JP2002162740A - Composition for photosensitive cover lay film and photosensitive cover lay film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive cover lay film with a sufficient mechanical strength, superior heat resistibility, good workability and superior adhesive property, which reduces little warp at the time of being pasted together with a flexible print board. SOLUTION: The photosensitive cover lay film can be laminated at a temp of 150 deg.C or lower and directly laminated on the print board without an adhesive, and has photosensitivity, a heat decomposition initiating temperature of 300 deg.C or higher after hardening, an elastic modules of 100-3,000 N/mm2 after hardening and a hardening temperature of 200 deg.C or lower, and includes a soluble polymide using imido siloxanediamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a photosensitive coverlay film and a photosensitive coverlay film, and more particularly, to a flexible printed circuit board used in the field of electronic materials. And a heat-resistant photosensitive coverlay film that is directly laminated without using the same.

[0002]

2. Description of the Related Art In recent years, electronic equipment has become more sophisticated and more sophisticated.
With miniaturization progressing rapidly, there is a demand for smaller and lighter electronic components. For this reason, the wiring board on which the electronic components are mounted is also compared to the ordinary rigid printed wiring board.
Flexible printed circuit board (FPC)
Is gaining more attention than ever before, and demand is rapidly increasing.

Incidentally, a polymer film called a coverlay film is bonded to the surface of the FPC for the purpose of protecting the conductor surface. As a method of bonding this cover lay film to the surface of the conductor surface, a cover lay film having a predetermined shape and an adhesive on one side is bonded to a conductor.
A method is generally used in which a PC is placed on a PC, aligned, and then thermocompression-bonded with a press or the like. However, the adhesives used here are mainly epoxy-based or acrylic-based adhesives, and have low heat resistance such as solder heat resistance and adhesive strength at high temperatures, or have poor flexibility. The performance of the polyimide film used could not be fully utilized.

When a coverlay film is bonded to an FPC using a conventional epoxy-based or acrylic-based adhesive, the coverlay film before bonding is in conformity with the joints between circuit terminals and components. You have to make holes and windows. However, not only is it difficult to make holes in the thin coverlay film, but the alignment of the holes in the coverlay film to the joints with the terminals and parts of the FPC is almost a manual operation.
Workability and positional accuracy are poor and costly.

In order to improve the workability and positional accuracy, a method of applying a photosensitive composition to a conductor surface to form a protective layer and the development of a photosensitive coverlay film (also referred to as a photosensitive dry film resist) have been developed. The workability and position accuracy have been improved.

However, since the above-mentioned photosensitive coverlay film uses an acrylic resin, the heat resistance temperature and the brittleness of the film are not sufficient, and a photosensitive polyimide is required for improvement, and an ester bond is formed. Polyimide having a methacryloyl group introduced through the
30207, JP-B-55-041422) and a photosensitive polyimide in which an amine compound having a methacryloyl group or a diisocyanate compound is introduced into a carboxyl group of a polyamic acid (JP-A-54-145794, JP-A-5-145794).
9-160140, JP-A-03-170547, JP-A-03-186847, and JP-A-61-118424).

However, since these photosensitive polyimides are obtained only after being exposed and developed in the state of polyamic acid and then imidized, they must be subjected to FPC at a temperature of 250 ° C. or higher. It was necessary to remove the acroyl group by heat, and at that time, there was a problem that the film thickness was greatly reduced.

[0008]

Accordingly, the above-mentioned conventional problems have been solved and a flexible printed circuit board which has sufficient mechanical strength, excellent heat resistance, further excellent workability and adhesiveness, and which has excellent mechanical strength. The study was conducted for the purpose of providing a composition for a photosensitive cover lay film and a photosensitive cover lay film which are less likely to warp when laminated.

[0009]

The present invention provides the following novel photosensitive coverlay film composition and photosensitive coverlay film, which can solve the above-mentioned problems. 1) A composition for a photosensitive coverlay film containing a soluble polyimide obtained using a siloxane diamine represented by the following general formula 2 as a raw material. (Wherein R ¹ is C ₁ -C ₁₂
An alkyl group or a phenyl group, x is an integer of 1 to 20,
y shows the integer of 1-40. )

[0010]

Embedded image 2) The composition for a photosensitive coverlay film according to 1), wherein the soluble polyimide is a polyimide obtained from a diamine containing 5-70 mol% of the siloxane diamine in the total diamine component as a raw material. 3) The composition for a photosensitive coverlay film according to 1), wherein the soluble polyimide is a polyimide obtained from a diamine containing 20 to 50 mol% of the siloxane diamine in the total diamine component as a raw material. 4) The composition for a photosensitive cover lay according to any one of 1) to 3), wherein the composition for a cover lay film contains a copolymerizable monomer having a carbon-carbon double bond. 5) The copolymerized monomer is bisphenol F EO-modified (n ≒ 2) diacrylate bisphenol A EO
Modified (n ≒ 2) diacrylate bisphenol SE
The photosensitive coverlay composition according to any one of 1) to 4), which is a diacrylate selected from O-modified (n Ｏ2) diacrylates. 6) A photosensitive coverlay film obtained from the composition according to any one of 1) to 5). 7) A photosensitive coverlay film using a soluble polyimide that has been imidized. (8) The photosensitive coverlay film according to (7), wherein the thermal decomposition onset temperature after curing is 300 ° C. or higher. 9) The photosensitive coverlay film according to 7) or 8), wherein the elastic modulus after curing is 10 to 3000 N / mm ² . 10) The photosensitive coverlay film according to any one of 7) to 9), wherein the curing temperature is 200 ° C or lower. 11) Can be laminated at a temperature of 150 ° C or less 7) to 1
0) The photosensitive coverlay film according to any one of the above items. 12) A printed board in which the photosensitive coverlay film according to any one of 6) to 11) is directly laminated on a printed board without using an adhesive.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photosensitive coverlay composition of the present invention contains a soluble polyimide obtained from a siloxane diamine represented by the following general formula (3). Therefore, in the case of polyamic acid, it is necessary to perform imidization.
Although it is necessary to expose to a high temperature of 50 ° C. or more for a long time, portions other than the copper foil or the polyimide may deteriorate, but in the present invention, no deterioration occurs.

A method for producing a soluble polyimide according to the present invention will be described. Polyimide is generally obtained by reacting a diamine and an acid dianhydride in an organic solvent to obtain a polyamic acid, followed by dehydration imidization or reaction with an acid dianhydride and a diisocyanate in a solvent. The polyamic acid used in the present invention is obtained by reacting a diamine and an acid dianhydride in an organic solvent. In an inert atmosphere such as argon or nitrogen, diamine is dissolved in an organic solvent or dispersed in a slurry state, and acid dianhydride is dissolved in an organic solvent and added in a slurry state or a solid state. I do.

The reaction temperature at this time is preferably from -20 ° C to 90 ° C. The reaction time is about 30 minutes to 24 hours.
The average molecular weight of the polyamic acid is 5,000 to 1,000,000
It is desirable that When the average molecular weight is less than 5,000, the molecular weight of the completed polyimide composition also becomes low, and the resin tends to become brittle even when the polyimide composition is used as it is. On the other hand, if it exceeds 1,000,000, the viscosity of the polyamic acid varnish tends to be too high and handling becomes difficult.

