WO2020188921A1 - Ester-diamine-containing polybenzoxazole precursor, photosensitive resin composition, dry film, cured product, and electronic component - Google Patents

Abstract

[Problem] To provide a photosensitive resin composition including an ester-diamine-containing polybenzoxazole precursor that achieves high dissolution contrast and furthermore is resistant to cracking and warping. [Solution] This ester-diamine-containing polybenzoxazole precursor is characterized by having a structure represented by general formula (1) and/or (2) and a structure represented by general formula (3).

Description

Esterdiamine-containing polybenzoxazole precursors, photosensitive resin compositions, dry films, cured products and electronic components

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

The photosensitive resin composition containing the polybenzoxazole precursor undergoes a cyclization reaction to a benzoxazole ring having a rigid hydroxyamide structure when heated, and the packing density between molecules also increases, resulting in insulation and heat resistance. It is widely used in various fields because it exhibits excellent properties such as mechanical strength. For example, application to flexible printed wiring boards, buffer coated films for semiconductor elements, and insulating films for rewiring layers of wafer level packages (WLP) is being promoted.

Conventionally, in a buffer coat film or an insulating film for a rewiring layer of a wafer level package, a polybenzoxazole precursor that enables pattern formation by finer photolithography instead of a photosensitive resin composition containing a polyimide precursor. Photosensitive resin compositions containing the above are attracting attention.
Examples of such a photosensitive resin composition include a positive resist composition composed of a polybenzoxazole precursor and photosensitive diazoquinone as disclosed in Patent Document 1. Then, such a photosensitive resin composition is applied and dried on a substrate such as a wafer to form a dry coating film, and the dry coating film is exposed to active energy rays and then developed. After forming a desired pattern film, the polybenzoxazole precursor is cyclized by heating at about 320 ° C. to form a polybenzoxazole pattern cured film.

Further, in recent semiconductor devices, with the demand for higher functionality and smaller size, excellent resolution for realizing finer pattern formation in a buffer coat film or an insulating film for a rewiring layer of a wafer level package. In addition, it is required to suppress cracks and warpage due to thinning of the wafer as a base material.

Special Fair 1-046862 Gazette

However, in the composition described in Patent Document 1, the balance between the solubility of the exposed portion and the solubility resistance of the unexposed portion at the time of development, which is necessary for realizing the resolution required for a recent semiconductor device, Since the so-called dissolution contrast is low, there is a problem that it is difficult to form a fine pattern, and further, cracks and warpage are not sufficiently suppressed.

The present invention has been made to solve such a problem, and an object thereof is to provide a photosensitive resin composition containing a polybenzoxazole precursor which realizes high dissolution contrast and is less likely to cause cracks and warpage. To provide.

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

As a result of diligent research toward the realization of the above object, the present inventors can remarkably improve the dissolution contrast of the photosensitive resin composition by introducing a diamine having an ester structure into the polybenzoxazole precursor, and further cure. We have found that the internal stress that sometimes occurs can be relaxed, and have completed the present invention.

That is, the ester diamine-containing polybenzoxazole precursor of the present invention is characterized by having at least one of the structures represented by the general formulas (1) and (2) and the structure represented by the following general formula (3). To do.

(In the general formulas (1) and (2),
X Is a divalent organic group,
Any of R ₁ to R ₄ has an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic group having 6 to 10 carbon atoms, a phenoxy group having 6 to 10 carbon atoms, and 6 carbon atoms. It is selected from a benzyl group of up to 10 and a benzyloxy group of 6 to 10 carbon atoms, and the other R ₁ to R ₄ are hydrogen atoms.
n indicates an integer of 1 or more,
In general formula (3),
X is a divalent organic group,
Y is a tetravalent organic group having at least 2 or more hydroxyl groups.
o indicates an integer of 1 or more. )

In the present invention, either R ₁ or R ₃ is 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 benzyl group having 6 to 10 carbon atoms. Selected from oxy groups, the other is a hydrogen atom,
It is preferable that R ₂ and R ₄ are hydrogen atoms.

In the present invention, in the general formula (3), Y is preferably one or more groups selected from the following structures.

(In the above structural formula,
One of * ₁ and * ₂ represents a connecting portion with an amino group, and the other represents a hydroxyl group. )

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

The photosensitive resin composition of the present invention is characterized by containing a polybenzoxazole precursor and a photosensitive agent.

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

The dry film of the present invention is characterized by providing a resin layer formed of the above-mentioned photosensitive resin composition on the film.

The cured product of the present invention is characterized by being formed by 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 element, is characterized by having the above-mentioned cured product as a forming material.

According to the ester diamine-containing polybenzoxazole precursor of the present invention, it is possible to provide a photosensitive resin composition effective for obtaining a dry coating film having high dissolution contrast and high temperature pattern retention.

[Esterdiamine-containing polybenzoxazole precursor]
The esterdiamine-containing polybenzoxazole precursor of the present invention is a polybenzoxazole precursor having at least one of the structures represented by the following general formulas (1) and (2) and the structure represented by the following general formula (3). According to the report, the photosensitive resin composition containing the photosensitive resin composition can obtain the development resistance of the unexposed portion without impairing the developability of the exposed portion, and further, the cured product has an amide bond and an ester bond having excellent flexibility. It is considered that the internal stress is relaxed.

In the above general formulas (1) and (2), X is a divalent organic group. The organic group may be an aliphatic group or an aromatic group, but is preferably an aromatic group, and the carbonyl in the above general formulas (1) and (2) on the aromatic ring. It is more preferable that it is combined with.
The number of carbon atoms of the divalent organic group is preferably 6 to 30, and more preferably 6 to 24.
Examples of the divalent organic group include groups having the following structures, but the group is not limited to these, and it is preferable to appropriately change the divalent organic group according to the intended use.

