JPH024631B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a composite material with excellent heat resistance.

[Conventional technology]

Currently, substrates for flexible printed wiring boards are manufactured by bonding polyimide film and metal foil through an adhesive layer.

As a result, the heat resistance of the adhesive is insufficient, making it impossible to fully demonstrate the heat resistance of the polyimide film, and the soldering heat resistance of the substrate is approximately 260°C.

Furthermore, Japanese Patent Publication No. 39-348 discloses that an aromatic polyamic acid solution obtained from a tetracarboxylic acid such as pyromellitic acid and an aromatic diamine such as 4,4'-diaminodiphenyl ether is applied to a metal foil to form a substrate. However, there is a problem that the obtained substrate curls.

On the other hand, if silicon wafers or ceramic substrates used in semiconductor manufacturing are coated with polyamic acid and heated to imidize, there is no problem if the polyimide film is thin, but if the film becomes thick, the silicon wafer or Warping occurs on the ceramic plate, which becomes a problem. These are based on the mismatch in expansion coefficients between polyimide and inorganic materials such as metals, silicon, and ceramics.

[Purpose of the invention]

The present invention provides a composite body such as a flexible printed wiring board that has excellent heat resistance and does not curl by using a polyamic acid varnish using a special diamine, and a silicon wafer coated with polyimide and a ceramic board that does not warp. With the goal.

[Structure of the invention]

That is, in the present invention, the molar ratio of 3,3'-dichlorobenzidine and other aromatic diamine is from 50:50 to
A polyimide film formed by polymerizing a diamine component consisting of 95:5 and a tetracarboxylic dianhydride component containing 50 mol% or more of pyromellitic dianhydride is formed on an inorganic material, or a polyimide film and an inorganic material are formed on the inorganic material. Alternatively, it relates to a composite formed by integrating a layer containing an inorganic material.

The composite according to the present invention is produced by coating an inorganic material with a polyamic acid varnish obtained by reacting the aromatic diamine component and the tetracarboxylic dianhydride component in an aprotic polar solvent, or It can be produced by adding an inorganic material in powder form to a varnish, coating it on a suitable substrate, and then imidizing it. Note that, before imidization, etching, lamination of another inorganic material, an organic material such as a polyimide film, etc. may be performed.

In the present invention, the molar ratio of 3,3'-dichlorobenzidine and other aromatic diamine is such that the former/latter is
50/50 to 95/5, preferably 65/35 to 90/
It is 10. If the amount of 3,3'-dichlorobenzidine is less than 50 mol%, curling or warping will occur when the composite is formed. Moreover, if it exceeds 95 mol%, it becomes brittle.

Tetracarboxylic dianhydride components other than pyromellitic dianhydride used in the present invention include 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4' -Diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-
Biphenyltetracarboxylic dianhydride, 3,3',
4,4'-biphenyltetracarboxylic dianhydride,
2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, perylenetetra Carboxylic dianhydride, 3,3,4,4'-diphenylpropanetetracarboxylic dianhydride, 3,3',4,
4'-Diphenylhexafluoropropanetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride ethylene bistrimelitate tetracarboxylic dianhydride, etc. These components are preferably used in an amount of 50 mol% or less.

Other aromatic diamines to be combined with 3,3'-dichlorobenzidine include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,
3'-diaminophenyl sulfone, 4,4'-diaminodiphenylpropane, 4,4' diaminodiphenylhexafluoropropane, m-phenylenediamine, p-phenylenediamine, 4,4''-diaminoterphenyl, 4,4-diaminoquarterphenyl, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diaminobenzotrifluoride, 2,5-diaminobenzotrifluoride, 1,4-bis(p-aminophenoxy) ) Benzene, 1,3-bis(p-aminophenoxy)
Benzene, 4,4'-di(m-aminophenoxy)
Diphenylsulfone, 4,4'-di(p-aminophenoxy)diphenylsulfone, 4,4'-di(o
-aminophenoxy)diphenylsulfone, 4,
Examples include 4'-bis(p-aminophenoxy))diphenyl. Further, a siloxane-containing diamine may be added for the purpose of improving adhesiveness if it is 5 mol % or less based on the total amine component.