It is also possible to compound various organic additives, inorganic fillers, or various reinforcing materials with the polyimide composition. Here, as the organic polar solvent used in the polyamic acid forming reaction, for example, sulfoxide solvents such as dimethylsulfoxide and diethylsulfoxide, N, N-dimethylformamide, N, N
-Formamide solvents such as diethylformamide,
Acetamide solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-
Pyrrolidone, pyrrolidone solvents such as N-vinyl-2-pyrrolidone, phenols, o-, m-, or p-cresol, xylenol, halogenated phenols, phenolic solvents such as catechol, ether solvents such as tetrahydrofuran, dioxane, Methanol, ethanol, alcohol solvents such as butanol and the like, cellosolves such as butyl cellosolve or hexamethylphosphoramide, γ-butyrolactone, and the like can be mentioned, and it is desirable to use these alone or as a mixture, and furthermore, xylene, toluene Aromatic hydrocarbons such as are also usable. The solvent is not particularly limited as long as it dissolves the polyamic acid. Since the polyamic acid is synthesized and then heated and decompressed to remove the solvent and imidize at the same time, it is advantageous in terms of the process to dissolve the polyamic acid and select one having a boiling point as low as possible. Next, the step of imidizing the polyamic acid will be described. When the polyamic acid is imidized, it produces water. The generated water easily hydrolyzes the polyamic acid and causes a decrease in molecular weight. As a method of imidation while removing water, 1) a method of adding an azeotropic solvent such as toluene or xylene to remove by azeotropic distillation, 2) an aliphatic acid dianhydride such as acetic anhydride and triethylamine, pyridine or picoline. -There is a chemical imidization method in which a tertiary amine such as isoquinoline is added.

[0015] The removal of water by azeotropic distillation of 1) cannot be avoided since water is present in the solution system and hydrolysis by water is inevitable. The chemical imidation method of 2) is more advantageous than the system of 1) in terms of hydrolysis because the generated water is chemically removed by the conversion of the aliphatic acid dianhydride into an aliphatic acid. is there. However, since aliphatic acid dianhydride / tertiary amine remains in the system, a step of removing these is necessary.

According to the present invention, the water produced by imidization is heated and decompressed and positively removed from the system to suppress hydrolysis and avoid a decrease in molecular weight. In addition, when the acid dianhydride used as a raw material is mixed with a tetracarboxylic acid that has been opened by hydrolysis or one in which one of the acid dianhydrides has been hydrolyzed, and the polymerization reaction of the polyamic acid is stopped. By decompression and heating during imidization, the ring-opened acid dianhydride is closed again to form an acid dianhydride, and reacts with the amine remaining in the system during imidization, and an improvement in molecular weight is expected. it can. The heating conditions for imidization are 80 to 400 ° C. The temperature is 100 ° C. or higher, preferably 120 ° C. or higher, at which imidization is efficiently performed and water is efficiently removed.
The maximum temperature is desirably set to a temperature not higher than the thermal decomposition temperature of the polyimide to be used. Usually, imidization is almost completed at about 250 to 350 ° C., so the maximum temperature can be set to this level. The pressure is preferably reduced as long as the pressure is such that water generated during imidization can be efficiently removed under the above heating conditions. Specifically, the pressure for heating under reduced pressure is 0.9 to 0.001 atm, preferably 0.8 to 0.001 atm, and more preferably 0.7 to 0.01 atm. The acid dianhydride used in this polyimide composition is not particularly limited as long as it is an acid dianhydride. For example, 2,2′-hexafluoropropylidene diphthalic acid dianhydride, 2,2-bis (4-
(Hydroxyphenyl) propanedibenzoate-3,3
', 4,4'-tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic acid, 1,2,2
3,4-cyclopentanetetracarboxylic dianhydride,
2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,
2-dicarboxylic dianhydride, bicyclo [2,2,2]-
Aliphatic or alicyclic tetracarboxylic dianhydrides such as oct-7-ene-2,3,5,6-tetracarboxylic dianhydride; pyromellitic dianhydride, 3,3 ′, 4,4 '-
Benzophenone tetracarboxylic dianhydride, 3,3 ',
4,4′-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′ , 4,4'-biphenylethertetracarboxylic dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride,
3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl Sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ',
4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene- Bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) ) Aromatic tetracarboxylic dianhydrides such as -4,4'-diphenylmethane dianhydride;
3,3a, 4,5,9b-Hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-
Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione;

[0017]

Embedded image (Wherein R ² represents a divalent organic group having an aromatic ring, and R ³ and R ⁴ each represent a hydrogen atom or an alkyl group.)

[0018]

Embedded image (Wherein, R ⁵ represents a divalent organic group having an aromatic ring, and R ⁶ and R ⁷ each represent a hydrogen atom or an alkyl group.) An anhydride and the like can be mentioned. These tetracarboxylic dianhydrides can be used alone or in combination of two or more. In particular, it is desirable to use an acid dianhydride having the structure of Chemical Formula 5 in order to express heat resistance and mechanical properties at a high level. (R ⁸ is a divalent organic group,
R ⁹ is a direct bond, -O -.- CH ₂ -.- (C = O) -.-
Represents C (CH ₃ ) ₂ ... C (CF ₃ ) ₂ —. )

[0019]

Embedded image In order to obtain polyimide highly soluble in organic solvents,
It is desirable to partially use 2,2′-hexafluoropropylidene diphthalic dianhydride and an ester dianhydride represented by the following general formula (6).

[0020]

Embedded image (Wherein, R ⁸ represents a divalent organic group, particularly —CH ₂ C
_{(CH 3) 2 CH 2 -} , - C q H 2q - structure selected from and of 7 is preferable. q is an integer of 1 to 20)

[0021]

Embedded image (Wherein R ¹⁰ is hydrogen, halogen, methoxy, C ₁ -C
_{Shows 16} alkyl groups. In the present invention, a siloxane diamine represented by Chemical Formula 8 is used as a diamine component serving as a raw material of a soluble polyimide. (In the formula, R ¹ is a C ₁ -C ₁₂ alkyl group or a phenyl group, x is an integer of 1 to 20, and y is an integer of 1 to 40.) In the formula, a preferable example of R ¹ is a methyl group. -An ethyl group and a phenyl group can be mentioned, and a methyl group is more preferable. Further, x is preferably 2 to 10, and particularly preferably 2 to 5. y = 4 to 30, preferably 5 to 20, and more preferably 8 to 15. Among them, the range of the value of y greatly affects the physical properties. If the value of y is small, the flexibility of the obtained polyimide is poor, and if it is too large, the polyimide heat resistance tends to be impaired.

[0022]

Embedded image Thereby, the elasticity of the photosensitive coverlay film obtained from the coverlay composition of the present invention can be reduced, and the warpage when the coverlay is laminated on the flexible printed circuit board can be prevented. The siloxane diamine is preferably used in an amount of 5 to 70 mol%, more preferably 20 to 50 mol%, based on all the diamine components. Further, when a diamine having a hydroxyl group and a carboxylic acid is used as a diamine component as a raw material of a soluble polyimide, an alkali-soluble polyimide can be designed. This enables development of the photosensitive coverlay film. The diamine having a hydroxyl group / carboxylic acid is not particularly limited as long as it has a hydroxyl group / carboxylic acid, and examples thereof include the following.

