JP7224844B2 - Photosensitive resin composition, dry film, cured product and electronic parts - Google Patents

Description

The present invention provides a photosensitive resin composition, a dry film having a resin layer formed from the photosensitive resin composition, a cured product formed from the photosensitive resin composition, and a printed wiring having the cured product as a forming material. It relates to electronic parts such as plates and semiconductor elements.

Polyimide is widely used in various fields due to its excellent properties such as high insulation, heat resistance and mechanical strength. For example, it is applied not only to the aerospace field but also to flexible printed wiring boards, buffer coat films for semiconductor elements, and insulating films for rewiring layers of wafer level packages (WLP).

Generally, polyimide has poor thermoplasticity and poor solubility in organic solvents, and is difficult to process. Therefore, polyimide is used in the form of a liquid photosensitive resin composition obtained by blending an organic solvent-soluble polyimide precursor (polyamic acid) and a photoreactive compound.
Specifically, the photosensitive resin composition is applied onto a substrate such as a wafer and dried to form a dry coating film, and the dry coating film is exposed to active energy rays and then developed. Thus, after forming a desired pattern film, the polyamic acid is subjected to a ring closure reaction at a high temperature to form a polyimide and is cured.

As such a photosensitive resin composition, a positive photosensitive resin composition containing polyamic acid and naphthoquinone diazide has been conventionally proposed (see Patent Document 1).

However, in the photosensitive resin composition as proposed in Patent Document 1, due to the carboxyl groups of the polyamic acid, even the unexposed areas are dissolved during development (film reduction phenomenon). However, there is a problem that a patterned film that does In other words, there is a demand for a material that exhibits a large dissolution rate difference between an exposed area and an unexposed area during development (high dissolution contrast).

Conventionally, in order to improve the dissolution contrast, the carboxyl groups of polyamic acids are esterified (see Patent Document 2).
However, due to the esterification of the carboxyl groups of the polyamic acid, the ring closure reaction of the polyamic acid requires a higher temperature, and the curing shrinkage due to the elimination of the ester moiety during the ring closure reaction. There were problems that could occur. Furthermore, since the esterification step is added to the process for synthesizing polyamic acid, there are problems such as a decrease in productivity and the possibility of generation of by-products due to the esterification.

In addition, from the viewpoint of cost reduction, such a photosensitive resin composition is required to have so-called high sensitivity, that is, to obtain developability even with a lower exposure amount of the exposed portion, and to reduce the size and height of the semiconductor element. It is required to have a so-called high resolution that enables fine pattern formation in accordance with functionalization.

JP-A-52-13315 JP-A-4-168441

The present invention has been made to solve such problems, and its main purpose is to obtain a high dissolution contrast without esterifying the carboxyl groups in the polyamic acid, and to obtain a dry coating film with high sensitivity and high resolution. It is an object of the present invention to provide a photosensitive resin composition effective in forming a

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 a photosensitive resin containing a polyamic acid having a repeating unit represented by a specific structure and an acid value within a specific numerical range and a photosensitizer. According to the composition, a high dissolution contrast can be obtained in a dry coating film, and the present inventors have completed the present invention based on the finding that the sensitivity and resolution are significantly improved.

（一般式（１）中、
Ｘは、２価の有機基であり、
ｎは、１以上の整数である。）

（上記一般式（３）中、
Ｙは、それぞれ独立して、酸素原子および炭素数１～５の２価の有機基から選択されるが、少なくとも１つは、酸素原子であり、
Ｒ_１は、それぞれ独立して、炭素数１～５のアルキル基または炭素数１～５のハロゲン化アルキル基であり、
ａは、０～３の整数であり、
ｂは、０～４の整数であり、
上記一般式（４）中、
Ｒ_２～Ｒ_５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_２～Ｒ_５が水素原子である。） That is, the photosensitive resin composition of the present invention is
(A) an alkali-soluble resin;
(B) a photosensitizer,
The alkali-soluble resin has a repeating unit represented by the following general formula (1), has an acid value (mgKOH/g) of 170 or more and 200 or less, and is at least an acid anhydride represented by the following chemical formula (2). and two or more diamine compounds satisfying the following general formula (3) or (4).

