JP7203649B2 - Esterdiamine-containing polybenzoxazole precursors, photosensitive resin compositions, dry films, cured products and electronic components - Google Patents

Description

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

In a photosensitive resin composition containing a polybenzoxazole precursor, when heated, the hydroxyamide structure undergoes a cyclization reaction to form rigid benzoxazole rings. It is widely used in various fields because it exhibits excellent properties such as mechanical strength. For example, it is being applied to flexible printed wiring boards, buffer coat films for semiconductor elements, and insulating films for rewiring layers of wafer level packages (WLP).

Conventionally, in buffer coat films and insulating films for rewiring layers of wafer-level packages, instead of photosensitive resin compositions containing polyimide precursors, polybenzoxazole precursors that enable finer pattern formation by photolithography are used. A photosensitive resin composition containing is attracting attention.
Examples of such a photosensitive resin composition include a positive resist composition composed of a polybenzoxazole precursor and a photosensitive diazoquinone as disclosed in Patent Document 1. Then, such a photosensitive resin composition is coated on a substrate such as a wafer and dried to form a dry coating film, the dry coating film is irradiated with an active energy ray to expose, and then developed. After forming a desired pattern film by heating, the polybenzoxazole precursor is cyclized by heating at about 320° C. to form a pattern cured film of polybenzoxazole.

In addition, in recent semiconductor devices, along with the demand for higher functionality and miniaturization, excellent resolution for realizing finer pattern formation is required for the buffer coat film and the insulating film for the rewiring layer of the wafer level package. In addition, suppression of cracks and warpage due to thinning of the substrate wafer is required.

Japanese Patent Publication No. 1-046862

However, in the composition described in Patent Document 1, the balance between the solubility of the exposed area and the resistance to dissolution of the unexposed area during development, which is necessary for realizing the resolution required for recent semiconductor devices, Since the so-called dissolution contrast is low, there is a problem that it is difficult to form a fine pattern, and cracks and warpage are suppressed insufficiently.

The present invention has been made to solve such problems, and the object thereof is to provide a photosensitive resin composition containing a polybenzoxazole precursor that achieves high dissolution contrast and is less likely to crack or warp. to provide.

Another object of the present invention is to provide electronic parts such as dry films, printed wiring boards, and semiconductor elements using the photosensitive resin composition.

As a result of intensive research aimed at realizing the above object, the present inventors have found that by introducing a diamine having an ester structure into a polybenzoxazole precursor, the dissolution contrast of the photosensitive resin composition can be significantly improved, and further curing The inventors have found that the internal stress that sometimes occurs can be relieved, leading to the completion of the present invention.

（一般式（１）および（２）中、
Ｘ は、２価の有機基であり、
Ｒ_１～Ｒ_４のいずれかが、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数６～１０の芳香族基、炭素数６～１０のフェノキシ基、炭素数６～１０のベンジル基および炭素数６～１０のベンジルオキシ基から選択され、それ以外のＲ_１～Ｒ_４が水素原子であり、
ｎは、１以上の整数を示し、
一般式（３）中、
Ｘは、２価の有機基であり、
Ｙは、少なくとも２以上水酸基を有する４価の有機基であり、
ｏは、１以上の整数を示す。） That is, the esterdiamine-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). do.

(In general formulas (1) and (2),
X is a divalent organic group,
R.₁～R₄is 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, or a benzyl group having 6 to 10 carbon atoms. and a benzyloxy group having 6 to 10 carbon atoms, other than R₁～R₄is a hydrogen atom,
n represents an integer of 1 or more,
In the general formula (3),
X is a divalent organic group,
Y is a tetravalent organic group having at least two hydroxyl groups,
o represents 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, or a benzyl group having 6 to 10 carbon atoms. oxy groups, the other being a hydrogen atom,
R ₂ and R ₄ are preferably hydrogen atoms.

（上記構造式中、
＊_１および＊_２のいずれかがアミノ基との連結部を表し、他方が、水酸基を表す。） In the present invention, Y in general formula (3) is preferably one or more groups selected from the following structures.

(In the above structural formula,
Either * ₁ or * ₂ 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 formulas (1) and (2) (ester diamine content) 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 naphthoquinonediazide compound.

