CN105301906B - Positive photosensitive polyimide resin composition - Google Patents

Abstract

The invention discloses a positive photosensitive polyimide resin composition, which contains (a) alkali-soluble polyimide, (b) photosensitizer and (c) crosslinking agent; said (c) The crosslinking agent is composed of one or two of benzoxazine compounds and compounds with more than two epoxy groups in one molecule in any proportion; the (a), (b), (c) The weight percentage is 100:10～50:5～20; the present invention uses 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane or 2,2-bis[4- (5-amino-2-pyridyloxy) phenyl] propane, 3,3-di-tert-butyl benzidine, and siloxane diamine are used as diamine components to prepare alkali-soluble polyimide resins, and the prepared positive photosensitive The permanent resin composition has high transmittance, low thermal expansion coefficient, high heat resistance and excellent photosensitive performance.

Description

Positive photosensitive polyimide resin composition

technical field

The present invention relates to a photosensitive polyimide resin composition, in particular to a photosensitive polyimide resin composition that can be positively developed in an alkaline aqueous solution and is soluble in commonly used organic solvents such as amides and lactones and a positive-type photosensitive resin composition suitable for protective layers of flexible printed circuit boards, surface protective films of semiconductor elements, interlayer insulating films, and insulating layers of organic electroluminescent elements.

Background technique

Photosensitive polyimide, which is a polymer material with dual properties of light sensitivity and heat resistance, is widely used in flexible printed circuit boards and integrated circuits due to its unique properties. With the miniaturization of various electronic products in life, various smart phones, thin TVs and high-performance microprocessors are flooding today's life, flexible printed circuit boards are developing in the direction of ultra-thin and ultra-dense and large-scale integration The upgrading of circuits is gradually accelerating, and at the same time, higher requirements are put forward for the performance of photosensitive polyimide. Because the traditional polyimide is formed by the imidization of aromatic tetracarboxylic acid and aromatic diamine, it has the disadvantages of solubility and processing difficulties, which limits its further application.

Many researchers have improved their solubility and processing properties by introducing special groups into the polyimide skeleton, such as introducing phenolic hydroxyl groups, hydroxyl groups, carboxyl groups, fluorine groups, sulfonic acid groups, etc. into the main chain or side chains. group. US Patent No. 8,859,170 B2 discloses a photosensitive polyimide resin composition with excellent heat resistance, electrical properties and other properties prepared by introducing groups such as hydroxyl groups, carboxyl groups, and carbonic acid groups into the main chain of polyimide. Japanese Patent Laying-Open Hei discloses a photosensitive polyimide resin composition whose solubility is improved by introducing carboxyl groups and ester bonds during the synthesis of polyamic acid. However, the photosensitive polyimide resin compositions disclosed above all have the disadvantages of unstable development time and poor adhesion in the development using aqueous alkali solution.

At the same time, Japanese Patent Application Publication No. 2004-263058 and U.S. Patent No. 7,579,134B2 also found that replacing a part of the aromatic diamine with siloxane diamine, and introducing a siloxane skeleton into the polyimide skeleton can impart aromatic Excellent flexibility and adhesiveness of family polyimide resin. Although the introduction of siloxane groups in the polyimide skeleton can endow the aromatic polyimide resin with excellent flexibility and adhesiveness, it also brings about the same effect of making the aromatic polyimide resin Disadvantages such as Tg drop. In recent years, studies have found that the introduction of diamines containing tert-butyl groups into the backbone of aromatic polyimides can make polyimides have good solubility and effectively improve the Tg temperature and thermal stability of polyimides. .

Zhao Xiaogang et al. introduced pyridine groups into the polyimide skeleton and found that the introduction of pyridine groups had no effect on the excellent performance of aromatic polyimide itself, and made its solubility, processability and optical properties significantly improved. This is due to the greater polarity of the pyridine molecule and the fact that the unshared electron pair on the pyridine nitrogen atom can form hydrogen bonds with water. In addition, the hydrocarbon group in the pyridine structure makes it have a considerable affinity with organic molecules, and the unshared electron pairs on the nitrogen atom can form complexes with some metal ions such as Ag, Ni, Cu, etc., resulting in better adhesion. In addition, in the pyridine ring, the nitrogen atom has both an electron-withdrawing inductive effect and an electron-withdrawing conjugation effect, which can endow polyimide with good optical properties.

