JPH0148299B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyamide-imide-based curable material that cures in response to radiation such as light and electron beams, and is particularly characterized by being photosensitive.

In recent years, there has been a high demand for curable materials that can be cured by light, electron beams, etc. to provide heat-resistant substances, and are mainly used as protective materials, insulating materials, solder resists, adhesives, coating materials, etc. in the electrical and electronic fields. It is also being applied as a heat-resistant photoresist in semiconductor devices.

This type of curable material not only requires good radiation sensitivity properties and excellent heat resistance after sensitive curing, but also exhibits good adhesion to adherends. Also, insulation properties,
It is also desired that the material satisfies various properties such as moisture resistance and chemical resistance. On the other hand, it is desired that the material has excellent storage stability without problems such as gelation over time in a solvent-free or organic solvent-containing state before sensitive curing with radiation.

However, there are few conventionally known curable materials that satisfy all of these required properties. Generally, materials with excellent radiation sensitivity tend to have poor storage stability, and many also lack adhesive strength to adherends.

For example, a photocurable heat-resistant photoresist is made by blending dichromate with polyamic acid that has not been completely imidized by reacting a polyimide precursor, that is, an aromatic tetracarboxylic acid component with a diamine. Are known. However, this type of material has extremely poor storage stability and must be used immediately after mixing the polyimide precursor and dichromate, which has major limitations on industrial application. Furthermore, since inorganic ions are included in the hardened material, its reliability is impaired when it is applied to semiconductor applications.

In addition, as another known heat-resistant photoresist, 2 mol of aromatic tetracarboxylic dianhydride is used.
There is a polyimide precursor made by reacting moles of allyl alcohol, then chlorinating two free carboxyl groups, and then condensing it with a diamine. However, this type of material also has problems in terms of storage stability, and the above condensation reaction removes chlorine ions, which are then included in the cured resist, so its reliability is still high for semiconductor applications. There was a risk of damage to sex.

From this point of view, the present invention aims to provide a radiation-sensitive polyamideimide-based curable material that satisfies all of the above-mentioned required properties, as being essentially different from the conventionally known curable materials as described above. The gist of this is that a dibasic acid or its derivative having at least one radiation-sensitive carbon-carbon double bond is used together with an aromatic tricarboxylic acid or its derivative as a polybasic acid component. It is a radiation-sensitive polyamide-imide-based curable material mainly composed of organic solvent-soluble polyamide-imide synthesized by

Thus, in the present invention, an aromatic tricarboxylic acid or a derivative thereof is used and reacted with a difunctional nitrogen-containing compound such as a diamine or diisocyanate to form the following structural formula: (However, in the formula, Y represents a trivalent aromatic group and R ₁ represents a divalent organic group.) In addition to the above-mentioned aromatic tricarboxylic acids or derivatives thereof, a dibasic acid having at least one radiation-sensitive carbon-carbon double bond or a derivative thereof is used, and this is reacted with a difunctional nitrogen-containing compound. The following structural formula; (In the formula, X is a divalent organic group having at least one radiation-sensitive carbon-carbon double bond, and R ₁ is a divalent organic group.) An organic solvent-soluble polyamide-imide having the above-mentioned amide structure as a repeating unit as well as the amide-imide structure represented by the above-mentioned structural formula (1) in its molecular skeleton was synthesized by This material was found to be extremely suitable as a magnetic material. That is, the above-mentioned polyamide-imide contains at least one radiation-sensitive carbon-carbon double bond in the X group of the amide structure represented by the structural formula (2), so it is sensitive to a type of radiation. It can be cured very well with an electron beam as
Depending on the type of group, it can be photocured in a short time by light such as ultraviolet light with or without the use of photosensitizers.

In addition, the product cured in this way exhibits excellent heat resistance due to the amide bonds and imide bonds contained in the molecular skeleton of polyamide-imide, and also has good adhesion to adherends, for example, compared to conventional Curable materials require etching of the surface of the adherend to improve adhesion, but practical adhesive strength can be obtained without such treatment, and in addition, the insulation properties and Various properties such as moisture resistance and chemical resistance can also be fully satisfied.

