JP7191622B2 - Photosensitive resin compositions, dry films, cured products, and electronic components - Google Patents

Description

The present invention relates to photosensitive resin compositions, dry films, cured products, and electronic parts.

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

On the other hand, in recent years, a so-called molding-first type fan-out wafer level package construction method has appeared, in which rewiring is formed after sealing a chip with a sealant. Therefore, as an insulating material for rewiring used in such a construction 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 mainly composed of epoxy resin.

However, at such a low temperature, the resin composition containing the PBO precursor does not undergo sufficient cyclization of the PBO precursor, resulting in various properties such as chemical resistance, thermal properties, and mechanical properties such as flexibility. I had a problem with it going down.

In order to solve these problems, various approaches have conventionally been proposed in which a cross-linking agent is added to a resin composition containing a PBO precursor. For example, Patent Document 1 proposes a resin composition containing an epoxy compound having a specific structure and an alkali-soluble resin selected from polyimide precursors, PBO precursors, and the like.

JP 2014-111718 A

According to the technique described in Patent Document 1, indeed, by blending an epoxy compound having a specific structure as a cross-linking agent into a resin composition, such a resin composition exhibits excellent chemical resistance even when cured at a low temperature. A hardened product of the same type is obtained.
However, in the wafer provided with the insulating film using the resin composition as described in Patent Document 1, there still remains the problem of warping and cracking of the insulating film. As a result of intensive investigation by the inventors of this problem, the use of the compound described in Patent Document 1 as a cross-linking agent causes an increase in the CTE (coefficient of linear thermal expansion) of the insulating film, and as a result, the wafer and the insulating film The inventors have found that warping occurs due to the difference in CTE between the two and that cracks occur in the insulating film due to the stress caused by this warping being applied to the insulating film.

Further, the inventors have noted that imparting mechanical properties such as flexibility to a low-temperature curing insulating film for rewiring causes an increase in CTE and a decrease in chemical resistance. That is, it was found that it is important to achieve both low CTE and flexibility for a resin composition suitable for an insulating film for rewiring.

Therefore, the main object of the present invention is to obtain 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., for rewiring. An object of the present invention is to provide a photosensitive resin composition suitable for use in insulating films.
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 inventors of the present invention have made extensive studies to achieve the above object. As a result, it was found that the above problems could be solved by including a bifunctional or more functional epoxy compound having a naphthalene skeleton as a cross-linking agent in a photosensitive resin composition containing a PBO precursor, and the present invention was completed. rice field.

That is, the photosensitive resin composition of the present invention is characterized by comprising (A) a polybenzoxazole precursor, (B) a photosensitive agent, and (C) a bifunctional or higher epoxy compound having a naphthalene skeleton. is.

The photosensitive resin composition of the present invention preferably further contains a cross-linking agent having a triazine ring structure.

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

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

The electronic component of the present invention is characterized by having 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. An insulating film for rewiring. It is possible to provide a photosensitive resin composition suitable for use in Further, according to the present invention, it is possible 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 components contained in the photosensitive resin composition of the present invention are described in detail below.

[(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 synthesized by a known method. For example, it can be obtained by reacting a dihydroxydiamine as an amine component with a dicarboxylic acid component such as a dicarboxylic acid dichloride, a dicarboxylic acid, or a 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, preferably a polyhydroxyamide having a repeating structure represented by the following general formula (1).

(Wherein, X represents a tetravalent organic group, Y represents a divalent organic group, n is an integer of 2 or more, preferably 10 to 200, more preferably 20 to 70.)

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

Examples of the dihydroxydiamines having the repeating structure include 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 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 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 acids having aromatic rings 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-cyclopentanedicarboxylic acid and other aliphatic dicarboxylic acids. Among them, 4,4'-dicarboxydiphenyl ether is preferred.

In the above general formula (1), the tetravalent organic group represented by X may be an aliphatic group or an aromatic group, but is preferably an aromatic group, and two hydroxy groups and two amino groups are at the ortho positions. Positioning on an aromatic ring is more preferred. 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 groups shown below, and a known aromatic group that can be contained in the polybenzoxazole precursor is selected depending on the application. do it.

Among the above aromatic groups, the tetravalent aromatic group is preferably a group shown below.