In view of this, in order to improve the above problems, it is necessary to develop a photosensitive resin composition material with better performance in heat resistance, flexibility, flexibility, electrical properties, and optical properties.

Contents of the invention

The purpose of the present invention is to develop a new type of photosensitive polyimide with excellent performance by introducing pyridine units or 3,3-di-tert-butyl benzidine and siloxane diamine into the alkali-soluble polyimide skeleton. The imine resin composition can be used in many high-tech fields requiring high transmittance, low thermal expansion coefficient and high heat resistance. The flexible printed circuit board protective layer is a protective layer obtained by forming a film of a photosensitive polyimide resin composition on a printed wiring board, forming a pattern, and curing.

The inventors found that using 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane or 2,2-bis[4-(5-amino-2-pyridyloxy)benzene Base] propane, 3,3-di-tert-butyl benzidine, and siloxane diamine are used as diamine components to prepare alkali-soluble polyimide resins, and the content of photosensitizers and crosslinking agents can be further mixed to obtain excellent performance. The above object can be achieved by using the photosensitive polyimide resin composition, and the present invention has been completed.

That is, the present invention provides a photosensitive polyimide resin composition containing: tetracarboxylic dianhydride, 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoro Propane or 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]propane, 3,3-di-tert-butylbenzidine, siloxanediamine and no pyridine units, 3,3 - 100 parts by mass of alkali-soluble polyimide resin obtained by diamine imidization of di-tert-butylbenzidine and siloxane, the content of photosensitizer is 10 to 50 parts by weight, and there are two or more in one molecule The content of epoxy groups and benzoxazine compounds is 5-20 parts by weight.

The object of the present invention is achieved through the following technical solutions: the present invention uses 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane or 2,2-bis[4-( 5-amino-2-pyridyloxy)phenyl]propane, 3,3-di-tert-butylbenzidine, and siloxane diamine are used as diamine components to prepare alkali-soluble polyimide resins, and further compound photosensitizers therein And the content of the crosslinking agent can obtain the photosensitive polyimide resin composition with excellent performance. The composition of the present invention contains (a) alkali-soluble polyimide, (b) photosensitizer and (c) crosslinking agent; One or two of the above epoxy-based compounds are composed in any proportion;

The weight percentage of (a), (b) and (c) is 100:10～50:5～20; wherein, (a) the alkali-soluble polyimide is composed of the polyimide unit of formula (1), And any polyimide unit in formula (2), formula (3), formula (4) or any two polyimide units according to any ratio or three kinds of polyimide units according to any ratio Composition; the polyimide unit of formula (1) accounts for 80～99 mol% of total polyimide unit;

In the formulas (1) to (4), X and A are independently a divalent organic group with a single bond; R is a hydroxyl group or a sulfonic acid group; Y represents a bis(trifluoromethyl) of a divalent organic group. group) methylene, dimethylmethylene; R ₁ is an alkylene group with 3-9 carbon atoms; R ₂ , R ₃ , R ₄ and R ₅ are independently independently an alkylene group with 1-8 carbon atoms An alkyl group or an aromatic group; m represents an integer of 2 or more.

Further, the 2-valent organic group of X in the formula (1) is two (trifluoromethyl) methyl, carbonyl, dimethylmethylene, oxygen atom, and the 2-valent organic group of A is two ( Trifluoromethyl) methyl, sulfo, oxymethylene, dimethylmethylene or methylene.

Further, the divalent organic group of X in the formula (2) is two (trifluoromethyl) methyl, carbonyl, dimethylmethylene, oxygen atom, and the divalent organic group of Y is two ( Trifluoromethyl)methylene, dimethylmethylene.

Furthermore, the divalent organic group of X in the formula (3) is a bis(trifluoromethyl)methyl group, a carbonyl group, a dimethylmethylene group, or an oxygen atom.

Further, the divalent organic group of X in the formula (4) is two (trifluoromethyl) methyl, carbonyl, dimethylmethylene, oxygen atom _; R is ethylene, propylene , 3-methylpropylene or butylene; R ₂ , R ₃ , R ₄ , and R ₅ are each independently methyl; m is an integer of 10-20.

Further, the polyimide unit of formula (1), formula (2), formula (3), formula (4) is by making tetracarboxylic dianhydride, 3,3-di-tert-butyl benzidine, 2, 2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane or 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]propane, siloxane di It is obtained by imidating a reaction mixture of an amine, a diamine not containing a pyridine unit, 3,3-di-tert-butylbenzidine, and a diamine of siloxane.

