阅读说明：本技术 含酯二胺的聚苯并噁唑前体、感光性树脂组合物、干膜、固化物和电子部件 (Polybenzoxazole precursor containing ester diamine, photosensitive resin composition, dry film, cured product, and electronic component ) 是由 秋元真步 于 2019-12-17 设计创作，主要内容包括：[课题]提供：实现高的溶解对比度、进而不易产生裂纹、翘曲的包含含酯二胺的聚苯并噁唑前体的感光性树脂组合物。[解决方案]本发明的含酯二胺的聚苯并噁唑前体的特征在于,具有：通式(1)和(2)所示的结构中的至少一者、和下述通式(3)所示的结构。([ problem ] to]Providing: a photosensitive resin composition containing a polybenzoxazole precursor containing an ester diamine, which has a high solubility contrast and is less likely to cause cracking or warping. [ solution ]]The polybenzoxazole precursor containing an ester diamine of the present invention is characterized by having: at least one of the structures represented by the general formulae (1) and (2), and a structure represented by the following general formula (3).)

1. A polybenzoxazole precursor comprising an esterdiamine, characterized by: at least one of the structures represented by the following general formulae (1) and (2), and a structure represented by the following general formula (3),

in the general formulae (1) and (2),

x is an organic group having a valence of 2,

R₁～R₄any one selected from alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, aromatic group having 6 to 10 carbon atoms, benzene having 6 to 10 carbon atomsAn oxy group, a C6-10 benzyl group and a C6-10 benzyloxy group, and R other than these₃～R₆Is a hydrogen atom, and is a hydrogen atom,

n represents an integer of 1 or more,

in the general formula (3), in the formula,

x is an organic group having a valence of 2,

y is a 4-valent organic group having at least 2 or more hydroxyl groups,

o represents an integer of 1 or more.

2. The polybenzoxazole precursor containing an esterdiamine according to claim 1,

R₁or R₃One of them is selected from an aromatic group having 6 to 10 carbon atoms, a phenoxy group having 6 to 10 carbon atoms, a benzyl group having 6 to 10 carbon atoms and a benzyloxy group having 6 to 10 carbon atoms, and the other is a hydrogen atom,

R₂and R₄Is a hydrogen atom.

3. The polybenzoxazole precursor containing an ester diamine according to claim 1 or 2, wherein Y is an aromatic group in the general formula (3).

4. The polybenzoxazole precursor containing an esterdiamine according to any one of claims 1 to 3, wherein Y is 1 or more groups selected from the following structures in the general formula (3),

in the structural formula,

*₁and₂either represents a linking portion with an amino group, and the other represents a hydroxyl group.

5. The polybenzoxazole precursor containing an ester diamine according to any one of claims 1 to 4, wherein a content of the structures represented by the general formulae (1) and (2) (an ester diamine content) is 0.1 mol% or more and 10 mol% or less.

6. A photosensitive resin composition comprising: a polybenzoxazole precursor containing an ester diamine according to any one of claims 1 to 5 and a photosensitizer.

7. The photosensitive resin composition according to claim 6, wherein the sensitizer is a naphthoquinone diazide compound.

8. A dry film comprising a film and a resin layer formed from the photosensitive resin composition according to claim 6 or 7.

9. A cured product comprising the photosensitive resin composition according to claim 6 or 7 or the resin layer of the dry film according to claim 8.

10. An electronic component, characterized by having the cured product of claim 9 as a forming material.

Technical Field

The present invention relates to: an ester diamine-containing polybenzoxazole precursor (also referred to as polyhydroxyamide), a photosensitive resin composition containing the ester diamine-containing polybenzoxazole precursor, a dry film provided with a resin layer formed from the photosensitive resin composition, a cured product formed from the photosensitive resin composition, and an electronic component such as a printed wiring board or a semiconductor element having the cured product as a forming material.

Background

Photosensitive resin compositions containing a polybenzoxazole precursor are widely used in various fields because they have been heated to cyclize a hydroxyamide structure into a rigid benzoxazole ring and increase the intermolecular bulk density, thereby exhibiting excellent characteristics such as insulation properties, heat resistance, and mechanical strength. For example, the present invention is being applied to flexible printed circuit boards, buffer coating films for semiconductor devices, and insulating films for rewiring layers of Wafer Level Packages (WLPs).

Conventionally, a photosensitive resin composition containing a polybenzoxazole precursor, which is capable of performing pattern formation by a finer photolithography method, has been attracting attention, instead of a photosensitive resin composition containing a polyimide precursor, in a buffer coating film and an insulating film for a rewiring layer of a wafer level package.

As such a photosensitive resin composition, a positive resist composition composed of a polybenzoxazole precursor and a photosensitive diazoquinone disclosed in patent document 1 can be mentioned. Then, after a desired pattern film is formed by applying the photosensitive resin composition onto a substrate such as a wafer and drying the composition to form a dried coating film, irradiating the dried coating film with active energy rays and exposing the coating film to light, and then developing the coating film, a pattern cured film of polybenzoxazole is formed by subjecting a polybenzoxazole precursor to a cyclization reaction by heating at about 320 ℃.

In recent semiconductor devices, with the demand for higher functionality and smaller size, buffer coating films and insulating films for rewiring layers of wafer level packages are required to have excellent resolution for finer pattern formation and further to suppress cracking and warpage due to thinning of wafers as substrates.

Documents of the prior art

Patent document

Patent document 1: japanese examined patent publication (Kokoku) No. 1-046862

Disclosure of Invention

Problems to be solved by the invention

However, the composition described in patent document 1 has a problem that it is difficult to form a fine pattern because the composition has a low solubility contrast, which is a balance between the solubility of an exposed portion and the solubility resistance of an unexposed portion during development, and is required to achieve the resolution required for recent semiconductor devices.

The present invention has been made to solve the above problems, and an object thereof is to provide: a photosensitive resin composition containing a polybenzoxazole precursor which realizes a high solubility contrast and is less likely to cause cracking or warping.

Another object of the present invention is to provide: a dry film using the photosensitive resin composition, and an electronic component such as a printed wiring board or a semiconductor element.

Means for solving the problems

The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that: the present inventors have completed the present invention by introducing a diamine having an ester structure into a polybenzoxazole precursor, thereby significantly improving the solubility contrast of a photosensitive resin composition and further relaxing internal stress generated during curing.

That is, the polybenzoxazole precursor containing an ester diamine of the present invention is characterized by having: at least one of the structures represented by the general formulae (1) and (2), and a structure represented by the following general formula (3).