In the above general formula (1), the divalent organic group represented by Y may be an aliphatic group or an aromatic group, but is preferably an aromatic group, and the carbonyl in the above general formula (1) on the aromatic ring. It is more preferable that the The number of carbon atoms in the divalent aromatic group is preferably 6-30, more preferably 6-24. Specific examples of the divalent aromatic group include, but are not limited to, the groups shown below, and a known aromatic group contained in the polybenzoxazole precursor may be selected depending on the application. Just do it.

（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。）

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

Among the above aromatic groups, the divalent organic group is preferably a group shown below.

(A) The polybenzoxazole precursor may contain two or more of the above polyhydroxyamide repeating structures. In addition, (A) the polybenzoxazole precursor may contain a structure other than the repeating structure of polyhydroxyamide, and may contain, for example, a repeating structure of polyamic acid or a benzoxazole structure.

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

(A) A polybenzoxazole precursor may be used individually by 1 type, and may be used in combination of 2 or more type.

[(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. A photoacid generator is a compound that generates an acid upon irradiation with light such as ultraviolet light or visible light. It is a compound that produces more than one basic substance. In the present invention, a photoacid generator can be suitably used as the (B) photosensitive agent.

Photoacid generators include naphthoquinonediazide compounds, diarylsulfonium salts, triarylsulfonium salts, dialkylphenacylsulfonium salts, diaryliodonium salts, aryldiazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters. , aromatic N-oxyimide sulfonates, aromatic sulfamides, benzoquinonediazosulfonic acid esters, and the like. Preferably, the photoacid generator is a dissolution inhibitor. Among them, a naphthoquinone diazide compound is preferable.

Specific examples of the naphthoquinonediazide compound include tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene naphthoquinonediazide adducts (for example, TS533, TS567, TS583, TS593 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.). ), naphthoquinone diazide adducts of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.), and 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α ,α-dimethylbenzyl}phenol naphthoquinonediazide adducts (eg, TKF-428 and TKF-528 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.) and the like can be used.

The photobase generator may be either an ionic photobase generator or a non-ionic photobase generator. It is advantageous, so it is preferable. Basic substances include, for example, secondary amines and tertiary amines.

Examples of ionic photobase generators 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, etc. can be used.

Examples of nonionic photobase generators include α-aminoacetophenone compounds, oxime ester compounds, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzylcarbamate groups, and alkoxybenzyls. A compound having a substituent such as a carbamate group is included. As other photobase generators, Wako Pure Chemical Industries, Ltd. WPBG-018 (trade name: 9-anthrylmethyl N, N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2 -hydroxyphenyl)-2-propenoyl]piperidine), WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate), WPBG-165 and the like can also be used.

(B) The photosensitive agent may be used alone or in combination of two or more. The blending amount of (B) the photosensitive agent is preferably 3 to 30 parts by mass with respect to 100 parts by mass of the non-volatile component of the (A) polybenzoxazole precursor.

[(C) Bifunctional or higher functional epoxy compound having a 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 groups of the polybenzoxazole precursor to form a crosslinked structure, thereby not only improving the chemical resistance of the cured product, but also, surprisingly, and contributes to lower CTE.

(C) The naphthalene-type epoxy compound is not particularly limited as long as it has a naphthalene skeleton and two or more epoxy groups. 6-diglycidylnaphthalene, 1,7-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, and 1,2,5,6-tetraglycidylnaphthalene, naphthol aralkyl-type epoxy resin, naphthalene skeleton-modified cresol novolak modified naphthalene-type epoxy resins, methoxynaphthalene-modified cresol novolak-type epoxy resins, naphthylene ether-type epoxy resins, and methoxynaphthalene dimethylene-type epoxy resins. (C) A naphthalene type epoxy compound may be used individually by 1 type, and may be used in combination of 2 or more type.

Commercially available products include HP-4032D, HP-4700, HP-4770, HP-5000, HP-6000, HP-4710 manufactured by DIC, and NC-7000L and NC-7300L manufactured by Nippon Kayaku.

(C) The naphthalene-type epoxy compound may or may not have a flexible chain in its structure. Therefore, for example, it is not necessary to have a straight chain structure with 5 to 10 atoms, or further 3 to 5 atoms between epoxy groups.

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

(C) The 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 non-volatile component of the (A) polybenzoxazole precursor. do. By setting it as such a range, an appropriate crosslinking density can be maintained for (A) the polybenzoxazole precursor.