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

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

Electronic parts of the present invention, such as printed wiring boards and semiconductor elements, are characterized by having the cured product as a forming material.

The esterdiamine-containing polybenzoxazole precursor of the present invention can provide a photosensitive resin composition effective for obtaining a dry coating film having high dissolution contrast and high-temperature pattern retention.

上記一般式（１）および（２）において、Ｘは、２価の有機基である。この有機基は、脂肪族基であっても、芳香族基であってもよいが、芳香族基であることが好ましく、芳香環上において、上記一般式（１）および（２）中におけるカルボニルと結合していることがより好ましい。
２価の有機基の炭素数は、６～３０であることが好ましく、６～２４であることがより好ましい。
２価の有機基としては、以下の構造を有する基が挙げられるが、これらに限定されるものではなく、用途に応じて適宜変更することが好ましい。

[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 a photosensitive resin composition containing this, the development resistance of the unexposed area is obtained without impairing the developability of the exposed area, and in the cured product, the amide bond and the ester bond that are excellent in flexibility It is thought that the internal stress is relieved.

In the above general formulas (1) and (2), X is a divalent organic group. This organic group may be an aliphatic group or an aromatic group, but is preferably an aromatic group. It is more preferable that the
The number of carbon atoms in the divalent organic group is preferably 6-30, more preferably 6-24.
Examples of divalent organic groups include groups having the following structures, but are not limited to these, and are preferably changed as appropriate according to the application.

In the structural formulas of the above divalent organic groups, A is a single bond, alkylene, -O-, -CO-, -S-, -SO ₂ -, -C(CF ₃ ) ₂ - and -C(CH ₃ ) ₂ -, * represents the linkage to the carbonyl.

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

In the above general formulas (1) and (2), any one of R ₁ to R ₄ , preferably R ₁ or R ₃ , particularly preferably R ₃ , is an alkyl group having 1 to 12 carbon atoms; 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, Other R ₁ to R ₄ are hydrogen atoms.
Examples of alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group and hexyl group.
Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy and pentoxy groups.
Aromatic groups having 6 to 10 carbon atoms include phenyl group, tolyl group, methylphenyl group, dimethylphenyl group, ethylphenyl group, diethylphenyl group, propylphenyl group, butylphenyl group, fluorophenyl group and pentafluorophenyl group. , chlorophenyl 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 and naphthyl group.
The phenoxy group having 6 to 10 carbon atoms includes methylphenoxy group, ethylphenoxy group, propylphenoxy group, dimethylphenoxy group, diethylphenoxy group, methoxyphenoxy group, ethoxyphenoxy group and dimethoxyphenoxy group.
The benzyl group having 6 to 10 carbon atoms includes benzyl group, methylbenzyl group, ethylbenzyl group, propylbenzyl group, dimethylbenzyl group, methoxybenzyl group, ethoxybenzyl group and methoxybenzyl group.
benzyloxy group having 6 to 10 carbon atoms, methylbenzyloxy group, benzyloxy group, benzylbenzyloxy group, ethylbenzyloxy group, propylbenzyloxy group, dimethylbenzyloxy group, methoxybenzyloxy group and ethoxy group; A benzyloxy group and the like can be mentioned.
Among the above, from the viewpoint of the dissolution contrast of the photosensitive resin composition, high-temperature pattern retention, sensitivity and linear thermal expansion coefficient, any one of R ₁ to R ₄ is an aromatic group having 6 to 10 carbon atoms, carbon 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 are preferable, and an aromatic group having 6 to 10 carbon atoms is more preferable, and a phenyl group and a tolyl group. , a methylphenyl group, a dimethylphenyl group, an ethylphenyl group and a diethylphenyl group are more preferable, and they have the effect of suppressing the film reduction phenomenon in the unexposed area and the effect of relieving the internal stress by suppressing the packing effect between molecules in the cured product. From the point of view, a phenyl group is particularly preferred.

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

In the esterdiamine-containing polybenzoxazole precursor of the present invention, the content of the structures represented by the general formulas (1) and (2) (esterdiamine content) is 0.1 mol% or more and 10 mol% or less. is preferably 0.1 mol % or more and 5 mol % or less. Thereby, the dissolution contrast during development of a dry coating film formed from the photosensitive resin composition containing the polybenzoxazole precursor of the present invention can be further improved.