(in the general formulae (1) and (2),

x is an organic group having a valence of 2,

R₁～R₄any one selected from alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, aromatic group having 6 to 10 carbon atoms, phenoxy group having 6 to 10 carbon atoms, benzyl group having 6 to 10 carbon atoms and benzyloxy group having 6 to 10 carbon atoms, and R other than the above₁～R₄Is a hydrogen atom, and is a hydrogen atom,

n represents an integer of 1 or more,

in the general formula (3), in the formula,

x is an organic group having a valence of 2,

y is a 4-valent organic group having at least 2 or more hydroxyl groups,

o represents an integer of 1 or more. )

In the present invention, R is preferred₁Or R₃One of them is selected from an aromatic group having 6 to 10 carbon atoms, a phenoxy group having 6 to 10 carbon atoms, a benzyl group having 6 to 10 carbon atoms and a benzyloxy group having 6 to 10 carbon atoms, and the other is a hydrogen atom,

R₂and R₄Is a hydrogen atom.

In the present invention, it is preferable that in the general formula (3), Y is 1 or more groups selected from the following structures.

(in the above-mentioned structural formula,

*₁and₂either represents a linking portion with an amino group, and the other represents a hydroxyl group. )

In the present invention, the content of the structures represented by the general formulae (1) and (2) (the content of the ester diamine) is preferably 0.1 mol% or more and 10 mol% or less.

The photosensitive resin composition of the present invention is characterized by comprising: a polybenzoxazole precursor, and a photosensitizer.

In the present invention, the photosensitizer is preferably a naphthoquinone diazide compound.

The dry film of the present invention is characterized by comprising a resin layer formed from the photosensitive resin composition on a film.

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

The electronic component of the present invention, such as a printed wiring board or a semiconductor device, is characterized by having the cured product as a material for forming the electronic component.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the polybenzoxazole precursor containing an esterdiamine of the present invention, there can be provided: a photosensitive resin composition effective for obtaining a dry coating film having a high solubility contrast and high-temperature pattern retention.

Detailed Description

[ Polybenzoxazole precursor containing ester diamine ]

The polybenzoxazole precursor containing an ester diamine according to the present invention is a polybenzoxazole precursor having at least one of the structures represented by the following general formulae (1) and (2) and the structure represented by the following general formula (3), and it is considered that a photosensitive resin composition containing the same can obtain development resistance of an unexposed portion without impairing the development property of an exposed portion, and further, in a cured product, an amide bond and an ester bond having excellent flexibility relax internal stress.

In the above general formulae (1) and (2), X is an organic group having a valence of 2. The organic group may be an aliphatic group or an aromatic group, preferably an aromatic group, and more preferably an aromatic ring, and is bonded to the carbonyl group in the general formulae (1) and (2).

The number of carbon atoms of the 2-valent organic group is preferably 6 to 30, more preferably 6 to 24.

Examples of the organic group having a valence of 2 include groups having the following structures, but are not limited thereto, and are preferably appropriately modified depending on the application.

In the structural formula of the 2-valent organic group, A is selected from single bond, alkylene, -O-, -CO-, -S-, -SO₂-、-C(CF₃)₂-and-C (CH)₃)₂-.

Among the above, the 2-valent organic group is particularly preferably a group having the following structure, from the viewpoint of obtaining excellent developability of the photosensitive resin composition and excellent mechanical properties of the cured film.

In the above general formulae (1) and (2), R₁～R₄Any one of them, preferably R₁Or R₃Any one of them, particularly preferably R₃Selected from alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, aromatic group having 6 to 10 carbon atoms, phenoxy group having 6 to 10 carbon atoms, benzyl group having 6 to 10 carbon atoms and benzyloxy group having 6 to 10 carbon atoms, and R other than these₁～R₄Is a hydrogen atom.

Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, and a hexyl group.

Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy, and pentoxy groups.

Examples of the aromatic group having 6 to 10 carbon atoms include phenyl, tolyl, methylphenyl, dimethylphenyl, ethylphenyl, diethylphenyl, propylphenyl, butylphenyl, fluorophenyl, pentafluorophenyl, chlorophenyl, bromophenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, diethoxyphenyl, methoxybenzyl, dimethoxybenzyl, ethoxybenzyl, diethoxybenzyl, aminophenyl, aminobenzyl, nitrophenyl, nitrobenzyl, cyanophenyl, cyanobenzyl, phenethyl, phenylpropyl, phenylamino, diphenylamino, biphenyl, and naphthyl groups.

Examples of the phenoxy group having 6 to 10 carbon atoms include a methylphenoxy group, an ethylphenoxy group, a propylphenoxy group, a dimethylphenoxy group, a diethylphenoxy group, a methoxyphenoxy group, an ethoxyphenoxy group, a dimethoxyphenoxy group and the like.

Examples of the benzyl group having 6 to 10 carbon atoms include benzyl, methylbenzyl, ethylbenzyl, propylbenzyl, dimethylbenzyl, methoxybenzyl, ethoxybenzyl, and methoxybenzyl groups.

Examples of the benzyloxy group having 6 to 10 carbon atoms include a methylbenzyloxy group, a benzyloxy group, a pentylbenzyloxy group, an ethylbenzyloxy group, a propylbenzyloxy group, a dimethylbenzyloxy group, a methoxybenzyloxy group, and an ethoxybenzyloxy group.

Among the above, R is R from the viewpoint of the solubility contrast, high-temperature pattern maintenance, sensitivity and linear thermal expansion coefficient of the photosensitive resin composition₁～R₄Any of them is preferably an aromatic group having 6 to 10 carbon atoms, a phenoxy group having 6 to 10 carbon atoms, a benzyl group having 6 to 10 carbon atoms, and a benzyloxy group having 6 to 10 carbon atoms, more preferably an aromatic group having 6 to 10 carbon atoms, further preferably a phenyl group, a tolyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, and a diethylphenyl group, and particularly preferably a phenyl group from the viewpoint of an effect of suppressing a film loss phenomenon at an unexposed portion and an effect of relaxing an internal stress based on an effect of suppressing intermolecular stacking in a cured product.

In the general formulae (1) and (2), n is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 2.

In the ester diamine-containing polybenzoxazole precursor of the present invention, the content of the structures represented by the general formulae (1) and (2) (the ester diamine content) is preferably 0.1 mol% or more and 10 mol% or less, and is preferably 0.1 mol% or more and 5 mol% or less. This can further improve the solubility contrast in developing a dried coating film formed from the photosensitive resin composition containing the polybenzoxazole precursor of the present invention.

In the general formula (3), X is an organic group having a valence of 2, and preferred embodiments thereof are the same as those of the general formulae (1) and (2), and therefore, the description thereof is omitted.

In the general formula (3), Y is a 4-valent organic group having at least 2 or more hydroxyl groups. The organic group may be an aliphatic group or an aromatic group, and is preferably an aromatic group.

The positional relationship between the hydroxyl group and the amino group of the 4-valent organic group is preferably ortho.

The number of carbon atoms of the 4-valent organic group is preferably 6 to 30, more preferably 6 to 24.