For example, diaminophenols such as 2,4-diaminophenol, 3,3'-diamino-4,4 '
-Dihydroxybiphenyl, 4,4'-diamino-3,
3'-dihydroxybiphenyl, 4,4'-diamino-
Hydroxybiphenyl compounds such as 2,2′-dihydroxybiphenyl and 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxybiphenyl, 3,3′-diamino-4,4′-dihydroxydiphenylmethane, 4,
4'-diamino-3,3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-
Hydroxyphenyl] propane, 2,2-bis [4-amino-3-hydroxyphenyl] propane, 2,2-bis
[3-amino-4-hydroxyphenyl] hexafluoropropane, 4,4′-diamino-2,2 ′, 5,5′-
Hydroxydiphenylalkanes such as hydroxydiphenylmethane such as tetrahydroxydiphenylmethane,
3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′-diamino-2,
Hydroxy diphenyl ether compounds such as 2′-dihydroxy diphenyl ether and 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxy diphenyl ether; 3,3′-diamino-4,4′-dihydroxy diphenyl sulfone; 4′-diamino-3,3′-dihydroxydiphenylsulfone, 4,4′-diamino-2,2′-dihydroxydiphenylsulfone, 4,
Diphenylsulfone compounds such as 4'-diamino-2,2 ', 5,5'-tetrahydroxydiphenylsulfone and bis [such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] propane (Hydroxyphenyl) phenyl] alkane compounds, 4,4′-
Bis (hydroxyphenoxy) biphenyl compounds such as bis (4-amino-3-hydroxyphenoxy) biphenyl and bis [such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone (Hydroxyphenoxy) phenyl] sulfone compound, 3,5-
Diaminobenzoic acids such as diaminobenzoic acid, 3,3′-
Diamino-4,4'-dicarboxybiphenyl, 4,4
'-Diamino-3,3'-dicarboxybiphenyl,
Carboxybiphenyl compounds such as 4,4'-diamino-2,2'-dicarboxybiphenyl and 4,4'-diamino-2,2 ', 5,5'-tetracarboxybiphenyl;3,3'-diamino-4,4'-dicarboxydiphenylmethane,4,4'-diamino-3,3'-dihydroxydiphenylmethane,4,4'-diamino-2,
2'-dihydroxydiphenylmethane, 2,2-bis
[3-amino-4-carboxyphenyl] propane, 2,
2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] hexafluoropropane, 4,4′-diamino-
Carboxydiphenylalkanes such as carboxydiphenylmethane such as 2,2 ', 5,5'-tetracarboxydiphenylmethane, 3,3'-diamino-4,4'-dicarboxydiphenylether, and 4,4'-diamino-
3,3′-dicarboxydiphenyl ether, 4,4
Carboxydiphenyl ether compounds such as'-diamino-2,2'-dicarboxydiphenyl ether and 4,4'-diamino-2,2 ', 5,5'-tetracarboxydiphenyl ether; 3,3'-diamino-4,4' −
Dicarboxydiphenylsulfone, 4,4′-diamino-3,3′-dicarboxydiphenylsulfone,
4,4′-diamino-2,2′-dicarboxydiphenylsulfone, 4,4′-diamino-2,2 ′, 5
Diphenylsulfone compounds such as 5′-tetracarboxydiphenylsulfone; bis [(carboxyphenyl) phenyl] alkane compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] propane; Bis (hydroxyphenoxy) biphenyl compounds such as 4'-bis (4-amino-3-hydroxyphenoxy) biphenyl, and 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone Bis [(carboxyphenoxy) phenyl] sulfone compound. In addition, the diamine used in the polyimide composition is not particularly limited as long as it is a diamine, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminophenylethane,
4,4′-diaminophenyl ether, 4,4′-didiaminophenyl sulfide, 4,4′-didiaminophenyl sulfone, 1,5-diaminonaphthalene, 3,3
-Dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1, 3,3-trimethylindane, 4,4'-
Diaminobenzanilide, 3,5-diamino-3′-trifluoromethylbenzanilide, 3,5-diamino-
4'-trifluoromethylbenzanilide, 3,4'-
Diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′- Tetrachloro-4,
4'-diaminobiphenyl, 2,2'-dichloro-4,
4'-diamino-5,5'-dimethoxybiphenyl,
3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane, 2,2-bis [4
-(4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) -biphenyl, 1,3'-bis (4- Aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2 ′ -Bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl and the like Aromatic diamine; two amino groups bonded to an aromatic ring such as diaminotetraphenylthiophene and the nitrogen of the amino group Aromatic diamine having a heteroatom other than a child; 1,1-methaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylene Diamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene dimethylenediamine, tricyclo [6,2,1,
0 ^2.7 ] -undecylenedimethyldiamine, 4,4'-
Aliphatic diamines and alicyclic diamines such as methylenebis (cyclohexylamine);

[0024]

Embedded imageMonosubstituted phenylenediamines represented by the formula:^Ten
Is -O-, -COO-, -OCO-, -CONH- and
And a divalent organic group selected from —CO— and ¹¹Is
It represents a monovalent organic group having a teroid skeleton. )
And the like. These diamines
Compounds may be used alone or in combination of two or more
Can be. Heat and dry the polyamic acid solution under reduced pressure
A specific method for imidization will be described. Decompression
Any method can be used as long as it can be dried by heating.
As a method, a vacuum oven, as a continuous method,
For example, a twin or triple screw extruder with a decompression device
Can be applied. These methods are selected according to the production amount.
Two- or three-screw extruder with decompression device
Is a general melting and extrusion of thermoplastic resin.
The melt extruder was accompanied by a device to remove the solvent by reducing the pressure.
Things. Polya with a twin or triple screw extruder
The amic acid solution is mixed with the solvent while being kneaded by an extruder.
Water generated during the imidization is removed, and soluble polyimide and
Become. The soluble polyimide thus obtained is
Of a coverlay film obtained from a composition containing
Improves adhesion and heat resistance after curing.
Can be further modified with epoxy.
Is preferred. Next, production of this epoxy-modified polyimide
The steps will be described. The aforementioned hydroxyl group or carboxylic acid
Is dissolved in an organic solvent
Epoxy resin having two or more xy groups,
Compounds that have a double bond or a triple bond with an epoxy group
To give an epoxy-modified polyimide.
You. The solvent used for the reaction does not react with the epoxy group,
Dissolves polyimide containing hydroxyl or carboxylic acid
It is not particularly limited as long as it is one. For example, dimethyl sulf
Sulfoxides such as foxide and diethylsulfoxide
Solvent, N, N-dimethylformamide, N, N-diethyl
Formamide solvents such as formamide, N, N-di
Methylacetamide, N, N-diethylacetamide
Which acetamide solvent, N-methyl-2-pyrrolide
, N-vinyl-2-pyrrolidone and other pyrrolidone-based solutions
Solvent, tetrahydrofuran, ether solvents such as dioxane
Solvent, methanol, ethanol, butanol, etc.
Solvent, cellosolve such as butyl cellosolve, or
Hexamethylphosphoramide, γ-butyrolactone, etc.
Furthermore, aromatic hydrocarbons such as xylene and toluene are also used.
Is available. Use these alone or as a mixture
Can be The solvent has a hydroxyl group or a carboxylic acid.
Especially those that dissolve the thermoplastic polyimide
Not determined. After that, the solvent is removed, so the hydroxyl group or
Or dissolve thermoplastic polyimide with carboxylic acid,
It is advantageous in the process to select the one with the lowest boiling point as possible
It is. The reaction temperature is between epoxy group and hydroxyl group / carboxy group.
At a temperature between 40 ° C and 130 ° C that reacts with
Is desirable. Especially two bonds with epoxy group or epoxy
For compounds having a double bond and a triple bond, a double bond
At a temperature at which the triple bond does not decompose or crosslink due to heat
It is desirable to react. Specifically, 40 degrees or more 1
00 degrees or less, more preferably 50 degrees or more and 90 degrees or less
It is. The reaction time is about several minutes to about eight hours.
An epoxy resin having two or more epoxy groups is an epoxy resin.
It is not particularly limited as long as it has two or more groups in the molecule.
Can be exemplified as follows.

For example, a bisphenol resin such as Epicoat 828 (manufactured by Yuka Shell) or an orthocresol novolak resin such as 180S65 (manufactured by Yuka Shell) 157
Bisphenol A novolak resin such as S70 (manufactured by Yuka Shell), trishydroxyphenylmethane novolak resin such as 1032H60 (manufactured by Yuka Shell), ESN3
Naphthalene aralkyl novolak resin such as 75, tetraphenylolethane 1031S (manufactured by Yuka Shell), Y
GD414S (Toto Kasei), Trishydroxyphenylmethane EPPN502H (Nippon Kayaku), Special bisphenol VG3101L (Mitsui Chemicals), Special naphthol NC
7000 (Nippon Kayaku), TETRAD-X, TETRA
Glycidylamine type resins such as DC (manufactured by Mitsubishi Gas Chemical Company) and the like. The compound having an epoxy group and a double bond is not particularly limited as long as it has an epoxy group and a double bond in a molecule, and examples thereof are as follows.