The beneficial effects of the present invention are:

1. The alkali-soluble polyimide resin is prepared by a one-step two-stage method, using polycondensation and thermal imidization, which has the advantages of simple process and simple operation compared with the two-step method;

2. The photosensitive polyimide resin is easy to prepare, and the prepared photosensitive polyimide resin has good photosensitive performance, excellent flexibility and adhesion, low linear expansion coefficient and low dielectric constant , better light transmittance.

Detailed ways

The positive photosensitive polyimide resin composition of the present invention contains (a) alkali-soluble polyimide, (b) photosensitizer and (c) cross-linking agent; said (c) cross-linking agent consists of One or two of benzoxazine compounds and compounds with more than two epoxy groups in one molecule are composed in any proportion;

The weight percentage of (a), (b) and (c) is 100:10～50:5～20; wherein, (a) the alkali-soluble polyimide is composed of the polyimide unit of formula (1), And any polyimide unit in formula (2), formula (3), formula (4) or any two polyimide units according to any ratio or three kinds of polyimide units according to any ratio Composition; the polyimide unit of formula (1) accounts for 80～99 mol% of total polyimide unit;

Wherein, in the formulas (1) to (4), X and A are independently a divalent organic group with a single bond; R is a hydroxyl group or a sulfonic acid group; Y represents the di(tri) of a divalent organic group. Fluoromethyl) methylene, dimethyl methylene; R ₁ is an alkylene group with 3-9 carbon atoms; R ₂ , R ₃ , R ₄ and R ₅ are independently carbon atoms with 1-8 An alkylene group or an aromatic group; m represents an integer of 2 or more.

Wherein, the divalent organic group of X in formula (1) is two (trifluoromethyl) methyl, carbonyl, dimethylmethylene, oxygen atom, and the divalent organic group of A is two (trifluoromethyl) Fluoromethyl) methyl, sulfo, oxymethylene, dimethylmethylene or methylene.

Wherein, the divalent organic group of X in formula (2) is two (trifluoromethyl) methyl, carbonyl, dimethylmethylene, oxygen atom, and the divalent organic group of Y is two (trifluoromethyl) Fluoromethyl)methylene, dimethylmethylene.

Among them, the divalent organic group of X in the formula (3) is a bis(trifluoromethyl)methyl group, a carbonyl group, a dimethylmethylene group, or an oxygen atom.

Wherein, the divalent organic group of X in the formula (4) is two (trifluoromethyl) methyl groups, carbonyl groups, dimethylmethylene groups, oxygen atoms _; R is ethylene group, propylene group, 3-methylpropylene or butylene; R ₂ , R ₃ , R ₄ , and R ₅ are each independently methyl; m is an integer of 10-20.

Wherein, the polyimide unit of formula (1), formula (2), formula (3), formula (4) is by making tetracarboxylic dianhydride, 3,3-di-tert-butyl benzidine, 2,2 - bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane or 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]propane, siloxane diamine It is obtained by imidating a reaction mixture of a diamine not containing a pyridine unit, 3,3-di-tert-butylbenzidine, and a diamine of siloxane.

Specific examples of the tetracarboxylic dianhydride serving as the structural unit of the alkali-soluble polyimide resin used in the present invention include pyromellitic dianhydride, 3,4,3′,4-biphenyltetracarboxylic Acid dianhydride, 4,4'-oxydicarboxylic dianhydride, 3,4,3',4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl Sulfone tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl) ether dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) Dicarboxylic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.2]phenyl)propane dianhydride, etc. Among them, bis(3,4-dicarboxyphenyl)ether dianhydride is preferably used.

In addition, as the siloxane diamine which becomes the structural unit of the alkali-soluble polyimide resin used in this invention, it is a compound which has a dimethylsilylene skeleton in a molecule|numerator at least. Siloxane diamines used in the silicone modification of resins. Among them, it is preferable to use siloxane diamine having a structure of the following formula (5) from the viewpoint of flame retardancy and compatibility.

In formula (5), n is an integer of 1-20, and m is an integer of 1-10. Since m is 1 or more, the siloxane diamine of formula (5) has a diphenylsilylene skeleton, and the flame retardancy of a siloxane polyimide resin improves.