The organic group having a valence of 4 includes groups having the following structures, but is not limited thereto, and is preferably appropriately modified depending on the application.

In the structural formula of the above-mentioned 4-valent organic group₁And₂either represents a linking portion with an amino group, and the other represents a hydroxyl group.

Among the above, from the viewpoint of improvement of photosensitivity due to light transmittance, the organic group having a valence of 4 is particularly preferably a group having a structure shown below.

In the general formula (3), o is an integer of 1 or more, preferably 10 to 40, more preferably 20 to 30.

In the ester diamine-containing polybenzoxazole precursor of the present invention, the content of the structure represented by the above general formula (3) is preferably 90 mol% or more and 99.9 mol% or less, and is preferably 95 mol% or more and 99.9 mol% or less. Thus, the photosensitive resin composition containing the ester diamine-containing polybenzoxazole precursor of the present invention can improve the excellent developer solubility at exposed portions as a dried coating film, and the insulation, heat resistance and mechanical strength as a cured film.

The number average molecular weight (Mn) of the polybenzoxazole precursor containing an esterdiamine is preferably 2000 or more and 50000 or less, more preferably 4000 or more and 25000 or less. This improves the solubility in an alkaline developing solution.

The weight average molecular weight (Mw) of the polybenzoxazole precursor is preferably 4000 to 10000, more preferably 8000 to 50000. This can further reduce the occurrence of cracks in the cured product.

Further, Mw/Mn is preferably 1 or more and 5 or less, more preferably 1 or more and 3 or less.

In the present invention, the number average molecular weight and the weight average molecular weight are values measured by Gel Permeation Chromatography (GPC) and calculated in terms of standard polystyrene.

The polybenzoxazole precursor containing an ester diamine can be obtained by reacting at least a diamine compound represented by the following general formula (4), a diamine compound represented by the following general formula (5), and a dicarboxylic acid component represented by the following general formula (6).

Z in the general formula (6) represents a leaving group formed of a hydroxyl group, a halogen group, or a cyclic compound composed of nitrogen, sulfur, carbon, oxygen, and an aromatic ring. Among them, a halogen group is preferable from the viewpoint of productivity.

For R in the above general formulae (4) to (6)₁～R₄X, Y, as described above.

Examples of the dicarboxylic acid component satisfying the general formula (6) 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, bis (4-carboxyphenyl) sulfone, 2-bis (p-carboxyphenyl) propane, 2-bis (4-carboxyphenyl) -1,1,1,3,3, 3-hexafluoropropane and other dicarboxylic acids having an aromatic ring, oxalic acid, malonic acid, succinic acid, 1, 2-cyclobutanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 1, 3-cyclopentanedicarboxylic acid and other aliphatic dicarboxylic acids, their dicarboxylic acid dihalides, dicarboxylic acid dihalides, Dicarboxylic acid esters thereof, and the like. Among them, 4,4 '-dicarboxydiphenyl ether (i.e., 4, 4' -diphenyletherdicarboxylic acid) and a dihalide thereof are preferable from the viewpoint of excellent developability with which the photosensitive resin composition can be obtained and mechanical characteristics of a cured film.

The polybenzoxazole precursor containing an ester diamine may be combined with a diamine compound other than the diamine compounds represented by the general formulae (4) and (5) (hereinafter, referred to as another diamine compound) within a range where the characteristic effects and polymerization reactivity are not impaired.