(In general formula (1),
X is a divalent organic group,
n is an integer of 1 or more. )

(In the above general formula (3),
each Y is independently selected from an oxygen atom and a divalent organic group having 1 to 5 carbon atoms, at least one of which is an oxygen atom;
each R ₁ is independently an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms;
a is an integer from 0 to 3,
b is an integer from 0 to 4,
In the above general formula (4),
any one of R ₂ to R ₅ is 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 6 carbon atoms; -10 benzyl groups and C6-10 benzyloxy groups, and R ₂ to R ₅ other than these are hydrogen atoms. )

In one embodiment of the present invention, the diamine compound is selected from compounds represented by formulas (5) to (7) below.

In one embodiment of the invention, the photosensitizer is 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.

The electronic component of the present invention is characterized by having the cured product as a forming material.

According to the photosensitive resin composition of the present invention, the dissolution contrast can be remarkably improved without esterifying the carboxyl groups of the polyamic acid. It is possible to solve the problem of curing shrinkage, the problem of decreased productivity, and the problem of generation of by-products due to the detachment of .
Moreover, according to the photosensitive resin composition of the present invention, a dry coating film having high sensitivity and resolution can be formed.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention contains (A) an alkali-soluble resin and (B) a photosensitive agent.
The components contained in the photosensitive resin composition of the present invention are described in detail below.
[(A) alkali-soluble resin]
The photosensitive resin composition of the present invention contains an alkali-soluble resin, and the alkali-soluble resin is a polyamic acid having repeating units represented by the following general formula (1).

In the above general formula (1), X represents a divalent organic group, and n represents an integer of 1 or more.

Also, this polyamic acid was obtained by reacting at least an acid anhydride represented by the following chemical formula (2) with two or more diamine compounds satisfying the following general formula (3) or (4): It is a thing.

In general formula (3) above, each Y is independently selected from an oxygen atom and a divalent organic group having 1 to 5 carbon atoms, at least one of which is an oxygen atom.
Examples of organic groups having 1 to 5 carbon atoms include methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, pentylene group and neopentylene group.
Each R ₁ is independently selected from an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of alkyl groups having 1 to 5 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group and neopentyl group.
Examples of halogenated alkyl groups having 1 to 5 carbon atoms include fluoromethyl group, fluoroethyl group, fluoropropyl group, difluoromethyl group, difluoroethyl group, difluoropropyl group, trifluoromethyl group, trifluoroethyl group and trifluoropropyl group. etc.
a is an integer of 0 to 3, preferably 0 or 1;
b is an integer from 0 to 4;
Examples of the compound satisfying general formula (3) include, but are not limited to, the following.

Among the compounds satisfying the general formula (3), the following compounds represented by the chemical formula (5) or (6) are preferable from the viewpoint of dissolution contrast, sensitivity and resolution of the photosensitive resin composition.

In the general formula (4), any one of R ₂ to R ₅ , preferably either R ₂ or R ₄ , is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. 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; is.
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 ₂ to R ₅ 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 preferred, and a phenyl group is particularly preferred from the viewpoint of the effect of suppressing the phenomenon of film reduction in unexposed areas.
Particularly preferably, either R ₂ or R ₄ is an aromatic group having 6 to 10 carbon atoms, and the other R ₂ to R ₅ are hydrogen atoms. Specific examples include the following compounds represented by the chemical formula (7). By using this compound, the dissolution contrast, sensitivity and resolution of the photosensitive resin composition can be further improved.

The diamine compound represented by the general formula (4) is obtained by reacting a compound represented by the following general formula (8) with a compound represented by the following general formula (9), and then reducing the nitro group. be able to.

In the general formula (8), Z represents a hydroxyl group or a halogen group selected from a fluoro group, a chloro group, a bromo group and an iodo group. Among these, a chloro group and a bromo group are preferable from the viewpoint of reactivity.
In the above general formula (9), R ₂ to R ₅ are as described above

When Z is a hydroxyl group, the reaction of the compounds represented by the general formulas (8) and (9) is performed using a dehydration condensing agent such as N,N'-dicyclohexylcarbodiimide (DCC) or p-toluenesulfonic acid. It is preferably carried out in the presence of an organic acid catalyst.
Moreover, when Z is a halogen group, the reaction of the compounds represented by the general formulas (8) and (9) is preferably carried out in the presence of an acid acceptor such as triethylamine.