On the other hand, as mentioned above, polyamide-imide before being cured by radiation is a very good material that does not gel in a short period of time even if it is left at room temperature in a solvent-free or organic solvent-containing state. It exhibits storage stability, and in this respect also has the advantage that, unlike the conventionally known photocurable heat-resistant photoresists, there are no major restrictions on industrial application.

In order to synthesize the organic solvent-soluble polyamideimide having the above-mentioned characteristics in the present invention, for example, the aromatic tricarboxylic acid or its derivative can be prepared by the following general formula; (However, in the formula, Y represents a trivalent aromatic group.) This and the following general formula; HOOC-X-COOH...(4) (However, in the formula, , X represents a divalent organic group having at least one radiation-sensitive carbon-carbon double bond) and a dibasic acid represented by the following general formula; OCN-R ₁ -NCO...(5 ) (wherein R ₁ represents a divalent organic group) It may be reacted with a diisocyanate compound represented by the following formula.

Typical aromatic monoanhydrides represented by the above general formula (3) include trimellitic anhydride and hemimellitic anhydride.
Other aromatic anhydrides may also be used. In addition,
In addition to the amide-imide structure represented by the above structural formula (1), an aromatic or aliphatic dianhydride may be used in combination with these aromatic anhydrides as necessary to form a heat-resistant structure in the molecular skeleton. , an amic acid structure derived from a dianhydride can also be introduced. However, the proportion used should be 5% by weight or less based on the total amount of the aromatic anhydride, and using too much is not desirable because it may adversely affect storage stability and other properties.

Specific examples of the aromatic or aliphatic dianhydrides include pyromellitic anhydride, benzophenone-3,4',3,4'-tetracarboxylic dianhydride, and naphthalene-2,3,6,7 -tetracarboxylic dianhydride, perylene-2,3,9,10-tetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,2',3 ，
3′-diphenyltetracarboxylic dianhydride, 2,
2-bis(3,4-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, Examples include ethylenetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic dianhydride.
These can be used alone or in combination of two or more.

In the dibasic acid represented by the general formula (4), the radiation-sensitive carbon-carbon double bond contained therein is
Depending on whether it is particularly sensitive to radiation such as ultraviolet rays, dibasic acids with relatively low photosensitivity (hereinafter referred to as group A dibasic acids) and those with relatively low photosensitivity are classified. They can be broadly classified into highly dibasic acids (hereinafter referred to as group b dibasic acids).

Examples of the group a dibasic acids include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, chlorinated maleic acid, and diphenylmethane-di-γ-ketocrotonic acid-4,4'. Also b
Group dibasic acids include 4-carboxycinnamic acid, 3-carboxycinnamic acid, cinnamylidenemalonic acid, m-phenylene diacrylic acid, 0-phenylene diacrylic acid, and the like.

The above dibasic acids may be used alone or in combination of two or more. When two or more types are used together, they may be selected from either group a dibasic acids or group b dibasic acids, or they may be used in an appropriate combination from both groups dibasic acids. can. Furthermore, the inventors have discovered p-phenylene diacrylic acid as a particularly effective dibasic acid among the above-mentioned group b dibasic acids, and although a separate application for this is pending, in this invention, Also included are systems in which such dibasic acids are used in combination with the various dibasic acids described above.

The dibasic acid represented by the general formula (4) as described above usually accounts for 5 to 80% of the total amount of the aromatic anhydride (or this and aromatic or aliphatic dianhydride). It is used in a proportion of mol %, preferably 10 to 60 mol %. If this amount is too large, it will become difficult to synthesize polyamideimide with a high degree of condensation through a polycondensation reaction with a diisocyanate compound, resulting in a loss of film-forming ability, and properties such as heat resistance may also be impaired. On the other hand, if it decreases too much, the radiation sensitivity characteristics will deteriorate.

Note that up to 95 mol%, preferably up to 50 mol% of the dibasic acid represented by general formula (4) may be replaced with another dibasic carboxylic acid. When such a dibasic carboxylic acid is used in combination, in addition to the amide structure represented by the above structural formula (2), an amide bond based on the above dibasic carboxylic acid is introduced into the molecular skeleton. .