Examples of the other diamine compound include: 4,4 '-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl ] ketone, bis [4- (3-aminophenoxy) phenyl ] sulfide, bis [4- (3-aminophenoxy) phenyl ] sulfone, 2-bis [4- (3-aminophenoxy) phenyl ] propane, 2-bis [4- (3-aminophenoxy) phenyl ] -1,1,1,3,3, 3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3, 3' -diaminodiphenyl ether, 3,4 '-diaminodiphenyl ether, 4' -diaminodiphenyl ether, 3,3 '-diaminodiphenyl sulfide, 3, 3' -diaminodiphenyl sulfoxide, and mixtures thereof, 3,4 '-diaminodiphenyl sulfoxide, 4' -diaminodiphenyl sulfoxide, 3 '-diaminodiphenyl sulfone, 3, 4' -diaminodiphenyl sulfone, 4 '-diaminodiphenyl sulfone, 3' -diaminobenzophenone, 3,4 '-diaminobenzophenone, 4' -diaminobenzophenone, 3 '-diaminodiphenylmethane, 3, 4' -diaminodiphenylmethane, 4 '-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl ] methane, 1-bis [4- (4-aminophenoxy) phenyl ] ethane, 1, 2-bis [4- (4-aminophenoxy) phenyl ] ethane, 1-bis [4- (4-aminophenoxy) phenyl ] propane, 3, 4' -diaminodiphenyl sulfone, 4 '-diaminodiphenyl sulfone, 3' -diaminobenzophenone, 1 '-diaminodiphenyl sulfone, 1, 4' -diaminodiphenyl methane, bis [4- (4-aminophenoxy) phenyl ] methane, 1-bis [4- (4-aminophenoxy) phenyl ] ethane, 1, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 1, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 2-bis [ 4-bis (4-phenylethane, 3, 4-diaminodiphenyl-bis (4-diaminodiphenyl) methane, 4-bis [ 4-amino) methane, 4-bis (4-amino) phenyl) propane, 4-bis (4-amino) propane, 4-amino-bis (4-amino) propane, 4-bis (4-phenyl) propane, 4-bis (4-amino) propane, 4-bis (4-amino-phenyl) propane, 4-phenyl) methane, 4-phenyl) propane, 4-bis (4-amino-phenyl) propane, 4-bis (4-amino) propane, 4-bis (4-phenyl) propane, 4-bis (4-amino) propane, 4-phenyl) propane, 4) propane, 4-bis (4) propane, 4) propane, 4) propane, 4) methane, 4) propane, 4) propane, 4, 1, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 1, 3-bis [4- (4-aminophenoxy) phenyl ] propane, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 1-bis [4- (4-aminophenoxy) phenyl ] butane, 1, 3-bis [4- (4-aminophenoxy) phenyl ] butane, 1, 4-bis [4- (4-aminophenoxy) phenyl ] butane, 2-bis [4- (4-aminophenoxy) phenyl ] butane, 2, 3-bis [4- (4-aminophenoxy) phenyl ] butane, 2- [4- (4-aminophenoxy) phenyl ] -2- [4- (4-aminophenoxy) -3-methylphenylphenyl ] butane, and the like Propane, 2-bis [4- (4-aminophenoxy) -3-methylphenyl ] propane, 2- [4- (4-aminophenoxy) phenyl ] -2- [4- (4-aminophenoxy) -3, 5-dimethylphenyl ] propane, 2-bis [4- (4-aminophenoxy) phenyl ] -1,1,1,3,3, 3-hexafluoropropane, 1, 4-bis (3-aminophenoxy) benzene, 1, 3-bis (3-aminophenoxy) benzene, 1, 4-bis (4-aminophenoxy) benzene, 4,4 '-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl ] ketone, bis [4- (4-aminophenoxy) phenyl ] sulfide, bis [4- (4-aminophenoxy) phenyl ] sulfoxide, bis [4- (4-aminophenoxy) phenyl ] sulfone, bis [4- (3-aminophenoxy) phenyl ] ether, bis [4- (4-aminophenoxy) phenyl ] ether, 1, 3-bis [4- (4-aminophenoxy) benzoyl ] benzene, 1, 3-bis [4- (3-aminophenoxy) benzoyl ] benzene, 1, 4-bis [4- (3-aminophenoxy) benzoyl ] benzene, 4' -bis [ (3-aminophenoxy) benzoyl ] benzene, bis [4- (4-aminophenoxy) phenyl ] sulfone, bis [4- (3-aminophenoxy) phenyl ] ether, and their salts, 1, 1-bis [4- (3-aminophenoxy) phenyl ] propane, 1, 3-bis [4- (3-aminophenoxy) phenyl ] propane, 3,4 '-diaminodiphenyl sulfide, 2-bis [3- (3-aminophenoxy) phenyl ] -1,1,1,3,3, 3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl ] methane, 1, 1-bis [4- (3-aminophenoxy) phenyl ] ethane, 1, 2-bis [4- (3-aminophenoxy) phenyl ] ethane, bis [4- (3-aminophenoxy) phenyl ] sulfoxide, 4' -bis [3- (4-aminophenoxy) benzoyl ] diphenyl ether, and the like, 4,4 ' -bis [3- (3-aminophenoxy) benzoyl ] diphenyl ether, 4 ' -bis [4- (4-amino-. alpha.,. alpha. -dimethylbenzyl) phenoxy ] benzophenone, 4 ' -bis [4- (4-amino-. alpha.,. alpha. -dimethylbenzyl) phenoxy ] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy } phenyl ] sulfone, 1, 4-bis [4- (4-aminophenoxy) phenoxy-. alpha.,. alpha. -dimethylbenzyl ] benzene, 1, 3-bis [4- (4-amino-6-trifluoromethylphenoxy) -alpha, alpha-dimethylbenzyl benzene, 1, 3-bis [4- (4-amino-6-fluorophenoxy) -alpha, alpha-dimethylbenzyl ] benzene, 1, 3-bis [4- (4-amino-6-methylphenoxy) -alpha, alpha-dimethylbenzyl ] benzene, 1, 3-bis [4- (4-amino-6-cyanophenoxy) -alpha, alpha-dimethylbenzyl ] benzene, 3 ' -diamino-4, 4 ' -benzoxy benzophenone, 4 ' -diamino-5, 5 ' -benzoxy benzophenone, 3,4 ' -diamino-4, 5 ' -benzoxy benzophenone, 3 ' -diamino-4-phenoxybenzophenone, 1, 3-bis [4- (4-amino-6-fluorophenoxy) -alpha, alpha-dimethylbenzyl ] benzene, and mixtures thereof, 4,4 ' -diamino-5-phenoxybenzophenone, 3,4 ' -diamino-4-phenoxybenzophenone, 3,4 ' -diamino-5 ' -phenoxybenzophenone, 3 ' -diamino-4, 4 ' -bigemhenoxybenzophenone, 4 ' -diamino-5, 5 ' -biphenyloxybenzophenone, 3,4 ' -diamino-4, 5 ' -biphenyloxybenzophenone, 3 ' -diamino-4-biphenyloxybenzophenone, 4 ' -diamino-5-biphenyloxybenzophenone, 3,4 ' -diamino-4-biphenyloxybenzophenone, 3,4 ' -diamino-5 ' -biphenyloxybenzophenone, and mixtures thereof, 1, 3-bis (3-amino-4-phenoxybenzoyl) benzene, 1, 4-bis (3-amino-4-phenoxybenzoyl) benzene, 1, 3-bis (4-amino-5-phenoxybenzoyl) benzene, 1, 4-bis (4-amino-5-phenoxybenzoyl) benzene, 1, 3-bis (3-amino-4-biphenyloxybenzoyl) benzene, 1, 4-bis (3-amino-4-biphenyloxybenzoyl) benzene, 1, 3-bis (4-amino-5-biphenyloxybenzoyl) benzene, 1, 4-bis (4-amino-5-biphenyloxybenzoyl) benzene, 2, 6-bis [4- (4-amino- α, an aromatic diamine in which a part or all of hydrogen atoms on an aromatic ring in the aromatic diamine are substituted with a halogen atom, an alkyl or alkoxy group having 1 to 3 carbon atoms, a cyano group, or a haloalkyl or alkoxy group having 1 to 3 carbon atoms in which a part or all of hydrogen atoms of the alkyl or alkoxy group are substituted with a halogen atom, and the like; 4, 4' -methylenebis (cyclohexylamine), isophoronediamine, trans-1, 4-diaminocyclohexane, cis-1, 4-diaminocyclohexane, 1, 4-cyclohexanedi (methylamine), 2, 5-bis (aminomethyl) bicyclo [2,2,1] heptane, 2, 6-bis (aminomethyl) bicyclo [2,2,1] heptane, 3, 8-bis (aminomethyl) tricyclo [5,2,1,0] decane, 1, 3-diaminoadamantane, 2-bis (4-aminocyclohexyl) propane, 2-bis (4-aminocyclohexyl) hexafluoropropane, 1, 3-propanediamine, 1, 4-tetramethylenediamine, 1, 5-pentamethylenediamine, 1, 6-hexamethylenediamine, N-methyl-ethyl-methyl-1, 4-diaminocyclohexane, N-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-methyl-ethyl-4, ethyl-methyl-ethyl-methyl-ethyl-methyl-4, ethyl-4, ethyl-4, 4-4, 4-methyl-4, 4-methyl-4-methyl-4-methyl-4-methyl, Aliphatic diamines such as 1, 7-heptamethylenediamine, 1, 8-octamethylenediamine and 1, 9-nonamethylenediamine. The other diamine compounds may be used alone or in combination of 2 or more.

[ photosensitive resin composition ]

The photosensitive resin composition of the present invention comprises: (A) a polybenzoxazole precursor containing the above esterdiamine, and (B) a sensitizer.

The photosensitive resin composition uses such an ester diamine-containing polybenzoxazole precursor, and thus the solubility contrast and internal stress of a dried coating film formed from the photosensitive resin composition can be significantly improved.