In the general formula (3), X is a divalent organic group, and preferred aspects thereof are the same as those of the general formulas (1) and (2), so description thereof is omitted here.

In general formula (3) above, Y is a tetravalent organic group having at least two hydroxyl groups. This organic group may be either an aliphatic group or an aromatic group, but is preferably an aromatic group.
Moreover, it is preferable that the positional relationship between the hydroxyl group of the tetravalent organic group and the amino group is the ortho position.
The number of carbon atoms in the tetravalent organic group is preferably 6-30, more preferably 6-24.
Examples of the tetravalent organic group include groups having the following structures, but the groups are not limited to these, and it is preferable to change them appropriately depending on the application.

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

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

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

In the esterdiamine-containing polybenzoxazole precursor of the present invention, the content of the structure represented by the general formula (3) is preferably 90 mol% or more and 99.9 mol% or less, and 95 mol% or more. , is preferably 99.9 mol % or less. As a result, the photosensitive resin composition containing the esterdiamine-containing polybenzoxazole precursor of the present invention has excellent developer solubility in the exposed area as a dry coating film, and insulating properties, heat resistance and mechanical properties as a cured film. Strength can be improved.

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

This ester diamine-containing polybenzoxazole precursor comprises 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 the components.

Z in the above general formula (6) represents a leaving group composed 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.
R ₁ to R ₄ , X and Y in general formulas (4) to (6) are as described above.

Dicarboxylic acid components satisfying the general formula (6) include, for example, 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 -Carboxyphenyl)propane, dicarboxylic acids having aromatic rings such as 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 and 1,3-cyclopentanedicarboxylic acid, dicarboxylic acid dihalides thereof, and dicarboxylic acid esters thereof. Among them, 4,4'-dicarboxydiphenyl ether (that is, 4,4'-diphenyletherdicarboxylic acid) and its dihalide are preferable because they provide excellent developability of the photosensitive resin composition and mechanical properties of the cured film.

This ester diamine-containing polybenzoxazole precursor is a diamine compound other than the diamine compounds represented by the above general formulas (4) and (5) (hereinafter referred to as other diamine compounds) within a range that does not impair the characteristic effects and polymerization reactivity ) can also be combined.
Other diamine compounds 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, 2,2-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) phenoxy)-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- aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 4,4'-bis[ (3-aminophenoxy)benzoyl]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] Methane, 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 ] Sulfone, 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- 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 rings in the above aromatic diamines are halogens. a halogen atom, an alkyl or alkoxyl group having 1 to 3 carbon atoms, a cyano group, or a halogenated alkyl group having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of an alkyl or alkoxyl group are substituted with halogen atoms, or Alkoxyl-substituted aromatic diamines such as 4,4′-methylenebis(cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis(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, 2,2-bis(4-aminocyclohexyl)propane, 2,2-bis(4-aminocyclohexyl)hexafluoropropane, 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 are included. 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 esterdiamine-containing polybenzoxazole precursor and (B) a photosensitive agent.
By using such an esterdiamine-containing polybenzoxazole precursor in a photosensitive resin composition, the dissolution contrast and internal stress of a dry coating film formed from the photosensitive resin composition can be significantly improved.

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

[(A) Esterdiamine-containing polybenzoxazole precursor]
The photosensitive resin composition of the present invention contains the above-described esterdiamine-containing polybenzoxazole precursor as a polybenzoxazole precursor, thereby improving the dissolution contrast of the formed dry coating film and the internal stress of the cured film. can be significantly improved.
The photosensitive resin composition of the present invention may be used in combination with a polybenzoxazole precursor other than the esterdiamine-containing polybenzoxazole precursor.
The content of the esterdiamine-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 content range, the effects of the present invention can be sufficiently obtained.

[(B) Photosensitizer]
The photosensitive resin composition of the present invention contains a photosensitive agent such as a photoacid generator and a photobase generator. Among these, photoacid generators are preferred from the viewpoint of dissolution contrast.
This photosensitive agent can be blended in a known and commonly used ratio. It is preferable to blend at a rate of 30 parts by mass.
Two or more kinds of such photosensitizers may be contained.