In the structural formula of the divalent organic group, A is a single bond, alkylene, -O-, -CO-, -S-, -SO _2- , -C (CF ₃ ) _2- and -C (CH _3). ) _2- Selected from, * represents the link to the carbonyl.

Among the above, the divalent organic group is particularly preferably a group having the structure shown below, because excellent developability of the photosensitive resin composition and excellent mechanical properties of the cured film can be obtained.

In the general formula (1) and _(2), one of R 1 ~ _{R 4} are preferably either _{R 1} or _{R 3,} particularly preferably is _{R 3,} an alkyl group having 1 to 12 carbon atoms, It is selected from an alkoxy group having 1 to 12 carbon atoms, 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. The other R ₁ to R ₄ are hydrogen atoms.
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 a methoxy group, an ethoxy group, a propoxy group, a butoxy group and a pentoxy group.
The aromatic group having 6 to 10 carbon atoms includes a phenyl group, a trill group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, a diethylphenyl group, a propylphenyl group, a butylphenyl group, a fluorophenyl group, and a pentafluorophenyl group. , Chlorphenyl group, bromophenyl group, methoxyphenyl group, dimethoxyphenyl group, ethoxyphenyl group, diethoxyphenyl group, methoxybenzyl group, dimethoxybenzyl group, ethoxybenzyl group, diethoxybenzyl group, aminophenyl group, aminobenzyl group , Nitrophenyl group, nitrobenzyl group, cyanophenyl group, cyanobenzyl group, phenethyl group, phenylpropyl group, phenylamino group, diphenylamino group, biphenyl group, naphthyl group and the like.
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 and a dimethoxyphenoxy group.
Examples of the benzyl group having 6 to 10 carbon atoms include a benzyl group, a methylbenzyl group, an ethylbenzyl group, a propylbenzyl group, a dimethylbenzyl group, a methoxybenzyl group, an ethoxybenzyl group and a methoxybenzyl group.
As the benzyloxy group having 6 to 10 carbon atoms, the methylbenzyloxy group includes a benzyloxy group, a betylbenzyloxy group, an ethylbenzyloxy group, a propylbenzyloxy group, a dimethylbenzyloxy group, a methoxybenzyloxy group and an ethoxy. Benzyloxy group and the like can be mentioned.
Among the above, the dissolution contrast of the photosensitive resin composition, a high temperature pattern maintaining property, from the viewpoint of sensitivity and linear thermal expansion coefficient, any one of R 1 _~ R ₄ is an aromatic group having 6 to 10 carbon atoms, carbon It is preferably 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, and a phenyl group or a tolyl group. , Methylphenyl group, dimethylphenyl group, ethylphenyl group and diethylphenyl group are more preferable, and the effect of suppressing the film loss phenomenon in the unexposed portion and the effect of relaxing the internal stress by suppressing the packing effect between molecules in the cured product. From the viewpoint, a phenyl group is particularly preferable.

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

In the ester diamine-containing polybenzoxazole precursor of the present invention, the content (ester diamine content) of the structures represented by the above general formulas (1) and (2) is 0.1 mol% or more and 10 mol% or less. It is preferable that it is 0.1 mol% or more and 5 mol% or less. Thereby, the dissolution contrast at the time of development of the dry coating film formed by the photosensitive resin composition containing the polybenzoxazole precursor of the present invention can be further improved.

In the above general formula (3), X is a divalent organic group, and its preferred embodiment and the like are the same as those in the general formulas (1) and (2), and thus the description thereof will be omitted here.

In the above general formula (3), Y is a tetravalent organic group having at least 2 or more hydroxyl groups. The organic group may be an aliphatic group or an aromatic group, but is preferably an aromatic group.
Further, the hydroxyl group contained in the tetravalent organic group preferably has an ortho position in the positional relationship with the amino group.
The tetravalent organic group preferably has 6 to 30 carbon atoms, and more preferably 6 to 24 carbon atoms.
Examples of the tetravalent organic group include groups having the following structures, but the group is not limited to these, and it is preferable to appropriately change the group according to the intended use.

In the structural formula of the tetravalent organic group, either * ₁ or * ₂ represents a connecting portion with an amino group, and the other represents a hydroxyl group.

Among the above, the tetravalent organic group is particularly preferably a group having the structure shown below from the viewpoint of improving the photosensitivity due to light transmission.

In the above general formula (3), o is an integer of 1 or more, preferably 10 to 40, and 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, preferably 95 mol% or more. , 99.9 mol% or less is preferable. As a result, the photosensitive resin composition containing the ester diamine-containing polybenzoxazole precursor of the present invention has excellent developer solubility in the exposed portion as a dry coating film, and insulating property, heat resistance, and machine as a cured film. The strength can be improved.

The number average molecular weight (Mn) of the ester diamine-containing polybenzoxazole precursor is preferably 2,000 or more and 50,000 or less, and more preferably 4,000 or more and 25,000 or less. This improves the solubility in the alkaline developer.
The weight average molecular weight (Mw) of the polybenzoxazole precursor is preferably 4,000 or more and 10,000 or less, and more preferably 8,000 or more and 50,000 or less. Thereby, the occurrence of cracks in the cured product can be further reduced.
Further, Mw / Mn is preferably 1 or more and 5 or less, and 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 numerical values measured by gel permeation chromatography (GPC) and converted with standard polystyrene.

The ester diamine-containing polybenzoxazole precursor is 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 represented by the following general formula (6). It can be obtained by reacting with a component.

