CN112585536A - Photosensitive resin composition, dry film, cured product, and electronic component - Google Patents

Abstract

Providing: and a photosensitive resin composition which is excellent in developability of an exposed portion, can give a cured film excellent in chemical resistance and flexibility even when cured at a low temperature of about 220 ℃, and is suitably used for an insulating film for rewiring. A photosensitive resin composition, comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a 2-or more functional epoxy compound, and (D) a plasticizer.

Description

Photosensitive resin composition, dry film, cured product, and electronic component

Technical Field

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

Background

Conventionally, as an insulating material for rewiring in a semiconductor device, 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 converted into a benzoxazole ring by a cyclization reaction under heating at a high temperature (>350 ℃) to have a rigid structure and an increase in the intermolecular bulk density, and therefore, a cured film having excellent chemical resistance, thermal properties, mechanical properties such as flexibility, and the like can be obtained from the resin composition containing the PBO precursor.

On the other hand, in recent years, a so-called Molding first type Fanout Wafer-Level Packaging process has been developed in which a chip is sealed with a sealing agent and then rewired is formed. Therefore, as an insulating material for rewiring used in the above-described process, a material that can be cured at a low temperature of about 220 ℃ 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, cyclization of the PBO precursor of the resin composition containing the PBO precursor does not proceed sufficiently, and there is a problem that various properties such as chemical resistance, thermal properties, mechanical properties such as flexibility and the like are deteriorated.

In addition, at such a low temperature, cyclization of the PBO precursor does not sufficiently proceed, and there is also a problem that cracking easily occurs in the cured film.

In order to solve these problems, various methods have been proposed in the past in which a crosslinking agent such as an epoxy compound is added to a resin composition containing a PBO precursor (for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-111718

Disclosure of Invention

Problems to be solved by the invention

However, when a crosslinking agent is blended, the crosslinked structure formed in the cured product improves physical properties such as chemical resistance even when cured at low temperature, but there is a problem of the dihedral back that the flexibility is lowered.

Further, if an epoxy compound is blended as a crosslinking agent, the development resistance of unexposed portions is improved, but there is room for improvement in the development property of exposed portions for good pattern formation.

Accordingly, a first main object of the present invention is to provide: the photosensitive resin composition is excellent in developability of exposed portions, and can give an insulating film excellent in chemical resistance and flexibility even when cured at a low temperature of about 220 ℃, and is suitable for use as an insulating film for rewiring.

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.

Further, if an epoxy compound is blended as a crosslinking agent, a self-standing cured film (self-standing film) free from cracking can be formed even at low temperature curing due to the crosslinking reaction, but in a crosslinked structure formed by the reaction of the phenolic hydroxyl group of the PBO precursor and the epoxy group of the epoxy compound, a hydroxyl group is generated in the crosslinked structure, and therefore, there is a problem of the bar-type backlight that dielectric characteristics are deteriorated. Further, there is room for improvement in chemical resistance and thermal characteristics.

Accordingly, a second main object of the present invention is to provide: a photosensitive resin composition which can form a free-standing film even when cured at a low temperature of about 220 ℃ and can provide an insulating film excellent in chemical resistance, thermal characteristics and dielectric characteristics and suitable for use as an insulating film for rewiring.

Another second 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.

Further, according to the technique described in patent document 1, by surely blending an epoxy compound having a specific structure as a crosslinking agent into a resin composition, the resin composition can obtain a cured product having excellent chemical resistance even when cured at low temperature.

However, the wafer including the insulating film using the resin composition described in patent document 1 still has problems of occurrence of warpage and occurrence of cracks in the insulating film. As a result of intensive studies by the inventors in view of the above problems, the inventors found that: when the compound described in patent document 1 is used as a crosslinking agent, the CTE (linear thermal expansion coefficient) of the insulating film increases, and as a result, warpage occurs due to the difference between the CTEs of the wafer and the insulating film, and further, stress due to the warpage is applied to the insulating film, thereby causing cracks in the insulating film.

The inventors have also paid attention to the problem of the dichotomous reversion that if mechanical properties such as flexibility are imparted to a low-temperature-cured insulating film for rewiring, an increase in CTE and a decrease in chemical resistance are caused instead. That is, it is known that it is important to achieve both low CTE and flexibility as a resin composition suitable for an insulating film for rewiring.

Accordingly, a third main object of the present invention is to provide: the photosensitive resin composition is excellent in chemical resistance even when cured at a low temperature of about 220 ℃, can give an insulating film having excellent flexibility and a low CTE, and is suitable for use as an insulating film for rewiring.

In addition, a third 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, they found that: the present inventors have found that the above problems can be solved by using a photosensitive resin composition containing a PBO precursor, which contains a 2-or more-functional epoxy compound as a crosslinking agent, in combination with a plasticizer having a self-polymerizable group, and blending the composition.

That is, the photosensitive resin composition of the first aspect of the present invention is characterized by comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a 2-or more functional epoxy compound, and (D) a plasticizer.

In the photosensitive resin composition according to the first aspect of the present invention, the plasticizer (D) is preferably a plasticizer having a self-polymerizable group (D1), and the plasticizer (D) having a self-polymerizable group is more preferably a 2-functional (meth) acrylic compound.

In the photosensitive resin composition according to the first aspect of the present invention, the plasticizer (D) is preferably a plasticizer (D2) having no self-polymerizable group, and the plasticizer (D) having no self-polymerizable group is more preferably at least one of a sulfonamide compound, a phthalate compound, and a maleate compound.

The photosensitive resin composition of the first embodiment of the present invention more preferably contains the plasticizer having a self-polymerizable group (D1) and the plasticizer having no self-polymerizable group (D2).

The photosensitive resin composition according to the first embodiment of the present invention preferably further comprises (E) a thermal acid generator.

In the photosensitive resin composition according to the first aspect of the present invention, the thermal acid generator (E) is preferably a sulfonic acid ester compound.

In the photosensitive resin composition of the first aspect of the present invention, the epoxy compound having (C)2 or more functional groups preferably has a naphthalene structure.

The photosensitive resin composition of the first embodiment of the present invention preferably further contains a crosslinking agent having a triazine ring structure.

The dry film according to the first aspect of the present invention is characterized by having a resin layer obtained by applying the photosensitive resin composition to a film and drying the applied resin layer.

The cured product of the first aspect 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 a first aspect of the present invention is characterized by having the cured product.

In addition, the present inventors have made intensive studies to achieve the above object. As a result, they found that: the present inventors have completed the present invention by solving the above problems by using an epoxy compound having 2 or more functions as a crosslinking agent in a photosensitive resin composition containing a PBO precursor in combination with a thermal acid generator.

That is, the photosensitive resin composition of the second aspect of the present invention is characterized by comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) an epoxy compound having 2 or more functions, and (D) a thermal acid generator.

In the photosensitive resin composition according to the second aspect of the present invention, the thermal acid generator (D) is preferably a sulfonic acid ester compound.

In the photosensitive resin composition according to the second aspect of the present invention, the epoxy compound having (C)2 or more functional groups preferably has a naphthalene structure.

A dry film according to a second aspect of the present invention is characterized by having a resin layer obtained by applying the photosensitive resin composition to a film and drying the applied resin layer.

The cured product of the second aspect 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 a second aspect of the present invention is characterized by having the cured product.

In addition, the present inventors have made intensive studies to achieve the above object. As a result, they found that: the present inventors have completed the present invention by solving the above problems by including an epoxy compound having 2 or more functions and a naphthalene skeleton as a crosslinking agent in a photosensitive resin composition containing a PBO precursor.

That is, the photosensitive resin composition of the third aspect of the present invention is characterized by comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) a 2-or more-functional epoxy compound having a naphthalene skeleton.

The photosensitive resin composition of the third embodiment of the present invention preferably further contains a crosslinking agent having a triazine ring structure.