Examples include allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and glycidyl vinyl ether. Epoxy group and 3
The compound having a heavy bond is not particularly limited as long as it has an epoxy group and a triple bond in the molecule, and examples thereof include the following. Examples include propargyl glycidyl ether / glycidyl propiolate / ethynyl glycidyl ether.

Thus, a solution of the epoxy-modified polyimide can be obtained. A thermosetting resin such as an epoxy resin or an acrylic resin, or a thermoplastic resin such as polyester, polyamide, polyurethane, or polycarbonate may be appropriately mixed with the epoxy-modified polyimide solution.

Further, even when mixed with a thermosetting resin other than the epoxy resin, good physical properties can be obtained, so that it is preferable. The thermosetting resin used here is bismaleimide
Bisallylnadiimide, phenolic resin, cyanate resin and the like can be mentioned. It is desirable to mix the epoxy-modified polyimide of the present invention with a curing agent for an epoxy resin, since a cured product having good physical properties can be obtained. For epoxy resin curing agents, amine-based, imidazole-based, acid anhydride-based,
Any acid system may be used. Further, various coupling agents may be mixed. In the composition for a photosensitive coverlay of the present invention, a photoreaction initiator is blended in order to impart photosensitivity. As an example of a compound that generates a radical by light having a long wavelength of about g line as a photoreaction initiator, an acylphosphine oxide compound represented by the following general formula (α · β) can be given. The radical generated thereby reacts with a reactive group having two bonds (vinyl, acroyl, methacryl, allyl, etc.) to promote crosslinking.

[0029]

Embedded image

[0030]

Embedded image (Wherein R ¹² , R ¹⁵ and R ¹⁷ are C ₆ H ₅ −, C ₆ H ₄ (C
_{H 3) -, C 6 H} 2 (CH 3) 3 -, (CH 3) 3 C-, C 6 H
₃ Cl ₂ —, R ¹³ , R ¹⁴ and R ¹⁶ are C ₆ H ₅ —, methoxy, ethoxy, C ₆ H ₄ (CH ₃ ) —, C ₆ H ₂ (CH ₃ ) ₃
Represents-. In particular, the acylphosphine oxide represented by the general formula (β) is preferable because it generates four radicals by α-cleavage. (General formula (α) generates two radicals) In order to cure the epoxy group attached to the side chain, a photocation generator may be used. For example, diphenyliodonium salts such as diphenyliodonium salt of dimethoxyanthraquinonesulfonic acid, triphenylsulfonium salts, pyrilinium salts, triphenylonium salts, diazonium salts and the like can be exemplified. At this time, it is preferable to mix an alicyclic epoxy or vinyl ether compound having high cationic curability.

In order to cure the epoxy group attached to the side chain, a photobase generator may be used. For example, urethane compounds obtained by the reaction of nitrobenzyl alcohol or dinitrobenzyl alcohol with isocyanate, or nitro-1-phenylethyl alcohol or dinitro-
Examples thereof include a urethane compound obtained by reacting 1-phenylethyl alcohol and isocyanate, and a urethane compound obtained by reacting dimethoxy-2-phenyl-2-propanol and isocyanate.

Various peroxides can be used as radical initiators in combination with the following sensitizers.
In particular, a combination of 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and a sensitizer is particularly preferable. The photosensitive coverlay used in the present invention has a practically usable sensitivity. To achieve this, a sensitizer may be included. Preferred examples of the sensitizer include Michler's ketone, bis-4,4'-diethylaminobenzophenone, benzophenone, camphorquinone, benzyl, 4,4'-dimethylaminobenzyl, 3,5-bis (diethylaminobenzylidene) -N-methyl -4-piperidone, 3,5-
Bis (dimethylaminobenzylidene) -N-methyl-4
-Piperidone, 3,5-bis (diethylaminobenzylidene) -N-ethyl-4-piperidone, 3,3'-carbonylbis (7-diethylamino) coumarin, riboflavin tetrabutyrate, 2-methyl-1- [4- ( Methylthio) phenyl] -2-morpholinopropane-1-
ON, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 3,5-dimethylthioxanthone, 3,5-diisopropylthioxanthone, 1-phenyl-2- (ethoxycarbonyl) oxyiminopropane -1-one,
Benzoin ether, benzoin isopropyl ether, benzanthrone, 5-nitroacenaphthene, 2-
Nitrofluorene, anthrone, 1,2-benzanthraquinone, 1-phenyl-5-mercapto-1H-tetrazole, thioxanthen-9-one, 10-thioxanthenone, 3-acetylindole, 2,6-di (p-
Dimethylaminobenzal) -4-carboxycyclohexanone, 2,6-di (p-dimethylaminobenzal)-
4-hydroxycyclohexanone, 2,6-di (p-diethylaminobenzal) -4-carboxycyclohexanone, 2,6-di (p-diethylaminobenzal) -4
-Hydroxycyclohexanone, 4,6-dimethyl-7
-Ethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 7-diethylamino-3- (1-methylbenzimidazolyl) coumarin, 3- (2-benzimidazolyl) -7-diethylaminocoumarin, 3- (2-
Benzothiazolyl) -7-diethylaminocoumarin, 2
-(P-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) quinoline,
-(P-dimethylaminostyryl) quinoline, 2- (p
-Dimethylaminostyryl) zenzothiazole, 2-
(P-dimethylaminostyryl) -3,3-dimethyl-3H-indole and the like, but are not limited thereto.