As the other dibasic carboxylic acids mentioned above, aromatic ones are preferred, but aliphatic or alicyclic carboxylic acids can also be used in combination within a range of 10 mol% or less. Specific examples of aromatic dibasic carboxylic acids include isophthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, methyl isophthalic acid, and methyl. Terephthalic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-2-
3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, etc. can be mentioned. Examples of aliphatic or alicyclic dibasic carboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malonic acid,
3,9-bis(2-carboxyethyl)-2,
Examples include 4,8,10-tetraoxaspiro[5,5]undecane.

The diisocyanate compound represented by the general formula (5) is preferably an aromatic one, but an aliphatic or alicyclic one may be used in combination in an amount of 10 mol % or less. Specific examples of aromatic diisocyanate compounds include dianiridine diisocyanate, bistolylene diisocyanate, naphthalene diisocyanate, m-(or P-)phenylene diisocyanate, 2,4-
(or 2,6-)tolylene diisocyanate,
Diphenyl ether diisocyanate, diphenylmethane diisocyanate, m- (or P-)
Examples include xylidene diisocyanate. Also,
Examples of aliphatic or alicyclic diisocyanate compounds include methylcyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isopropylidene bis(4-cyclohexyl isocyanate), dicyclohexyl ether diisocyanate, and hexamethylene diisocyanate.

A polybase consisting of the above diisocyanate compound, the above aromatic anhydride (or this and dianhydride), and the dibasic acid represented by general formula (4) (or this and other dibasic carboxylic acid) The proportion of the diisocyanate compound to be used is generally equimolar to 10 mol % or less of the diisocyanate compound.

The reaction between the polybasic acid component and the diisocyanate compound in such proportions is preferably carried out by heating in an organic solvent. As the organic solvent, one that can dissolve at least one of the two components and is inert to both components is used. Preferably, one that can dissolve both components and dissolve the reaction product polyamideimide is used. do. Examples of preferred solvents include N-methyl-2-
Examples include pyrrolidone, dimethylacetamide, dimethylformamide, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfolamide, methylformamide, formamide, and N-acetyl-2-pyrrolidone. These organic solvents may be used alone or in combination of two or more. Further, if desired, a non-polar solvent such as benzene, toluene, xylene, chlorobenzene, naphtha, etc. may be used in combination with these polar solvents.

The amount of organic solvent used is not particularly limited as long as polyamideimide having film-forming ability is obtained, but generally, the concentration of polyamideimide is 10 to 60%.
It may be used in a proportion of % by weight.

The reaction temperature and reaction time vary depending on the type of polybasic acid component, diisocyanate compound, and organic solvent used, but are usually 80 to 120°C.
The reaction temperature may be raised to 160 to 200° C. and the reaction may be carried out until the intrinsic viscosity of the produced polyamide-imide reaches a desired value.

The intrinsic viscosity of the produced polyamideimide is N
-C=0.5 at 30°C in methyl-2-pyrrolidone
The viscosity ηinh in g/100ml is usually in the range of 0.1 to 1.5, particularly preferably in the range of 0.2 to 1.0. If the intrinsic viscosity is too low, the film-forming ability will be poor and practicality will be poor.

The organic solvent-soluble polyamideimide of the present invention can be advantageously synthesized by the method described above, but it can also be synthesized by other methods. For example, there is a method in which a diamine compound as another difunctional nitrogen-containing compound is used in place of the diisocyanate compound in the above-mentioned method.

In the method using a diamine compound, an aromatic tricarboxylic acid anhydride monohalide is used, and a dibasic acid represented by the general formula (4) or other dibasic carboxylic acid used as necessary is used. Each free carboxyl group is halogenated in advance,
It is desirable to involve the reaction with a diamine compound after that. This is because it is difficult to synthesize polyamideimide with a high degree of condensation through reaction with a diamine compound if the free carboxyl group remains as it is. but,
According to this method, halogen ions are released by reaction with the diamine compound, which may impose restrictions on the use of the material as a curable material. On the other hand, such a problem does not occur in the method using the diisocyanate compound.