A dry film according to a third aspect of the present invention is characterized by having a resin layer obtained by applying the photosensitive resin composition to a film and drying the applied resin layer.

The cured product according to the third aspect 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 a third aspect of the present invention is characterized by having the cured product.

ADVANTAGEOUS EFFECTS OF INVENTION

First, according to the present invention, there can be provided: the photosensitive resin composition is excellent in developability of exposed portions, can give a cured film excellent in chemical resistance and flexibility even when cured at a low temperature of about 220 ℃, and is suitable for use as an insulating film for rewiring. Further, according to the present invention, there can be provided: 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.

Second, according to the present invention, there can be provided: a photosensitive resin composition which can form a free-standing film even when cured at a low temperature of about 220 ℃ and can provide a cured film having excellent chemical resistance, thermal properties and dielectric properties, and which is suitable for use as an insulating film for rewiring. Further, according to the present invention, there can be provided: 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.

Third, according to the present invention, there can be provided: a photosensitive resin composition which is suitable for use as an insulating film for rewiring, and which is excellent in chemical resistance even when cured at a low temperature of about 220 ℃ and can give a cured film having excellent flexibility and a low CTE. Further, according to the present invention, there can be provided: 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.

Detailed Description

The components contained in the photosensitive resin composition of the present invention will be described in detail below.

[ (A) polybenzoxazole precursor ]

The photosensitive resin composition of the first, second, and third embodiments of the present invention contains (a) a polybenzoxazole precursor. (A) The method for synthesizing the polybenzoxazole precursor is not particularly limited, and the polybenzoxazole precursor can be synthesized by a known method. For example, the compound 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.

(A) The polybenzoxazole precursor is preferably a polyhydroxyamide, preferably a polyhydroxyamide having a repeating structure of the following general formula (1).

(wherein X represents a 4-valent organic group, Y represents a 2-valent organic group, and n is an integer of 2 or more, preferably 10 to 200, more preferably 20 to 70.)

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

Examples of the dihydroxydiamines having the above-mentioned repeating structure include 3,3 '-diamino-4, 4' -dihydroxybiphenyl, 4 '-diamino-3, 3' -dihydroxybiphenyl, bis (3-amino-4-hydroxyphenyl) propane, bis (4-amino-3-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone, 2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3, 3-hexafluoropropane, 2-bis (4-amino-3-hydroxyphenyl) -1,1,1,3,3, 3-hexafluoropropane and the like. Among them, 2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3, 3-hexafluoropropane is preferable.

Examples of the dicarboxylic acid component having the above-mentioned repeating structure include isophthalic acid, terephthalic acid, 5-t-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2, 6-naphthalenedicarboxylic acid, 4 ' -dicarboxybiphenyl, 4 ' -dicarboxydiphenyl ether, 4 ' -dicarboxytetraphenylsilane, dicarboxylic acids having an aromatic ring such as bis (4-carboxyphenyl) sulfone, 2-bis (p-carboxyphenyl) propane, 2-bis (4-carboxyphenyl) -1,1,1,3,3, 3-hexafluoropropane, and aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, 1, 2-cyclobutanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, and 1, 3-cyclopentanedicarboxylic acid. Among them, 4' -dicarboxydiphenyl ether is preferable.

In the general formula (1), the 4-valent organic group represented by X may be an aliphatic group or an aromatic group, and is preferably an aromatic group, and more preferably 2 hydroxyl groups and 2 amino groups are located at the ortho-position on the aromatic ring. The number of carbon atoms of the 4-valent aromatic group is preferably 6 to 30, more preferably 6 to 24. Specific examples of the 4-valent aromatic group include those shown below, but are not limited thereto, and known aromatic groups that can be included in the polybenzoxazole precursor may be selected according to the application.

Among the above aromatic groups, the aromatic group having a valence of 4 is preferably a group shown below.

In the general formula (1), the 2-valent organic group represented by Y may be an aliphatic group or an aromatic group, and is preferably an aromatic group, and more preferably an aromatic ring bonded to the carbonyl group in the general formula (1). The number of carbon atoms of the 2-valent aromatic group is preferably 6 to 30, more preferably 6 to 24. Specific examples of the aromatic group having a valence of 2 include those shown below, but are not limited thereto, and known aromatic groups contained in the polybenzoxazole precursor may be selected according to the application.

(wherein A represents a group selected from the group consisting of a single bond and-CH₂-、-O-、-CO-、-S-、-SO₂-、-NHCO-、-C(CF₃)₂-、-C(CH₃)₂-a group having a valence of 2 in the group consisting. )

Among the aromatic groups, the 2-valent organic group is preferably a group shown below.

(A) The polybenzoxazole precursor can comprise a repeat structure of 2 or more of the above polyhydroxy amides. The polybenzoxazole precursor (a) may have a structure other than the repeating structure of the polyhydroxyamide, and may have, 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 1000 to 100000, more preferably 5000 to 50000. The number average molecular weight herein is a value measured by Gel Permeation Chromatography (GPC) and converted to standard polystyrene. The weight average molecular weight (Mw) of the polybenzoxazole precursor (A) is preferably 5000 to 200000, more preferably 10000 to 100000. The weight average molecular weight herein is a value measured by GPC and converted to standard polystyrene. The Mw/Mn is preferably 1 to 5, more preferably 1 to 3.

(A) The polybenzoxazole precursor may be used alone in 1 kind or in combination of 2 or more kinds.

[ (B) photosensitizer ]

The photosensitive resin composition of the first, second and third embodiments of the present invention contains (B) a photosensitizer. The photosensitizer (B) 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 upon irradiation with light such as ultraviolet light or visible light, and the photobase generator is a compound that generates 1 or more types of basic substances upon a change in molecular structure or cleavage of molecules upon similar irradiation with light. In the present invention, a photoacid generator can be suitably used as the (B) sensitizer.

Examples of the photoacid generator include naphthoquinone diazide 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 sulfonamides, and benzoquinone diazosulfonate esters. The photoacid generator is preferably a dissolution inhibitor. Among them, naphthoquinone diazide compounds are preferable.

Specific examples of the naphthoquinone diazide compound include naphthoquinone diazide adducts of tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (e.g., TS533, TS567, TS583, and TS593, available from sanbao chemical research, ltd.), naphthoquinone diazide adducts of tetrahydroxybenzophenone (e.g., BS550, BS570, and BS599, available from sanbao chemical research, ltd.), and naphthoquinone diazide adducts of 4- {4- [1, 1-bis (4-hydroxyphenyl) ethyl ] - α, α -dimethylbenzyl } phenol (e.g., TKF-428 and TKF-528, available from sanbao chemical research, ltd.), and the like.

The photobase generator may be an ionic photobase generator or a nonionic photobase generator, but an ionic photobase generator is preferable because of high sensitivity of the composition and favorable formation of a pattern film. Examples of the basic substance include secondary amines and tertiary amines.

Examples of the ionic photobase generators include salts of aromatic carboxylic acids and tertiary amines, and ionic PBG manufactured by Wako pure chemical industries, WPBG-082, WPBG-167, WPBG-168, WPBG-266, and WPBG-300.

Examples of the nonionic photobase generators include α -aminoacetophenone compounds, oxime ester compounds, and compounds having a substituent such as an N-formylated aromatic amino group, an N-acylated aromatic amino group, a nitrobenzylcarbamate group, or an alkoxybenzylcarbamate group. As other photobase generators, WPBG-018 (trade name: 9-anthracylmethanol, N' -diethylcarbamate), WPBG-027 (trade name: (E) -1- [3- (2-hydroxyphenyl) -2-propenoyl ] piperidine), WPBG-140 (trade name: 1- (anthracenol-2-yl) ethyl imidocarboxylato), WPBG-165, and the like, available from Wako pure chemical industries, Ltd.