A photoacid generator is a compound that generates an acid upon irradiation with light such as ultraviolet light or visible light. Salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters, aromatic N-oximidosulfonates, aromatic sulfamides and benzoquinone diazosulfonic acid esters can be mentioned.
Among the above, naphthoquinonediazide compounds are preferred from the viewpoint of dissolution contrast.
Specific examples of the naphthoquinonediazide compound include, for example, tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene naphthoquinonediazide adducts (for example, TS533, TS567, TS583, TS593), naphthoquinonediazide adducts of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 from Sambo Kagaku Kenkyusho Co., Ltd.), and 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α ,α-dimethylbenzyl}phenol naphthoquinonediazide adducts (eg, TKF-428 and TKF-528 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.).

Photobase generators generate one or more basic substances (secondary amines, tertiary amines, etc.) by changing the molecular structure or by cleaving the molecules when irradiated with light such as ultraviolet rays or visible light. It is a compound that
The photobase generator may be an ionic photobase generator or a nonionic photobase generator, but from the viewpoint of the sensitivity of the photosensitive resin composition, the ionic photobase generator is preferred.
Examples of the ion-type photobase generator include salts of carboxylic acids containing aromatic components and tertiary amines. 167, WPBG-168, WPBG-266 and WPBG-300.
Examples of nonionic photobase generators include α-aminoacetophenone compounds, oxime ester compounds, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzyl carbamate groups and alkoxybenzyls. A compound having a substituent such as a carbamate group is included.
As other photobase generators, Wako Pure Chemical Industries, Ltd. WPBG-018 (trade name: 9-anthrylmethyl N, N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2 -hydroxyphenyl)-2-propenoyl]piperidine), WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate) and WPBG-165.

[Crosslinking agent]
The photosensitive resin composition of the present invention can contain a cross-linking agent. By adding a cross-linking agent, sufficient properties 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 includes known and commonly used cross-linking agents.
In the present specification, the cross-linking agent is preferably a compound capable of reacting with phenolic hydroxyl groups in the polybenzoxazole precursor to form a cross-linked structure.
Here, the compound that reacts with the phenolic hydroxyl group in the polybenzoxazole precursor includes 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 include a cross-linking agent having an alcoholic hydroxyl group in which a hydroxyl group is bonded to, 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 cross-linking agent having a cyclic ether group, particularly an epoxy group, and a cross-linking agent having a methylol group to which an alcoholic hydroxyl group, particularly a hydroxyl group is bonded, are preferred.
The cross-linking agents may be used singly or in combination of two or more.
The amount of the cross-linking agent blended 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 having an 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. A 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 2-4. When the photosensitive resin composition contains a crosslinking 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 epoxy groups, bifunctional or higher functional epoxy compounds having a naphthalene skeleton are preferred. Not only is it possible to obtain an insulating film with excellent flexibility and chemical resistance, but it is also possible to reduce the CTE, which is in a trade-off relationship with flexibility, and it is possible to suppress the occurrence of warping and cracking of the insulating film. A bisphenol A type epoxy compound can also be preferably used from the viewpoint of flexibility.

（一般式（７）中、Ｒ^Ａ１は２～１０価の有機基を示す。Ｒ^Ａ２は、それぞれ独立に、水素原子または炭素数１～４のアルキル基を示す。ｒは２～１０の整数を示す。） (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, more preferably a compound represented by the following general formula (7).

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

In general formula (7), R ^{1 A1} is preferably an optionally substituted alkylene group having 1 to 3 carbon atoms.

In general formula (7), R ^A2 is preferably a hydrogen atom.