The diamine compound represented by the general formula (4) is not limited to those synthesized by the above method, and commercially available ones may be used.

Acid anhydrides other than the acid anhydride represented by the above chemical formula (2) (hereinafter referred to as other acid anhydrides) can be used in the synthesis of the polyamic acid as long as the characteristics of the present invention are not impaired. .
For example, other acid anhydrides include pyromellitic anhydride, biphenyl-3,4,3′,4′-tetracarboxylic dianhydride, benzophenone-3,4,3′,4′-tetracarboxylic dianhydride, anhydride, diphenylsulfone-3,4,3′,4′-tetracarboxylic dianhydride, 4,4′-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, butane-1,2, 3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, cyclobutanetetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic acid dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3,5,6-tetracarboxylic dianhydride, 3-ethylcyclohexa-1- Ene-3-(1,2),5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3-(1,2),5,6-tetracarboxylic dianhydride, 1 -methyl-3-ethylcyclohex-1-ene-3-(1,2),5,6-tetracarboxylic dianhydride, 1-ethylcyclohexane-1-(1,2),3,4-tetra Carboxylic dianhydride, 1-propylcyclohexane-1-(2,3),3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1-(2,3),3-(2 ,3)-tetracarboxylic dianhydride, dicyclohexyl-3,4,3′,4′-tetracarboxylic dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid dianhydride, 1-propylcyclohexane-1-(2,3),3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1-(2,3),3-(2, 3)-tetracarboxylic dianhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6 - including tetracarboxylic dianhydride, etc.

Diamine compounds other than the diamine compounds represented by the general formulas (3) and (4) (hereinafter referred to as other diamine compounds) may be used in the synthesis of the polyamic acid as long as the characteristics of the present invention are not impaired. can be done.
For example, 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′-diamino Diphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4' -diaminobenzophenone, 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)-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-hexa Fluoropropane, 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-dimethyl benzyl]benzene, 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluoro phenoxy)-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-phenoxy Benzophenone, 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-biphenoxy benzophenone, 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- biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile and part of the hydrogen atoms on the aromatic rings in the above aromatic diamines, or Halogenated alkyl having 1 to 3 carbon atoms, all of which are halogen atoms, alkyl or alkoxyl groups having 1 to 3 carbon atoms, cyano groups, or alkyl or alkoxyl groups in which some or all of the hydrogen atoms of the alkyl or alkoxyl groups are substituted with halogen atoms 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- and aliphatic diamines such as nonamethylenediamine.

In a preferred embodiment, the polyamic acid having a repeating unit represented by the general formula (1) comprises an acid anhydride represented by the following chemical formula (2), a diamine compound represented by the following chemical formula (5), and the following chemical formula (6) It is a reaction product with a diamine compound represented by. Thereby, the dissolution contrast, sensitivity and resolution of the photosensitive resin composition can be further improved.
In addition to the diamine compounds represented by the following chemical formulas (5) and (6), a diamine compound represented by the following chemical formula (7) may also be used. Thereby, the dissolution contrast, sensitivity and resolution of the photosensitive resin composition can be further improved.

When the total content of structural units derived from the diamine component in the polyamic acid is 100 mol parts, the composition ratio of the diamine compound represented by the general formula (5) is 25 mol parts or more and 75 mol parts or less. It is preferably 45 mol parts or more and 65 mol parts or less, and particularly preferably 55 mol parts. Thereby, the sensitivity and resolution of the photosensitive resin composition can be further improved.
The proportion of the diamine compound represented by the general formula (6) is preferably 25 mol parts or more and 75 mol parts or less, more preferably 35 mol parts or more and 55 mol parts or less. Mole parts are particularly preferred. Thereby, the sensitivity and resolution of the photosensitive resin composition can be further improved.
Further, the composition ratio of the diamine compound represented by the general formula (7) is preferably 5 mol parts or more and 20 mol parts or less, more preferably 7 mol parts or more and 15 mol parts or less. Mole parts are particularly preferred. Thereby, the dissolution contrast, sensitivity and resolution of the photosensitive resin composition can be further improved.