(B) The photosensitizer may be used alone in 1 kind, or may be used in combination with 2 or more kinds. (B) The amount of the photosensitizer to be mixed is preferably 3 to 30 parts by mass per 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (a).

[ (C) 2-functional or higher epoxy Compound ]

The photosensitive resin composition of the first and second embodiments of the present invention contains (C) an epoxy compound having 2 or more functional groups as a crosslinking agent. (C) The epoxy compound having 2 or more functions is thermally reacted with the hydroxyl group of the polybenzoxazole precursor to form a crosslinked structure. The photosensitive resin composition of the third embodiment of the present invention contains (C) an epoxy compound having 2 or more functions having a naphthalene skeleton (hereinafter, also simply referred to as "(C) naphthalene-type epoxy compound") as the (C) epoxy compound having 2 or more functions. (c) The naphthalene epoxy compound thermally reacts with the hydroxyl group of the polybenzoxazole precursor to form a crosslinked structure, thereby improving the chemical resistance of a cured product, surprisingly improving the flexibility of the cured product, and contributing to lowering the CTE. (C) The number of functional groups of the 2-or more-functional epoxy compound is preferably 2 to 4.

Examples of the (C) 2-or more functional epoxy compound include epoxidized vegetable oils; bisphenol a type epoxy compounds; hydroquinone type epoxy compounds; bisphenol type epoxy compounds; thioether-type epoxy compounds; a brominated epoxy compound; novolac type epoxy compounds; diphenol novolak-type epoxy compounds; bisphenol F type epoxy compounds; hydrogenated bisphenol a type epoxy compounds; glycidyl amine type epoxy compounds; hydantoin type epoxy compounds; an alicyclic epoxy compound; trishydroxyphenylmethane-type epoxy compounds; a bixylenol-type or biphenol-type epoxy compound or a mixture thereof; bisphenol S type epoxy compounds; bisphenol a novolac type epoxy compounds; a tetrahydroxyphenylethane-type epoxy compound; a heterocyclic epoxy compound; a diglycidyl phthalate compound; tetraglycidyl toloyl ethane compounds; an epoxy compound having a naphthalene skeleton; an epoxy compound having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy compounds; a copolymerized epoxy compound of cyclohexylmaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivatives; CTBN-modified epoxy compounds, etc., but are not limited thereto. (C) The epoxy compound having 2 or more functions may be used alone in 1 kind or in combination of 2 or more kinds.

Among the (C) 2-or more-functional epoxy compounds in the photosensitive resin compositions of the first and second embodiments, (C) 2-or more-functional epoxy compounds having a naphthalene skeleton are also preferable. Not only can an insulating film having more excellent flexibility and chemical resistance be obtained, but also the CTE can be lowered in a relationship of the two-tone back to the flexibility, and the occurrence of warpage and cracks in the insulating film can be suppressed. In addition, from the viewpoint of flexibility, a bisphenol a type epoxy compound can also be suitably used.

The (c) 2-or more-functional epoxy compound having a naphthalene skeleton is not particularly limited as long as it has a naphthalene skeleton and has 2 or more epoxy groups, and examples thereof include modified naphthalene-type epoxy resins such as 1, 2-diglycidylnaphthalene, 1, 5-diglycidylnaphthalene, 1, 6-diglycidylnaphthalene, 1, 7-diglycidylnaphthalene, 2, 7-diglycidylnaphthalene, triglycidylcaphthalene, and 1,2,5, 6-tetraglycidylnaphthalene, naphthol aralkyl-type epoxy resins, naphthalene skeleton-modified cresol novolak-type epoxy resins, methoxynaphthalene-modified cresol novolak-type epoxy resins, naphthalene ether-type epoxy resins, and methoxynaphthalene dimethylene-type epoxy resins.

Commercially available products include HP-4032D, HP-4700, HP-4770, HP-5000, HP-6000, HP-4710, and NC-7000L, NC-7300L, all available from DIC corporation.

(c) The 2 or more functional epoxy compound having a naphthalene skeleton may or may not have a flexible chain in its structure, but even if it does not have a flexible chain, the flexibility of the cured product of the photosensitive resin composition of the present invention can be improved, and therefore, for example, a linear structure having 5 to 10 atoms, further 3 to 5 atoms, may not be present between epoxy groups.

(C) The epoxy equivalent of the 2-or more-functional epoxy compound is preferably 100 to 500g/eq, more preferably 100 to 300 g/eq.

(C) The amount of the 2-or more-functional epoxy compound is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 30 parts by mass, per 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (a). In the photosensitive resin composition of the third aspect of the present invention, the amount of the naphthalene epoxy compound (c) 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). By setting the content in such a range, the polybenzoxazole precursor (a) can be maintained at an appropriate crosslinking density.

(other crosslinking Agents)

The photosensitive resin composition of the first, second and third aspects of the present invention may contain (C) a crosslinking agent other than the 2-or more-functional epoxy compound. In the present specification, the other crosslinking agent is preferably a compound other than the epoxy compound, which reacts with the phenolic hydroxyl group of the polybenzoxazole precursor to form a crosslinked structure. Examples of the functional group that reacts with the phenolic hydroxyl group of the polybenzoxazole precursor include a cyclic ether group such as an epoxy group, a cyclic thioether group such as an episulfide group, and an alcoholic hydroxyl group in which an alkylene group having 1 to 12 carbon atoms is bonded to a hydroxyl group such as a hydroxymethyl group.

Among other crosslinking agents, crosslinking agents having a triazine ring structure are 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, and is preferably a crosslinking agent represented by the following general formula (2).

(in the formula, R^21A、R^22A、R^23A、R^24A、R^25AAnd R^26APreferably, each independently is an alkylene group having 1 to 3 carbon atoms. R^21B、R^22B、R^23B、R^24B、R^25BAnd R^26BPreferably, each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. )

In the above general formula (2), R^21A、R^22A、R^23A、R^24A、R^25AAnd R^26AMore preferably each methylene. In addition, R^21B、R^22B、R^23B、R^24B、R^25BAnd R^26BMore preferably each independently a methyl group or a hydrogen atom.

The other crosslinking agents may be used alone in 1 kind, or may be used in combination with 2 or more kinds. The amount of the other crosslinking agent is preferably 0.1 to 30 parts by mass per 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (a) in order to prevent deterioration of developability by crosslinking. Further, it is more preferably 0.1 to 20 parts by mass.

((D) plasticizer)

The photosensitive resin composition of the first embodiment of the present invention contains (D) a plasticizer. The photosensitive resin composition according to the third aspect of the present invention preferably contains (D) a plasticizer. The plasticizer (D) is not particularly limited as long as it is a compound for improving plasticity, and may be a plasticizer (D1) having a self-polymerizable group or a plasticizer (D2) having no self-polymerizable group. Examples of the self-polymerizable group include a (meth) acryloyl group, a vinyl group, and an allyl group. In the present specification, the term (meth) acryloyl group refers to a general term for acryloyl group, methacryloyl group and a mixture thereof, and the same applies to other similar expressions. In the present invention, by blending (D) a plasticizer, the cyclization reaction of the polybenzoxazole precursor (a) can be promoted, the low-temperature curability can be further improved, and a cured product having excellent chemical resistance can be obtained. Originally, in curing at a low temperature of about 220 ℃, the cyclization ratio of the polybenzoxazole precursor (a) is low, and if a crosslinking agent is added, the low-temperature curability can be improved, but the cyclization ratio can be further reduced because a functional group generated by the cyclization reaction reacts with the crosslinking agent. The detailed mechanism is not clear, but it is believed that: 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, so that (a) the thermal molecular motion of the polybenzoxazole precursor is improved, and the cyclization reaction is promoted. In the present invention, a plasticizer is added to obtain a cured product having more excellent flexibility. Further, in the present invention, by blending (C) an epoxy compound having 2 or more functional groups, the unexposed portions are excellent in development resistance, and as a result, if a plasticizer is blended, the developability of the exposed portions is improved, and more favorable pattern formation can be achieved by photolithography. (D) The plasticizer may be used alone in 1 kind, or may be used in combination with 2 or more kinds. (D) The plasticizer is preferably one which does not undergo a crosslinking reaction with the other ingredients of the composition. In addition, (D) the plasticizer preferably does not have a function of thermal acid generation. In addition, the plasticizer (D) has a self-polymerizable group, and thus the flexibility of the cured product can be further improved. (D) The plasticizer does not have a self-polymerizable group, and thus the chemical resistance of the cured product can be further improved. As the plasticizer (D), it is preferable to use a plasticizer having a self-polymerizable group (D1) and a plasticizer having no self-polymerizable group (D2) in combination, and a cured product having more excellent flexibility and chemical resistance can be obtained. In the photosensitive resin compositions of the first and third aspects of the present invention, the amount of the plasticizer (D) is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (a). The photosensitive resin composition according to the second embodiment of the present invention may contain (D) a plasticizer.