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

Moreover, 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 divalent to decavalent organic group represented by R ^A1 in the general formula (7), and R ^A1 is a di(trifluoromethyl)methylene group. is preferred. Moreover, 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 aggregation action between polymer molecular chains is reduced, and the mobility and flexibility between molecular chains are improved, thereby improving the thermal molecular motion of the polybenzoxazole precursor. However, it is thought that low-temperature curability is imparted by promoting the cyclization reaction. The plasticizer is not particularly limited as long as it is a compound that improves plasticity, and includes bifunctional (meth)acrylic compounds, sulfonamide compounds, phthalate compounds, maleate compounds, aliphatic dibasic acid esters, and phosphate esters. , and ether compounds such as crown ethers. Among them, a bifunctional (meth)acrylic compound is preferred. The bifunctional (meth)acrylic compound is preferably a compound that does not form a crosslinked structure with other components in the composition. Moreover, 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, diol (such as ethylene oxide and propylene oxide) alkylene oxide adduct di(meth)acrylates and bifunctional polyester (meth)acrylates are preferred, and bifunctional polyesters (meth)acrylates are preferred. ) acrylates are more preferred.

As the di(meth)acrylate of the alkylene oxide adduct of the diol, specifically, one obtained by modifying the diol with alkylene oxide and then adding a (meth)acrylate to the terminal thereof is preferable, and a diol having an aromatic ring is more preferable. . Examples thereof include bisphenol A EO (ethylene oxide) adduct diacrylate and bisphenol A PO (propylene oxide) adduct diacrylate. A specific structure of the di(meth)acrylate, which is an alkylene oxide adduct of a diol, is shown in the following general formula (8), but is not limited thereto.

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

(Thermal acid generator, sensitizer, adhesion agent, other ingredients)
In the photosensitive resin composition of the present invention, a known thermal acid generator for promoting the cyclization reaction of the polybenzoxazole precursor and a known thermal acid generator for improving the photosensitivity are added to the extent that the effects of the present invention are not impaired. A known sensitizer and a known adhesion agent such as a silane coupling agent for improving the adhesion to the substrate can also be blended. In addition, various organic or inorganic low-molecular-weight or high-molecular-weight compounds may be added to the photosensitive resin composition of the present invention in order to impart processing properties and various functionalities. For example, surfactants, leveling agents, fine particles and the like can be used. Fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as silica, carbon, and layered silicate. In addition, various colorants, fibers, and the like may be added to the photosensitive resin composition of the present invention.

[solvent]
The 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. Examples include N,N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N,N'-dimethylacetamide, Diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoramide , pyridine, γ-butyrolactone and diethylene glycol monomethyl ether.

The content of the solvent in the photosensitive resin composition is not particularly limited, and it is preferable to change it appropriately according to its use. It can be 50 parts by mass or more and 9000 parts by mass or less with respect to 100 parts by mass.
In addition, the photosensitive resin composition may contain two or more solvents.

[Dry film]
The dry film of the present invention comprises a film (for example, a support (carrier) film) and a resin layer formed on the film using the photosensitive resin composition. The dry film may further include a protective film (so-called protective film) on the resin layer formed on the film.

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

From the viewpoint of improving mechanical strength, the thermoplastic resin film as described above is preferably a uniaxially or biaxially stretched film.

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

(resin layer)
The resin layer is formed using the photosensitive resin composition described above, and the thickness thereof is not particularly limited, and is preferably changed according to the application. can be:

The resin layer is coated on the film with a photosensitive resin composition to a uniform thickness using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, or the like. It can be formed by coating and drying.
In another embodiment, the resin layer can be formed by applying a photosensitive resin composition on the 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 becomes 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 and surface-treated paper can be used.

Although the thickness of the protective film is not particularly limited, it 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 using the above photosensitive resin composition. Moreover, the cured product may be one in which a pattern is formed (hereinafter sometimes referred to as a pattern film).
The method for producing the cured product of the present invention is described below.

[First step]
In the method for producing a cured product of the present invention, a photosensitive resin composition is applied on a substrate to form a coating film, and then 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 using a spin coater, a bar coater, a blade coater, a curtain coater, a screen printer, etc., or a spray application using a spray coater. and an inkjet method.

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

The transfer of the dry film onto the substrate is preferably carried out under pressure and heat using a vacuum laminator or the like. By using such a vacuum laminator, even if the circuit board surface has irregularities, the resin layer of the dry film fills the irregularities of the circuit board under vacuum conditions. , there is no entrapment of air bubbles, and the filling of recesses on the substrate surface is improved.