In the present invention, the polyamic acid has an acid value (mgKOH/g) of 170 or more and 200 or less. Thereby, the dissolution contrast of the photosensitive resin composition can be significantly improved. More preferably, the polyamic acid has an acid value of 180 or more and 190 or less.
In the present invention, the acid value means a value measured by a method according to the method described in "JIS K 2501-2003 Petroleum and lubricating oils - Neutralization value test method".
Specifically, a sample is dissolved in a titration solvent in which xylene and dimethylformaldehyde are mixed at a mass ratio of 1:1, and titrated with a 0.1 mol/L potassium hydroxide/ethanol solution by potentiometric titration. The displacement point on the titration curve is defined as the end point, and the acid value is calculated from the amount of potassium hydroxide solution titrated to the end point.

In the present invention, the number average molecular weight (Mn) of the polyamic acid is preferably 2,000 or more and 50,000 or less, more preferably 4,000 or more and 25,000 or less. This can improve the solubility of the polyamic acid in an alkaline developer.
The weight average molecular weight (Mw) of the polyamic acid is preferably 4,000 or more and 100,000 or less, more preferably 8,000 or more and 50,000 or less. Thereby, a good cured film free from cracks can be obtained.
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.

The photosensitive resin composition of the present invention contains a polyamic acid as described above, which can significantly improve the dissolution contrast, sensitivity and resolution of the photosensitive resin composition.
In addition, the photosensitive resin composition of the present invention may contain two or more polyamic acids.

[(B) Photosensitizer]
The photosensitive resin composition of the present invention contains a photosensitive agent such as a photoacid generator, a photopolymerization initiator and a photobase generator. Among these, photoacid generators are preferred from the viewpoint of dissolution contrast.
The photosensitizer can be blended in a known and commonly used ratio. For example, the photoacid generator is 5 to 40 parts by weight, preferably 10 to 30 parts by weight, with respect to 100 parts by weight of polyamic acid. Blending is preferred.
In addition, the photosensitive resin composition may contain two or more kinds of photosensitive agents.

Photoacid generators are compounds that generate acids upon irradiation with light such as ultraviolet rays and visible light. Salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters, aromatic N-oxyimidosulfonates, 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 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.), and 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α ,α-dimethylbenzyl}phenol naphthoquinonediazide adducts (eg, TKF-428 and TKF-528 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.).

Photopolymerization initiators are compounds that generate radicals and the like upon irradiation with light such as ultraviolet rays and visible light. Phosphine oxide-based photopolymerization initiators and titanocene-based photopolymerization initiators are included.
Examples of commercially available oxime ester photopolymerization initiators include Irgacure OXE01 and Irgacure OXE02 manufactured by BASF Japan, N-1919 and NCI-831 manufactured by ADEKA.
Specific examples of α-aminoacetophenone-based photopolymerization initiators include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone and and N,N-dimethylaminoacetophenone, commercially available products of which include Omnirad 907, Omnirad 369 and Omnirad 379 manufactured by IGM Resins.
Specific examples of acylphosphine oxide photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and bis(2,6- dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and the like, and commercially available products thereof include Omnirad TPO manufactured by IGM Resins and Omnirad 819 manufactured by IGM Resins. be able to.
Specific examples of titanocene-based photopolymerization initiators include bis(cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadienyl)- bis(2,3,4,5,6 pentafluorophenyl) titanium and bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl) titanium, Commercially available products include Omnirad 784 manufactured by IGM Resins.

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.

[Other ingredients]
To the photosensitive resin composition of the present invention, as long as the effects of the present invention are not impaired, a known sensitizer for further improving photosensitivity, a silane coupling agent for improving adhesion to a substrate, etc. A known adhesion agent or the like may be blended.
Furthermore, 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, such as surfactants. , leveling agents, plasticizers, 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. Further, various colorants and fibers 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.
In addition, the photosensitive resin composition may contain two or more kinds of 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. In addition, 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. You can:

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 the photoacid generator as the photosensitizer (B), for example. 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, or the like, 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 exposed coating film is treated with a developer to remove the exposed portions of the coating film, thereby obtaining a pattern 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 rinse 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 ester group-containing polyimide precursor contained in the photosensitive resin composition is ring-closed to form a polyimide.