Z in the general formula (6) represents a hydroxyl group, a halogen group, or a leaving group composed of a cyclic compound composed of nitrogen, sulfur, carbon, oxygen, and an aromatic ring. Above all, a halogen group is preferable from the viewpoint of productivity.
_R 1 _~ R 4 in the general formula (4) ~ (6), X, for Y is as described above.

Examples of the dicarboxylic acid component satisfying the general formula (6) include isophthalic acid, terephthalic acid, 5-tert-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2,6. -Naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis (4-carboxyphenyl) sulfone, 2,2-bis (p) -Dicarboxylic acid having an aromatic ring such as -carboxyphenyl) propane, 2,2-bis (4-carboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, oxalic acid, malonic acid, succinic acid , 1,2-Cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid and other aliphatic dicarboxylic acids, their dicarboxylic acid dihalides, their dicarboxylic acid esters and the like. Of these, 4,4'-dicarboxydiphenyl ether (that is, 4,4'-diphenyl ether dicarboxylic acid) and its dihalide are preferable because excellent developability of the photosensitive resin composition and mechanical properties of the cured film can be obtained.

This esterdiamine-containing polybenzoxazole precursor is a diamine compound other than the diamine compounds represented by the above general formulas (4) and (5) (hereinafter, other diamine compounds) as long as the characteristic effect and the polymerization reactivity are not impaired. Can be combined.
Other amine compounds include 4,4'-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, and bis. [4- (3-Aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-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, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide , 3,3'-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diamino Benzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4) -Aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] propane, 1,2-bis [ 4- (4-Aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1, 1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, 1,4-bis [4- (4-aminophenoxy) phenyl] Butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl] butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-Aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) Enoxy) -3-methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-Aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoro Propane, 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- (4- (4-)4-) Aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4'-bis [ (3-Aminophenoxy) Benzene] Benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) phenyl] propane, 3,4' -Diaminodiphenyl sulfide, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] Methan, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] Sulfoxide, 4,4'-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- ( 4-Amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4) -Aminophenoxy) Phenoxy} phenyl ] Benzene, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] ] Benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy)- )-Α, α-Dimethylbenzyl] Benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4- (4- (4- (4- (4-) Amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3 , 4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone , 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-Diamino-4,5'-dibiphenoxybenzophenone,3,3'-diamino-4-biphenoxybenzophenone,4,4'-diamino-5-biphenoxybenzophenone,3,4'-diamino-4-biphenoxybenzophenone , 3,4'-Diamino-5'-biphenoxybenzophenone, 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-biphenoxybenzoyl) benzene , 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-bi) Phenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the above aromatic diamine are c. A logene atom, an alkyl or alkoxyl group having 1 to 3 carbon atoms, a cyano group, or an alkyl halide group having 1 to 3 carbon atoms in which a part or all of the hydrogen atoms of the alkyl group or alkoxyl group are substituted with halogen atoms or 4,4'-Methylenebis (cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis (methylamine), such as aromatic diamine substituted with an alkoxyl group. ), 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-diaminoadamantan, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoroppropane, 1,3 -Propanediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylene Aliphatic diamines such as diamines can be mentioned. Other diamine compounds may be used alone or in combination of two or more.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention contains (A) the above-mentioned ester diamine-containing polybenzoxazole precursor, and (B) a photosensitive agent.
By using such an ester diamine-containing polybenzoxazole precursor in the photosensitive resin composition, the dissolution contrast and internal stress of the dry coating film formed by the photosensitive resin composition can be remarkably improved.

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

[(A) Esterdiamine-containing polybenzoxazole precursor]
The photosensitive resin composition of the present invention contains the ester diamine-containing polybenzoxazole precursor as described above as the polybenzoxazole precursor, so that the dissolution contrast of the dry coating film formed and the internal stress of the cured film can be reduced. It can be significantly improved.
The photosensitive resin composition of the present invention may be used in combination with a polybenzoxazole precursor other than the ester diamine-containing polybenzoxazole precursor.
The content of the ester diamine-containing polybenzoxazole precursor in the photosensitive resin composition is preferably 50% by mass or more and 99% by mass or less, and preferably 60% by mass or more and 90% by mass or less in the non-volatile component. More preferred. With such a range of contents, the effect of the present invention can be sufficiently obtained.

[(B) Photosensitizer]
The photosensitive resin composition of the present invention contains a photosensitive agent, and examples thereof include a photoacid generator and a photobase generator. Among these, a photoacid generator is preferable from the viewpoint of dissolution contrast.
This photosensitizer can be blended in a known and commonly used ratio. For example, for the photoacid generator, 5 to 40 parts by mass, preferably 10 to 40 parts by mass, based on 100 parts by mass of the ester diamine-containing polybenzoxazole precursor. It is preferable to mix in a ratio of 30 parts by mass.
In addition, such a photosensitizer may contain 2 or more kinds.

The photoacid generator is a compound that generates an acid when irradiated with light such as ultraviolet rays or visible light. For example, a naphthoquinone diazide compound, a diarylsulfonium salt, a triarylsulfonium salt, a dialkylphenacylsulfonium salt, a diaryliodonium salt, or an aryldiazonium. Examples thereof include salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters, aromatic N-oxyimide sulfonates, aromatic sulfamides and benzoquinone diazosulfonic acid esters.
Among the above, the naphthoquinone diazide compound is preferable from the viewpoint of dissolution contrast.
Specific examples of the naphthoquinone diazide compound include, for example, a naphthoquinone diazide adduct of tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (for example, TS533, TS567, TS583 manufactured by Sanpo Chemical Laboratory Co., Ltd.). TS593), a naphthoquinone diazide adduct of tetrahydroxybenzophenone (eg, BS550, BS570, BS599 manufactured by Sanpo Chemical Research Institute), and 4- {4- [1,1-bis (4-hydroxyphenyl) ethyl] -α. , Α-Dimethylbenzyl} phenol naphthoquinonediazide adduct (for example, TKF-428, TKF-528 manufactured by Sanpo Chemical Laboratory Co., Ltd.) and the like.