The curable material of the present invention is mainly composed of an organic solvent-soluble polyamideimide synthesized by the method described above, and when it is cured using an electron beam as radiation, the curable material expressed by the general formula (4) is Regardless of the type of dibasic acid containing at least one radiation-sensitive carbon-carbon double bond, it is possible to irradiate it with an electron beam without using a sensitizer or the like. Therefore, it has the characteristic of being able to cure quickly.

Furthermore, even in the case of curing using light such as ultraviolet rays as the radiation, when the dibasic acid represented by the general formula (4) consists mainly of a group B dibasic acid, the same method as above is applied. It can be sufficiently cured by ultraviolet irradiation without using a photosensitizer. On the other hand, if the dibasic acid is a
When the composition is mainly composed of a group dibasic acid, a practical curing speed can be obtained by adding a photosensitizer to the polyamideimide.

As the above-mentioned photosensitizer, a wide range of conventionally known ones can be used, including carbonyl compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl, benzyl dimethyl ketal, and organic compounds such as benzyl sulfide. These include sulfur compounds, halogen compounds, and photoreducible dyes. When using a photosensitizer, the amount used is
The amount may be 10 parts by weight or less per 100 parts by weight. In addition,
Of course, such a photosensitizer may be incorporated when curing with electron beams or when using a group b dibasic acid.

In addition to the above-mentioned photosensitizer, a peroxide can be added to the curable material of the present invention, if necessary. Specific examples include benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl perbenzoate, dicumyl peroxide,
Examples include organic peroxides such as azobisisobutyronitrile. When such a peroxide is used, heat resistance after curing can be further improved by further post-heating treatment after radiation curing. The amount used may be about 0.5 to 5 parts by weight per 100 parts by weight of polyamideimide.

In addition, as another optional component, monofunctional or polyfunctional monomers having double bonds, which are reactive diluents for ultraviolet curable or electron beam curable resins, may be added within a range that does not reduce heat resistance. You may. Even if the various optional components mentioned above are added, the storage stability characteristic of this type of material will not be impaired.

As mentioned above, the curable material of this invention has excellent storage stability, but when storing it for a long period of time, it must be stored in a dark room or in a cold room, taking into account its photosensitivity. It is advisable to save it.

On the other hand, in use, the above-mentioned material is applied to an adherend using a bar coater, applicator, spinner, etc., dried under appropriate conditions, and then cured by irradiation with radiation. If necessary, by performing post-heat treatment to further improve heat resistance and adhesion, we can create a cured film with excellent properties such as heat resistance, adhesion, insulation properties, moisture resistance, and chemical resistance. Can be formed. Also, when masking irradiation is performed during this curing work,
After the above-mentioned curing, a desired pattern in which only the cured portion remains can be formed by developing with a solvent that dissolves the uncured polymer.

Next, examples of this invention will be described. In the following, parts and % mean parts by weight and % by weight, respectively.

Example 1 13.44 g (0.07 mol) of trimellitic anhydride, 3.48 g (0.03 mol) of fumaric acid, 26.46 g (0.105 mol) of diphenyl ether diisocyanate and N-
111 g of methyl-2-pyrrolidone was placed in a 300 ml four-necked flask, heated to 120°C to start the reaction, continued at the same temperature for 3 hours to sufficiently release carbon dioxide gas, and then heated to 160°C. The reaction continued for 1 hour.

The viscosity ηinh (C=0.5g/100ml, in N-methyl-2-pyrrolidone at 30°C) of the polyamideimide thus obtained was 0.32. 5 parts of benzoin isobutyl ether was blended with 100 parts of this polyamideimide, and N-methyl-
A 2-pyrrolidone solution was prepared to form the curable material of this invention.

This material was subjected to the following storage stability test and photocurability test.

A. Storage stability test The curable material was left at room temperature to examine changes in properties over time. As a result, no gelation occurred even after 3 months, and no changes in properties were observed visually.