(D1) plasticizer having self-polymerizable group

The plasticizer having a self-polymerizable group (D1) is preferably a 2-functional (meth) acrylic compound. The 2-functional (meth) acrylic compound is preferably a compound that does not form a crosslinked structure with other components in the composition. In addition, the 2-functional (meth) acrylic compound is preferably a compound that forms a linear structure by self-polymerization.

The 2-functional (meth) acrylic compound is not particularly limited as long as it is a compound having 2 (meth) acryloyl groups, and specific examples thereof include: 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, 1, 9-nonanediol diacrylate, 1, 10-decanediol diacrylate and other diol diacrylates, 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, diol diacrylate obtained by adding at least 1 of ethylene oxide and propylene oxide to neopentyl glycol, caprolactone-modified hydroxypentanoic acid neopentyl glycol diacrylate and other diol diacrylates, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate, 1, 6-hexanediol diacrylate, 1, 9-nonanediol diacrylate, 1, 10-decanediol diacrylate and the like, Bisphenol A diglycidyl ether acrylic acid adduct, tricyclodecane dimethanol diacrylate, diacrylate of diol obtained by adding at least 1 of ethylene oxide and propylene oxide to tris (2-hydroxyethyl) isocyanurate bisphenol A, diacrylate having a cyclic structure such as hydrogenated dicyclopentadienyl diacrylate and cyclohexyl diacrylate, diacrylate of isocyanuric acid such as ethylene oxide-modified diacrylate isocyanurate, 2-functional polyester acrylate, and methacrylate corresponding thereto.

Commercially available products include LIGHT ACRYLATE 1,6HX-A, 1,9ND-A, 3EG-A, 4EG-A (trade name of Cochinchinensis chemical Co., Ltd.), HDDA, 1,9 NDA, DPGDA, TPGDA (trade name of DAICEL ALLNEX Co., Ltd.), BISCATE #195, #230D, #260, #310HP, #335HP, #700HV, #540 (trade name of Osaka organic chemical Co., Ltd.), ARONIX M-208, M-211B, M-215, M-220, M-225, M-240, M-270, M-6200, M-6250, M-6500 (trade name of east Asia synthetic Co., Ltd.), ESNK TERBPE-200, BPE-500, and BPE-900 (trade name of Nippon chemical industries, Ltd.).

Among the 2-functional (meth) acrylic compounds, di (meth) acrylates and 2-functional polyester (meth) acrylates of alkylene oxide adducts of glycols (of ethylene oxide, propylene oxide, etc.) are preferred, and 2-functional polyester (meth) acrylates are more preferred.

Specifically, the di (meth) acrylate which is an alkylene oxide adduct of a diol is preferably one obtained by modifying a diol with an alkylene oxide and adding a (meth) acrylate to a terminal, and more preferably one having an aromatic ring in the diol. For example, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate and the like can be given. Specific structures of di (meth) acrylates of alkylene oxide adducts of diols are shown below, but the structures are not limited thereto.

(wherein m + n is 2 or more, preferably 2 to 40, more preferably 3.5 to 25.)

As the 2-functional polyester (meth) acrylate, M-6200, M-6250, and M-6500 (trade name available from Toyo chemical Co., Ltd.) are preferable.

(D1) The amount of the plasticizer having a self-polymerizable group is preferably 3 to 40 parts by mass based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor, and sufficient chemical resistance can be further exhibited in low-temperature curing.

(D2) plasticizer having no self-polymerizable group)

Examples of the plasticizer having no self-polymerizable group (D2) include N-butylSulfonamide compounds such as benzenesulfonamide and N-ethyl-p-toluenesulfonamide, phthalate compounds such as dimethyl phthalate, diethyl phthalate and di (2-ethylhexyl) phthalate, maleate compounds such as di (2-ethylhexyl) maleate, trimellitate esters such as tris (2-ethylhexyl) trimellitate, aliphatic dibasic acid esters such as dimethyl adipate and dibutyl adipate, phosphate esters such as trimethyl phosphate and tris (butoxyethyl) phosphate, and phosphate esters (C) such as (C) butyl₆H₅O)₂P(O)OC₆H₄C(CH₃)₂C₆H₄OP(O)(OC₆H₅)₂And ether compounds such as aromatic condensed phosphoric acid esters and crown ethers. Among them, sulfonamide compounds, phthalate compounds, and maleate compounds are preferable.

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

(in the general formula (3), R³¹Is an organic group, a nitro group, a halogen atom, a sulfo group, a sulfonyl group, an amino group or an amido group, R³²Is a hydrogen atom or an organic group, and n is an integer of 0 to 5. When n is 2 or more, R³¹May be the same or different. )

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

(in the general formula (4), R⁴¹And R⁴²Each independently is 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, R⁴¹And R⁴²Optionally bonded to form a ring. R⁴³Is a hydrogen atom or an organic group, R⁴⁴Is a hydrogen atom or an organic group. )

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

(D2) The amount of the plasticizer having no self-polymerizable group is preferably 1 to 50 parts by mass, and more preferably 10 to 50 parts by mass, based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor. When the amount is 1 part by mass or more, the plasticizing effect is easily exhibited, and when it is 50 parts by mass or less, the properties of the obtained cured film are not impaired.

((E) thermal acid generator)

The photosensitive resin composition of the second aspect of the present invention contains (E) a thermal acid generator. The photosensitive resin compositions according to the first and third aspects of the present invention preferably contain (E) a thermal acid generator. In the present invention, it is considered that (a) a phenolic hydroxyl group of the polybenzoxazole precursor reacts with (C) an epoxy group of the epoxy compound having 2 or more functional groups to form a crosslinked structure, but in the reaction between the hydroxyl group and the epoxy group, generation of a hydroxyl group in the crosslinked structure deteriorates the dielectric characteristics, and therefore, there is room for improvement in the use as an insulating material. The detailed mechanism is not clear, but in the present invention, if the thermal acid generator is blended, the thermal acid generator functions as a catalyst for the cyclization reaction of the polybenzoxazole precursor (a), and the cyclization reaction at low temperature can be accelerated, and the number of hydroxyl groups in the crosslinked structure is reduced, so that the dielectric characteristics are improved, and further, the cyclization reaction is accelerated, so that a cured product having more excellent chemical resistance and heat resistance can be obtained. The thermal acid generator may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

(E) The thermal acid generator is not particularly limited as long as it generates an acid by heat. Examples of the generated acid include sulfonic acid, carboxylic acid, acetic acid, hydrochloric acid, nitric acid, bromic acid, and iodic acid, and from the viewpoint of efficiency of cyclization, a strong acid is preferable, and sulfonic acids such as arylsulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid, perfluoroalkylsulfonic acids such as trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, and camphorsulfonic acid, and alkylsulfonic acids such as methanesulfonic acid, ethanesulfonic acid, and butanesulfonic acid are preferable. These acids are blended in the photosensitive resin composition as a thermal acid generator, for example, as a compound latent by a covalent bond such as onium salt or imide sulfonate.