The sensitizer is preferably added in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polyimide resin of the present invention.
The content is more preferably 0.3 to 20 parts by weight. 0.1
If the amount is out of the range of from 50 to 50 parts by weight, the sensitizing effect may not be obtained or the developability may be adversely affected. As the sensitizer, one compound may be used, or several compounds may be used as a mixture. In addition, the composition for a photosensitive coverlay used in the present invention can contain a photopolymerization auxiliary agent in order to achieve a practically usable photosensitive sensitivity. Examples of the photopolymerization auxiliary include 4-diethylaminoethyl benzoate, 4-dimethylaminoethyl benzoate, 4-diethylaminopropyl benzoate, 4
-Dimethylaminopropylbenzoate, 4-dimethylaminoisoamylbenzoate, N-phenylglycine, N-methyl-N-phenylglycine, N- (4-cyanophenyl) glycine, 4-dimethylaminobenzonitrile, ethylene glycol dithioglycolate, ethylene Glycol di (3-merbutopropionate), trimethylolpropane thioglycolate, trimethylolpropane tri (3-mercaptopropionate), pentaerythritol tetrathioglycolate, pentaerythritol tetra (3-mercaptopropionate) , Trimethylolethanetrithioglycolate, trimethylolpropanetrithioglycolate, trimethylolethanetri (3-mercaptopropionate),
Dipentaerythritol hexa (3-mercaptopropionate), thioglycolic acid, α-mercaptopropionic acid, t-butylperoxybenzoate, t-butylperoxymethoxybenzoate, t-butylperoxynitrobenzoate, t-butylperoxyethyl Benzoate, phenylisopropylperoxybenzoate, di-tert-butyldiperoxyisophthalate, tri-tert-butyltriperoxytrimellitate, tri-tert-butyltriperoxytrimesitate, tetra-tert-butyltetraperoxypyromellitate, 2,5-dimethyl −
2,5-di (benzoylperoxy) hexane, 3,3
', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3,4,4'-tetra (t-
Amyl peroxycarbonyl) benzophenone, 3,3
', 4,4'-tetra (t-hexylperoxycarbonyl) benzophenone, 2,6-di (p-azidobenzal) -4-hydroxycyclohexanone, 2,6-di (p
-Azidobenzal) -4-carboxycyclohexanone, 2,6-di (p-azidobenzal) -4-methoxycyclohexanone, 2,6-di (p-azidobenzal)-
4-hydroxymethylcyclohexanone, 3,5-di (p-azidobenzal) -1-methyl-4-piperidone, 3,5-di (p-azidobenzal) -4-piperidone, 3,5-di (p-azibenzal) -N-acetyl-4
-Piperidone, 3,5-di (p-azidobenzal) -N-
Methoxycarbonyl-4-piperidone, 2,6-di (p-
Azidobenzal) -4-hydroxycyclohexanone,
2,6-di (m-azidobenzal) -4-carboxycyclohexanone, 2,6-di (m-azidobenzal) -4-
Methoxycyclohexanone, 2,6-di (m-azidobenzal) -4-hydroxymethylcyclohexanone,
3,5-di (m-azidobenzal) -N-methyl-4-piperidone, 3,5-di (m-azidobenzal) -4-piperidone, 3,5-di (m-azidobenzal) -N-acetyl- 4-piperidone, 3,5-di (m-azidobenzal)
-N-methoxycarbonyl-4-piperidone, 2,6-di (p-azidocinnamylidene) -4-hydroxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4
-Carboxycyclohexanone, 2,6-di (p-azidocinnamylidene) -4-cyclohexanone, 3,5-
Di (p-azidocinnamylidene) -N-methyl-4-piperidone, 4,4′-diazidochalcone, 3,3′diazidochalcone, 3,4′-diazidochalcone, 4,3
'-Diazidochalcone, 1,3-diphenyl-1,2,2
3-propanetrione-2- (o-acetyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (on-propylcarbonyl) oxime,
1,3-diphenyl-1,2,3-propanetrione-
2- (o-methoxycarbonyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (o-
Ethoxycarbonyl) oxime, 1,3-diphenyl-
1,2,3-propanetrione-2- (o-benzoyl) oxime, 1,3-diphenyl-1,2,3-propanetrione-2- (o-phenyloxycarbonyl)
Oxime, 1,3-bis (p-methylphenyl) -1,
2,3-propanetrione-2- (o-benzoyl) oxime, 1,3-bis (p-methoxyphenyl) -1,
2,3-propanetrione-2- (o-ethoxycarbonyl) oxime, 1- (p-methoxyphenyl) -3-
(P-Nitrophenyl) -1,2,3-propanetrione-2- (o-phenyloxycarbonyl) oxime can be used, but is not limited thereto. Further, as another auxiliary agent, trialkylamines such as triethylamine, tributylamine, and triethanolamine can be mixed.

The photopolymerization aid is preferably blended in an amount of 0.1 to 50 parts by weight, more preferably 0.3 to 20 parts by weight, based on 100 parts by weight of the soluble polyimide.
If the amount is outside the range of 0.1 to 50 parts by weight, the intended sensitizing effect may not be reduced or may have an unfavorable effect on the developability. In addition, one kind of compound may be used as the photopolymerization aid, or several kinds may be mixed. Further, the composition for coverlay used in the present invention may further contain a copolymerizable monomer in addition to the above-mentioned sensitizer and photopolymerization aid in order to achieve a practically usable photosensitivity. The copolymerized monomer is a compound having a carbon-carbon double bond and facilitates photopolymerization. Examples of the copolymerizable monomers include bisphenol F EO modified (n ≒ 2) diacrylate, bisphenol A EO modified (n ≒ 2) diacrylate, sphenol S EO modified (n ≒ 2) diacrylate, and 1,6-hexanediol diacrylate. Acrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylolpropane tetraacrylate, tetraethylene glycol diacrylate, 1,6 -Hexanediol dimethacrylate,
Neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, tetramethylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxy Polyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2-hydroxypropyl methacrylate, stearyl methacrylate,
Phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1 ,
3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3 dimethacryloxypropane,
2,2-bis [4- (methacryloxyethoxy) phenyl]
Propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol di Acrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2-hydroxy1-acryloxy-3-methacryloxypropane, trimethylol Propane trimethacrylate, tetramethylol methane triacrylate, tetramethylol methane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, nonylphenoxy Polyethylene glycol acrylate, nonylphenoxy polypropylene glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4-butanediol di Methacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate Methacrylate,
1,4-cyclohexanedimethanol dimethacrylate,
Dipropylene glycol diacrylate, tricyclodecane dimethanol diacrylate, 2,2-hydrogenated bis
[4- (acryloxy-polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy-polypropoxy) phenyl] propane, 2,4-diethyl-1,5-
Pentanediol diacrylate, ethoxylated thimethylolpropane triacrylate, propoxylated thymethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxylated pentathritol tetraacrylate , Ditrimethylolpropane tetreacrylate,
Dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl allyl ether, 1,3,5-triacryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallylcitrate Rate, triallyl phosphate, allobarbital, diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-diaryloxy-2-propanol, diallyl sulfide diallyl maleate, 4, Preferred are 4'-isopropylidene diphenol dimethacrylate, 4,4'-isopropylidene diphenol diacrylate, and the like, but not limited thereto. There. In order to improve the crosslink density, it is particularly desirable to use a bifunctional or higher functional monomer. Further, from the viewpoint that warpage when a coverlay obtained from the composition for a photosensitive coverlay of the present invention is laminated on a flexible printed board can be reduced, a copolymer monomer and a bisphenol FEO modified (n ≒) are used.
2) Diacrylate, bisphenol A EO modified (n
≒ 2) It is preferable to use at least one or more diacrylates selected from diacrylate and bisphenol S EO modified (n ≒ 2) diacrylate.