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 300° 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 polyamic acid A)
Into a 0.1-liter flask equipped with a stirrer and a thermometer, 40 g of N-methylpyrrolidone was charged, and 11.25 mmol of 4,4'-diaminodiphenyl ether (ODA) represented by the following chemical formula (5) and the following chemical formula ( 3.75 mmol of 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) shown in 6) was dissolved with stirring.
After that, 13.38 mmol of 4,4'-oxydiphthalic dianhydride (ODPA) represented by the following chemical formula (2) was added in 5 g portions over 30 minutes while stirring was continued at room temperature for 16 hours. of varnish. Polyamic acid A had a number average molecular weight (Mn) of 9,856, a weight average molecular weight (Mw) of 23,852, and Mw/Mn of 2.42.
The acid value of the resulting polyamic acid A was measured according to JIS K 2501-2003 and found to be 199 (mgKOH/g).

(Reference Example 2: Synthesis of polyamic acid B)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 9.75 mmol of ODA and 5.25 mmol of BAPP were dissolved with stirring.
Thereafter, 13.84 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a polyamic acid B varnish. Polyamic acid B had a number average molecular weight (Mn) of 10,475, a weight average molecular weight (Mw) of 25,454, and Mw/Mn of 2.43.
The acid value of the obtained polyamic acid B was measured in the same manner as in Reference Example 1 and found to be 192 (mgKOH/g).

(Reference Example 3: Synthesis of polyamic acid C)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 8.25 mmol of ODA and 6.75 mmol of BAPP were dissolved with stirring.
After that, 13.80 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a polyamic acid C varnish. Polyamic acid C had a number average molecular weight (Mn) of 10,579, a weight average molecular weight (Mw) of 24,966, and Mw/Mn of 2.36.
The acid value of the resulting polyamic acid C was measured in the same manner as in Reference Example 1 and found to be 185 (mgKOH/g).

(Reference Example 4: Synthesis of polyamic acid D)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 6.75 mmol of ODA and 8.25 mmol of BAPP were dissolved with stirring.
Thereafter, 13.76 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a polyamic acid D varnish. Polyamic acid D had a number average molecular weight (Mn) of 10,872, a weight average molecular weight (Mw) of 26,524, and Mw/Mn of 2.46.
The acid value of the obtained polyamic acid D was measured in the same manner as in Reference Example 1 and found to be 179 (mgKOH/g).

(Reference Example 5: Synthesis of polyamic acid E)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 5.25 mmol of ODA and 9.75 mmol of BAPP were dissolved with stirring.
Thereafter, 13.72 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a polyamic acid E varnish. Polyamic acid E had a number average molecular weight (Mn) of 9,720, a weight average molecular weight (Mw) of 26,147, and Mw/Mn of 2.69.
The acid value of the obtained polyamic acid E was measured in the same manner as in Reference Example 1 and found to be 173 (mgKOH/g).

(Reference Example 6: Synthesis of polyamic acid F)
Into a 0.1 liter flask equipped with a stirrer and a thermometer, 40 g of N-methylpyrrolidone was charged, and ODA 7.50 mmol, BAPP 6.00 mmol and (2-phenyl-4-aminophenyl) represented by the following chemical formula (7) )-4-aminobenzoate (PHBAAB) 1.50 mmol was dissolved with stirring.
Thereafter, 13.80 mmol of 4,4′-oxydiphthalic dianhydride (ODPA) was added as a solid in 5 g portions over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a polyamic acid F varnish. Polyamic acid F had a number average molecular weight (Mn) of 10,382, a weight average molecular weight (Mw) of 24,897, and Mw/Mn of 2.40.
The acid value of the resulting polyamic acid F was measured in the same manner as in Reference Example 1 and found to be 185 (mgKOH/g).