B Photo-curing test A curable material was coated onto the adherend using a bar coater to a dry thickness of 10μ, and heated at 100°C.
It was heated and dried for 30 minutes. Next, pattern mask the above coating surface and calculate the input per unit length.
Using two high-pressure mercury lamps with an output of 80 W/cm and a lamp output of 1 KW, the material was irradiated from a distance of 15 cm at a speed of 1 m/min for photocuring. After photocuring, the coating was immersed in N-methyl-2-pyrrolidone for 30 minutes at room temperature, and the masked areas were dissolved and disappeared, but the cured areas that were not masked remained as they were, leaving a clear pattern. Been formed.

On the other hand, in the above test, the entire coating film was photocured without a pattern mask, and the photocured film was subjected to a thermal decomposition test in nitrogen at a heating rate of 10°C/min, and the weight loss was determined from the thermal decomposition curve. When we investigated the temperature when the temperature was 10%, we found that it was 360℃.
Further, the following heat resistance and adhesion tests were conducted and the results were as follows.

<Heat resistance> For those using copper foil as the adherend, 100
℃ and 150℃ for 120 hours, and the cured film was examined to see if there were any abnormalities such as deterioration or peeling, but no abnormalities were observed at either temperature.

<Adhesion> For adherends such as copper foil, polyester film, glass, aluminum plate, stainless steel plate, Kapton film, nickel plated plate, aluminum plated plate, etc., cross-cut the cured film into a 2 mm square and apply Nitto Electric Co., Ltd. After pressing No. 29 cellophane tape manufactured by Kogyo Co., Ltd., it was rapidly peeled off and the number of peeled pieces in 100 cross-cuts was determined. The results were all 0/100 except for the stainless steel plate which was 50/100.

The stainless steel plate was further heat-treated at 200° C. for 30 minutes after photo-curing, resulting in 5/100 pieces.

Example 2 The polyamideimide obtained in Example 1 was prepared as a 30% solution of N-methyl-2-pyrrolidone without adding benzoin isobutyl ether, and used as the curable material of the present invention without adding benzoin isobutyl ether. A linear hardenability test was conducted.

<Electron beam curing test> The above material was coated onto the adherend using a bar coater to a dry thickness of 10 μm, and after heating and drying at 100°C for 30 minutes, an electron beam was applied at an accelerating voltage.
It was irradiated and cured at 1.3 MeV with an absorbed dose of 10 Mrad. Below, various properties were investigated using the same procedure as the photocuring test described in Example 1, and all the properties of pattern development, heat resistance, and adhesion were as good as when photocuring. .

Example 3 100 parts of the polyamideimide obtained in Example 1,
N,N′-diphenylmethane-bismaleimide 30
1 part and 5 parts of benzoin isopropyl ether were added, and these were dissolved in N-methyl-2-pyrrolidone by heating to a solid content of 30% to obtain the curable material of the present invention.

When this material was subjected to the same storage stability test as in Example 1, no changes in properties such as an increase in viscosity were visually observed even after 3 months had passed. Further, when the same photo-curing test as in Example 1 was carried out, a clear cured pattern could be formed, the heat resistance was good, and the 10% weight loss temperature was 390°C, and the adhesion was 5/100.

Example 4 The number of moles of trimellitic anhydride used was 0.06 mole,
While reducing the number of moles of fumaric acid used to 0.037 moles,
Polyamideimide was synthesized in the same manner as in Example 1, except that 0.003 mol of pyromellitic anhydride was used as the polybasic acid component other than these. ηinh of this polyamideimide (C=0.5g/100ml, N-
(30°C) in methyl-2-pyrrolidone was 0.35. 5 parts of benzoin isobutyl ether was blended with 100 parts of this polyamideimide, and N with a solid content of 30% was added.
-Methyl-2-pyrrolidone solution was prepared to form the curable material of this invention.

When this material was subjected to the same photocuring test as in Example 1, it was possible to form a clear cured pattern, and the heat resistance was also good, with a 10% weight loss temperature of 370
℃, adhesion was 0/100.