As the diamine not containing siloxane used as the structural unit of the alkali-soluble polyimide resin used in the present invention, one having no dimethylsilylene skeleton or diphenylsilylene skeleton in the molecule can be used. Diamines, as specific examples, bis(3-amino-4-hydroxyphenyl) hexafluoropropane, bis(3-amino-4-hydroxyphenyl) sulfone, bis(3-amino-4- Hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methane, bis(3-amino-4-hydroxyphenyl) ether, bis(3-amino-4-hydroxy)biphenyl, bis(3 -diamines containing hydroxyl groups such as amino-4-hydroxyphenyl)fluorene; diamines containing sulfonic acid such as 3-sulfonic acid-4,4'-diaminodiphenyl ether.

As the diamine not containing siloxane used as the structural unit of the alkali-soluble polyimide resin used in the present invention, one having no dimethylsilylene skeleton or diphenylsilylene skeleton in the molecule can be used. Diamines, as specific examples, bis(3-amino-4-hydroxyphenyl) hexafluoropropane, bis(3-amino-4-hydroxyphenyl) sulfone, bis(3-amino-4- Hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methane, bis(3-amino-4-hydroxyphenyl) ether, bis(3-amino-4-hydroxy)biphenyl, bis(3 -diamines containing hydroxyl groups such as amino-4-hydroxyphenyl)fluorene; diamines containing sulfonic acid such as 3-sulfonic acid-4,4'-diaminodiphenyl ether.

In addition, in order to improve the storage stability of the positive photosensitive resin composition, it is preferable to use end-capping agents such as monoamines, acid anhydrides, monocarboxylic acids, monoacyl chloride compounds, and monoactive ester compounds to make the main alkali-soluble polyimide resin components The chain ends are capped. When a monoamine is used as an end-blocking agent, the introduced ratio of the monoamine is preferably 5 mol % or more and 50 mol % or less with respect to the total amine components. As the monoamine, there are 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol and the like.

The positive photosensitive resin composition of the present invention preferably contains a solvent. Examples of solvents include polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethylsulfoxide .

The synthesis process is as follows:

In this experiment, alkali-soluble polyimide was prepared by one-step two-stage method. The specific synthesis steps are as follows: under dry nitrogen flow, firstly, 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl] Hexafluoropropane or 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]propane, siloxane diamine or siloxane-free diamine dissolved in a certain amount of N-methyl - 2-Pyrrolidone (NMP), then add tetracarboxylic dianhydride, add a certain amount of solvent NMP, make it react at 60°C for 45min, then add as end-capping agent, react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder .

The positive photosensitive polyimide resin composition of this invention contains a photosensitizer. By containing a photosensitizer, an acid is generated in an ultraviolet-ray exposed portion, and the solubility of the exposed portion to an aqueous alkali solution increases, so that it can be used as a positive photosensitive resin composition. Examples of the photosensitizer include quinonediazido compounds, sulfonium salts, phosphonium salts, diazonium salts, and iodine salts. Among them, it is preferable to use a quinonediazide compound from the viewpoint of exhibiting an excellent dissolution inhibitory effect and obtaining a positive-type photosensitive resin composition with high sensitivity and low film loss.

Content of the photosensitizer in the positive photosensitive polyimide resin composition of this invention is 10-50 mass parts with respect to 100 mass parts of alkali-soluble polyimide resins. When content of a photosensitizer is less than this range, sufficient sensitivity cannot be acquired, and when it exceeds this range, the heat resistance of a resin composition will tend to fall.

As the quinonediazide compound, a compound containing a diazidenaphthoquinone-5-sulfonyl group and a compound containing a diazidenaphthoquinone-4-sulfonyl group can be preferably used. By using the above-mentioned quinonediazide compound, it is possible to obtain a positive-type photosensitive resin combination that reacts with the i-line (wavelength 365nm), h-line (wavelength 405nm), and g-line (wavelength 436nm) of a mercury lamp, which is a general ultraviolet ray. things.

As a compound having two or more epoxy groups in one molecule, for example, bisphenol A type epoxy resin; bisphenol F type epoxy resin; alkylene glycol type rings such as propylene glycol diglycidyl ether, etc. epoxy resins; polyalkylene glycol-type epoxy resins such as polypropylene glycol diglycidyl ether; silicone resins containing epoxy groups such as polymethyl (glycidyl ether oxypropyl) siloxane, etc. As the benzoxazines used as the crosslinking agent, bisphenol F type benzoxazines can be used.