The copolymerized monomer is preferably blended in an amount of 1 to 200 parts by weight, more preferably 3 to 150 parts by weight, based on 100 parts by weight of the soluble polyimide of the present invention. If the amount is out of the range of 1 to 200 parts by weight, the intended effect may not be obtained or the developing property may be unfavorably affected. In addition, as a copolymerization monomer, one kind of compound may be used, or several kinds may be mixed and used. The composition for coverlay used in the present invention may contain a suitable organic solvent. If it is dissolved in an appropriate organic solvent, it can be used in a solution (varnish) state, which is convenient when forming a film. The solvent used in this case is preferably an aprotic polar solvent from the viewpoint of solubility, specifically, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-benzyl-2.
-Pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-acetyl-ε-caprolactam, dimethylimidazolidinone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, γ-butyrolactone , Dioxane, dioxolan, tetrahydrofuran, and the like are preferred examples. These may be used alone or as a mixed system. This organic solvent may be a solvent in which the solvent used in the synthesis reaction of the polyimide is left as it is, or may be a newly added solvent to the isolated polyimide precursor. In order to improve the coating property, a solvent such as toluene, xylene, diethyl ketone, methoxybenzene, or cyclopentanone may be mixed within a range that does not adversely affect the solubility of the polymer. The solution of the composition for coverlay obtained in this manner is dried to obtain a film-shaped photosensitive coverlay film. At this time, it may be applied on a support such as a film of a metal or PET, dried and dried, and then peeled off from the support and handled as a single film. It can also be used in a state. The drying temperature of the coverlay composition is desirably set at a temperature at which the epoxy or the double bond / triple bond is not broken by heat, and specifically 180 ° C. or less, preferably 150 ° C.
It is below ° C. The photosensitive coverlay film thus obtained will be described. Usually, the process of FPC is
Adhesive coating, drying, and continuous lamination with copper foil on a long film. Good productivity. However, as described in the prior art, a hole and a window are formed in the cover lay film before bonding to match the joints with the terminals and components of the circuit, and the holes and the like of the cover lay film are formed by the FPC. Positioning to match a terminal part or a joint with a part is almost a manual operation, and furthermore, since it is bonded in a batch with a small work size, workability and positional accuracy are poor and cost is high. The photosensitive coverlay film of the present invention can be laminated at a temperature of 150 ° C. or less, and can be directly laminated on a printed circuit board without using an adhesive. The laminating temperature is preferably low, preferably 130 ° C. or lower, more preferably 110 ° C. or lower. In addition, the photosensitive coverlay of the present invention is capable of forming a hole for bonding to the FPC terminal portion by exposing and developing the coverlay after bonding the FPC and the coverlay. Can be improved.
FPC is joined by exposing it to a high temperature of 200 ° C. or more for several seconds when joining with solder. Therefore, it is preferable that the heat-resistant temperature of the coverlay after curing is higher, and the thermal decomposition temperature of the photosensitive coverlay alone after curing is 300 ° C or higher, preferably,
The temperature is 320 ° C or higher, more preferably 340 ° C or higher. The smaller the elastic modulus of the coverlay alone after the coverlay is formed, the better. This is to reduce the occurrence of stress due to mismatch between the elastic modulus and the coefficient of thermal expansion between the coverlay film and the base film. The elastic modulus of the coverlay alone after the coverlay is 10 to 3000 N / mm ² ,
Desirably, it is 10 to 2500 N / mm ² , more preferably 10 to 2000 N / mm ² . Copper is mainly used for the conductor layer of the FPC. When copper is exposed to a temperature exceeding 200 ° C., the crystal structure of copper gradually changes and the strength decreases. Therefore, it is necessary to set the curing temperature to 200 ° C. or lower. The step of laminating the photosensitive coverlay film thus obtained and the FPC will be described. This step is a step of protecting, with a coverlay film, the conductor surface of the FPC on which a circuit is formed in advance by a conductor such as a copper foil. Specifically, the FPC and the coverlay film are bonded together by heat lamination, hot press or hot vacuum lamination. The temperature at this time is desirably set at a temperature at which the epoxy or the double bond / triple bond is not broken by heat.
0 ° C. or lower, preferably 150 ° C. or lower, more preferably 130 ° C. or lower.

Next, after irradiating the film with light through a photomask having a predetermined pattern, an unexposed portion is dissolved and removed with a basic solution to obtain a desired pattern. This developing step may be performed using a general positive type photoresist current developing device.

As the developer, a basic solution or an organic solvent can be used. For example, the developer may be a solution of one type of compound or a solution of two or more types of compounds as long as it is an aqueous solution or an organic solvent exhibiting basicity. The basic solution is usually a solution in which a basic compound is dissolved in water or an alcohol such as methanol. The concentration of the basic compound is usually 0.1 to 50% w / w%,
From the influence on the supporting substrate and the like, the content is preferably 0.1 to 30% by weight /% by weight. In order to improve the solubility of polyimide, water-soluble organic liquids such as methanol, ethanol, propanol, isopropyl alcohol, N-methyl-2-pyrrolidone N, N-dimethylformamide, N, N-dimethylacetamide, etc. A cleaning medium may be further contained. Examples of the basic compound include an alkali metal, an alkaline earth metal or an ammonium ion, a hydroxide or a carbonate, and an amine compound.Specifically, 2-dimethylaminoethanol, 3-
Dimethylamino-1-propanol, 4-dimethylamino-1-butanol, 5-dimethylamino-1-pentanol, 6-dimethylamino-1-hexanol, 2-dimethylamino-2-methyl-1-propanol, 3-dimethylamino-2,2-dimethyl-1-propanol, 2-diethylaminoethanol, 3-diethylamino-1-propanol, 2-diisopropylaminoethanol, 2-di-
n-butylaminoethanol, N, N-dibenzyl-2-aminoethanol, 2- (2-dimethylaminoethoxy) ethanol, 2- (2-diethylaminoethoxy) ethanol, 1-dimethylamino-2-propanol, 1-diethylamino -2-propanol, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine,
N-lauryldiethanolamine, 3-diethylamino-
1,2-propanediol, triethanolamine, triisopropanolamine, N-methylethanolamine, N-ethylethanolamine, Nn-butylethanolamine, Nt-butylethanolamine, diethanolamine, diisopropanolamine , 2-aminoethanol, 3-amino-1-propanol, 4-amino-
1-butanol, 6-amino-1-hexanol, 1-amino-2-propanol, 2-amino-2,2-dimethyl-1
-Propanol, 1-aminobutanol, 2-amino-1
-Butanol, N- (2-aminoethyl) ethanolamine, 2-amino-2-methyl-1,3-propanediol,
2-amino-2-ethyl-1,3-propanediol, 3-
Amino-1,2-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, Potassium bicarbonate, ammonium bicarbonate,
Tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, aminomethanol, 2-aminoethanol, 3
-Aminopropanol, 2-aminopropanol, methylamine, ethylamine, propylamine, isopropylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, trimethylamine,
Although it is preferable to use triethylamine, tripropylamine, triisopropylamine, or the like, other compounds may be used as long as they are soluble in water or alcohol and the solution exhibits basicity. In addition, an organic solvent other than the basic solution can be used for the developing solution. In this case, even if the organic solvent is used alone,
A mixed system of a good solvent which dissolves the present photosensitive polyimide well and a poor solvent which does not dissolve it very much may be used. The pattern formed by the development is then washed with a rinsing liquid to remove the developing solvent. Preferable examples of the rinsing liquid include methanol, ethanol, isopropyl alcohol, and water having good miscibility with the developing liquid. By heating the pattern bound by the above process at a selected temperature from 20 ° C. to 200 ° C., the resin pattern made of the polyimide of the present invention is bound with high resolution. This resin pattern has high heat resistance and excellent mechanical properties.

[0038]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

In the examples, ESDA was 2,2-bis (4
-Hydroxyphenyl) propanedibenzoate-3,
3 ', 4,4'-tetracarboxylic dianhydride, BAPS
-M is bis [4- (3-aminophenoxy) phenyl]
Sulfone and DMAc represent N, N-dimethylacetamide, and DMF represents N, N-dimethylformamide. Thermal decomposition start temperature is TG / DT manufactured by Seiko Denshi Kogyo
According to A220, the temperature range from room temperature to 500 ° C. was measured at a heating rate of 10 ° C./min in the air, and the temperature at which the weight loss was 5% was defined as the thermal decomposition starting temperature. The measurement of the elastic modulus is J
According to IS C 2318. Peel adhesion strength is JI
It carried out according to the peeling strength (90 degrees) of SC6481. However, the width was measured with a width of 3 mm and converted to 1 cm. The weight average molecular weight was measured using GPC manufactured by Waters under the following conditions. (Column: manufactured by Shodex
KD-806M 2 tubes, temperature 60 ° C., detector: RI, flow rate: 1 ml / min, developing solution: DMF (lithium bromide 0.0
3M, phosphoric acid 0.03M), sample concentration: 0.2 wt%,
Injection volume: 20 μl, reference substance: polyethylene oxide) Measurement of imidation ratio: polyamic acid solution (DMF solution)
Is cast on a PET film, and 100 ° C. for 10 minutes, 1
After heating at 30 ° C for 10 minutes, peel off the PET film, fix it on a pin frame, 150 ° C for 60 minutes, 200 ° C for 60 minutes, 250 ° C
Heat for 60 minutes to obtain a 5 μm thick polyimide film.
Dissolve the polyimide prepared in Examples or Comparative Examples in DMF, cast on PET film,
After heating for a minute, the film was peeled off from the PET film, fixed to a pin frame, and placed in a vacuum oven at 80 ° C. and 5 mmHg for 12 minutes.
After heating and drying for a period of time, a polyimide film having a thickness of 5 μm was obtained. The IR of each film is measured, and the ratio of imide absorption / benzene ring absorption is determined. When the ratio of the absorption of imide obtained in the above / benzene ring ratio was 100%,
% Of the imide absorption / benzene ring ratio is determined. This is defined as the imidation ratio.