Photobase generators generate one or more basic substances (secondary amines, tertiary amines, etc.) by changing the molecular structure by irradiation with light such as ultraviolet rays or visible light, or by cleaving molecules. It is a compound that
The photobase generator may be an ionic photobase generator or a nonionic photobase generator, but an ionic photobase generator is preferable from the viewpoint of the sensitivity of the photosensitive resin composition.
Examples of the ionic photobase generator include a salt of an aromatic component-containing carboxylic acid and a tertiary amine, and examples of this commercially available product include WPBG-082 and WPBG- of ionic PBG manufactured by Wako Pure Chemical Industries, Ltd. 167, WPBG-168, WPBG-266, WPBG-300 and the like.
Examples of the nonionic photobase generator include α-aminoacetophenone compound, oxime ester compound, N-formylated aromatic amino group, N-acylated aromatic amino group, nitrobenzyl carbamate group and alcooxybenzyl. Examples thereof include compounds having a substituent such as a carbamate group.
Other photobase generators include WPBG-018 (trade name: 9-anthrylmethyl N, N'-diesylcarbamate) and WPBG-027 (trade name: (E) -1- [3- (2), manufactured by Wako Pure Chemical Industries, Ltd. -Hydroxyphenyl) -2-propenoyl] piperidine), WPBG-140 (trade name: 1- (anthraquinone-2-yl) ethyl imidazolecarboxylate), WPBG-165 and the like.

[Crosslinking agent]
The photosensitive resin composition of the present invention can contain a cross-linking agent. By adding a cross-linking agent, sufficient characteristics of the cured product can be obtained even at a low temperature of about 220 ° C. The cross-linking agent is not particularly limited, and examples thereof include known and commonly used cross-linking agents.
In the present specification, the cross-linking agent is preferably a compound capable of reacting with a phenolic hydroxyl group in the polybenzoxazole precursor to form a cross-linked structure.
Here, as the compound that reacts with the phenolic hydroxyl group in the polybenzoxazole precursor, a cyclic ether group such as an epoxy group, a cross-linking agent having a cyclic thioether group such as an episulfide group, and an alkylene group having 1 to 12 carbon atoms such as a methylol group. Examples thereof include a cross-linking agent having an alcoholic hydroxyl group to which a hydroxyl group is bonded, a compound having an ether bond such as an alkoxymethyl group, a cross-linking agent having a triazine ring structure, and a urea-based cross-linking agent.
Among these, a cyclic ether group, particularly a cross-linking agent having an epoxy group and an alcoholic hydroxyl group, particularly a cross-linking agent having a methylol group to which a hydroxyl group is bonded are preferable.
As the cross-linking agent, one type may be used alone, or two or more types may be used in combination.
The blending amount of the cross-linking agent in the photosensitive resin composition of the present invention is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the non-volatile component of the polybenzoxazole precursor. Further, 0.1 to 20 parts by mass is more preferable.

(Crosslinking agent with epoxy group)
The photosensitive resin composition of the present invention preferably contains a cross-linking agent having an epoxy group as a cross-linking agent. The cross-linking agent having an epoxy group thermally reacts with the hydroxyl group of the polybenzoxazole precursor to form a cross-linked structure. The number of functional groups of the cross-linking agent having an epoxy group is preferably 2 to 4. When the photosensitive resin composition contains a cross-linking agent having an epoxy group, low-temperature curability can be obtained, and the dissolution contrast of the formed dry coating film can be further improved.
Among the cross-linking agents having an epoxy group, a bifunctional or higher functional epoxy compound having a naphthalene skeleton is preferable. Not only can an excellent insulating film be obtained due to its flexibility and chemical resistance, but it is also possible to reduce the CTE, which has a trade-off relationship with flexibility, and it is possible to suppress the occurrence of warpage and cracks in the insulating film. Further, a bisphenol A type epoxy compound can also be preferably used from the viewpoint of flexibility.

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

(In the general formula ^{(7), .R A2 R A1} is showing 2-10 divalent organic group are each independently an integer of .r 2 to 10 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms Shows.)

In the general formula (7), ^RA1 is preferably an alkylene group having 1 to 3 carbon atoms which may have a substituent.

In the general formula (7), ^RA2 is preferably a hydrogen atom.

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

Further, the cross-linking 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 preferably has a 2- to 10-valent organic group represented by ^RA1 in the general formula (7), and ^RA1 is a di (trifluoromethyl) methylene group. Is preferable. Further, the cross-linking 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, the plasticizing action of the plasticizer, that is, the aggregating action between polymer molecular chains is reduced, and the mobility and flexibility between the molecular chains are improved, so that the thermal molecular motion of the polybenzoxazole precursor is improved. However, it is considered that low temperature curability is imparted by promoting the cyclization reaction. The plasticizing agent is not particularly limited as long as it is a compound that improves plasticity, and is a bifunctional (meth) acrylic compound, a sulfonamide compound, a phthalate ester compound, a maleic acid ester compound, an aliphatic dibasic acid ester, and a phosphoric acid ester. , Ether compounds such as crown ether and the like. Of these, a bifunctional (meth) acrylic compound is preferable. The bifunctional (meth) acrylic compound is preferably a compound that does not form a crosslinked structure with other components in the composition. Further, the bifunctional (meth) acrylic compound is preferably a compound that forms a linear structure by self-polymerization from the viewpoint of further relaxing the internal stress of the cured product. The blending amount of the plasticizer in the photosensitive resin composition of the present invention is preferably 3 to 40 parts by mass with respect to 100 parts by mass of the non-volatile component of the polybenzoxazole precursor.