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

[ (A) Polybenzoxazole precursors containing esterdiamines ]

The photosensitive resin composition of the present invention comprises the aforementioned polybenzoxazole precursor containing an esterdiamine as a polybenzoxazole precursor, and thus the solubility contrast of a formed dried coating film and the internal stress of a cured film can be significantly improved.

The photosensitive resin composition of the present invention can be used in combination with a polybenzoxazole precursor other than the above polybenzoxazole precursor containing an ester diamine.

The content of the polybenzoxazole precursor containing an esterdiamine in the photosensitive resin composition is preferably 50% by mass or more and 99% by mass or less, and more preferably 60% by mass or more and 90% by mass or less, in the nonvolatile content. The effect of the present invention can be sufficiently obtained by the content range.

[ (B) photosensitizer ]

The photosensitive resin composition of the present invention contains a photosensitizer, and examples thereof include a photoacid generator and a photobase generator. Among them, from the viewpoint of the solubility contrast, a photoacid generator is preferable.

The sensitizer may be blended in a known and commonly used ratio, and for example, the photoacid generator is blended in a ratio of preferably 5 to 40 parts by mass, more preferably 10 to 30 parts by mass, to 100 parts by mass of the polybenzoxazole precursor containing the ester diamine.

It should be noted that the sensitizer may contain 2 or more.

The photoacid generator is a compound that generates an acid by irradiation with light such as ultraviolet light or visible light, and examples thereof 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 sulfonic acid esters, aromatic sulfonamides, benzoquinone diazosulfonic acid esters, and the like.

Among the above, naphthoquinone diazide compounds are preferable from the viewpoint of the solubility contrast.

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 is a compound that generates 1 or more basic substances (such as secondary amines and tertiary amines) by changing the molecular structure or cleaving molecules upon irradiation with light such as ultraviolet light or visible light.

The photobase generator may be an ionic photobase generator or a nonionic photobase generator, and an ionic photobase generator is preferred from the viewpoint of sensitivity of the photosensitive resin composition.

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

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, and an alkoxybenzylcarbamate group.

Examples of the other photobase generators include WPBG-018 (trade name: 9-anthracenyl N, N' -diacetalcabamate), WPBG-027 (trade name: (E) -1- [3- (2-hydroxyphenyl) -2-propenoyl ] piperidine), WPBG-140 (trade name: 1- (anthracenyl-2-yl) ethylimidazolecylate), and WPBG-165 manufactured by Wako pure chemical industries, Ltd.

[ crosslinking agent ]

The photosensitive resin composition of the present invention may contain a crosslinking agent. By adding the crosslinking agent, sufficient characteristics of a cured product can be obtained even at a low temperature of about 220 ℃. The crosslinking agent is not particularly limited, and known and commonly used crosslinking agents can be mentioned.

The crosslinking agent in this specification is preferably a compound that reacts with a phenolic hydroxyl group in the polybenzoxazole precursor to form a crosslinked structure.

Here, as the compound that reacts with the phenolic hydroxyl group in the polybenzoxazole precursor, there can be mentioned: a crosslinking agent having a cyclic ether group such as an epoxy group, a cyclic thioether group such as an episulfide group, a crosslinking agent having an alcoholic hydroxyl group in which an alkylene group having 1 to 12 carbon atoms such as a hydroxymethyl group is bonded to a hydroxyl group, a compound having an ether bond such as an alkoxymethyl group, a crosslinking agent having a triazine ring structure, and a urea-based crosslinking agent.

Among them, a crosslinking agent having a cyclic ether group, particularly an epoxy group, and a crosslinking agent having an alcoholic hydroxyl group, particularly a hydroxymethyl group to which a hydroxyl group is bonded are preferable.

The crosslinking agent may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

The amount of the crosslinking agent to be blended in the photosensitive resin composition of the present invention is preferably 0.1 to 30 parts by mass per 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor. Further, it is more preferably 0.1 to 20 parts by mass.

(crosslinking agent having epoxy group)

The photosensitive resin composition of the present invention preferably contains a crosslinking agent having an epoxy group as a crosslinking agent. The crosslinking agent having an epoxy group thermally reacts with the hydroxyl group of the polybenzoxazole precursor to form a crosslinked structure. The number of functional groups of the crosslinking agent having an epoxy group is preferably 2 to 4. The photosensitive resin composition can be cured at low temperature by including a crosslinking agent having an epoxy group, and the solubility contrast of the formed dried coating film can be further improved.

Among the crosslinking agents having an epoxy group, an epoxy compound having 2 or more functions and having a naphthalene skeleton is 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 reverse relationship with 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.

(crosslinking agent having hydroxymethyl group)

The photosensitive resin composition of the present invention preferably contains a crosslinking agent having a hydroxymethyl group as a crosslinking agent. The crosslinking agent having a methylol group preferably has 2 or more methylol groups, and more preferably a compound represented by the following general formula (7).

(in the general formula (7), R^A1Represents an organic group having a valence of 2 to 10. R^A2Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. r represents an integer of 2 to 10. )

In the above general formula (7), R^A1Preferably an alkylene group having 1 to 3 carbon atoms which may be optionally substituted.

In the above general formula (7), R^A2Preferably a hydrogen atom.

In the general formula (7), r is preferably an integer of 2 to 4, more preferably 2.

The crosslinking agent having a phenolic hydroxyl group preferably has a fluorine atom, and more preferably has a trifluoromethyl group. The fluorine atom or the trifluoromethyl group is preferably R in the general formula (7)^A1R is an organic group having a valence of 2 to 10^A1Bis (trifluoromethyl) methylene is preferred. The crosslinking agent having a phenolic hydroxyl group preferably has a bisphenol structure, and more preferably has a bisphenol AF structure.

[ plasticizer ]

The photosensitive resin composition of the present invention preferably contains a plasticizer. In the present invention, it is considered that the plasticizing action of the plasticizer, that is, the aggregation action between the polymer molecular chains is reduced, the mobility and flexibility between the molecular chains are improved, the thermal molecular motion of the polybenzoxazole precursor is improved, the cyclization reaction is promoted, and the low-temperature curability is provided. The plasticizer is not particularly limited as long as it is a compound for improving plasticity, and examples thereof include 2-functional (meth) acrylic compounds, sulfone amide compounds, phthalate compounds, maleate compounds, aliphatic dibasic acid esters, phosphate esters, ether compounds such as crown ethers, and the like. Among them, 2-functional (meth) acrylic compounds are preferable. 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, from the viewpoint of further relaxing the internal stress of the cured product, the 2-functional (meth) acrylic compound is preferably a compound having a linear structure formed by self-polymerization. The amount of the plasticizer to be blended in the photosensitive resin composition of the present invention is preferably 3 to 40 parts by mass based on 100 parts by mass of the nonvolatile component of the polybenzoxazole precursor.

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.