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

Examples of the sulfonate 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-methylbenzenesulfonate, phenyl p-toluenesulfonate, ethyl p-toluenesulfonate, methyl p-toluenesulfonate, 2-phenylethyl p-toluenesulfonate, n-propyl p-toluenesulfonate, n-butyl p-toluenesulfonate, tert-butyl p-toluenesulfonate, n-hexyl p-toluenesulfonate, n-heptyl p-toluenesulfonate, n-octyl p-toluenesulfonate, 2-methoxyethyl p-toluenesulfonate, propargyl p-toluenesulfonate, 3-butynyl p-toluenesulfonate, ethyl trifluoromethanesulfonate, n-butyl trifluoromethanesulfonate, Ethyl perfluorobutanesulfonate, methyl perfluorobutanesulfonate, benzyl (4-hydroxyphenyl) methylsulfinic hexafluoroantimonate, benzyl (4-hydroxyphenyl) methylsulfinic hexafluorophosphate, trimethylsulfonium methylsulfate, tri-p-sulfonium trifluoromethanesulfonate, 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.

The sulfonate compound is preferably a compound represented by the following general formula (5).

(in the general formula (5), R⁵¹Represents a hydrogen atom or an alkyl group, R⁵²Represents a hydrogen atom or an organic group. )

R⁵¹The alkyl group may be a straight chain or a branched chain. The number of carbon atoms is preferably 1 to 10, more preferably 1 to 6.

R⁵²The organic group may be a linear, branched or cyclic group. The number of carbon atoms is preferably 1 to 16, more preferably 1 to 11.

The sulfonate is preferably a compound represented by the following general formula (6).

(in the general formula (6), R⁶¹Represents a hydrogen atom or an alkyl group, R⁶²、R⁶³Each independently represents a hydrogen atom or an organic group. R⁶²And R⁶³Optionally bonded to form a ring. )

R⁶¹The alkyl group may be a straight chain or a branched chain. The number of carbon atoms is preferably 1 to 10, more preferably 1 to 6.

R⁶²、R⁶³The organic group may be a linear or branched one.

In the general formulae (5) and (6), as described above, examples of the organic group include alkyl groups having 1 to 12 carbon atoms, and the organic group may be linear or branched.

(E) Among the thermal acid generators, those generating an acid at 120 to 220 ℃ are preferable. In the case of a thermal acid generator which generates an acid at 120 ℃ or higher, the reaction does not proceed easily during prebaking, and development residue is not easily generated. Further, a thermal acid generator which generates an acid at 150 to 220 ℃ is preferable. The generation of acid can be confirmed at the weight reduction temperature based on TG-DTA.

(E) The amount of the thermal acid generator to be added is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 1 to 3 parts by mass, based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor (a).

(sensitizer, sealing agent, other ingredients)

The photosensitive resin composition of the present invention may contain a known sensitizer for improving photosensitivity, or a known sealing agent such as a silane coupling agent for improving adhesiveness to a substrate, within a range not to impair the effects of the present invention. Further, in order to impart processing characteristics and various functionalities to the photosensitive resin composition of the present invention, various 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. In addition, 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 is not particularly limited as long as the above-mentioned components and other additives contained in the photosensitive resin composition of the present invention are dissolved in the solvent. Examples thereof include N, N '-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N' -dimethylacetamide, diethylene glycol dimethyl ether, cyclopentanone, γ -butyrolactone, α -acetyl- γ -butyrolactone, tetramethylurea, 1, 3-dimethyl-2-imidazolidinone, N-cyclohexyl-2-pyrrolidone, dimethyl sulfoxide, 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 may be determined as appropriate depending on the coating film thickness and viscosity. For example, the amount of the polybenzoxazole precursor (a) may be 50 to 9000 parts by mass per 100 parts by mass of the polybenzoxazole precursor.

The photosensitive resin composition of the present invention is preferably 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 the applied film. The resin layer is laminated so as to be in contact with the substrate.

The dry film of the present invention can be produced as follows: the photosensitive resin composition of the present invention can be produced by uniformly applying the photosensitive resin composition to a film by an appropriate method such as a blade coater, a lip coater, a comma coater, or a film coater, drying the applied film to form the resin layer, and preferably laminating a film (so-called protective (covering) film) thereon. The protective film and the support film may be made of the same film material, or different films may be used.

In the dry film of the present invention, the film material of the support film and the protective film may be any known material as a user in the dry film.

As the support film, for example, a thermoplastic film such as a polyester film of polyethylene terephthalate having a thickness of 2 to 150 μm can be used.

As the protective film, a polyethylene film, a polypropylene film, or the like can be used, but the adhesion with the resin layer is preferably smaller than the adhesion with the support film.

The film 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 according to a predetermined procedure. The pattern film as a cured product thereof can be produced by a known and commonly used production method, and for example, in the case of a positive photosensitive resin composition containing a photoacid generator as a photosensitizer (B), it is produced by the following steps.

First, as step 1, a photosensitive resin composition is applied to a substrate and dried, or a resin layer is transferred from a dry film to a substrate, thereby obtaining a coating film. As a method for applying the photosensitive resin composition to the substrate, a method conventionally used for applying the photosensitive resin composition, for example, a method of applying by a spin coater, a bar coater, a blade coater, a curtain coater, a screen printer, or the like, a method of applying by spraying by a spray coater, an inkjet method, or the like can be used. As a method for drying the coating film, methods such as air drying, heat drying in an oven or a hot plate, and vacuum drying can be used. Further, it is desirable that the drying of the coating film is performed under conditions that do not cause cyclization of the polybenzoxazole precursor in the photosensitive resin composition. Specifically, the drying may be performed by natural drying, air-blowing drying, or heat drying at 70 to 140 ℃ for 1 to 30 minutes. Preferably, drying is carried out on a hot plate for 1 to 20 minutes. Further, vacuum drying may be performed, and in the above case, drying may 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 used for semiconductor substrates such as silicon wafers, wiring boards, various resins, metals, and the like.

Next, as step 2, the coating film is exposed through a photomask having a pattern, or is directly exposed. The exposure light is light having a wavelength that can activate the photoacid generator as the (B) sensitizer. Specifically, the maximum wavelength of the exposure light is preferably in the range of 350 to 440 nm. As described above, by appropriately mixing a sensitizer, the photosensitivity can be adjusted. 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. Thus, the exposed portion of the coating film is removed, and a patterned film of the photosensitive resin composition of the present invention can be formed.

As a method used for the development, any method can be selected from conventionally known developing methods of photoresists, for example, a spin spray method, a paddle method, a dipping method with ultrasonic treatment, and the like. Examples of the developer include aqueous solutions of inorganic bases such as sodium hydroxide, sodium carbonate, sodium silicate, and aqueous ammonia, organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine, and quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide. If necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol, or isopropyl alcohol, or a surfactant may be added to these components. Thereafter, the coating film is washed with a washing liquid as necessary to obtain a patterned film. The rinse solution may be used alone or in combination with distilled water, methanol, ethanol, isopropanol, or the like. In addition, as the developer, the above-mentioned solvent can be used.

Thereafter, as 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, the heating is performed in an inert gas at 150 ℃ or higher and lower than 350 ℃ for about 5 to 120 minutes. The heating temperature is more preferably in the range of 180 to 250 ℃. The photosensitive resin composition of the first aspect of the present invention contains (C) the epoxy compound having 2 or more functions and (D) the plasticizer, the photosensitive resin composition of the second aspect of the present invention contains (C) the epoxy compound having 2 or more functions and (E) the thermal acid generator, and the third photosensitive resin composition of the present invention contains (C) the naphthalene-type epoxy compound, and therefore, the cyclization is promoted and the heating temperature can be set to be lower than 250 ℃ and further lower than 220 ℃. The heating is performed by using, for example, a hot plate, an oven, or an oven of an elevated temperature type capable of setting a temperature program. As the atmosphere (gas) at this time, air may be used, or an inert gas such as nitrogen or argon may be used.