[0040]

Example 1 In a 2000 ml separable flask equipped with a stirrer, 8.60 g (0.02 mol) of BAPS-M and KF801 manufactured by Shin-Etsu Chemical as a siloxane diamine were used.
0 (in the above formula 1, x = 3, y = 10, R = C
H ₃ ) 33.2 g (0.04 mol), DMF 200 g
Then, 57.65 g (0.10 mol) of ESDA was added at once with vigorous stirring, and stirring was continued for 30 minutes. Next, 6.1 g (0.04 mol) of diaminobenzoic acid was dissolved in 75 g of DMF, added to the above solution, and stirred for 30 minutes to obtain a polyamic acid solution. The weight average molecular weight (hereinafter referred to as Mw) of this polyamic acid was 60,000.

This polyamic acid solution was placed in a Teflon (registered trademark) -coated vat and placed in a vacuum oven for 15 minutes.
0 ° C 10 minutes, 160 ° C 10 minutes, 170 ° C 10 minutes, 180
10 minutes at 190 ° C, 30 minutes at 210 ° C, 5 mmHg
Heated under reduced pressure. Remove from vacuum oven, 1
A thermoplastic polyimide having 00 g of carboxylic acid was obtained. The Mw of this polyimide was 65,000, and the imidation ratio was 1
00%. (Synthesis of Epoxy-Modified Polyimide) 33 g of the synthesized thermoplastic polyimide was dissolved in 63 g of dioxolan, 0.1 g of triethylamine and 50 mg of methoxyethanol were added, and then 0.85 g (6 mmol) of glycidyl methacrylate was added. The mixture was heated and stirred at 70 ° C. for 10 hours, and then 3.0 g (8 mmol) of Yuka Shell Epoxy 828 was added, followed by heating and stirring for 5 hours to synthesize an epoxy-modified polyimide solution. 0.5 g of 4,4'-diaminodiphenylsulfone (hereinafter abbreviated as DDS) is added to 100 g of the above epoxy-modified polyimide solution, and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide is used as a photoreaction initiator in an amount of 0.5 g. 5 g (1.2 mmol), 25 g of Aronix M-208 (bisphenol FEO modified (n @ 2) diacrylate) manufactured by Toagosei
Is applied on a 25 μm-thick pet film, dried at 45 ° C. for 5 minutes, peeled off the pet film, fixed with a pin frame, and dried at 65 ° C. for 5 minutes to obtain a photosensitive polyimide of 60 μm thickness / 25 μm thickness A two-layer PET film was obtained. Copper foil / photosensitive polyimide film 60
/ 25 μm thickness PET film
Lamination was performed under the conditions of 00 ° C. and 100 N / cm. After lamination, exposure was performed for 3 minutes (exposure condition: light of 400 nm was 10 mJ / cm ² ), and the PET film was peeled off for 1 minute.
Post-baking was performed at 00 ° C. for 3 minutes, and cured at 180 ° C. for 2 hours. The peel adhesive strength of this flexible copper-clad board was 9.8 N / cm (1.0 kgf / cm),
A line / space pattern of 00 μm could be formed, and no defects such as swelling were observed even when immersed in a 260 ° C. solder bath for 1 minute. The elasticity of the cured coverlay film after the copper foil of the flexible copper-clad board is removed by etching is 1000 N / mm ² , and the elongation is 25%.
The thermal decomposition onset temperature was 370 ° C. A copper foil / photosensitive polyimide film 60/25 μm thick PET film was overlaid and laminated at 100 ° C. and 100 N / cm. After lamination, line / space =
Cover with a 100/100 μm mask and expose for 3 minutes (exposure conditions: 400 nm light at 10 mJ / cm ² );
After the ET film was peeled off, it was post-baked at 100 ° C. for 3 minutes, and a 0.5% solution of tetramethyl hydroxide in isopropyl alcohol / water = 50/50 weight ratio (liquid temperature 4
(0 ° C.), and cured at 180 ° C. for 2 hours. When the pattern of this photosensitive coverlay film was observed with a microscope, the line / space was 100/100 μm.
Was able to draw the pattern of. Next, the warpage when the coverlay of the present invention is used as the coverlay on the flexible printed circuit board is measured. Kanebuchi Chemical Co., Ltd. polyimide film Apical NPI (25 μm thick) and DuPont film adhesive Pyralux (LF10
Laminate at 180 ° C. with the adhesive surfaces of 0) together.
Peel off the release paper, and use Mitsui Metal's electrolytic copper foil 3EC-VLP
(1 ounce) and laminated at 180 ° C. and cured at 180 ° C. to form a three-layer structure of base film (polyimide) / adhesive / copper foil. This is etched into a line /
An FPC (FIG. 1) in which a line having a space of 200 μm / 200 μm is drawn on one side is created. To this, a two-layer film of the aforementioned photosensitive polyimide 60 μm thick / 25 μm PET film was laminated at 100 ° C. so that the photosensitive polyimide layer was aligned with the copper foil, and exposed for 3 minutes (exposure conditions: light of 400 nm). 10mJ / cm ² ), PET
The film was peeled off and cured at 180 ° C. for 2 hours to prepare an FPC covered with a coverlay. This FPC is 10
When cut into cm squares and observed for warpage, there was no warpage.

[0042]

Example 2 33 g of the thermoplastic polyimide having a carboxylic acid synthesized in Example 1 and 66 g of dioxolane, 4,4
0.5 g of '-diaminodiphenylsulfone (hereinafter abbreviated as DDS), 0.5 g of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (1.2 g
Mmol), Aronix M-208 (bisphenol F EO-modified (n 変 性 2) diacrylate) manufactured by Toagosei
The solution to which 25 g was added was applied on a 25 μm-thick pet film, dried at 45 ° C. for 5 minutes, the pet film was peeled off, fixed with a pin frame, dried at 65 ° C. for 5 minutes, and the photosensitive polyimide 60 μm thickness / 25 μm A two-layer film of a thickness PET film was obtained. In the same manner as in Example 1, the adhesive strength of this flexible copper-clad board was 10.8 N / cm.
(1.1 kg weight / cm) and 100 μm line /
A pattern of spaces can be formed and 260
No defects such as swelling were observed even when immersed in a solder bath at ℃ for 1 minute. The elasticity of the cured photosensitive polyimide after removing the copper foil of the flexible copper adhesive plate by etching is 15
At 00 N / mm ² , the elongation was 20% and the thermal decomposition onset temperature was 375 ° C. Next, the warpage when the photosensitive coverlay of the present invention was used as the coverlay on the flexible printed circuit board was measured in the same manner as in Example 1, and no warpage was found.

[0043]

Example 3 <Synthesis of Polyimide Having Hydroxyl Group>
In a 2,000 ml separable flask equipped with a stirrer, 12.91 g (0.03 mol) of BAPS-M, DMF2
60 g was taken, and 57.65 g (0.1 mol) of ESDA was added at once with vigorous stirring, and stirring was continued for 30 minutes. Then, 2,2'-bis (3-amino-4-
(Hydroxyphenyl) hexafluoropropane 14.6
5 g (0.04 mol) was added and the mixture was stirred for 30 minutes, and then silicon diamine KF80102 manufactured by Shin-Etsu Chemical
4.9 g (0.03 mol) was added and stirred for 30 minutes to obtain a polyamic acid solution. The Mw of this polyamic acid is
It was 550,000. At this time, the reaction was carried out by cooling with ice water. This polyamic acid solution is placed on a Teflon-coated vat and placed in a vacuum oven at 150 ° C. for 10 minutes and at 160 ° C.
10 minutes, 170 ° C 10 minutes, 180 ° C 10 minutes, 190 ° C 1
The mixture was heated under reduced pressure at a pressure of 5 mmHg for 30 minutes at 210 ° C. for 0 minutes. It was taken out from the vacuum oven to obtain 105 g of a thermoplastic polyimide having a hydroxyl group. Mw of this polyimide
Was 60,000, and the imidation ratio was 100%.