The di (meth) acrylate which is an alkylene oxide adduct of a diol is specifically preferably one obtained by modifying a diol with an alkylene oxide and then 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. The specific structure of the di (meth) acrylate ester of the alkylene oxide adduct of diol is shown by the following general formula (8), but is not limited thereto.

In the general formula (8), p + q is 2 or more, preferably 2 to 40, more preferably 3.5 to 25.

(thermal acid generator, sensitizer, sealer, other ingredients)

In the photosensitive resin composition of the present invention, a known thermal acid generator may be added to further promote the cyclization reaction of the polybenzoxazole precursor, a known sensitizer may be added to improve the photosensitivity, and a known sealing agent such as a silane coupling agent may be added to improve the adhesiveness to the base material, as long as the effects of the present invention are not impaired. 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 as described above. For example, a surfactant, a leveling agent, fine particles, and the like can be used. The fine particles include organic fine particles of polystyrene, polytetrafluoroethylene, or the like, inorganic fine particles of silica, carbon, layered silicate, or the like. In addition, various colorants, fibers, and the like may be blended in the photosensitive resin composition of the present invention.

[ solvent ]

The photosensitive resin composition of the present invention may contain a solvent. The solvent is not particularly limited as long as the above components can be dissolved therein, and 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, diethylene glycol monomethyl ether, and the like.

The content of the solvent in the photosensitive resin composition is not particularly limited, and is preferably appropriately changed depending on the application, and for example, may be 50 parts by mass or more and 9000 parts by mass or less with respect to 100 parts by mass of the ester diamine-containing polybenzoxazole precursor contained in the photosensitive resin composition.

The photosensitive resin composition may contain 2 or more solvents.

[ Dry film ]

The dry film of the present invention comprises: a film (e.g., a support (carrier) film), and a resin layer formed on the film by using the photosensitive resin composition. The dry film may include a film (so-called protective film) which is formed on the resin layer on the film and is protected (covered).

(film)

The film is not particularly limited, and for example, the following can be used: polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamide-imide films, polypropylene films, and polystyrene films.

Among them, polyethylene terephthalate is preferable from the viewpoint of heat resistance, mechanical strength, handling properties, and the like. In addition, a laminate of these films may be used as the film.

In addition, from the viewpoint of improving mechanical strength, the thermoplastic resin film is preferably a film stretched in a uniaxial direction or a biaxial direction.

The thickness of the thin film is not particularly limited, and may be, for example, 10 to 150 μm.

(resin layer)

The resin layer is formed using the photosensitive resin composition, and the thickness thereof is not particularly limited, and is preferably appropriately changed depending on the application, and may be, for example, 1 μm or more and 150 μm or less.

The resin layer may be formed as follows: the photosensitive resin composition can be formed by coating a film to a uniform thickness by a comma coater, a blade coater, a lip coater, a bar coater, a pressure coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like, and drying the coating.

In another embodiment, the resin layer may be formed by coating the photosensitive resin composition on the protective film and drying the coating.

(protective film)

In the present invention, a releasable protective film is preferably laminated on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer.

The peelable protective film is not particularly limited as long as the adhesive strength between the resin layer and the protective film is smaller than the adhesive strength between the resin layer and the film when the protective film is peeled, and for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used.

The thickness of the protective film is not particularly limited, and may be, for example, 10 μm or more and 150 μm or less.

[ cured product ]

The cured product of the present invention is characterized by being formed using the photosensitive resin composition. The cured product may be patterned (hereinafter, referred to as a patterned film in some cases).

The following is a description of the method for producing a cured product of the present invention.

[ step 1]

The method for producing a cured product of the present invention comprises the steps of: the photosensitive resin composition is applied to a substrate to form a coating film and dried, or the resin layer is transferred from the dry film to the substrate to form a dried coating film.

The method for applying the photosensitive resin composition to the substrate is not particularly limited, and examples thereof include: a method of coating with a spin coater, a bar coater, a blade coater, a curtain coater, a screen printer, or the like; a method of spray coating with a spray coater; and, an ink jet method and the like.

As a method for drying the coating film, methods such as air drying, heat drying by 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 the condition that ring closure of the polyimide precursor in the photosensitive resin composition is not caused.

Specifically, it is preferable to perform natural drying, air-blowing drying, or heat drying at 70 to 140 ℃ for 1 to 30 minutes. In addition, the operation method is simple, so that the drying is preferably performed for 1 to 20 minutes by using a hot plate.

Further, vacuum drying may be performed, and in this case, drying may be performed at room temperature for 20 minutes to 1 hour.

The transfer of the dry film onto the substrate is preferably performed under pressure and heat using a vacuum laminator or the like. When a substrate having a circuit formed thereon is used by using such a vacuum laminator, the resin layer of the dry film fills the irregularities of the circuit substrate under vacuum conditions even if the surface of the circuit substrate has irregularities, so that there is no mixing of air bubbles and the filling property of the recesses on the surface of the substrate is improved.

Examples of the base material include a printed wiring board and a flexible printed wiring board each having a circuit formed in advance of copper or the like, and further include: copper-clad laminates of all grades (FR-4 and the like) made of materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/nonwoven fabric epoxy, glass cloth/paper epoxy, synthetic fiber epoxy, and copper-clad laminates for high-frequency circuits made of fluororesin/polyethylene/polyphenylene ether (polyphenylene oxide)/cyanate ester, and metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, and the like.

[2 nd step ]

Then, the coating film is selectively irradiated with an active energy ray through a photomask having a pattern or non-selectively without passing through the photomask, and exposed.

The active energy ray is, for example, a wavelength capable of activating a photoacid generator as the (B) photosensitizer. Specifically, the maximum wavelength of the active energy ray is preferably in the range of 350 to 410 nm.

The exposure amount varies depending on the film thickness, and is usually 10 to 1000mJ/cm²Preferably 20 to 800mJ/cm²Within the range of (1).

The exposure machine used for the irradiation with the active energy rays may be a device that is equipped with a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like and irradiates ultraviolet rays in the range of 350 to 450nm, and a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser using CAD data from a computer) may be used.

[3 rd step ]

This step is performed as needed, and the coating film is heated in a short time, whereby a part of the polyimide precursor in the unexposed portion can be ring-closed. Here, the closed loop ratio is about 30%. The heating time and the heating temperature are appropriately changed depending on the type of the polyimide precursor, the coating film thickness, and the type of the photosensitive agent (B).

[4 th step ]

Next, the exposed coating film is treated with a developer to remove the exposed portion of the coating film, thereby obtaining a pattern film.

In this step, a conventionally known method for developing a photoresist, for example, a spin spray method, a paddle method, a dipping method with ultrasonic treatment, or the like may be selected as an arbitrary method.

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.

[5 th Process ]

Subsequently, the patterned film is heated to obtain a cured coating film (cured product).

In this heating step, the polybenzoxazole precursor contained in the photosensitive resin composition undergoes a cyclization reaction to form polybenzoxazole.