The application of the photosensitive resin composition of the present invention is not particularly limited, and the photosensitive resin composition can be suitably used as a coating material, a printing ink, an adhesive, or a material for forming a display device, a semiconductor device, an electronic component, an optical component, or a building material, for example. Specifically, the material for forming a display device can be used as a layer forming material or an image forming material for a color filter, a thin film for a flexible display, a resist material, an alignment film, and the like. The material for forming a semiconductor device can be used for a resist material, a layer forming material such as a buffer coating film, or the like. Further, the material for forming electronic components can be used as a sealing material or a layer forming material for a printed circuit board, an interlayer insulating film, a wiring cover film, and the like. Further, the material for forming the optical member can be used as an optical material or a layer forming material for holograms, optical waveguides, optical paths, optical path members, antireflection films, and the like. Further, the resin composition can be used as a building material 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 therefrom functions as a component imparting heat resistance and insulation properties, for example, as a permanent film formed of polybenzoxazole or the like, and therefore, is particularly suitable for use as a surface protective film of a semiconductor device, a display device or a light-emitting device, an interlayer insulating film, an insulating film for rewiring, a protective film for a flip chip device, a protective film for a device having a bump structure, an interlayer insulating film for a multilayer circuit, an insulating material for a passive component, a solder resist film, a protective film for a printed wiring board such as a cover film, a liquid crystal alignment film, or the like. In particular, the photosensitive resin composition of the present invention is excellent in chemical resistance of a cured product, and therefore, is suitable as a material for forming a layer to be laminated, for example, an interlayer insulating film and an insulating film for rewiring.

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the following, all of the terms "part(s)" and "%" are based on mass unless otherwise specified.

(Synthesis of polybenzoxazole precursor (A1))

In a four-neck separable flask equipped with a thermometer, a stirrer, a raw material inlet and a nitrogen gas inlet, 40.3g (0.11 mol) of 2, 2-bis (3-amino-4-hydroxyphenyl) -1,1,1,3,3, 3-hexafluoropropane was dissolved in 1500g of N-methyl-2-pyrrolidone, and then 35.4g (0.12 mol) of diphenyl ether-4, 4' -dicarboxylic acid dichloride was added dropwise while cooling the temperature of the reaction system to 0 to 5 ℃.

After the completion of the dropwise addition, the temperature of the reaction system was returned to room temperature, and the mixture was directly stirred for 6 hours. Thereafter, 1.8g (0.1 mol) of pure water was added, and the reaction was further carried out at 40 ℃ for 1 hour. After completion of the reaction, 2000g of pure water was added dropwise to the reaction mixture. The precipitate was collected by filtration and washed, and then dried under vacuum to obtain an alkali-soluble polyhydroxyamide (a1) having a repeating structure shown below as a polybenzoxazole precursor.

The weight average molecular weight was 32000, the number average molecular weight was 12500, and the PDI was 2.56.

< first embodiment 1>

(preparation of Positive photosensitive resin composition)

100 parts by mass of the polybenzoxazole precursor (a1) synthesized above was mixed with a photoacid generator (B1), an epoxy compound (C1 to C3) and the respective components at the ratios shown in table 1 below, and then γ -butyrolactone was added so that the polymer became 30% by mass to form a varnish. Each epoxy compound was compounded so that the ratio of the epoxy group to the phenolic OH of the polybenzoxazole precursor (a1) was 5: 1.

(evaluation of elongation)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute and at 220 ℃ for 60 minutes to obtain a cured film. Subsequently, the cured film was peeled off under conditions of 121 ℃ at 100% RH for 60 minutes using a PCT device (HAST SYSTEM TPC-412MD, manufactured by ESPEC Co., Ltd.), and the film properties such as elongation at break were examined. Elongation at break was determined from a tensile test using EZ-SX manufactured by Shimadzu corporation, and the measurement was performed 5 times with a gripper pitch of 30mm and a tensile speed of 3 mm/min, and the maximum value of the values was defined as elongation at break. The elongation was evaluated according to the following criteria.

A +: over 30 percent

A: more than 20 percent and less than 30 percent

B: more than 10 percent and less than 20 percent

C: less than 10%

(chemical resistance test)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute and at 220 ℃ for 60 minutes to obtain a cured film. The samples thus obtained were immersed in gamma-butyrolactone (GBL) at 25 ℃ for 10 minutes, respectively, and the change was evaluated before and after the immersion.

A +: less than 0.5 percent

A: more than 0.5% and less than 1.0%

B: more than 1.0 percent and less than 5 percent

C: over 5 percent

(measurement of residual film ratio at unexposed portion and dissolution rate at exposed portion)

The varnish prepared above was coated on a silicon substrate subjected to copper sputtering by a spin coater. The resultant was dried on a hot plate at 100 ℃ for 3 minutes to obtain a dried film of the photosensitive resin composition having a thickness of 10 μm. The obtained dried film was irradiated with 800mJ/cm of light through a patterned mask by a high-pressure mercury lamp²I-ray of (2). After exposure, the resist was developed in a 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution and washed with water to obtain a positive pattern.

The residual film ratio (%) was calculated from the residual film thickness of the unexposed area at the time when the residual film of the exposed area became 0, and evaluated according to the following criteria.

A +: more than 95 percent

A: more than 90 percent and less than 95 percent

B: more than 80 percent and less than 90 percent

C: less than 80 percent

In addition, the dissolution rate of the exposed portion was calculated as the time (second) for which the dry film thickness (nm)/the residual film at the exposed portion became 0.

[ Table 1]

< photosensitive agent (B) >

(B1) Naphthoquinone diazide compound (TKF-428 made by Sanbao chemical research of Kabushiki Kaisha)

< (C) 2-functional or higher epoxy Compound

(C1) EPICLON860(DIC corporation)

(C2) HP4032D (DIC corporation)

(C3) HP4700(DIC corporation)

< (D) plasticizer

(D1-1) ARONIX M-6250 (2-functional polyester acrylate, manufactured by Toyo Synthesis Co., Ltd.)

(D1-2)) NK ESTER BPE-900 (2-functional methacrylate, manufactured by Newzhongcun chemical industries Co., Ltd.)

(D2-1) N-butylbenzenesulfonamide (manufactured by Daba Industrial Chemicals)

< (E) thermal acid generator

(E1) WPAG618 (Fuji film and Guangdong drug industries Co., Ltd.)

< crosslinking agent having triazine Ring Structure >

1, 1: MW390(Sanwa Chemical Co., Ltd.)

< organic solvent >

A, 2: GBL (gamma-butyrolactone)

As is clear from the results shown in table 1, the photosensitive resin composition of the first embodiment of the present invention is excellent in developability of exposed portions, and when cured at a low temperature of about 220 ℃, a cured film excellent in chemical resistance and flexibility can be obtained.