(Other cross-linking agents)
The photosensitive resin composition of the present invention may contain (C) a cross-linking agent other than the di- or more functional epoxy compound having a naphthalene skeleton. In this specification, the other cross-linking agent is preferably a compound other than the naphthalene-type epoxy compound that reacts with the phenolic hydroxyl group of the polybenzoxazole precursor to form a cross-linked structure. 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, and an alkylene group having 1 to 12 carbon atoms such as a methylol group. Group-bonded alcoholic hydroxyl groups can be mentioned.

（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。） Among other cross-linking agents, a cross-linking agent having a triazine ring structure is preferable, and in the present invention, the elongation rate of the cured product can be further improved. The cross-linking agent having this triazine ring structure is not particularly limited, but is preferably a cross-linking agent represented by the following general formula (2).

(wherein 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 preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

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

Other cross-linking agents may be used alone or in combination of two or more. In order not to impair developability due to cross-linking, the amount of the other cross-linking agent is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of non-volatile components of the polybenzoxazole precursor. Further, 0.1 to 20 parts by mass 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, the cyclization reaction of (A) the polybenzoxazole precursor is promoted, the low-temperature curability is further improved, and a cured product with excellent chemical resistance can be obtained. . Originally, in low-temperature curing at about 220 ° C., the cyclization rate of (A) polybenzoxazole precursor is low, and the low-temperature curability can be improved by blending a cross-linking agent. and the cross-linking agent can further reduce the cyclization rate. 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 molecular chains are improved, resulting in (A) It is considered that the thermal molecular motion of the polybenzoxazole precursor was improved and the cyclization reaction was promoted. Moreover, in the present invention, a cured product having excellent flexibility can be obtained by blending a plasticizer. Furthermore, in the present invention, the compounding of the naphthalene-type epoxy compound (C) improves the developability of the unexposed area, whereas the compounding of the plasticizer improves the developability of the exposed area. Pattern formation becomes possible. The plasticizers may be used singly or in combination of two or more. The plasticizer is preferably a plasticizer that does not cross-link with other ingredients in the composition. Moreover, it is preferable that the plasticizer does not have the function of generating thermal acid.

The plasticizer may be a plasticizer with self-polymerizable groups or a plasticizer without self-polymerizable groups. A (meth)acryloyl group, a vinyl group, an allyl group, etc. are mentioned as a self-polymerizable group. In the present specification, (meth)acryloyl group is a generic term for acryloyl group, methacryloyl group and mixtures thereof, and the same applies to other similar expressions.

The photosensitive resin composition of the present invention can further improve the flexibility of the cured product by containing a plasticizer having a self-polymerizable group. A bifunctional (meth)acrylic compound is preferred as the plasticizer having a self-polymerizable group. The bifunctional (meth)acrylic compound is preferably a compound that does not form a crosslinked structure with other components in the composition. Also, 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 is a compound having two (meth)acryloyl groups, and specific examples thereof include 1,4-butanediol diacrylate and 1,6-hexanediol diacrylate. , 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, a diol diacrylate obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, Glycol diacrylates such as caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate, bisphenol A diglycidyl ether acrylic acid adduct , tricyclodecane dimethanol diacrylate, tris(2-hydroxyethyl)isocyanurate diol diacrylate obtained by adding at least one of ethylene oxide and propylene oxide to bisphenol A, hydrogenated dicyclopentadienyl Examples include diacrylates, diacrylates having a cyclic structure such as cyclohexyl diacrylate, isocyanuric acid diacrylates such as isocyanuric acid ethylene oxide-modified diacrylates, bifunctional polyester acrylates, and methacrylates corresponding to these.

Commercially available products include light acrylate 1,6HX-A, 1,9ND-A, 3EG-A, 4EG-A (manufactured by Kyoeisha Chemical Co., Ltd.), HDDA, 1,9-NDA, DPGDA, TPGDA (Daicel). Allnex (trade name), Viscoat #195, #230, #230D, #260, #310HP, #335HP, #700HV, #540 (trade name manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-208, M -211B, M-215, M-220, M-225, M-240, M-270, M-6200, M-6250, M-6500 (trade names manufactured by 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, diol (such as ethylene oxide and propylene oxide) alkylene oxide adduct di(meth)acrylates and bifunctional polyester (meth)acrylates are preferred, and bifunctional polyesters (meth)acrylates are preferred. ) 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 alkylene oxide and then adding a (meth)acrylate to the terminal thereof is preferable, and a diol having an aromatic ring is more preferable. . Examples thereof include bisphenol A EO (ethylene oxide) adduct diacrylate and bisphenol A PO (propylene oxide) adduct diacrylate. Specific structures of di(meth)acrylates, which are alkylene oxide adducts of diols, are shown below, but are 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, more preferably 3.5 to 25.)