The heating condition is preferably appropriately adjusted, and may be set to a temperature of 150 ℃ or higher and lower than 350 ℃ for about 5 minutes to 120 minutes, for example.

For heating, for example, a hot plate, an oven, and an oven of an elevated temperature type capable of setting a temperature program can be used.

The atmosphere (gas) may be heated, or the atmosphere may be heated, or the inert gas such as nitrogen or argon may be used.

[ use ]

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 material for forming, for example, a coating material, a printing ink, an adhesive, a display device, a semiconductor element, an electronic component, an optical component, a building material, or the like.

Specifically, examples of the material for forming the display device include a layer forming material and an image forming material among a color filter, a thin film for a flexible display, a resist material, an alignment film, and the like.

Examples of the material for forming the semiconductor element include a resist material, a buffer coating film, and a layer forming material in an insulating film for a rewiring layer of a Wafer Level Package (WLP).

Examples of the material for forming the electronic component include sealing materials and layer forming materials in printed wiring boards, interlayer insulating films, wiring coating films, and the like.

Examples of the material for forming the optical member include optical materials and layer-forming materials in holograms, optical waveguides, optical circuits, optical circuit 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 can be suitably used as a surface protective film, a buffer coating film, an interlayer insulating film, an insulating film for rewiring, a protective film for flip chip devices, a protective film for devices having a bump structure, an interlayer insulating film for multilayer circuits, an insulating material for passive components, a protective film for printed wiring boards such as solder resists and cover films, and a liquid crystal alignment film for semiconductor devices, display devices, and light emitting devices.

Examples

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

(reference example 1 Synthesis of polybenzoxazole precursor A-1)

In a 0.5-liter flask equipped with a stirrer and a thermometer, 0.489g (1.61mmol) of (2-phenyl-4-aminophenyl) -4-aminobenzoate (PHBPAA) represented by the following chemical formula (a) and 28.02g (76.5mmol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane represented by the following chemical formula (b) were charged, and the mixture was dissolved in 215g of N-methylpyrrolidone with stirring.

Then, 25.29g (85.7mmol) of 4, 4' -diphenylether dicarboxylic acid dichloride represented by the following formula (c) was added over 10 minutes while keeping the flask inside at 0 to 5 ℃ and keeping the solid, and the mixture was stirred in an ice bath for 30 minutes.

After that, stirring was continued at room temperature for 18 hours. The stirred solution was put into 1L of ion-exchanged water (resistivity value: 18.2 M.OMEGA.. multidot.cm), and the precipitate was collected. Then, the obtained solid was dissolved in 420mL of acetone, and 1L of ion-exchanged water was added thereto. The precipitated solid was recovered and then dried under reduced pressure to obtain a carboxyl-terminal ester diamine-containing polybenzoxazole precursor represented by the following chemical formula. The weight average molecular weight was 31000 as determined by GPC method using standard polystyrene.

The content of the esterdiamine in the polybenzoxazole precursor containing the esterdiamine was 2 mol%.

(reference example 2 Synthesis of polybenzoxazole precursor A-2)

In a 0.5-liter flask equipped with a stirrer and a thermometer, PHBPAA 0.474(1.56mmol) and bis (3-amino-4-hydroxyphenyl) hexafluoropropane 10.88g (29.7mmol) were charged, and dissolved in N-methylpyrrolidone 85g with stirring.

Then, 10.09g (34.2mmol) of 4, 4' -diphenylether dicarboxylic acid dichloride was added to the flask over 10 minutes while keeping the temperature of the flask in the range of 0 to 5 ℃ and the solid constant, and the mixture was stirred in an ice bath for 30 minutes.

After that, stirring was continued at room temperature for 18 hours. The stirred solution was put into 700mL of ion-exchanged water (resistivity value: 18.2 M.OMEGA.. multidot.cm), and the precipitate was collected. Then, the obtained solid was dissolved in 420mL of acetone, and 1L of ion-exchanged water was added thereto. The precipitated solid was recovered and then dried under reduced pressure to obtain a polybenzoxazole precursor containing an ester diamine at the carboxyl terminal. The weight average molecular weight of the polycarbonate resin composition was 26900 in terms of polystyrene standard by GPC method.

The content of the esterdiamine in the polybenzoxazole precursor containing the esterdiamine was 5 mol%.

(reference example 3 Synthesis of polybenzoxazole precursor A-3)

In a 0.5 liter flask equipped with a stirrer and a thermometer, 10.0g (27.3mmol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane was dissolved with stirring in 1500g of N-methylpyrrolidone.

Thereafter, 8.78g (29.8mmol) of 4, 4' -diphenylether dicarboxylic acid dichloride was added to the flask over 10 minutes while keeping the temperature of the flask in the range of 0 to 5 ℃ and the solid constant, and the mixture was stirred in an ice bath for 30 minutes.

After that, stirring was continued at room temperature for 18 hours. The stirred solution was put into 700mL of ion-exchanged water (resistivity value: 18.2 M.OMEGA.. multidot.cm), and the precipitate was collected. Then, the obtained solid was dissolved in 420mL of acetone, and 1L of ion-exchanged water was added thereto. The precipitated solid was recovered and then dried under reduced pressure to obtain a carboxyl-terminated polybenzoxazole precursor. The weight average molecular weight, determined in terms of polystyrene standards by GPC, was 29500, the number average molecular weight was 11600, and the PDI was 2.54.

< example 1-1 >)

The polybenzoxazole precursor a-1(100 parts by mass) and the diazonaphthoquinone compound a (10 parts by mass, TKF-428, manufactured by sanbao chemical industries, inc., ltd., photosensitizer) obtained in reference example 1 were dissolved in γ -butyrolactone (300 parts by mass), and then filtered through a 0.2 μm filter to obtain varnish a-1 of a photosensitive resin composition.

< example 1-2 >

A varnish A-2 of a photosensitive resin composition was obtained in the same manner as in example 1-1, except that the polybenzoxazole precursor A-1 was changed to the polybenzoxazole precursor A-2.

< comparative example 1-1 >)

A varnish A-3 of a photosensitive resin composition was obtained in the same manner as in example 1-1, except that the polybenzoxazole precursor A-1 was changed to the polybenzoxazole precursor A-3.

[ evaluation of elongation ]

The varnishes A-1, A-2 and A-3 obtained in examples 1-1 to 1-2 and comparative example 1-1 were each coated on a 6-inch silicon wafer by a spin coater, and dried on a hot plate at 110 ℃ for 3 minutes to obtain a coating film having a film thickness of about 30 μm. Then, the coated silicon wafer was heated at 150 ℃/30 minutes and 320 ℃/60 minutes in an oven.