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

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

The active energy ray used has a wavelength capable of activating, for example, the photoacid generator as the photosensitizer (B). 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, etc., but can generally be in the range of 10 to 1000 mJ/cm ² , preferably 20 to 800 mJ/cm ² .
The exposure machine used for the 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 irradiating ultraviolet rays in the range of 350 to 450 nm. In addition, a direct writing device (eg, a laser direct imaging device that draws an image with a laser directly from CAD data from a computer) can also be used.

[Third step]
This step is carried out as necessary, and a portion of the polyimide precursor in the unexposed area may be ring-closed by heating the coating film for a short period of 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) the type of photosensitive agent.

[Fourth step]
Then, the patterned film can be obtained by treating the exposed coating film with a developer to remove the exposed portions in the coating film.
In this step, any method can be selected from conventionally known photoresist development methods, such as the rotary spray method, the paddle method, and the immersion method accompanied by ultrasonic treatment.

Examples of the developer include inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine and triethanolamine; tetramethylammonium hydroxide and tetrabutylammonium hydroxide. and aqueous solutions of quaternary ammonium salts such as
If necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol or isopropyl alcohol or a surfactant may be added.

After that, the coating film is washed with a rinsing liquid as necessary to obtain a pattern film.
Distilled water, methanol, ethanol, isopropyl alcohol, and the like can be used alone or in combination as the rinsing liquid. 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).
Through 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, for example, at a temperature of 150° C. or more and less than 350° C. for about 5 minutes to 120 minutes.
For heating, for example, a hot plate, an oven, and a temperature-programmable oven can be used.
It may be in a heated atmosphere (gas), in air, or in an inert gas such as nitrogen or argon.

[Use]
Applications of the photosensitive resin composition of the present invention are not particularly limited.

Specifically, materials for forming display devices include layer-forming materials and image-forming materials for color filters, films for flexible displays, resist materials, alignment films, and the like.
Materials for forming semiconductor elements include resist materials, buffer coat films, and layer forming materials for insulating films for rewiring layers of wafer level packages (WLP).
Materials for forming electronic components include sealing materials and layer-forming materials for printed wiring boards, interlayer insulating films, wiring coating films, and the like.
Materials for forming optical components include optical materials and layer-forming materials for holograms, optical waveguides, optical circuits, optical circuit components, antireflection films, and the like.
Furthermore, as building materials, it can be used for paints, coating agents, and the like.

INDUSTRIAL APPLICABILITY The photosensitive resin composition of the present invention is mainly used as a pattern forming material, and is used particularly for surface protective films, buffer coat films, interlayer insulating films, rewiring insulating films, and flip chips of semiconductor devices, display devices and light emitting devices. Appropriate as protective films for devices, protective films for devices having a bump structure, interlayer insulating films for multilayer circuits, insulating materials for passive components, protective films for printed wiring boards such as solder resists and coverlay films, and liquid crystal alignment films. Available.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to the examples. In the following description, "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, 0.489 g (1.61 mmol) of (2-phenyl-4-aminophenyl)-4-aminobenzoate (PHBPAA) represented by the following chemical formula (a) ) 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.
After that, the flask was immersed in an ice bath, and while the inside of the flask was maintained at 0 to 5°C, 25.29 g (85.7 mmol) of 4,4'-diphenyletherdicarboxylic acid chloride represented by the following chemical formula (c) was added as a solid. Add over 10 minutes and stir in ice bath for 30 minutes.

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

(Reference Example 2: Synthesis of polybenzoxazole precursor A-2)
0.474 (1.56 mmol) of PHBPAA and 10.88 g (29.7 mmol) of bis(3-amino-4-hydroxyphenyl)hexafluoropropane were placed in a 0.5 liter flask equipped with a stirrer and thermometer, Dissolved with stirring in 85 g of N-methylpyrrolidone.
After that, the flask was immersed in an ice bath, and 10.09 g (34.2 mmol) of 4,4'-diphenyletherdicarboxylic acid chloride was added as a solid over 10 minutes while maintaining the inside of the flask at 0 to 5°C. for 30 minutes.
Stirring was then continued at room temperature for 18 hours. The stirred solution was put into 700 mL of ion-exchanged water (specific resistance: 18.2 MΩ·cm), and the precipitate was recovered. After that, the obtained solid was dissolved in 420 mL of acetone and put into 1 L of deionized water. After collecting the precipitated solid, it was dried under reduced pressure to obtain a polybenzoxazole precursor containing a carboxyl group-terminated esterdiamine. The weight average molecular weight determined by GPC standard polystyrene conversion was 26,900.
The esterdiamine content in the esterdiamine-containing polybenzoxazole precursor was 5 mol %.