Preferred bifunctional polyester (meth)acrylates are M-6200, M-6250 and M-6500 (trade names of Toagosei Co., Ltd.).

The 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, and exhibits sufficient chemical resistance in low-temperature curing. can be done.

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. Plasticizers 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). ), maleate ester compounds such as di(2-ethylhexyl) maleate, trimellitate esters such as tris(2-ethylhexyl) trimellitate, dimethyl adipate, aliphatic dibasic compounds such as dibutyl adipate acid esters, phosphate esters such as trimethyl phosphate, tris(butoxyethyl) phosphate, ( _C6H5O ) _{2P (} O) _{OC6H4C ( CH3} ) _{2C6H4OP (} O) ₍ OC ₆ H ₅ ) ₂ , ether compounds such as aromatic condensed phosphates and crown ethers. Among them, sulfonamide compounds, phthalate compounds, and maleate compounds 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 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 amido group; R ³² is a hydrogen atom or an organic group; n is 0; is an integer of up to 5. When n is 2 or more, each R ³¹ may be the same or different.)

The maleic acid 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 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 amido group, and R ⁴¹ and R ⁴² are , may combine to form a ring, R ⁴³ is a hydrogen atom or an organic group, and R ⁴⁴ is a hydrogen atom or an organic group.)

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

The 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 non-volatile component of the polybenzoxazole precursor. preferable. If the blending amount is 1 part by mass or more, the plasticizing effect is likely to appear, and if it is 50 parts by mass or less, the properties of the resulting cured film are not impaired.

In the present invention, it is preferable to use a plasticizer having a self-polymerizable group and a plasticizer having no self-polymerizable group in combination, and a cured product having excellent 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, the phenolic hydroxyl group of (A) the polybenzoxazole precursor reacts with the epoxy group of (C) the naphthalene-type epoxy compound to form a crosslinked structure. Since hydroxyl groups are generated in the structure, the dielectric properties deteriorate, so 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, it acts as a catalyst for the cyclization reaction of (A) the polybenzoxazole precursor, thereby promoting the cyclization reaction at low temperature. Dielectric properties are improved by reducing the number of hydroxyl groups in the crosslinked structure, and a cured product having better chemical resistance and heat resistance can be obtained by promoting the cyclization reaction. One of the thermal acid generators may be used alone, or two or more thereof may be used in combination.

The thermal acid generator is not particularly limited as long as it generates acid by heat. Examples of the acid generated include sulfonic acid, carboxylic acid, acetic acid, hydrochloric acid, nitric acid, bromic acid, and iodic acid. From the viewpoint of cyclization efficiency, strong acids are preferred, such as benzenesulfonic acid and p-toluene. Sulfonic acids such as arylsulfonic acids such as sulfonic acids, perfluoroalkylsulfonic acids such as trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, camphorsulfonic acid, alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid, butanesulfonic acid is preferred. These acids are blended into the photosensitive resin composition as thermal acid generators, for example, as salts such as onium salts or as compounds latent by covalent bonds such as imidosulfonates.

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

Sulfonic acid ester compounds 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, 2-methoxyethyl p-toluenesulfonate, propargyl p-toluenesulfonate, 3-butynyl p-toluenesulfonate, ethyl trifluoromethanesulfonate, n-butyl trifluoromethanesulfonate, perfluorobutanesulfone Ethyl acid, methyl perfluorobutanesulfonate, benzyl (4-hydroxyphenyl) methylsulfonium hexafluoroantimonate, benzyl (4-hydroxyphenyl) methylsulfonium hexafluorophosphate, trimethylsulfonium methylsulfate, tri-p-sulfonium trifluoromethane sulfonate, trimethylsulfonium trifluoromethanesulfonate, pyridinium-p-toluenesulfonate, ethyl perfluorooctanesulfonate, 1,4-butanesultone, 2,4-butanesultone, 1,3-propanesultone, 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 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 that R ⁵¹ can take may be linear or branched. Also, the number of carbon atoms is preferably 1-10, more preferably 1-6.

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

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 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 combine to form a ring is also good.)