Among the bifunctional (meth) acrylic compounds, di (meth) acrylates of diols (such as ethylene oxide and propylene oxide) adducts of alkylene oxides and bifunctional polyester (meth) acrylates are preferable, and bifunctional polyesters (meth) acrylates are preferable. ) Acrylate is more preferable.

As the di (meth) acrylate of the alkylene oxide adduct of the diol, specifically, the diol is preferably alkylene oxide-modified and then the (meth) acrylate is added to the terminal, and the diol having an aromatic ring is more preferable. .. For example, bisphenol A EO (ethylene oxide) adduct diacrylate, bisphenol A PO (propylene oxide) adduct diacrylate and the like can be mentioned. The specific structure of the di (meth) acrylate of the alkylene oxide adduct of the diol is shown in the following general formula (8), but the structure is not limited thereto.

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

(Thermal acid generator, sensitizer, adhesive, other ingredients)
The photosensitive resin composition of the present invention contains a known thermoacid generator for further promoting the cyclization reaction of the polybenzoxazole precursor and for improving the photosensitivity without impairing the effect of the present invention. It is also possible to add a known sensitizer or a known adhesive such as a silane coupling agent in order to improve the adhesiveness to the substrate. Further, in order to impart processing characteristics and various functionalities to the photosensitive resin composition of the present invention, various other organic or inorganic low molecular weight or high molecular weight compounds may be blended. For example, a surfactant, a leveling agent, fine particles and the like can be used. The fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as silica, carbon and layered silicate. Further, various colorants, fibers and the like may be blended with 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 it can dissolve each of the above components, and for example, N, N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N, N'-dimethylacetamide, Diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide , Pyridone, 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 changed as appropriate according to the intended use. For example, the ester diamine-containing polybenzoxazole precursor contained in the photosensitive resin composition is used. It can be 50 parts by mass or more and 9000 parts by mass or less with respect to 100 parts by mass.
The photosensitive resin composition may contain two or more kinds of solvents.

[Dry film]
The dry film of the present invention includes a film (for example, a support (carrier) film) and a resin layer formed on the film by using the photosensitive resin composition. Further, the dry film may be provided with a film (so-called protective film) that further protects (covers) the resin layer formed on the film.

(the film)
The film is not particularly limited, and for example, a film made of a polyester film such as polyethylene terephthalate and polyethylene naphthalate, a polyimide film, a polyamide-imide film, a polypropylene film, and a thermoplastic resin such as a polystyrene film can be used. it can.
Among these, polyethylene terephthalate is preferable from the viewpoint of heat resistance, mechanical strength, handleability and the like. Further, a laminate of these films can also be used as a film.

Further, the thermoplastic resin film as described above is preferably a film stretched in the uniaxial direction or the biaxial direction from the viewpoint of improving the mechanical strength.

The thickness of the film is not particularly limited, but can be, for example, 10 to 150 μm.

(Resin layer)
The resin layer is formed by using the above-mentioned photosensitive resin composition, and its thickness is not particularly limited and is preferably changed as appropriate depending on the intended use. For example, 1 μm or more and 150 μm. It can be as follows.

The resin layer has a uniform thickness of the photosensitive resin composition on the film with a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer coater, a gravure coater, a spray coater, and the like. It can be formed by applying and drying.
Further, in another embodiment, the resin layer can be formed by applying a photosensitive resin composition on a protective film and drying it.

(Protective film)
In the present invention, it is preferable to laminate a peelable protective film 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 force between the resin layer and the protective film is smaller than the adhesive force between the resin layer and the film when the protective film is peeled off. For example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper and the like can be used.

The thickness of the protective film is not particularly limited, but can 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 by using the above-mentioned photosensitive resin composition. Further, the cured product may be one in which a pattern is formed (hereinafter, referred to as a pattern film in some cases).
Hereinafter, a method for producing a cured product of the present invention will be described.

[First step]
In the method for producing a cured product of the present invention, a photosensitive resin composition is applied onto a substrate to form a coating film, which is dried, or the resin layer is transferred from the dry film onto the substrate. This includes a step of forming a dry coating film.

The method of applying the photosensitive resin composition onto the substrate is not particularly limited, and for example, a method of applying the photosensitive resin composition using a spin coater, a bar coater, a blade coater, a curtain coater, a screen printing machine, or the like, or spray coating with a spray coater. And the inkjet method.

As a method for drying the coating film, a method such as air drying, heat drying using an oven or a hot plate, and vacuum drying is used.
Further, it is desirable that the coating film is dried under conditions that do not cause ring closure of the polyimide precursor in the photosensitive resin composition.
Specifically, it is preferable to carry out natural drying, blast drying, or heat drying at 70 to 140 ° C. for 1 to 30 minutes. Moreover, since the operation method is simple, it is preferable to dry for 1 to 20 minutes using a hot plate.
Vacuum drying is also possible, and in this case, it can be performed at room temperature for 20 minutes to 1 hour.

It is preferable that the transfer of the dry film onto the substrate is performed under pressure and heating using a vacuum laminator or the like. By using such a vacuum laminator, when a circuit-formed substrate is used, even if the surface of the circuit board is uneven, the resin layer of the dry film fills the unevenness of the circuit board under vacuum conditions. , No air bubbles are mixed in, and the hole filling property of the concave portion on the substrate surface is improved.