(Reference Example 3: Synthesis of polybenzoxazole precursor A-3)
In a 0.5 liter flask equipped with a stirrer and thermometer, 10.0 g (27.3 mmol) of bis(3-amino-4-hydroxyphenyl)hexafluoropropane was dissolved in 1500 g of N-methylpyrrolidone with stirring. .
After that, the flask was immersed in an ice bath, and 8.78 g (29.8 mmol) of 4,4'-diphenyletherdicarboxylic acid chloride was added as a solid over 10 minutes while maintaining the inside of the flask at 0 to 5°C. for 30 minutes.
Stirring was then continued at room temperature for 18 hours. The stirred solution was put into 700 mL of ion-exchanged water (specific resistance: 18.2 MΩ·cm), and the precipitate was recovered. After that, the obtained solid was dissolved in 420 mL of acetone and put into 1 L of deionized water. After collecting the precipitated solid, it was dried under reduced pressure to obtain a carboxyl-terminated polybenzoxazole precursor. The weight average molecular weight determined by GPC standard polystyrene conversion was 29,500, the number average molecular weight was 11,600, and the PDI was 2.54.

<Example 1-1>
γ- After dissolving in butyrolactone (300 parts by mass), it was 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>>
Each of the varnishes A-1, A-2 and A-3 obtained in Examples 1-1 to 1-2 and Comparative Example 1-1 above was coated on a 6-inch silicon wafer using a spin coater and hot coated. It was dried on a plate at 110° C. for 3 minutes to obtain a coating film having a thickness of about 30 μm. Next, using an oven, the coated silicon wafer was heated at 150° C./30 minutes and 320° C./60 minutes.
The obtained cured film was peeled off from the silicon wafer, and the elongation percentage 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)
A: The elongation rate was 15% or more.
○: The elongation rate was 10% or more and less than 15%.
x: The elongation rate was less than 10%.

<<Glass transition temperature evaluation>>
The glass transition temperature (Tg) of the cured film obtained in elongation evaluation was measured by TMA (thermo-mechanical analysis) and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: 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.

（評価基準）
◎： 内部応力が、２５ＭＰａ未満であった。
〇： 内部応力が、２５ＭＰａ以上、３０ＭＰａ未満であった。
×： 内部応力が、３０ＭＰａ以上であった。 <<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 above were each applied onto a 6-inch silicon wafer using a spin coater, followed by a hot plate. and dried at 110° C. for 3 minutes to obtain a coating film having a thickness of about 6 μm. Next, using an oven, the coated silicon wafer was heated at 150° C./30 minutes and 320° C./60 minutes.
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, the internal stress was measured using the formula (1) and evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1.

(Evaluation criteria)
A: 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.

（評価基準）
◎：コントラストが、１００以上であった。
○：コントラストが、２０以上、１００未満であった。
×：溶解速度比が、２０未満であった。 <<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 above were coated on a 6-inch silicon wafer using a spin coater and placed on a hot plate. and dried at 110° C. for 3 minutes to obtain a coating film having a thickness of about 8 μm. The obtained coating film was exposed to i-line through a mask to form an exposed portion and an unexposed portion in the same substrate. After exposure, the film was developed with a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 120 seconds and rinsed with water to obtain a positive cured film pattern.
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 obtained. Contrast was calculated from the following formula and evaluated according to the following criteria. The evaluation results are summarized in Table 1.