The alkyl group that R ⁶¹ can take may be linear or branched. The number of carbon atoms is preferably 1-10, more preferably 1-6.

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

Among thermal acid generators, those that generate acid at 120 to 220° C. are preferred. In the case of a thermal acid generator that generates acid at 120° C. or higher, the reaction does not easily proceed during prebaking, and development residue is less likely to occur. Further, thermal acid generators that generate acid at 150 to 220° C. are preferred. The generation of acid can be confirmed at the weight loss temperature 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 non-volatile component of the polybenzoxazole precursor. More preferably, it is 1 to 3 parts by mass.

(Sensitizer, adhesion agent, other ingredients)
In the photosensitive resin composition of the present invention, a known sensitizer for further improving photosensitivity, a silane coupling agent for improving adhesion to a substrate, etc., within a range that does not impair the effects of the present invention. A known adhesion agent or the like can also be blended. In addition, various organic or inorganic low-molecular-weight or high-molecular-weight compounds may be added to the photosensitive resin composition of the present invention in order to impart processing properties and various functionalities. For example, surfactants, leveling agents, fine particles and the like can be used. Fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as silica, carbon, and layered silicate. In addition, various colorants, fibers, and the like may be added to 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 higher epoxy compound having a naphthalene skeleton, and other additives. It is not particularly limited 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- Butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoramide, pyridine, γ-butyrolactone, diethylene glycol monomethyl ether. These may be used alone or in combination of two or more. The amount of solvent to be used can be appropriately determined according to the coating film thickness and viscosity. For example, it can be used in the range of 50 to 9000 parts by mass with respect to 100 parts by mass of the (A) polybenzoxazole precursor.

The photosensitive resin composition of the present invention is preferably of 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 the film. This resin layer is used by laminating so as to be in contact with the substrate.

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, lip coater, comma coater, film coater, etc., and drying to form the above resin layer. and preferably by laminating a film (so-called protective (cover) film) thereon. The protective film and the support film may be made of the same film material or may be made of different films.

In the dry film of the present invention, any film materials known for use in dry films can be used as film materials for the support film and the protective film.
As the support film, 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 a weaker adhesion to the resin layer than the support film is preferred.

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

[Cured product]
The cured product of the present invention is obtained by curing the above-described photosensitive resin composition of the present invention through predetermined steps. The pattern film, which is the cured product, may be produced by a known and commonly used production method. For example, in the case of (B) a positive photosensitive resin composition containing a photoacid generator as a photosensitive agent, the following steps manufacture.

First, as step 1, a coating film is obtained by coating and drying a photosensitive resin composition on a substrate, or by transferring a resin layer from a dry film onto the substrate. The method for applying the photosensitive resin composition onto the substrate includes methods conventionally used for applying photosensitive resin compositions, such as spin coaters, bar coaters, blade coaters, curtain coaters, screen printers, and the like. a method of applying with a spray coater, a method of spraying with a spray coater, an inkjet method, or the like. As a method for drying the coating film, methods such as air drying, heat drying using an oven or a hot plate, and vacuum drying are used. Moreover, it is desirable to dry the coating film under conditions that do not cause cyclization of the polybenzoxazole precursor in the photosensitive resin composition. Specifically, natural drying, air drying, or heat drying can be performed at 70 to 140° C. for 1 to 30 minutes. Drying is preferably carried out on a hot plate for 1-20 minutes. Vacuum drying is also possible, and in this case, it can be carried out 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. The exposure light used has a wavelength capable of activating the photoacid generator as the photosensitizer (B). Specifically, the exposure light preferably has a maximum wavelength in the range of 350 to 440 nm. As described above, photosensitivity can be adjusted by appropriately blending a sensitizer. As an exposure device, a contact aligner, mirror projection, stepper, laser direct exposure device, or the like can be used.

Next, as step 3, the coating film is treated with a developer. As a result, the exposed portions in the coating film can be removed to form a pattern film of the photosensitive resin composition of the present invention.

As a method used for development, any method can be selected from conventionally known photoresist development methods, such as a rotary spray method, a paddle method, an immersion method accompanied by 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 such as If necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol or isopropyl alcohol or a surfactant may be added. After that, the coating film is washed with a rinsing liquid as necessary to obtain a pattern film. Distilled water, methanol, ethanol, isopropyl alcohol and the like can be used alone or in combination as the rinse liquid. Moreover, you may use the said solvent as a developer.