Content of the crosslinking agent in the photosensitive polyimide resin composition of this invention is 5-20 mass parts of crosslinking agents with respect to 100 mass parts of photosensitive polyimide resins. If the content of the crosslinking agent is less than this range, the effect of suppressing volatilization and diffusion of the cyclic siloxane is insufficient, and if it exceeds this range, flexibility will be lacking and the film will tend to become hard, which is not preferable. Moreover, when an epoxy resin and a benzoxazine are used together as a crosslinking agent, it is preferable to use a benzoxazine in the ratio of 0.5-10 mass parts with respect to 1 mass part of epoxy resins. This is because if the amount of benzoxazines is too small, the effect of suppressing volatilization and diffusion of the cyclic siloxane is insufficient, and if it is too large, the film tends to be hard because of lack of flexibility.

Preparation of photosensitive polyimide varnish: In the obtained alkali-soluble polyimide resin, add a certain amount of epoxy resin or benzoxazine crosslinking agent, and add solvent γ-butyrolactone at the same time, at room temperature Stir and dissolve. After the dissolution is uniform, add a certain amount of quinonediazide compound under dark light, stir and dissolve, dissolve evenly and filter to obtain a photosensitive polyimide varnish, and store it in dark light for future use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example

The present invention will be described more specifically by way of examples below.

Example 1

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.75g (7.5mmo), 1,3-bis(3-aminopropyl ) Tetramethyldisiloxane 0.124g (0.5mmol) was dissolved in 8g of N-methyl-2-pyrrolidone (NMP), then 3.12g (10mmol) of bis(3,4-dicarboxyphenyl) was added thereto ) ether dianhydride (ODPA), add 2g of NMP, make it react at 60°C for 45min, then add 0.327g (3mmol) of 4-aminophenol as an end-capping agent, and react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder A-1.

Preparation of photosensitive polyimide varnish: Add 0.6 g of bisphenol A type epoxy resin to 3 g of the obtained resin alkali-soluble polyimide resin, and add 3 g of solvent GBL at the same time, stir and dissolve at room temperature, and wait until it is uniformly dissolved , add 0.6g of DNQ under dark light, and add 1.5g of GBL at the same time, stir to dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 2

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.93g (8mmo), 3,3-di-tert-butylbenzidine 0.1468g (0.5mmol), be dissolved in the N-methyl-2-pyrrolidone (NMP) of 8g, then add 3.12g (10mmol) bis(3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it subsequently, in Add 2g of NMP, make it react at 60°C for 45min, then add 0.327g (3mmol) of 4-aminophenol as an end-capping agent, and react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-2).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-2) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 3

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.93g (8mmo), 2,2-bis[4-(5-amino -2-pyridyloxy)phenyl]propane 0.24g (0.5mmol), dissolved in 8g of N-methyl-2-pyrrolidone (NMP), then added 3.12g (10mmol) bis (3,4-di Carboxyphenyl) ether dianhydride (ODPA), add 2g NMP, make it react at 60°C for 45min, then add 0.327g (3mmol) of 4-aminophenol as an end-capping agent, react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-3).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-3) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 4

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.75g (7.5mmo), 3,3-di-tert-butylbenzidine 0.1468 g (0.5mmol), 0.124g (0.5mmol) of 1,3-bis(3-aminopropyl) tetramethyldisiloxane (0.5mmol) were dissolved in 8g of N-methyl-2-pyrrolidone (NMP), then to Add 3.12g (10mmol) bis(3,4-dicarboxyphenyl) ether dianhydride (ODPA), add 2gNMP, make it react at 60°C for 45min, then add 4-aminophenol 0.327 g (3mmol), reacted for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-4).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-4) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Example 5

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.75g (7.5mmo), 2,2-bis[4-(5- Amino-2-pyridyloxy)phenyl]hexafluoropropane 0.275g (0.5mmol), 1,3-bis(3-aminopropyl)tetramethyldisiloxane 0.124g (0.5mmol) were dissolved in 8g of N -Methyl-2-pyrrolidone (NMP), then add 3.12g (10mmol) bis(3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it, add 2gNMP, make it react at 60°C After 45 min, 0.327 g (3 mmol) of 4-aminophenol was added as an end-capping agent and reacted for 0.5 h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-5).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-5) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 6