(Evaluation criteria)
A: 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 above were applied onto silicon wafers with a spin coater, and heated with a hot plate to 110 C. for 3 minutes to obtain a coating film having a thickness of about 8 .mu.m.
The resulting coating film was irradiated with broad light through a patterned photomask using a high-pressure mercury lamp (with an i-line filter). The exposure amount was increased by 50 mJ/cm ² in the range of 100 to 1000 mJ/cm ² after passing through the photomask.
The dried coating film after exposure was developed using a 2.38% TMAH aqueous solution and rinsed with water to form a positive pattern film.
The amount of exposure at which the exposed portion was completely eluted was defined as the minimum amount of exposure, and evaluation was made according to the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: The minimum exposure dose was less than 400 mJ/cm ² .
○: The minimum exposure dose was 400 mJ/cm ² or more and 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 the examples had high glass transition temperature, elongation, dissolution contrast and sensitivity, and low internal stress.

<Example 2-1>
Polybenzoxazole precursor A-1 (100 parts by mass) obtained in Reference Example 1 above, diazonaphthoquinone compound A (10 parts by mass, manufactured by Sambo Kagaku Kogyo Co., Ltd., TKF-428, photosensitizer) and difunctional ( A meth)acrylic compound (10 parts by mass, manufactured by Toagosei Co., Ltd., M-6250, plasticizer) is dissolved in γ-butyrolactone (300 parts by mass), filtered through a 0.2 μm filter, and a photosensitive resin composition is obtained. Varnish B-1 was obtained.

<Example 2-2>
Polybenzoxazole precursor A-1 (100 parts by mass) obtained in Reference Example 1 above, diazonaphthoquinone compound A (10 parts by mass, manufactured by Sambo Chemical Industry Co., Ltd., TKF-428, photosensitizer) and difunctional or more is dissolved in γ-butyrolactone (300 parts by mass), filtered through a 0.2 μm filter, and varnish C of the photosensitive resin composition. -1 was obtained.

<Example 2-3>
Polybenzoxazole precursor A-1 (100 parts by mass) obtained in Reference Example 1 above, diazonaphthoquinone compound A (10 parts by mass, manufactured by Sambo Chemical Industry Co., Ltd., TKF-428, photosensitizer) and the following chemical formula ( TM-BIP-A (10 parts by mass, cross-linking agent) represented by d) was dissolved in γ-butyrolactone (300 parts by mass), filtered through a 0.2 μm filter, and varnish D- of the photosensitive resin composition. 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 the 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 evaluated 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 the 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 evaluated based on the same evaluation criteria. The evaluation results are summarized in Table 2.

<<Dissolution contrast evaluation>>
Contrast was determined in the same manner 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>>
Sensitivity was determined in the same manner 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, each example has a high glass transition temperature and dissolution contrast even when cured at a low temperature, and has a low internal stress. Confirmed.

Claims (10)

An esterdiamine-containing polybenzoxazole precursor having 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 general formulas (1) and (2),
X is a divalent organic group,
R.₁～R₄is 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, or a benzyl group having 6 to 10 carbon atoms. and a benzyloxy group having 6 to 10 carbon atoms, other than R₃～R₆is a hydrogen atom,
n represents 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 two hydroxyl groups,
o represents an integer of 1 or more. ) 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, and
2. The esterdiamine-containing polybenzoxazole precursor of claim 1, wherein _R2 and _R4 are hydrogen atoms. 3. The esterdiamine-containing polybenzoxazole precursor according to claim 1 or 2, wherein Y in general formula (3) is an aromatic group. The esterdiamine-containing polybenzoxazole precursor according to any one of claims 1 to 3, wherein Y in general formula (3) is one or more groups selected from the following structures.

(In the above structural formula,
Either * ₁ or * ₂ represents a linking portion with an amino group, and the other represents a hydroxyl group. ) 5. Any one of claims 1 to 4, wherein the content of the structures represented by the general formulas (1) and (2) (ester diamine content) is 0.1 mol % or more and 10 mol % or less. Esterdiamine-containing polybenzoxazole precursors according to . A photosensitive resin composition comprising the esterdiamine-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 said photosensitive agent is a naphthoquinonediazide compound. A dry film comprising a resin layer formed from the photosensitive resin composition according to claim 6 or 7 on the film. A cured product formed from the photosensitive resin composition according to claim 6 or 7 or the resin layer of the dry film according to claim 8. An electronic component comprising the cured product according to claim 9 as a forming material.