JPH08230101A - Polyimide film laminated with metal foil - Google Patents

Abstract

PURPOSE: To integrally laminate a metal foil and a polyimide substrate layer with high adhesion by laying the metal foil over a multilayer extruded polyimide thin film provided by integrally laminating thermoplastic aromatic polyimide layers of a low logarithmic viscosity on a side of a high temperature-resistant polyimide substrate layer, and then heating and pressurizing the layers. CONSTITUTION: A multilayer extruded polyimide film 2 of a metal foil-laminated polyimide film 1 is formed by integral lamination of a thermoplastic aromatic polyimide thin film on at least one side of a high temperature-resistant aromatic polyimide substrate layer, which is achieved by, for example, the multilayer extrusion of a substrate layer polyimide precursor solution together with a thin film polyimide solution or its precursor solution. The metal foil-laminated polyimide film 1 is formed by laying a metal foil 3 on the thermoplastic aromatic polyimide thin film of the multilayer extruded polyimide film 2 and then heating and pressuring them for lamination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The polyimide film laminated with a metal foil according to the present invention has an extremely high heat resistance as an aromatic polyimide film having a thermoplastic aromatic polyimide layer on its surface.
Aromatic polyimide having dimensional stability and mechanical properties, strong adhesion between the thermoplastic aromatic polyimide layer and the aromatic polyimide film, and further having a thermoplastic aromatic polyimide layer on the surface Since the film and the metal foil are bonded together by thermocompression bonding of the thermoplastic aromatic polyimide thin layer and the metal foil without using any thermosetting adhesive such as epoxy resin, It has high heat resistance. The metal foil-laminated polyimide film of the present invention is useful for printed circuit boards, TAB tapes, composite lead frames, and the like.

[0002]

2. Description of the Related Art Conventionally, a composite material (for example, a copper clad substrate) composed of a metal foil and a heat-resistant film (for example, aromatic polyimide) support has been manufactured by using an aromatic polyimide film and a metal foil such as epoxy resin. It was common to manufacture by laminating by heat-bonding via a thermosetting adhesive.

However, since the thermosetting adhesive layer in the above composite material has a constant use temperature of 200 ° C. or less at which an appropriate adhesive force can be maintained, the process step of being exposed to high temperature such as soldering treatment, Alternatively, there is a problem that it cannot be used in applications exposed to high temperatures, and it has been expected that a composite material having more heat resistance will be used as a composite material of a metal foil and a heat resistant film.

As a countermeasure against this, various studies have been conducted on heat-resistant adhesives. However, known adhesives having high heat resistance require a high temperature in the laminating process or a complicated laminating process. In addition, there are problems such that the obtained laminate often does not exhibit sufficient adhesiveness, which is not practical.

On the other hand, some methods have been studied for producing a "adhesive-free composite material" in which a metal layer is formed on an aromatic polyimide film support without using any thermosetting adhesive or the like. Has been done. For example, as a method for producing the "adhesive-free composite material", a solution of an aromatic polyimide precursor (aromatic polyamic acid) is cast on a metal foil.
A method for forming a composite material by forming a film, or plating a metal on an aromatic polyimide film, and / or
Alternatively, a method for producing a composite material by vacuum vapor deposition has been proposed.

However, in the above casting film forming method, it is extremely difficult to sufficiently thicken the support layer, or the solvent evaporation / removal step in the film forming step takes an extremely long time for production. There was a problem that it was poor. Further, the above-mentioned metal plating method and / or metal vapor deposition method,
It is difficult to increase the thickness of the metal layer sufficiently, and the productivity is low in this respect. In addition, recently
Lamination of a thermoplastic aromatic polyimide and a metal foil,
Alternatively, a method for producing a laminate by using a thermoplastic polyimide for laminating an aromatic polyimide film and a metal foil (JP-A-62-53827, JP-A-6-93238, and JP-A-6-218880). Issue).

However, there are problems that the above-mentioned thermoplastic polyimide has poor heat resistance and dimensional stability, and that it has poor adhesion to an aromatic polyimide film. For the purpose of improving this, a method of modifying the surface of the aromatic polyimide film by plasma treatment or the like is performed. However, this method has problems that the number of steps of plasma treatment is increased and the adhesiveness does not always reach a satisfactory level.