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.75g (7.5mmo), 2,2-bis[4-(5- Amino-2-pyridyloxy)phenyl]propane 0.24g (0.5mmol), 1,3-bis(3-aminopropyl)tetramethyldisiloxane 0.124g (0.5mmol) dissolved in 8g of N-methyl disiloxane Base-2-pyrrolidone (NMP), then add 3.12g (10mmol) bis(3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it, add 2gNMP, make it react at 60°C for 45min, Subsequently, 0.327 g (3 mmol) of 4-aminophenol was added as an end-capping agent, and reacted for 0.5 h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-6).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-6) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 7

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.57g (7.0mmo), 3,3-di-tert-butylbenzidine 0.1468 g (0.5mmol), 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]propane 0.24g (0.5mmol), 1,3-bis(3-aminopropyl)tetramethyl Disiloxane 0.124g (0.5mmol) was dissolved in 8g of N-methyl-2-pyrrolidone (NMP), then 3.12g (10mmol) of two (3,4-dicarboxyphenyl) ether dianhydrides were added thereto (ODPA), add 2g of NMP, let it react at 60°C for 45min, then add 0.327g (3mmol) of 4-aminophenol as an end-capping agent, and react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-7).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-7) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 8

Under dry nitrogen flow, first make 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF) 2.57g (7.0mmo), 3,3-di-tert-butylbenzidine 0.1468 g (0.5mmol), 2,2-bis[4-(5-amino-2-pyridyloxy)phenyl]hexafluoropropane 0.275g (0.5mmol), 1,3-bis(3-aminopropyl) tetra Methyldisiloxane 0.124g (0.5mmol) was dissolved in 8g of N-methyl-2-pyrrolidone (NMP), then 3.12g (10mmol) of bis(3,4-dicarboxyphenyl) ether was added thereto For dianhydride (ODPA), add 2g of NMP and make it react at 60°C for 45min, then add 0.327g (3mmol) of 4-aminophenol as an end-capping agent, and react for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-8).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-8) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 9

Alkali-tolerant photosensitive resin synthesis reference example 7

Preparation of photosensitive polyimide varnish: In 3 g of resin alkali-soluble polyimide resin (A-7) obtained, 0.6 g of bisphenol F type benzoxazine was added, and 3 g of solvent GBL was added at the same time, stirring and dissolving at room temperature , after being uniformly dissolved, add 0.6g of DNQ in dark light, and at the same time add 1.5g of GBL to stir and dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light for future use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 10

For the synthesis of alkali-tolerant photosensitive resin, refer to Example 7.

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-7) 3g that obtains, add bisphenol A type epoxy resin 0.54g, bisphenol F type benzoxazine 0.06g At the same time, add 3g of solvent GBL, stir and dissolve at room temperature. After the dissolution is uniform, add DNQ0.6g under dark light, and add GBL1.5g and stir to dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light spare.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 11

Alkali-tolerant photosensitive resin synthesis reference example 8

Preparation of photosensitive polyimide varnish: In 3 g of the obtained resin alkali-soluble polyimide resin (A-8), 0.6 g of bisphenol F type benzoxazine was added, and 3 g of solvent GBL was added at the same time, stirring and dissolving at room temperature , after being uniformly dissolved, add 0.6g of DNQ in dark light, and at the same time add 1.5g of GBL to stir and dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light for future use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Example 12

For the synthesis of alkali-tolerant photosensitive resin, refer to Example 8.

The preparation of photosensitive polyimide varnish: in the obtained resin alkali-soluble polyimide resin (A-8) 3g, add bisphenol A type epoxy resin 0.54g, bisphenol F type benzoxazine 0.06g At the same time, add 3g of solvent GBL, stir and dissolve at room temperature. After the dissolution is uniform, add DNQ0.6g under dark light, and add GBL1.5g and stir to dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light spare.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Comparative example 1

Under dry nitrogen flow, firstly, 3.11 g (8.5 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (hereinafter referred to as BAHF), dissolved in 8 g of N-methyl-2- In pyrrolidone (NMP), then add 3.12g (10mmol) bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it subsequently, add 2gNMP, make it react at 60 ℃ for 45min, then add 0.327g (3mmol) of 4-aminophenol as the terminal agent, reacted for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-9).