< example 1>

(evaluation of cyclization acceleration)

100 parts by mass of the polybenzoxazole precursor (A1) synthesized as described above was mixed with 10 parts by mass of a photosensitizer (B1) (TKF-428, manufactured by Sanbao chemical research Co., Ltd.), 17 parts by mass of an epoxy compound having 2 or more functions shown in Table 2 below and 10 parts by mass of a plasticizer, and then gamma-butyrolactone was added so that the polymer became 30% by mass to form a varnish. The epoxy compound having 2 or more functions was added so that the epoxy group was 10: 1.

the resulting varnish was applied to a wafer by means of a spin coater MS-A150 manufactured by MIKASA. After drying at 120 ℃ for 10 minutes on a hot plate, heating was carried out at 150 ℃ for 30 minutes and then at the curing temperature shown in Table 2 below for 1 hour to obtain a cured product (rate of temperature rise 4 ℃/min). Thereafter, the silicon wafer was exposed to an autoclave test (PCT) apparatus at 121 ℃ and 100% RH for 1 hour, and then peeled off. The obtained cured film (FT-IR Spectrum Two, manufactured by Perkinelmer) was subjected to IR measurement, and from the obtained Spectrum, the cyclization ratio of the benzoxazole ring was determined according to the following formula. Each composition was cured at 320 ℃ for 1 hour, as a cyclization ratio of 100%.

A：1050cm^-1C-O of nearby, oxazole ring origin

B：1595cm^-1Nearby, C ═ C derived from fully aromatic ring → benchmark peak

The calculation method comprises the following steps:

[ Table 2]

1, 1: EPICLON860(DIC corporation)

A, 2: N-Butylbenzenesulfonamide (available from Daba Industrial chemical Co., Ltd.)

3, a: n-ethyl-p-toluenesulfonamide

4, v: bis (2-ethylhexyl) phthalate (manufactured by TCI Co., Ltd.)

5, a step of: maleic acid di (2-ethylhexyl) ester (manufactured by TCI Co., Ltd.)

The PBO precursor reacted with the epoxy compound, and thus, the cyclization ratio of reference example 1-3 containing an epoxy compound having 2 or more functions was further reduced as compared with reference example 1-2 containing no epoxy compound, showing a value as low as 38%. The cyclization ratio of reference examples 1-4 to 1-7 in which the plasticizer was added was improved to 57 to 68%, and it was confirmed that the effect of the plasticizer promoted the cyclization ratio.

(preparation of Positive photosensitive resin composition)

100 parts by mass of the polybenzoxazole precursor (a1) synthesized above was mixed with a photoacid generator (B1), an epoxy compound (C1 to C3) and the respective components at the ratios shown in table 3 below, and then γ -butyrolactone was added so that the polymer became 30% by mass to form a varnish. Each epoxy compound was compounded so that the ratio of the epoxy group to the phenolic OH of the polybenzoxazole precursor (a1) was 5: 1.

(evaluation of elongation)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. Subsequently, the cured film was peeled off under conditions of 121 ℃ at 100% RH for 60 minutes using a PCT device (HAST SYSTEM TPC-412MD, manufactured by ESPEC Co., Ltd.), and the film properties such as elongation at break were examined. Elongation at break was determined from a tensile test using EZ-SX manufactured by Shimadzu corporation, and the maximum value of the elongation at break was determined by 5 measurements with a gripper pitch of 30mm and a tensile rate of 3 mm/min. The elongation was evaluated according to the following criteria.

A +: over 30 percent

A: more than 20 percent and less than 30 percent

B: more than 10 percent and less than 20 percent

C: less than 10%

(chemical resistance test)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. On the obtained samples, the samples were immersed in gamma-butyrolactone (GBL) at 25 ℃ for 10 minutes, respectively, and the change was evaluated before and after the immersion.

A +: less than 0.5 percent

A: more than 0.5% and less than 1.0%

B: more than 1.0 percent and less than 5 percent

C: over 5 percent

(measurement of residual film ratio at unexposed portion and dissolution rate at exposed portion)

The varnish prepared above was coated on a silicon substrate subjected to copper sputtering by a spin coater. The resultant was dried on a hot plate at 100 ℃ for 3 minutes to obtain a dried film of the photosensitive resin composition having a thickness of 10 μm. The obtained dried film was irradiated with 800mJ/cm of light through a patterned mask by a high-pressure mercury lamp²I-ray of (2). After exposure, the resist was developed in a 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution and washed with water to obtain a positive pattern.

The residual film ratio (%) was calculated from the residual film thickness of the unexposed area at the time when the residual film of the exposed area became 0, and evaluated according to the following criteria.

A +: more than 95 percent

A: more than 90 percent and less than 95 percent

B: more than 80 percent and less than 90 percent

C: less than 80 percent

In addition, the dissolution rate of the exposed portion was calculated as the time (second) for which the dry film thickness (nm)/the residual film at the exposed portion became 0.

[ Table 3]

< photosensitive agent (B) >

(B1) Naphthoquinone diazide compound (TKF-428 made by Sanbao chemical research of Kabushiki Kaisha)

< (C) 2-functional or higher epoxy Compound

(C1) EPICLON860(DIC corporation)

(C2) HP4032D (DIC corporation)

(C3) HP4700(DIC corporation)

< (D) plasticizer

(D2-1): n-butylbenzenesulfonamide (Daba Industrial chemical)

(D2-3): bis (2-ethylhexyl) phthalate (manufactured by TCI Co., Ltd.)

(D2-4): maleic acid di (2-ethylhexyl) ester (manufactured by TCI Co., Ltd.)

(D1-1) ARONIX M-6250 (2-functional polyester acrylate, manufactured by Toyo Synthesis Co., Ltd.)

< (E) thermal acid generator

(E1) WPAG618 (Fuji film and Guangdong drug industries Co., Ltd.)

< crosslinking agent having triazine Ring Structure >

1, 1: MW390(Sanwa Chemical Co., Ltd.)

< organic solvent >

A, 2: GBL (gamma-butyrolactone)

As is clear from the results shown in table 3, the photosensitive resin composition of the first embodiment of the present invention is excellent in developability of exposed portions, and when cured at a low temperature of about 220 ℃, a cured film excellent in chemical resistance and flexibility can be obtained.

< second embodiment >

(preparation of Positive photosensitive resin composition)

100 parts by mass of the polybenzoxazole precursor (a1) synthesized above was mixed with a photoacid generator (B1), an epoxy compound (C1 to C3) and the respective components at the ratios shown in table 4 below, and then γ -butyrolactone was added so that the polymer became 30% by mass to form a varnish. Each epoxy compound was compounded so that the ratio of the epoxy group to the phenolic OH of the polybenzoxazole precursor (a1) was 5: 1.

(evaluation of self-supporting film)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. Subsequently, the cured film was peeled off under conditions of 121 ℃ and 100% RH for 60 minutes using a PCT device (HAST SYSTEM TPC-412MD, manufactured by ESPEC Co., Ltd.), and the obtained self-supporting film was regarded as good, while the film which was broken and could not be obtained was regarded as poor.

(measurement of dielectric constant/dielectric loss tangent)

The dielectric loss tangent Df as a dielectric property was measured by the following method.

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. Subsequently, the cured film was peeled off at 121 ℃ and 100% RH for 60 minutes by a PCT device (HAST SYSTEM TPC-412MD, manufactured by ESPEC Co., Ltd.) to obtain a self-supporting film. The obtained cured film was used as a test piece and measured by the SPDR (Split Post Dielectric Resonator) Resonator method. The analyzer used a VECTOR type network analyzer E5071C manufactured by Keysight Technologies, Inc., an SPDR resonator, and the calculation program used a program manufactured by QWED corporation. The frequency was 10GHz and the measurement temperature was 25 ℃.

Evaluation of dielectric constant:

a: less than 3.0

B: 3.0 or more

Evaluation of dielectric loss tangent:

a: less than 0.01

B: 0.01 or more and less than 0.015

C: 0.015 or more

(chemical resistance test)

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. The samples thus obtained were immersed in gamma-butyrolactone (GBL) at 25 ℃ for 10 minutes, respectively, and the change was evaluated before and after the immersion.

A: non-cracked

B: the film loss is less than 1%

C: film loss of more than 1%

(measurement of 5% weight loss temperature)

The free-standing film obtained by heating at 220 ℃ for 60 minutes and obtained in the above (measurement of dielectric constant and dielectric loss tangent) is cut into pieces of 1 to 2mm square, and TG-DTA measurement (30 to 580 ℃) is performed on 5 to 10mg of the obtained sample in a nitrogen atmosphere, and the temperature at which the weight change becomes 5% is measured.