As the base material, in addition to printed wiring boards and flexible printed wiring boards whose circuits are formed in advance with copper, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, etc. It is made of materials such as copper-clad laminates for high-frequency circuits using synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc., and all grades (FR-4, etc.) of copper-clad laminates. In addition, metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

[Second step]
Next, the coating film is irradiated with active energy rays and exposed selectively through a photomask having a pattern or non-selectively through a photomask.

As the active energy ray, for example, one having a wavelength capable of activating the photoacid generator as the (B) photosensitizer is used. Specifically, the active energy ray preferably has a maximum wavelength in the range of 350 to 410 nm.
The amount of exposure varies depending on the film thickness and the like, but is generally in the range of 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .
The exposure machine used for the above-mentioned active energy ray irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates ultraviolet rays in the range of 350 to 450 nm. Further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) can also be used.

[Third step]
The step is performed as needed, and a part of the polyimide precursor in the unexposed portion may be closed by heating the coating film for a short time. Here, the ring closure rate is about 30%. The heating time and heating temperature are appropriately changed depending on the type of polyimide precursor, coating film thickness, and (B) type of photosensitizer.

[4th step]
Next, the exposed coating film is treated with a developing solution to remove the exposed portion in the coating film, whereby a pattern film can be obtained.
In this step, any method can be selected from conventionally known photoresist developing methods, such as a rotary spray method, a paddle method, and a dipping method accompanied by ultrasonic treatment.

The developing solution includes inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate and aqueous ammonia, organic amines such as ethylamine, diethylamine, triethylamine and triethanolamine, tetramethylammonium hydroxide and tetrabutylammonium hydroxide. Examples thereof include aqueous solutions such as quaternary ammonium salts.
Further, if necessary, a water-soluble organic solvent such as methanol, ethanol, isopropyl alcohol or a surfactant may be added in an appropriate amount.

Then, if necessary, the coating film is washed with a rinsing solution to obtain a patterned film.
Distilled water, methanol, ethanol, isopropyl alcohol and the like can be used alone or in combination as the rinsing solution. Moreover, you may use the said solvent as a developer.

[Fifth step]
Next, the pattern film is heated to obtain a cured coating film (cured product).
By the heating step, the polybenzoxazole precursor contained in the photosensitive resin composition undergoes a cyclization reaction to become polybenzoxazole.

The heating conditions are preferably adjusted as appropriate, and can be set to, for example, about 5 minutes to 120 minutes at a temperature of 150 ° C. or higher and lower than 350 ° C.
For heating, for example, a hot plate, an oven and a heating oven in which a temperature program can be set can be used.
It may be under a heating atmosphere (gas) or air, or under an inert gas such as nitrogen or argon.

[Use]
The use of the photosensitive resin composition of the present invention is not particularly limited, and for example, it is suitably used as a forming material for paints, printing inks, adhesives, display devices, semiconductor elements, electronic parts, optical parts, building materials and the like.

Specifically, examples of the material for forming the display device include a layer forming material and an image forming material in a color filter, a 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 coat film, an insulating film for a rewiring layer of a wafer level package (WLP), and the like.
Examples of the material for forming the electronic component include a sealing material and a layer forming material in a printed wiring board, an interlayer insulating film, a wiring coating film, and the like.
Examples of the material for forming the optical component include an optical material and a layer forming material in holograms, optical waveguides, optical circuits, optical circuit components, antireflection films, and the like.
Further, as a building material, it can be used as a paint, a coating agent, or the like.

The photosensitive resin composition of the present invention is mainly used as a pattern forming material, and in particular, a surface protective film, a buffer coat film, an interlayer insulating film, an insulating film for rewiring, and a flip chip of a semiconductor device, a display device, and a light emitting device. Suitable as a protective film for 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 resist and coverlay film, and a liquid crystal alignment film. Available.

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

(Reference Example 1: Synthesis of Polybenzoxazole Precursor A-1)
0.489 g (1.61 mmol) of (2-phenyl-4-aminophenyl) -4-aminobenzoate (PHBPAA) represented by the following chemical formula (a) in a 0.5 liter flask equipped with a stirrer and a thermometer. ) And 28.02 g (76.5 mmol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane represented by the following chemical formula (b) were charged and dissolved in 215 g of N-methylpyrrolidone with stirring.
Then, the flask is immersed in an ice bath, and 25.29 g (85.7 mmol) of 4,4'-diphenyl ether dicarboxylic acid chloride represented by the following chemical formula (c) remains as a solid while keeping the inside of the flask at 0 to 5 ° C. It was added over 10 minutes and stirred in an ice bath for 30 minutes.

Then, stirring was continued for 18 hours at room temperature. The stirred solution was put into 1 L of ion-exchanged water (specific resistance value 18.2 MΩ · cm), and the precipitate was recovered. Then, the obtained solid was dissolved in 420 mL of acetone and put into 1 L of ion-exchanged water. The precipitated individual was recovered and dried under reduced pressure to obtain a carboxyl group-terminated ester diamine-containing polybenzoxazole precursor represented by the following chemical formula. The weight average molecular weight determined by GPC method standard polystyrene conversion was 31,000.
The content of ester diamine in the ester diamine-containing polybenzoxazole precursor was 2 mol%.