(Reference Example 7: Synthesis of polyamic acid a)
Into a 0.1-liter flask equipped with a stirrer and a thermometer, 40 g of N-methylpyrrolidone was charged, and 15.00 mmol of ODA was dissolved with stirring.
Thereafter, 13.98 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a varnish of polyamic acid a. The number average molecular weight (Mn) of polyamic acid a was 10,476, the weight average molecular weight (Mw) was 25,980, and Mw/Mn was 2.48.
The acid value of the obtained polyamic acid a was measured in the same manner as in Reference Example 1 and found to be 220 (mgKOH/g).

(Reference Example 8: Synthesis of polyamic acid b)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 15.00 mmol of BAPP was dissolved with stirring.
After that, 13.83 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a varnish of polyamic acid b. The number average molecular weight (Mn) of polyamic acid b was 10,952, the weight average molecular weight (Mw) was 26,613, and Mw/Mn was 2.43.
The acid value of the obtained polyamic acid b was measured in the same manner as in Reference Example 1 and found to be 156 (mgKOH/g).

(Reference Example 9: Synthesis of polyamic acid c)
A 0.1-liter flask equipped with a stirrer and a thermometer was charged with 40 g of N-methylpyrrolidone, and 8.25 mmol of ODA and 6.75 mmol of BAPP were dissolved with stirring.
After that, 18.83 mmol of 4,4'-biphthalic dianhydride (BPDA) represented by the following chemical formula (11) was added as a solid in 5 g increments over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain polyamic acid c. of varnish. The number average molecular weight (Mn) of polyamic acid c was 9,648, the weight average molecular weight (Mw) was 25,760, and Mw/Mn was 2.67.
The acid value of the obtained polyamic acid c was measured in the same manner as in Reference Example 1 and found to be 190 (mgKOH/g).

(Reference Example 10: Synthesis of polyamic acid d)
Into a 0.1-liter flask equipped with a stirrer and a thermometer, 40 g of N-methylpyrrolidone was charged, and 8.25 mmol of ODA and 4,4'-bis(4-aminophenoxy)biphenyl represented by the following chemical formula (12) were added. (4-APBP) 6.75 mmol was dissolved with stirring.
After that, 13.84 mmol of ODPA as a solid was added in portions of 5 g over 30 minutes, and stirring was continued at room temperature for 16 hours to obtain a varnish of polyamic acid d. Polyamic acid d had a number average molecular weight (Mn) of 9,510, a weight average molecular weight (Mw) of 25,772, and Mw/Mn of 2.71.
The acid value of the obtained polyamic acid d was measured in the same manner as in Reference Example 1 and found to be 191 (mgKOH/g).

<Example 1>
A photosensitive resin composition was obtained by mixing the alkali-soluble resin A obtained in Reference Example 1, a photosensitive agent, and a silane coupling agent having an arylamino group according to the following composition.
(Photosensitive resin composition composition)
・Polyamic acid A 100 parts by mass ・Photosensitizer 20 parts by mass (TKF-525, naphthoquinonediazide compound, manufactured by Sambo Chemical Industry Co., Ltd.)
・ Silane coupling agent 7 parts by mass (manufactured by Shin-Etsu Silicone Co., Ltd., KBM-573)

<Examples 2 to 7 and Comparative Examples 1 to 4>
A photosensitive resin composition was obtained in the same manner as in Example 1, except that the alkali-soluble resin was changed to one shown in Table 1.

<<Dissolution contrast evaluation>>
The photosensitive resin compositions obtained in the above Examples and Comparative Examples were applied onto a silicon substrate and heated at 120° C. for 4 minutes using a hot plate to form a dry coating film.
The dry coating film was irradiated with broad light through a patterned photomask using a high-pressure mercury lamp (with an i-line filter). Note that the exposure dose was 500 mJ/cm ² .
The dried coating film after exposure is developed using a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution at 25° C., and a development speed measuring device (RDA-790 manufactured by Litho Tech Japan Co., Ltd.) is used. Then, the dissolution rate of the dried coating film in the exposed and unexposed areas was measured.
The dissolution rate (μm/min)=reduced film thickness (μm)/development time (min). In the formula, the reduced film thickness means the difference in the thickness of the dry coating film before and after development, and the development time means the time during which the dry coating film is immersed in the aqueous TMAH solution.