Further, in the multi-layer extrusion molding method, "a multi-layer extruded polyimide film in which a thin layer of thermocompression-bonding aromatic polyimide is laminated on one surface of a specific heat-resistant aromatic polyimide with at least one base layer" A method of thermocompression bonding with a "metal foil" (Japanese Patent Application Laid-Open No. 4-33847-8) has been proposed. However, when this multilayer extrusion die is used, the degree of polymerization of the polyamic acid is high, and therefore the thermocompression-bonding fragrance is used. Since the fluidity of the group polyimide becomes poor, it is necessary to set the thermocompression bonding conditions at a high pressure.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to support an aromatic polyimide layer having a high heat resistance and a metal foil integrally bonded and laminated with a high adhesive force, the support comprising an aromatic polyimide. And a metal foil are laminated by a polyimide layer to provide a metal foil laminated polyimide film.

[0010]

That is, the present invention provides:
In a laminate in which a metal foil is bonded to at least one side of an aromatic polyimide film by a thermoplastic aromatic polyimide layer, a low logarithmic viscosity thermoplastic aromatic polyimide layer is integrally formed on at least one side of the high heat resistant aromatic polyimide layer. After the thermoplastic polyimide layer having a low logarithmic viscosity of the multilayer extruded polyimide film and the metal foil are laminated, the metal foil laminated polyimide film is characterized by being heated and pressed to be laminated. is there.

The present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a three-layer metal foil laminated polyimide film comprising a multilayer extruded polyimide film (support film) of the present invention and a metal foil, and FIG. 2 is a multilayer extruded polyimide of the present invention. It is sectional drawing which shows the example of the polyimide film of 5 layers of metal foil lamination which consists of a film (support film) and the metal foil laminated | stacked on the both surfaces.

The multilayer extruded polyimide film used in the metal foil laminated polyimide film of the present invention is
Suitably, an aromatic tetracarboxylic dianhydride or a derivative thereof and an aromatic diamine compound, and particularly preferably further obtained by polymerizing an aromatic dicarboxylic acid anhydride or a derivative thereof or an aromatic monoamine, obtained by imidization, Logarithmic viscosity (N, N-dimethylacetamide, 30 ° C., 0.
5 g / 100 ml) is 0.1 to 1.2 and the glass transition temperature (Tg) is 200 to 300 ° C., and the thin film B made of a low logarithmic viscosity thermoplastic aromatic polyimide is a substrate made of a highly heat resistant aromatic polyimide. The layer A is integrally laminated on at least one surface of the layer A, for example, by a multi-layer coextrusion molding-solution casting film formation method of a polyimide precursor solution for the base layer A and a polyimide solution for the thin film B or a precursor solution thereof. It is composed of.

The above-mentioned multilayer extruded polyimide film is disclosed, for example, in Japanese Patent Application Laid-Open No. HEI 3-
It can be preferably produced by applying the method described in No. 180343.

That is, an aromatic polyimide solution or a precursor solution (dope solution for a thin film) in which a thermoplastic aromatic polyimide or a precursor thereof is uniformly dissolved, and an aromatic compound which gives a highly heat-resistant aromatic polyimide An aromatic polyimide precursor solution (a dope solution for a base layer) in which a polyimide precursor is uniformly dissolved is simultaneously supplied to an extrusion molding machine having two or more extrusion molding dies to discharge the die. From the outlet, both solutions are continuously extruded as a thin film of at least two layers onto a smooth support (metal support), and the multilayer thin film on the support is dried to evaporate the solvent considerably. To form a self-supporting multilayer film (containing a part of the solvent), and then the multilayer film is peeled off from the support, and finally, the multilayer film is heated to a high temperature (250 to 500). ) Sufficiently the solvent by heating treatment and imidized polyamic acid which is a polyimide precursor with substantially removed, can be continuously manufactured.

The above-mentioned multilayer extruded polyimide film preferably has a total thickness of 6 to 250 μm, particularly 8 to 200 μm, and more preferably 10 to 150 μm.