Thereafter, in step 4, the pattern film is heated to obtain a cured coating film (cured product). This heating cyclizes the polybenzoxazole precursor 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 heating temperature is 180 to 250°C. Since the photosensitive resin composition of the present invention contains (C) a naphthalene-type epoxy compound, cyclization is promoted, and the heating temperature can be less than 250°C, further 220°C or less. Heating is performed, for example, by using a hot plate, an oven, or a temperature-programmable oven. As the atmosphere (gas) at this time, air may be used, or an inert gas such as nitrogen or argon may be used.

Applications of the photosensitive resin composition of the present invention are not particularly limited. Used. Specifically, as a material for forming a display device, it can be used as a layer-forming material or an image-forming material, such as a color filter, a flexible display film, a resist material, an alignment film, or the like. In addition, as a material for forming a semiconductor device, it can be used as a resist material, a layer forming material such as a buffer coat film, and the like. Furthermore, as a material for forming electronic parts, it can be used as a sealing material or a layer forming material for a printed wiring board, an interlayer insulating film, a wiring coating film, and the like. Furthermore, as a material for forming optical parts, it can be used as an optical material or a layer forming material for holograms, optical waveguides, optical circuits, optical circuit parts, antireflection films, and the like. Furthermore, as building materials, it can be used for paints, coating agents, and the like.

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

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. In the following description, "parts" and "%" are 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-necked 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. It was added dropwise while cooling the temperature to 0-5°C.
After completion of dropping, the temperature of the reaction system was returned to room temperature, and the mixture was stirred for 6 hours. After that, 1.8 g (0.1 mol) of pure water was added, and the mixture was further reacted at 40° C. for 1 hour. After completion of the reaction, the reaction solution was added dropwise to 2000 g of pure water. The precipitate was collected by filtration, washed, and dried in a 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)
With respect to 100 parts by mass of the polybenzoxazole precursor (A1) synthesized above, the photoacid generator (B1), epoxy compounds (C1, C2, *1), and each After blending the components, γ-butyrolactone was added to make the varnish so that the polymer content was 30% by mass.

(Preparation of cured film)
A varnish was applied to the wafer using a spin coater MS-A150 manufactured by Mikasa. After drying on a hot plate at 120° C. for 10 minutes, it was cured 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 physical property testing. After that, it was exposed to 121° C./100% RH for 1 hour using a pressure cooker test (PCT) device, and separated from the silicon wafer.

(CTE)
The coefficient of linear thermal expansion (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 × 3 mm, distance between chucks: 16 mm
Force: 0.03 N, nitrogen flow rate: 100 mL/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 with a cured film of 10 to 12 μm was cut into 2 cm squares, immersed in GBL (γ-butyrolactone), washed with water, dried, and observed with an optical microscope for film reduction of the cured film before and after immersion. It was evaluated according to the evaluation criteria.
A+: Film reduction less than 1% A: Film reduction 1% or more and less than 3% B: Film reduction 3% or more and less than 5% C: Film reduction 5% or more

(stretch)
The elongation of the cured film was measured using EZ-SX manufactured by shimadzu under the following conditions.
[Tensile test conditions]
Sample size: 50 mm x 5 mm, distance between grips: 30 mm
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) Naphthoquinone diazide compound (TKF-428 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.)

（Ｃ２）ＨＰ４７００（ＤＩＣ社製）

<(C) Difunctional or higher functional epoxy compound having a 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: A cross-linking agent having a triazine ring structure (MW390 manufactured by Sanwa Chemical Co., Ltd.)

*3: Bifunctional polyester acrylate (M6250 manufactured by Toagosei Co., Ltd.)
* 4: N-butylbenzenesulfonamide (BM-4 manufactured by Dai-Hachi Kagaku Kogyo Co., Ltd.)

*5: Thermal acid generator (WPAG618 manufactured by Fujifilm 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 has excellent chemical resistance and excellent flexibility even when cured at a low temperature of about 220°C. It can be seen that a cured film is obtained.

Claims (5)

(A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) at least one epoxy compound having a naphthalene skeleton of the following structural formula ,
A photosensitive resin composition, wherein the photosensitive agent (B) is a naphthoquinone diazide compound .

2. The photosensitive resin composition according to claim 1, further comprising a cross-linking agent having a triazine ring structure. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 1 or 2 on a film and drying the composition. 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 .