Example 5 Diphenylmethane diisocyanate instead of 0.105 mol of diphenyl ether diisocyanate
Polyamideimide was synthesized in the same manner as in Example 1 except that 0.105 mol was used. The ηinh (same as above) of this polyamideimide was 0.41.
5 parts of benzoin isobutyl ether was blended with 100 parts of this polyamide-imide to prepare an N-methyl-2-pyrrolidone solution with a solid content of 30% to prepare the curable material of the present invention.

When this material was subjected to the same photocuring test as in Example 1, it was possible to form a clear cured pattern, and the heat resistance was also good, with a 10% weight loss temperature of 375
℃, adhesion was 0/100.

Example 6 The number of moles of trimellitic anhydride used was 0.05 mole,
While the number of moles of fumaric acid used is 0.03 moles, terephthalic acid is used as a polybasic acid component other than these.
except that 0.02 mole was used and 0.107 mole of diphenylmethane diisocyanate was used instead of 0.105 mole of diphenyl ether diisocyanate.
Polyamideimide was synthesized in the same manner as in Example 1. ηinh of this polyamideimide (same as above)
was 0.35. To 100 parts of this polyamideimide,
Add 5 parts of benzoin isopropyl ether and add this to N-methyl-2-pyrrolidone to a solids content of 30%.
The curable material of the present invention was obtained by heating and melting to obtain the following.

When this material was subjected to the same photocuring test as in Example 1, it was possible to form a clear cured pattern, and the heat resistance was also good, with a 10% weight loss temperature of 357
℃, adhesion was 0/100.

Example 7 Polyamideimide was synthesized in the same manner as in Example 1, except that 0.03 mol of 4-carboxycinnamic acid was used instead of 0.03 mol of fumaric acid. The ηinh (same as above) of this polyamideimide is 0.46,
The reaction solution containing this polyamideimide was used as the curable material of the present invention.

When this material was subjected to the same photocuring test as in Example 1, it was possible to form a clear cured pattern, and the heat resistance was also good, with a 10% weight loss temperature of 412
℃, adhesion was 0/100.

Example 8 Polyamideimide was synthesized in the same manner as in Example 1, except that the number of moles of trimellitic anhydride used was 0.05 mole and 0.05 mole of m-phenylene diacrylic acid was used instead of 0.03 mole of fumaric acid. did. The ηinh (same as above) of this polyamide-imide was 0.42, and a reaction solution containing this polyamide-imide was used as the curable material of the present invention.

When this material was subjected to the same photo-curing test as in Example 1, it was possible to form a clear cured pattern, and the heat resistance was also good, with a 10% weight loss temperature of 432
℃, adhesion was 0/100.

Claims (1)

[Scope of Claims] 1. A radiation-sensitive carbon compound as a polybasic acid component together with an aromatic tricarboxylic acid or a derivative thereof.
An organic solvent-soluble compound synthesized by using a dibasic acid or its derivative having at least one carbon double bond in combination in a ratio of 5 to 80 mol% of the latter dibasic acid or its derivative in the total amount of both. A radiation-sensitive polyamide-imide-based curable material containing a photosensitizer in an amount of 0 to 10 parts by weight based on 100 parts by weight of the polyamide-imide. 2. The dibasic acid having at least one radiation-sensitive carbon-carbon double bond is maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, chlorinated maleic acid, diphenylmethane di-
The radiation-sensitive polyamideimide-based curable material according to claim 1, which comprises a dibasic acid having relatively low photosensitivity such as γ-ketocrotonic acid-4,4'. 3. The dibasic acid having at least one radiation-sensitive carbon-carbon double bond is 4-carboxycinnamic acid, 3-carboxycinnamic acid, cinnamylidenemalonic acid, m-phenylene diacrylic acid. ,o
- The radiation-sensitive polyamideimide-based curable material according to claim 1, which comprises a dibasic acid with high photosensitivity such as phenylene diacrylic acid. 4. The radiation-sensitive polyamide-imide curing according to any one of claims 1 to 3, which is made by blending a peroxide with an organic solvent-soluble polyamide-imide or a mixture thereof and a photosensitizer. sexual material.