The preparation of photosensitive polyimide varnish: in the resin alkali-soluble polyimide resin (A-9) 3g that obtains, add bisphenol A type epoxy resin 0.6g, add solvent gamma-butyrolactone (GBL simultaneously) )3g, stir and dissolve at room temperature, after the dissolution is uniform, add 0.6g of diazide quinone compound (DNQ) under dark light, add GBL1.5g and stir to dissolve at the same time, dissolve evenly and obtain photosensitive polyimide by filtration Varnish, kept in dark light for later use.

Comparative example 2

Under dry nitrogen flow, firstly, 3.11 g (8.5 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (hereinafter referred to as BAHF), dissolved in 8 g of N-methyl-2- In pyrrolidone (NMP), then add 3.12g (10mmol) bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it subsequently, add 2gNMP, make it react at 60 ℃ for 45min, then add 0.327g (3mmol) of 4-aminophenol as the terminal agent, reacted for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-10).

Preparation of photosensitive polyimide varnish: In 3 g of resin alkali-soluble polyimide resin (A-10) obtained, 0.6 g of bisphenol F type benzoxazine was added, and solvent GBL 3 g was added at the same time, stirred and dissolved at room temperature , after being uniformly dissolved, add 0.6g of DNQ in dark light, and at the same time add 1.5g of GBL to stir and dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light for future use.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

Comparative example 3

Under dry nitrogen flow, firstly, 3.11 g (8.5 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (hereinafter referred to as BAHF), dissolved in 8 g of N-methyl-2- In pyrrolidone (NMP), then add 3.12g (10mmol) bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA) to it subsequently, add 2gNMP, make it react at 60 ℃ for 45min, then add 0.327g (3mmol) of 4-aminophenol as the terminal agent, reacted for 0.5h. This was followed by stirring at 180° C. for 4 hours. After stirring, the solution was poured into 300 mL of water to obtain a white precipitate. Collect the precipitate by filtration, wash it with water three times, then wash it three times with hot water, and finally dry it in a vacuum dryer at 80°C for 20 hours to obtain a white alkali-soluble polyimide resin powder (A-11).

Preparation of photosensitive polyimide varnish: in obtained resin alkali-soluble polyimide resin (A-11) 3g, add bisphenol A type epoxy resin 0.54g, bisphenol F type benzoxazine 0.06g At the same time, add 3g of solvent GBL, stir and dissolve at room temperature. After the dissolution is uniform, add DNQ0.6g under dark light, and add GBL1.5g and stir to dissolve, dissolve evenly and filter to obtain photosensitive polyimide varnish, store in dark light spare.

Coating, exposure, development and curing of photosensitive polyimide. The specific steps are as follows: first, the film is coated by spin coating, and then pre-baked for 7 minutes (at 150° C.). After the pre-baked, exposure is carried out for 3 minutes respectively. Subsequently, a developing experiment was carried out (the developing solution was 2.38wt% tetramethylammonium hydroxide aqueous solution), and the developing time was 3 minutes, and then the developed samples were subjected to curing treatment (220° C., curing time 1 hour).

To the embodiment 1～12 of gained and comparative example 1～3 photosensitive polyimide coating film row following evaluation:

1. Evaluation of Sensitivity

Expose the glass substrate to hexamethyldisilazane (HMDS) vapor for 30 seconds, spin coat each photosensitive resin composition, and pre-bake it on a hot plate at 90°C for 120 seconds to remove the solvent. It was volatilized to form a photosensitive resin composition layer with a film thickness of 3.0 μm. Next, the obtained photosensitive resin composition layer was exposed through a predetermined mask having a hole having a diameter of 5 μm using a high-pressure mercury lamp. Then, after developing the exposed photosensitive resin composition layer at 25° C. for 60 seconds with an alkaline developer (2.38% tetramethylammonium hydroxide aqueous solution), it was rinsed with deionized water for 20 seconds. The optimum i-ray exposure amount when analyzing a 5 μm hole by these operations was taken as the sensitivity.