<Synthesis of Epoxy-Modified Polyimide> 33 g of the hydroxyl-containing polyimide synthesized above was dissolved in 66 g of dioxolane, and 0.1 g of triethylamine was added thereto.
And 1.42 g (10 mmol) of glycidyl methacrylate dissolved in 25 g of dioxolane were added. Heat and stir at 60 ° C for 5 hours, and then HP40
32 4.08 g (epoxy equivalent 136) was added, and 60
The reaction was carried out at 5 ° C. for 5 hours to synthesize an epoxy-modified polyimide.

The above epoxy-modified polyimide solution 100
g to 3,5′-carbonylbis [7-
(Dimethylamino) coumarin] 0.3 g, benzophenone 1 g, tributylamine 0.5 g, Toagosei Aronix M-208 (bisphenol F EO modified (n ≒
2) 25 g of diacrylate) and 3 g of tri (ethane acrylate) isocyanurate were added to prepare a photosensitive composition. This solution was applied on a 25 μm thick pet film, dried at 45 ° C. for 5 minutes, and the pet film was peeled off.
It is fixed with a pin frame, dried at 65 ° C. for 5 minutes, and a photosensitive polyimide 60 μm thickness / 25 μm thickness PET film 2
A layer film was obtained. As in the case of Example 1, the adhesive strength of this flexible copper-clad board is 10 N / cm (1.02 kgf / cm), a pattern of 100 μm line / space can be formed, and soldering at 260 ° C. 1 for bath
No defects such as swelling were observed even when immersed. The elasticity of the cured photosensitive polyimide after the copper foil of the flexible copper-clad board is removed by etching is 1250 / mm ² ,
The elongation was 25% and the thermal decomposition onset temperature was 380 ° C. Next, the warpage when the photosensitive coverlay of the present invention was used as the coverlay on the flexible printed circuit board was measured in the same manner as in Example 1, and no warpage was found.

[0046]

Comparative Example 1 BAPS-M (43.05 g, 0.1 mol) and DMF (200 g) were placed in a 2,000 ml separable flask equipped with a stirrer, and ESDA 57.65 g.
(0.10 mol) was added at once with vigorous stirring, and stirring was continued for 30 minutes to obtain a polyamic acid solution. Mw of this polyamic acid was 62,000.

This polyamic acid solution is placed on a Teflon-coated vat and placed in a vacuum oven at 150 ° C. for 10 minutes.
160 ° C for 10 minutes, 170 ° C for 10 minutes, 180 ° C for 10 minutes, 1
The mixture was heated under reduced pressure at a pressure of 5 mmHg at 90 ° C for 10 minutes and 210 ° C for 30 minutes. It was taken out from the vacuum oven to obtain 95 g of soluble polyimide. Mw of this polyimide is 64,000,
The soluble polyimide 3 having an imidation ratio of 100%
0 g, a solution obtained by dissolving 3 g of Yuka Shell Epoxy 828 in 67 g of dioxolane was applied on a 25 μm thick pet film, dried at 45 ° C. for 5 minutes, peeled off the pet film, fixed with a pin frame, and fixed at 65 ° C. for 5 minutes. Dried, PE
The T film was peeled off and dried at 100 ° C. for 5 minutes to obtain a soluble polyimide 60 μm film. Of this film
The elastic modulus was 3200 N / mm ² . A soluble polyimide 60 μm film was placed on an FPC on which a line with a line / space of 200 μm / 200 μm was drawn on one side, and a Teflon sheet was pulled up and down as a release paper, and pressed at 250 ° C. and 3 MPa pressure to form a coverlay. To make an FPC. This was cut into a 10 cm square as in Example 1 and the warpage was measured.
cm.

[0048]

The composition for a photosensitive coverlay film and the photosensitive coverlay film of the present invention can be laminated at a temperature of 150 ° C. or less, and can be directly laminated on an FPC without using an adhesive. It is possible. In addition, it has excellent properties such as heat resistance, and has little warpage when laminated on an FPC.

[Brief description of the drawings]

FIG. 1 shows a line / space in an embodiment of the present invention.
² shows a 10 μm ² FPC of 200 μm / 200 μm.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 71/00 C08L 71/00 B 5E314 79/08 79/08 Z G03F 7/004 512 G03F 7/004 512 7/027 7/027 7/075 521 7/075 521 H05K 3/28 H05K 3/28 FDF term (reference) 2H025 AA00 AA10 AA13 AA14 AB11 AB15 AC01 AD01 BC32 BC42 BC43 CB25 EA08 FA03 FA17 4F071 AA51 AG15 AF20Y AH12 BC01 4F100 AB17D AB33D AK25B AK25J AK42 AK49B AK49C AK49J AK49K AK52B AK52J AK53B AK53J AL01B AL06B AT00A BA02 BA03 BA07 BA10A BA10B BA10C CB00 GB43 JB08B JB16B JJ03 JK01 JK07 JL01 JL04 JL11 JN17B 4J002 CH052 CM041 FD150 GQ00 4J043 PA05 PA08 QB26 RA05 SA06 SA62 SA71 SA85 SB02 TA22 UA132 UA142 UA152 UA262 UB022 UB052 UB122 UB162 UB302 UB351 WA09 ZA23 ZB11 ZB50 5E314 AA27 AA36 CC15 FF06 FF19 GG08

Claims (12)

[Claims] A photosensitive coverlay film composition containing a soluble polyimide obtained from a siloxane diamine represented by the following general formula 1. (Wherein R ¹ is
C ₁ -C ₁₂ alkyl or phenyl, x is 1-2
Integer of 0 and y show the integer of 1-40. ) 2. A polyimide obtained from a diamine containing 5 to 70 mol% of the siloxane diamine in the total diamine component as a raw material.
A composition for a photosensitive coverlay film as described in the above. 3. The composition for a photosensitive coverlay film according to claim 1, wherein the soluble polyimide is a polyimide obtained by using a diamine containing 20 to 50 mol% of the siloxane diamine in the total diamine component as a raw material. 4. The composition for a photosensitive cover lay according to claim 1, wherein the composition for a cover lay film contains a copolymerizable monomer having a carbon-carbon double bond. 5. The method according to claim 1, wherein said copolymerizable monomer is bisphenol F.
4. A diacrylate selected from EO-modified (n ≒ 2) diacrylate, bisphenol A EO-modified (n ≒ 2) diacrylate, and bisphenol S EO-modified (n ≒ 2) diacrylate.
5. The composition for a photosensitive cover lay according to any one of 4. 6. A photosensitive coverlay film obtained from the composition according to claim 1. 7. A photosensitive coverlay film using a soluble polyimide which has been imidized. 8. The photosensitive coverlay film according to claim 7, wherein the thermal decomposition onset temperature after curing is 300 ° C. or higher. 9. An elastic modulus after curing of 10 to 3000 N / mm.
Photosensitive coverlay film according to claim 7 or 8, characterized in that it is ^2. 10. The photosensitive coverlay film according to claim 7, wherein the curing temperature is 200 ° C. or lower. 11. The photosensitive coverlay film according to claim 7, which can be laminated at a temperature of 150 ° C. or lower. 12. A printed circuit board wherein the photosensitive coverlay film according to claim 6 is directly laminated on a printed circuit board without using an adhesive.