The aprontic polar solvent includes N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, dimethylsulfoxide,
Sulfolane, methylsulfolane, tetramethylurea, hexamethylphosphoramide, butyl lactone and the like are preferred. Two or more of these may be used in combination. In addition, these and xylene, toluene,
Add solvents such as phenol, acetone, methyl ethyl ketone, diacetone alcohol, cellosolves, cellosolve acetates, carbitols, methyl isobutyl ketone, cresol, xylenol, dioxane, cyclohexanone, hexafluoroisopropanol to the extent that polyamic acid does not precipitate. can be used.

The molar ratio of all diamine components and all tetracarboxylic dianhydride components is preferably equivalent, but it is acceptable even if one of the components is inadequate within 5 mol %.

The concentration of the polyamic acid varnish is preferably between 3 and 25% by weight in terms of viscosity and processability.

The reaction temperature to obtain polyamic acid varnish is 0.
The temperature is preferably ~50°C, but when the viscosity is finally adjusted, it is better to carry out the reaction at 70~80°C once the viscosity has reached a high level.

The polyamic acid varnish thus obtained is combined with an inorganic material to form a composite, examples of which are as follows.

In other words, (1) FPC substrates and amorphous solar cell substrates coated on metal foils such as copper, iron, aluminum, and stainless steel; (2) coated on chips of silicon, gallium arsenide, etc., and used as multilayer wiring interlayer insulation films. multilayer wiring
LSI, (3) A semiconductor device in which a passivation film is coated on an LSI chip and used as an α-ray shielding film.

(4) Copper, iron, aluminum, stainless steel, nickel, 42
Metal substrates such as alloy and amber used as insulating films for insulation between metal plates and wiring, (5) Liquid crystal display devices coated on glass plates and used as liquid crystal alignment films, (6) Alumina, silicon carbide (7) Enameled wire used as an insulating coating for conductive films such as copper wire; (8) Vapor deposition or sputtering on polyimide film. (9) Magnetic tapes, magnetic disks, etc. made by coating a polyimide film with varnish containing magnetic particles.

When used for flexible printed wiring boards, it is applied to copper foil using a coater, die, etc.
The solvent is removed by heating and the ring is closed to effect imidization. The imidization is preferably carried out in an inert gas to prevent oxidation of the metal foil.

When coating silicon wafers, ceramic plates, etc., it is best to coat with a spinner.

〔Example〕

Example 1 215.05 g of 3,3'-dichlorobenzidine, 30 g of 4,4'-diaminodiphenyl ether, 2000 g of N-methylpyrrolidone, N ,N
- Add 2000 g of dimethylacetamide, stir the contents, and cool the flask on ice. 218 g of pyromellitic dianhydride was gradually added and reacted at 10°C for 9 hours. The reduced viscosity of the produced polyamic acid is 2.13
dl/g (solvent N-methylpyrrolidone, concentration 0.1
g/100ml, temperature 25°C). This solution
Coated on 35μm rolled copper foil and heated at 100℃ in nitrogen atmosphere
Heat for 30 minutes at 250℃, then fix the copper foil and heat at 250℃ for 10 minutes.
Heat treatment was performed at 400°C for 10 minutes to obtain a substrate for a flexible printed wiring board with a coating thickness of 25 μm. This board is initially
After etching, it did not curl. As a result of the solder heat resistance test, no blistering occurred even at 350℃.

〔Effect of the invention〕

The present invention has excellent heat resistance, prevents curling,
A composite with less warpage was obtained.

Claims (1)

[Claims] 1. A diamine component consisting of a molar ratio of 3,3'-dichlorobenzidine and other aromatic diamine of 50:50 to 95:5, and a tetracarboxylic dianhydride component containing 50 mol% or more of pyromellitic dianhydride. A composite body formed by forming a polyimide film on an inorganic material, or integrating the polyimide film and an inorganic material or a layer containing an inorganic material.