM-4 manufactured by Daihachi Chemical Industry Co., Ltd.)

* 5: Thermal acid generator (WPAG618 manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.)

* 6: GBL (γ-butyrolactone)

From the results shown in the above table, the photosensitive resin composition of the present invention is excellent in chemical resistance, even when cured at a low temperature of about 220 ° C., and has a low CTE having excellent flexibility. It can be seen that a cured film is obtained.

Claims (5)

  A photosensitive resin composition comprising (A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) a difunctional or higher functional epoxy compound having a naphthalene skeleton.   The photosensitive resin composition according to claim 1, further comprising a crosslinking agent having a triazine ring structure.   A dry film comprising a resin layer obtained by applying and drying the photosensitive resin composition according to claim 1 on the film.   A cured product obtained by curing the photosensitive resin composition according to claim 1 or 2 or the resin layer of the dry film according to claim 3. An electronic component comprising the cured product according to claim 4.