The obtained cured film was peeled from the silicon wafer, and the elongation was measured by a tensile test using EZ-SX manufactured by Shimadzu corporation, and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(evaluation criteria)

Very good: the elongation is 15% or more.

Good: the elongation is 10% or more and less than 15%.

X: the elongation is less than 10%.

[ glass transition temperature evaluation ]

The cured film obtained in the elongation evaluation was evaluated by measuring the glass transition temperature (Tg) by TMA (thermomechanical analysis) based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(evaluation criteria)

Very good: the glass transition temperature is 300 ℃ or higher.

Good: the glass transition temperature is 250 ℃ or higher and less than 300 ℃.

X: the glass transition temperature is less than 250 ℃.

Internal stress evaluation

The varnishes A-1, A-2 and A-3 obtained in examples 1-1 to 1-2 and comparative example 1-1 were each coated on a 6-inch silicon wafer by a spin coater, and dried on a hot plate at 110 ℃ for 3 minutes to obtain a coating film having a film thickness of about 6 μm. Then, the coated silicon wafer was heated in an oven at 150 ℃/30 minutes and 320 ℃/60 minutes.

The internal stress was measured by equation (1) from the radius of curvature obtained from the change in the amount of warpage of the silicon wafer before and after the formation of the cured film, and the evaluation was performed based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(evaluation criteria)

Very good: the internal stress is lower than 25 MPa.

Good: the internal stress is 25MPa or more and less than 30 MPa.

X: the internal stress is 30MPa or more.

[ evaluation of solubility contrast ]

The varnishes A-1, A-2 and A-3 obtained in examples 1-1 to 1-2 and comparative example 1-1 were applied to a 6-inch silicon wafer by a spin coater, and dried on a hot plate at 110 ℃ for 3 minutes to obtain a coating film having a film thickness of about 8 μm. The obtained coating film was subjected to i-ray exposure through a mask to form exposed portions and unexposed portions in the same substrate. After exposure, the resist was developed in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 120 seconds, and washed with water to obtain a pattern of a positive cured film.

The exposed portion developing speed and the unexposed portion developing speed were obtained until the film thickness of the exposed portion became 0.

The contrast was calculated from the following formula and evaluated on the basis of the following criteria. The evaluation results are summarized in Table 1.

(evaluation criteria)

Very good: the contrast ratio is 100 or more.

O: the contrast ratio is 20 or more and less than 100.

X: the dissolution rate ratio is lower than 20.

< evaluation of sensitivity >)

The varnishes A-1, A-2 and A-3 obtained in examples 1-1 to 1-2 and comparative example 1-1 were applied to a silicon wafer by a spin coater, and then heated and dried at 110 ℃ for 3 minutes by a hot plate to obtain a coating film having a film thickness of about 8 μm.

The obtained coating film was irradiated with a broad-band light through a photomask having a pattern by a high-pressure mercury lamp (with an i-ray filter). The exposure amount is 50mJ/cm per exposure time²Rising to 100-1000 mJ/cm after passing through the photomask²Is carried out within the range of (1).

The dried coating film after exposure was developed with a 2.38% TMAH aqueous solution and washed with water to form a positive pattern film.

The exposure amount at which the exposed portion was not dissolved at all was set as the minimum exposure amount, and the evaluation was performed based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(evaluation criteria)

Very good: the minimum exposure is less than 400mJ/cm²。

O: the minimum exposure is 400mJ/cm²Above and below 700mJ/cm²。

X: the minimum exposure is 700mJ/cm²The above.

[ Table 1]

As is clear from the evaluation results shown in table 1 above, in the examples, the glass transition temperature, elongation, dissolution contrast and sensitivity were high, and the internal stress was low.

< example 2-1 >)

A varnish B-1 of a photosensitive resin composition was obtained by dissolving the polybenzoxazole precursor A-1(100 parts by mass) obtained in reference example 1, the diazonaphthoquinone compound A (10 parts by mass, manufactured by Sanbao chemical industries, TKF-428, a photosensitizer) and the 2-functional (meth) acrylic compound (10 parts by mass, manufactured by Toyo Seisaku K.K., M-6250, a plasticizer) in γ -butyrolactone (300 parts by mass), and then filtering the mixture with a 0.2 μ M filter.

< example 2-2 >

A varnish C-1 of a photosensitive resin composition was obtained by dissolving the polybenzoxazole precursor A-1(100 parts by mass) obtained in reference example 1, the naphthoquinone diazide compound A (10 parts by mass, TKF-428 manufactured by Sanbao chemical industries, Ltd., a photosensitizer) and the epoxy compound having 2 or more functions (10 parts by mass, HP-4032D manufactured by DIC Co., Ltd., a crosslinking agent) in γ -butyrolactone (300 parts by mass), and then filtering the mixture with a 0.2 μm filter.

< example 2-3 >

A varnish D-1 of ｃA photosensitive resin composition was obtained by dissolving the polybenzoxazole precursor A-1(100 parts by mass) obtained in reference example 1, the diazonaphthoquinone compound A (10 parts by mass, TKF-428 manufactured by Sanbao chemical industries, Ltd., ｃA photosensitizer) and TM-BIP-A (10 parts by mass, ｃA crosslinking agent) represented by the following chemical formulｃA (D) in γ -butyrolactone (300 parts by mass) and then filtering the mixture with ｃA 0.2 μm filter.

[ glass transition temperature evaluation ]

The glass transition temperature was measured by the same method as described above except that the varnishes were changed to the varnishes B-1, C-1 and D-1 obtained in examples 2-1 to 2-3 and the heating of the coated silicon wafer in the oven was changed to 150 ℃/30 minutes and 220 ℃/60 minutes, and evaluation was performed based on the same evaluation criteria. The evaluation results are summarized in Table 2.

Internal stress evaluation

The internal stress was measured and evaluated based on the same evaluation criteria as described above, except that the varnishes were changed to the varnishes B-1, C-1 and D-1 obtained in examples 2-1 to 2-3, and the heating of the coated silicon wafer in the oven was changed to 150 ℃/30 minutes and 220 ℃/60 minutes. The evaluation results are summarized in Table 2.

[ evaluation of solubility contrast ]

The contrast was determined in the same manner as described above except that the varnishes were changed to the varnishes B-1, C-1 and D-1 obtained in examples 2-1 to 2-3, and evaluation was performed based on the same evaluation criteria. The evaluation results are summarized in Table 2.

< evaluation of sensitivity >)

Sensitivity was determined in the same manner as described above except that the varnishes were changed to the varnishes B-1, C-1 and D-1 obtained in examples 2-1 to 2-3, and evaluation was performed based on the same evaluation criteria. The evaluation results are summarized in Table 2.

[ Table 2]

As is clear from the evaluation results shown in table 2 above, each example had a high glass transition temperature and a high dissolution contrast and had a low internal stress even in the case of curing at a low temperature.