A: More than 80mJ/cm ² and less than 100mJ/cm ²

B: More than 100mJ/cm ² and less than 160mJ/cm ²

C: More than 160mJ/cm ² and less than 250mJ/cm ²

D: more than 250mJ/ ^cm2

2. Transparency evaluation

A coating film with a film thickness of 3.0 μm was formed on a glass substrate. Next, exposure is performed through a predetermined mask using an i-ray stepper. After carrying out overlay image development at 25 degreeC for 60 second with an alkaline developing solution (2.38 mass % tetramethylammonium hydroxide aqueous solution), it rinsed with deionized water for 1 minute. The developed coating film was irradiated with light of 300 mJ/cm ² at a wavelength of 365 nm using an ultra-high pressure mercury lamp, and then heated at 220° C. for 45 minutes in an oven. The transmittance of the cured film was measured at a wavelength of 400 nm using a spectrophotometer.

A: More than 95%

B: More than 90% and less than 95%

C: More than 85% and less than 90%

D: more than 75%, less than 85%

E: Less than 75%

3. Determination of Tg

Measured by differential scanning calorimetry (DSC), the test conditions are as follows: 10-15 mg of the sample is placed in a crucible, and put into the test on a differential scanner. The test conditions are: nitrogen atmosphere, heating rate 10 ° C / min, temperature The test range is from room temperature to 450°C.

4. Determination of linear thermal expansion coefficient

The CTE of the polyimide film (5mm*20mm) prepared in each embodiment was measured with a static thermomechanical analyzer (TMA). Sample load: 0.05N; heating rate: 5°C/min; temperature range: 30°C-260°C. Calculate the CTE according to the relationship curve between the obtained length change and temperature.

5. Determination of dielectric constant

Cut a polyimide film of appropriate size, spray gold on its front and back surfaces, and use HM-5011 spectrum analyzer to analyze its dielectric constant in a wide spectrum range.

Test results: Here, the degree of photolithography was observed through an electron microscope. In Examples 1-9, good photolithographic patterns can be obtained by exposing for 3 minutes under a 365nm (i-line)-436nm (g-line) ultraviolet light source. As can be seen from Table 1, the photosensitive polyimide prepared in the present invention has a positive photosensitive resin composition and photosensitivity with higher light transmittance, low coefficient of thermal expansion, high heat resistance and excellent photosensitivity. The resin composition, among which Examples 1, 3, 4-9 have better light transmittance, and wherein the transmittance of Example 6-9 can reach more than 90%.

Table 1

The above-mentioned embodiments are only preferred embodiments of the present invention, and should not be used to limit the protection scope of the present invention. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection required by the present invention.

Claims (4)

1. A positive photosensitive polyimide resin composition comprising (a) an alkali-soluble polyimide, (b) a photosensitizer, and (c) a crosslinking agent; the crosslinking agent (c) is composed of one or two of benzoxazine compounds and compounds with more than 2 epoxy groups in one molecule according to any proportion; the weight percentage of the (a), (b) and (c) is 100: 10-50: 5-20; wherein (a) the alkali-soluble polyimide is composed of a polyimide unit of formula (1) and any one or two of polyimide units of formula (2), formula (3) and formula (4) in any proportion or three polyimide units in any proportion; the polyimide units of the formula (1) account for 80-99 mol% of the total polyimide units;

in the formulae (1) to (4), X and A are each independently 2A divalent organic group, the 2-valent organic group of X is a bis (trifluoromethyl) methylene, a carbonyl group, a dimethylmethylene, an oxygen atom, the 2-valent organic group of A is a bis (trifluoromethyl) methylene, a sulfo group, an oxymethylene group, a dimethylmethylene or a methylene group; r is hydroxyl or sulfonic group; y represents a bis (trifluoromethyl) methylene group or a dimethylmethylene group of a 2-valent organic group; r₁Alkylene of 3 to 9 carbon atoms; r₂、R₃、R₄And R₅Each independently is an alkylene group or an aromatic group having 1 to 8 carbon atoms; m represents an integer of 2 or more.

2. The positive photosensitive polyimide resin composition according to claim 1, wherein R in the formula (4)₁Is ethylene, propylene, 3-methylpropylene or butylene; r₂、R₃、R₄、R₅Each independently is methyl; m is an integer of 10 to 20.

3. The positive photosensitive polyimide resin composition according to any one of claims 1 to 2, wherein the (b) photosensitizer is an o-quinonediazide compound.

4. The positive photosensitive polyimide resin composition according to any one of claims 1 to 2, wherein when the crosslinking agent (c) is composed of a compound having 2 or more epoxy groups in one molecule and a benzoxazine-based compound, the mass percentages of the two compounds are 1: 0.5 to 10.