(Reference Example 2: Synthesis of Polybenzoxazole Precursor A-2)
PHBPAA 0.474 (1.56 mmol) and bis (3-amino-4-hydroxyphenyl) hexafluoropropane 10.88 g (29.7 mmol) were charged in a 0.5 liter flask equipped with a stirrer and a thermometer. It was dissolved by stirring in 85 g of N-methylpyrrolidone.
Then, the flask is immersed in an ice bath, and 10.09 g (34.2 mmol) of 4,4'-diphenyl ether dicarboxylic acid chloride is added as a solid over 10 minutes while keeping the inside of the flask at 0 to 5 ° C. in the ice bath. Was stirred for 30 minutes.
Then, stirring was continued for 18 hours at room temperature. The stirred solution was poured into 700 mL of ion-exchanged water (specific resistance value 18.2 MΩ · cm), and the precipitate was recovered. Then, the obtained solid was dissolved in 420 mL of acetone and put into 1 L of ion-exchanged water. The precipitated individual was recovered and dried under reduced pressure to obtain an ester diamine-containing polybenzoxazole precursor at the terminal of a carboxyl group. The weight average molecular weight determined by GPC method standard polystyrene conversion was 26,900.
The content of ester diamine in the ester diamine-containing polybenzoxazole precursor was 5 mol%.

(Reference Example 3: Synthesis of Polybenzoxazole Precursor A-3)
10.0 g (27.3 mmol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane was stirred and dissolved in 1500 g of N-methylpyrrolidone in a 0.5 liter flask equipped with a stirrer and a thermometer. ..
Then, the flask is immersed in an ice bath, and 8.78 g (29.8 mmol) of 4,4'-diphenyl ether dicarboxylic acid chloride is added as a solid over 10 minutes while keeping the inside of the flask at 0 to 5 ° C. Was stirred for 30 minutes.
Then, stirring was continued for 18 hours at room temperature. The stirred solution was poured into 700 mL of ion-exchanged water (specific resistance value 18.2 MΩ · cm), and the precipitate was recovered. Then, the obtained solid was dissolved in 420 mL of acetone and put into 1 L of ion-exchanged water. The precipitated individual was recovered and dried under reduced pressure to obtain a carboxyl group-terminated polybenzoxazole precursor. The weight average molecular weight determined by GPC method standard polystyrene conversion was 29,500, the number average molecular weight was 11,600, 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, manufactured by Sanpo Chemical Industry Co., Ltd., TKF-428, photosensitizer) obtained in Reference Example 1 above were added to γ-. After dissolving in butyrolactone (300 parts by mass), the mixture was filtered through a 0.2 μm filter to obtain varnish A-1 as 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 growth rate >>
The varnishes A-1, A-2 and A-3 obtained in Examples 1-1 to 1-2 and Comparative Example 1-1 were each applied on a 6-inch silicon wafer using a spin coater and hot. The plate was dried at 110 ° C. for 3 minutes to obtain a coating film having a film thickness of about 30 μm. Next, the silicon wafer with a coating film was heated at 150 ° C./30 minutes and 320 ° C./60 minutes using an oven.
The obtained cured film was peeled off from a silicon wafer, and the elongation rate was measured from a tensile test using an EZ-SX manufactured by Shimadzu Corporation, and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
⊚: The growth rate was 15% or more.
〇: The growth rate was 10% or more and less than 15%.
X: The elongation rate was less than 10%.

<< Glass transition temperature evaluation >>
The cured film obtained in the elongation rate evaluation was evaluated by measuring the glass transition temperature (Tg) by TMA (thermomechanical analysis) and based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
⊚: The glass transition temperature was 300 ° C. or higher.
◯: The glass transition temperature was 250 ° C. or higher and lower than 300 ° C.
X: The glass transition temperature was less than 250 ° C.

<< 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 applied on a 6-inch silicon wafer using a spin coater and hot-plate. The mixture was dried at 110 ° C. for 3 minutes to obtain a coating film having a film thickness of about 6 μm. Next, the silicon wafer with a coating film was heated at 150 ° C./30 minutes and 320 ° C./60 minutes using an oven.
The internal stress was measured using Eq. (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 was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(Evaluation criteria)
⊚: The internal stress was less than 25 MPa.
◯: The internal stress was 25 MPa or more and less than 30 MPa.
X: The internal stress was 30 MPa or more.

<< Dissolution Contrast Evaluation >>
The varnishes A-1, A-2 and A-3 obtained in Examples 1-1 to 1-2 and Comparative Example 1-1 were applied onto a 6-inch silicon wafer using a spin coater and applied to a hot plate. The mixture was dried at 110 ° C. for 3 minutes to obtain a coating film having a film thickness of about 8 μm. The obtained coating film was subjected to i-line exposure via a mask to form an exposed portion and an unexposed portion on the same substrate. After exposure, it was developed in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 120 seconds and rinsed with water to obtain a pattern of a positive cured film.
The developing speed of the exposed portion and the developing speed of the unexposed portion until the film thickness of the exposed portion became 0 were determined. The contrast was calculated from the following formula and evaluated according to the following criteria. The evaluation results are summarized in Table 1.

(Evaluation criteria)
⊚: The contrast was 100 or more.
◯: The contrast was 20 or more and less than 100.
X: The dissolution rate ratio was less than 20.

<< Sensitivity evaluation >>
The varnishes A-1, A-2 and A-3 obtained in Examples 1-1 to 1-2 and Comparative Example 1-1 were applied onto a silicon wafer with a spin coater, and 110 by a hot plate. The mixture was heated and dried at ° C. for 3 minutes to obtain a coating film having a film thickness of about 8 μm.
The obtained coating film was irradiated with broad light through a photomask having a pattern using a high-pressure mercury lamp (with an i-ray filter). The exposure amount was increased by 50 mJ / cm ² and the exposure was carried out in the range of 100 to 1000 mJ / cm ² after the photomask was transmitted.
The dried coating film after exposure was developed with a 2.38% TMAH aqueous solution and rinsed with water to form a positive pattern film.
The exposure amount at which the exposed portion was not completely eluted was set as the minimum exposure amount and evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
⊚: The minimum exposure amount was less than 400 mJ / cm ² .
○: the minimum exposure amount, 400 mJ / cm ² or more was less than 700 mJ / cm ^2.
X: The minimum exposure amount was 700 mJ / cm ² or more.