The ratio of the dissolution rate of the exposed area to the dissolution rate of the unexposed area (dissolution rate of unexposed area/dissolution rate of exposed area) was calculated and evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1 together with the numerical values of the ratios.
(Evaluation criteria)
⊚: The dissolution rate ratio was 10 or more.
A: The dissolution rate ratio was 7 or more and less than 10.
○: The dissolution rate ratio was 3 or more and less than 7.
x: The dissolution rate ratio was less than 3.

<<Sensitivity evaluation>>
The photosensitive resin compositions obtained in the above Examples and Comparative Examples were applied on a silicon substrate with a spin coater, and dried by heating at 120° C. for 4 minutes with a hot plate to form a dry coating film of the photosensitive resin composition. formed.
The dry coating film was irradiated with broad light through a patterned photomask using a high-pressure mercury lamp (with an i-line filter). The exposure dose was increased by 50 mJ/cm ² in the range of 0 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.
In Comparative Examples 1 to 3, since the dissolution contrast was low and pattern formation could not be performed, the sensitivity could not be evaluated and was indicated as "-".
(Evaluation criteria)
A: The minimum exposure amount was 300 mJ/cm ² or less.
Good: The minimum exposure dose was greater than 300 mJ/cm ² and less than or equal to 500 mJ/cm ² .
x: The minimum exposure dose was greater than 500 mJ/cm ² .

<<Resolution Evaluation>>
The photosensitive resin compositions obtained in the above Examples and Comparative Examples were applied on a silicon substrate with a spin coater, and dried by heating at 120° C. for 4 minutes with a hot plate to form a dry coating film of the photosensitive resin composition. formed.
The dried coating film was irradiated with broad light from a high-pressure mercury lamp (with an i-line filter) through a photomask having a square pattern of 50 μm on a side. Note that the exposure dose was set to 25 mJ/cm ² .
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 length of one side of the square pattern was reduced by 5 μm, and when observed with an electron microscope (SEM “JSM-6010”), no collapse or residue was observed, and the limit of forming a good pattern was reached. The length of one side was defined as the resolution, and evaluation was made according to the following evaluation criteria. The evaluation results are summarized in Table 1.
In Comparative Examples 1 to 3, since the dissolution contrast was low and pattern formation could not be performed, the sensitivity could not be evaluated and was indicated as "-".
(Evaluation criteria)
A: A square pattern having a side of 10 µm or less was able to be formed.
Good: A square pattern with a side of 10 μm or less could not be formed, but a square pattern with a side of 10 μm or less and 20 μm or less could be formed.
x: A square pattern with a side of 20 μm or less could not be formed.

As is clear from the evaluation results shown in the table above, it was confirmed that the photosensitive resin composition obtained in each example had high dissolution contrast, sensitivity and resolution.
In particular, in Examples 3 and 6, in which the polyamic acid had an acid value (mgKOH/g) of 180 or more and 190 or less, it was confirmed that the dissolution contrast was particularly excellent.

Claims (5)

(A) an alkali-soluble resin and (B) a naphthoquinonediazide compound ,
The alkali-soluble resin has a repeating unit represented by the following general formula (1), has an acid value (mgKOH/g) of 170 or more and 200 or less, and is at least an acid represented by the following chemical formula (2) A polyamic acid obtained by reacting an anhydride with a diamine compound represented by the following general formulas (5) and (6), or a diamine compound represented by general formulas (5), (6) and (7) A photosensitive resin composition characterized by:

(In general formula (1),
X is a divalent organic group,
n is an integer of 1 or more. )

Claim 1, wherein the diamine compound contains a diamine compound represented by the general formula (5) in a range of 35 to 75 mol% and a diamine compound represented by the general formula (6) in a range of 25 to 65 mol%. The photosensitive resin composition according to . A dry film comprising a resin layer formed from the photosensitive resin composition according to claim 1 or 2 on the film. A cured product formed from the photosensitive resin composition according to claim 1 or 2 or the resin layer of the dry film according to claim 3 . An electronic component comprising the cured product according to claim 4 as a forming material.