A: above 300 DEG C

B: lower than 300 deg.C

(measurement of Tg)

DMA dynamic viscoelasticity measurement

The varnish prepared above was spin-coated on a silicon wafer and heated at 110 ℃ for 3 minutes to form a coating film having a film thickness of 40 μm. Then, the coating film was heated at 120 ℃ for 10 minutes in an inert gas oven under a nitrogen atmosphere, and then heated at 4 ℃/minute for 60 minutes at 220 ℃ to obtain a cured film. Subsequently, the cured film was peeled off at 121 ℃ and 100% RH for 60 minutes by a PCT device (HAST SYSTEM TPC-412MD, manufactured by ESPEC Co., Ltd.) to obtain a self-supporting film. The cured film was cut into a size of 20mm X5 mm with a stainless steel knife (knife thickness: 0.25mm), and measured with a dynamic viscoelasticity measuring apparatus (G2 RSA, TA Instruments). The measurement is carried out in the temperature rise process of room temperature to 350 ℃, and is carried out at the temperature rise speed of 5 ℃/minute, the load of 0.5N, the frequency of 1Hz and the distance of 10mm between the grippers. The peak top of tan δ was taken as Tg.

A: tg of 260 ℃ or higher

B: tg of less than 260 DEG C

(measurement of residual film ratio at unexposed portion and dissolution rate at exposed portion)

The varnish prepared above was coated on a silicon substrate subjected to copper sputtering by a spin coater. The resultant was dried on a hot plate at 100 ℃ for 3 minutes to obtain a dried film of the photosensitive resin composition having a thickness of 10 μm. The obtained dried film was irradiated with 800mJ/cm of light through a patterned mask by a high-pressure mercury lamp²I ray of. After exposure, the resist was developed in a 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution and washed with water to obtain a positive pattern.

The residual film ratio (%) was calculated from the residual film thickness of the unexposed area at the time when the residual film of the exposed area became 0, and evaluated according to the following criteria.

A: over 90 percent

B: less than 90 percent

In addition, the dissolution rate of the exposed portion was calculated as the time (second) for which the dry film thickness (nm)/the residual film at the exposed portion became 0.

[ Table 4]

< photosensitive agent (B) >

(B1) Naphthoquinone diazide compound (TKF-428 made by Sanbao chemical research of Kabushiki Kaisha)

< (C) 2-functional or higher epoxy Compound

(C1) EPICLON860(DIC corporation)

(C2) HP4032D (DIC corporation)

(C3) HP4700(DIC corporation)

< (E) thermal acid generator

(E1) WPAG618 (Fuji film and Guangdong drug industries Co., Ltd.)

(E2) WPAG699 (Fuji film and Guangdong drug industries Co., Ltd.)

< organic solvent >

A, 2: GBL (gamma-butyrolactone)

As is clear from the results shown in table 4, the photosensitive resin composition of the second embodiment of the present invention can form a free-standing film even when cured at a low temperature of about 220 ℃.

< third embodiment >

(preparation of Positive photosensitive resin composition)

100 parts by mass of the polybenzoxazole precursor (a1) synthesized above was mixed with a photoacid generator (B1), an epoxy compound (C2 to C4) and the respective components at the ratios shown in table 5 below, and then γ -butyrolactone was added so that the polymer became 30% by mass to form a varnish.

(preparation of cured film)

The wafer was coated with a varnish by a spin coater MS-A150 manufactured by MIKASA. After drying at 120 ℃ for 10 minutes on a hot plate, heat treatment was carried out at 150 ℃ for 30 minutes and at 220 ℃ for 1 hour to cure (rate of temperature rise 4 ℃ C./minute), thereby obtaining a cured film for physical property testing. Thereafter, the silicon wafer was exposed to an autoclave test (PCT) apparatus at 121 ℃ and 100% RH for 1 hour, and then peeled off.

(CTE)

The linear thermal expansion Coefficient (CTE) of the cured film was measured under the following conditions using TMAQ400 manufactured by TA Instruments Japan, and evaluated according to the following evaluation criteria.

TMA measurement conditions

Test piece: 15mm × 3mm, chuck spacing: 16mm

Force: 0.03N, nitrogen flow: 100 mL/min

Temperature program: 30 ℃→ 350 ℃ (10 ℃/min)

A: CTE less than 45ppm/° C

B: CTE is 45 ppm/DEG C or more and less than 50 ppm/DEG C

C: CTE of 50 ppm/DEG C or more

(chemical resistance)

A wafer having a cured film of 10 to 12 μm was cut into a 2cm square, immersed in GBL (gamma-butyrolactone), washed with water, dried, and subjected to evaluation by the following evaluation criteria, with the film loss of the cured film before and after immersion observed with an optical microscope.

A +: the film loss is less than 1%

A: the film loss is more than 1 percent and less than 3 percent

B: the film loss is more than 3 percent and less than 5 percent

C: film loss of 5% or more

(elongation)

The elongation of the cured film was measured under the following conditions using EZ-SX manufactured by Shimadzu corporation.

[ tensile test conditions ]

Sample size: 50mm × 5mm, gripper spacing: 30mm

Speed: 3 mm/min, number of measurements: 6 times of

A +: elongation at break of 40% or more

A: the elongation at break is more than 30 percent and less than 40 percent

B: the elongation at break is more than 10 percent and less than 30 percent

C: the elongation at break is less than 10%

[ Table 5]

< photosensitive agent (B) >

(B1) Naphthoquinone diazide compound (TKF-428 made by Sanbao chemical research of Kabushiki Kaisha)

< (c) an epoxy compound having 2 or more functions and having a naphthalene skeleton >

(C2) HP4032D (DIC corporation)

(C3) HP4700(DIC corporation)

(C4) Epoxy Compound (EX-214P manufactured by NAGESE CHEMTEX Co., Ltd.)

1, 1: crosslinking agent having triazine Ring Structure (Sanwa Chemical Co., Ltd., MW390 manufactured by Ltd.)

(D1-1) 2-functional polyester acrylate (M6250, manufactured by Toyo Seisaku-sho Co., Ltd.)

(D2-1) N-butylbenzenesulfonamide (BM-4, eighth chemical Industrial Co., Ltd.)

(E1) Thermal acid generator (Fuji film and Wako pure chemical industries, WPAG618)

A, 2: GBL (gamma-butyrolactone)

As is clear from the results shown in table 5, even when the photosensitive resin composition of the third embodiment of the present invention is cured at a low temperature of about 220 ℃, a cured film having excellent chemical resistance and excellent flexibility and a low CTE can be obtained.

Claims (12)

1. A photosensitive resin composition, comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a 2-or more functional epoxy compound, and (D) a plasticizer.

2. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 1 to a film and drying the applied film.

3. A cured product obtained by curing the photosensitive resin composition according to claim 1 or the resin layer of the dry film according to claim 2.

4. An electronic component comprising the cured product according to claim 3.

5. A photosensitive resin composition, comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) an epoxy compound having 2 or more functions, and (E) a thermal acid generator.

6. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 5 to a film and drying the applied film.

7. A cured product obtained by curing the photosensitive resin composition according to claim 5 or the resin layer of the dry film according to claim 6.

8. An electronic component comprising the cured product according to claim 7.

9. A photosensitive resin composition, comprising: (A) a polybenzoxazole precursor, (B) a photosensitizer, and (c) a 2-or more-functional epoxy compound having a naphthalene skeleton.

10. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 9 to a film and drying the applied film.

11. A cured product obtained by curing the photosensitive resin composition according to claim 9 or the resin layer of the dry film according to claim 10.

12. An electronic component comprising the cured product according to claim 11.