As is clear from the evaluation results shown in Table 1 above, it was confirmed that in the examples, the glass transition temperature, elongation, melting contrast and sensitivity were high, and the internal stress was low.

<Example 2-1>
Polybenzooxazole precursor A-1 (100 parts by mass), diazonaphthoquinone compound A (10 parts by mass, manufactured by Sanpo Chemical Industry Co., Ltd., TKF-428, photosensitizer) and bifunctional (photosensitive agent) obtained in Reference Example 1 above. Meta) Acrylic compound (10 parts by mass, manufactured by Toa Synthetic Co., Ltd., M-6250, plasticizer) is dissolved in γ-butylolactone (300 parts by mass) and then filtered through a 0.2 μm filter to prepare a photosensitive resin composition. The crocodile B-1 was obtained.

<Example 2-2>
Polybenzooxazole precursor A-1 (100 parts by mass), diazonaphthoquinone compound A (10 parts by mass, manufactured by Sanpo Chemical Industry Co., Ltd., TKF-428, photosensitizer) and bifunctional or higher obtained in Reference Example 1 above. Epoxy compound (10 parts by mass, manufactured by DIC, HP-4032D, cross-linking agent) was dissolved in γ-butylolactone (300 parts by mass), filtered through a 0.2 μm filter, and varnish C of the photosensitive resin composition. I got -1.

<Example 2-3>
The polybenzoxazole precursor A-1 (100 parts by mass), diazonaphthoquinone compound A (10 parts by mass, manufactured by Sanpo Chemical Industry Co., Ltd., TKF-428, photosensitizer) obtained in Reference Example 1 and the following chemical formula ( TM-BIP-A (10 parts by mass, cross-linking agent) represented by d) is dissolved in γ-butylolactone (300 parts by mass), filtered through a 0.2 μm filter, and varnish D- of the photosensitive resin composition. I got 1.

<< Glass transition temperature evaluation >>
The varnish was changed to the varnishes B-1, C-1 and D-1 obtained in Examples 2-1 to 2-3, and the silicon wafer with a coating film was heated by an oven at 150 ° C./30 minutes. The glass transition temperature was measured by the same method as described above except that the temperature was changed to 220 ° C./60 minutes, and the evaluation was performed based on the same evaluation criteria. The evaluation results are summarized in Table 2.

<< Internal stress evaluation >>
The varnish was changed to the varnishes B-1, C-1 and D-1 obtained in Examples 2-1 to 2-3, and the silicon wafer with a coating film was heated by an oven at 150 ° C./30 minutes. The internal stress was measured by the same method as described above except that the temperature was changed to 220 ° C./60 minutes, and the evaluation was performed based on the same evaluation criteria. The evaluation results are summarized in Table 2.

<< Dissolution Contrast Evaluation >>
Contrast was obtained by the same method as described above except that the varnish was changed to the varnishes B-1, C-1 and D-1 obtained in Examples 2-1 to 2-3, and the same evaluation was performed. Evaluated based on criteria. The evaluation results are summarized in Table 2.

<< Sensitivity evaluation >>
The sensitivity was obtained by the same method as described above except that the varnish was changed to the varnishes B-1, C-1 and D-1 obtained in Examples 2-1 to 2-3, and the same evaluation was performed. Evaluated based on criteria. The evaluation results are summarized in Table 2.

As is clear from the evaluation results shown in Table 2 above, in each example, even when cured at a low temperature, it has a high glass transition temperature and melting contrast, and has a low internal stress. It was confirmed.

Claims (10)

1. An ester diamine-containing polybenzoxazole precursor, which comprises at least one of the structures represented by the following general formulas (1) and (2) and a structure represented by the following general formula (3).
   

   

   

   

   (In the general formulas (1) and (2),
   X Is a divalent organic group,
   Any of R ₁ to R ₄ has an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic group having 6 to 10 carbon atoms, a phenoxy group having 6 to 10 carbon atoms, and 6 carbon atoms. It is selected from a benzyl group of up to 10 and a benzyloxy group of 6 to 10 carbon atoms, and the other R ₃ to R ₆ are hydrogen atoms.
   n indicates an integer of 1 or more,
   In general formula (3),
   X is a divalent organic group,
   Y is a tetravalent organic group having at least 2 or more hydroxyl groups.
   o indicates an integer of 1 or more. )
2. Either R ₁ or R ₃ 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. , The other is a hydrogen atom,
   The ester diamine-containing polybenzoxazole precursor according to claim 1, wherein R ₂ and R ₄ are hydrogen atoms.
3. The ester diamine-containing polybenzoxazole precursor according to claim 1 or 2, wherein Y is an aromatic group in the general formula (3).
4. The ester diamine-containing polybenzoxazole precursor according to any one of claims 1 to 3, wherein Y is one or more groups selected from the following structures in the general formula (3).
   

   

   (In the above structural formula,
   One of * ₁ and * ₂ represents a connecting portion with an amino group, and the other represents a hydroxyl group. )
5. Any one of claims 1 to 4, wherein the content (ester diamine content) of the structure represented by the general formulas (1) and (2) is 0.1 mol% or more and 10 mol% or less. The ester diamine-containing polybenzoxazole precursor according to.
6. A photosensitive resin composition containing the ester diamine-containing polybenzoxazole precursor according to any one of claims 1 to 5 and a photosensitive agent.
7. The photosensitive resin composition according to claim 6, wherein the photosensitive agent is a naphthoquinone diazide compound.
8. A dry film comprising a resin layer formed of the photosensitive resin composition according to claim 6 or 7 on the film.
9. A cured product, which is formed of 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 according to claim 9 as a forming material.