This multilayer extruded polyimide film is one in which each polyimide layer is integrally and firmly bonded without peeling into two or three layers at the boundary between the base layer A and the thin film B. The three-layer type is suitable because it has less curl. In the metal foil-laminated polyimide film of the present invention, the multilayer extruded polyimide film may be a film having a two-layer structure composed of a base layer A and a thin layer B. It may be a film having a three-layer structure composed of B and B ′. In this case, the metal foil laminated polyimide film has 5 layers. In the film having the three-layer structure, the book layers B and B ′ have almost the same thickness (the book layer thickness ratio B / B ′ is 0.8 to 1.2, particularly 0.9 to 1.
Within the range of 1), the curl property becomes extremely small, which is optimal.

In the present invention, the aromatic polyimide having high heat resistance preferably has high heat resistance and has a glass transition temperature (Tg) of 330 ° C. or higher.
The aromatic diamine component and the aromatic tetracarboxylic acid component are preferably obtained by polymerization and imidization in an organic polar solvent, preferably at a ratio of about equimolar. Such an aromatic polyimide can be produced by a method known per se.

Examples of the aromatic diamine component include benzene-based diamines such as 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene and 1,2-diaminobenzene, 4,4 '. -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,
Diphenyl (thio) ether type diamine such as 4'-diaminodiphenyl thioether, 3,3'-diaminobenzophenone, benzophenone type diamine such as 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylphosphine, 4,4 ' Diphenylphosphine-based diamines such as diaminodiphenylphosphine, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylpropane,
Diphenylalkylene-based diamines such as 4,4′-diaminodiphenylpropane, 3,3′-diaminodiphenylsulfide, diphenylsulfide-based diamines such as 4,4′-diaminodiphenylsulfide, 3,3′-
Diphenyl sulfone-based diamines such as diaminodiphenyl sulfone and 4,4′-diaminodiphenyl sulfone,
Benzidine, benzidines such as 3,3′-dimethylbenzidine, bis (aminophenoxy) benzene-based diamines such as 1,3-bis (3-aminophenoxy) benzene,
Examples include bis (aminophenoxy) biphenyl-based diamines such as 4,4 ′-(3-aminophenoxy) biphenyl and bis [(aminophenoxy) phenyl] sulfone such as bis [(4-aminophenoxy) phenyl] sulfone. They can be used alone or as a mixture.

As the aromatic diamine component, 1,4-
Phenylenediamine such as diaminobenzene (p-phenylenediamine) alone or in an amount of 50 mol% or more thereof,
It is preferable to use a mixture with 4,4′-diaminodiphenyl ether or the like.

As the above-mentioned aromatic tetracarboxylic acid component, aromatic tetracarboxylic acid and its acid anhydride,
Examples thereof include salts and esters, and acid dianhydrides are particularly preferable. Examples of the aromatic tetracarboxylic acid include 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3', 3,4'-biphenyltetracarboxylic acid, pyromellitic acid, 3,3 ', 4. , 4'-benzophenone tetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) ether, bis (3,4-dicarboxyphenyl) thioether, bis (3,4-dicarboxyphenyl) phosphine, bis (3,4-dicarboxyphenyl) sulfone and the like can be mentioned.

They can be used alone or as a mixture. Among them, aromatic tetracarboxylic acid dianhydride is preferable, and particularly, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride is used alone or in an amount of 30 mol% or more and pyromellitic dianhydride is 70 mol% or less. It is preferred to use a mixture of

In the present invention, as the highly heat-resistant aromatic polyimide, 30 mol% or more, particularly 50 mol% or more of the 3,3 ', 4,4'-biphenyltetracarboxylic acid component (the balance is preferably pyrrole) is used. Meritic acid component) and 50 mol%
An aromatic polyimide composed of the above p-phenylenediamine component (the balance is preferably 4,4′-diaminodiphenyl ether component) is preferable because the resulting metal foil laminated polyimide film has good dimensional accuracy. .

As the organic polar solvent used in the above polymerization reaction, a solvent that uniformly dissolves each monomer component and polyamic acid, which is a polyimide precursor produced by both monomer components, is used. Examples of such organic polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-
Examples thereof include amide solvents such as methylcaprolactam, dimethyl sulfoxide, hexamethylphosphamide, dimethyl sulfone, tetramethylene sulfone, dimethyltetramethylene sulfone, pyridine and ethylene glycol. These organic polar solvents are benzene,
It can also be used as a mixture with other organic solvents such as toluene, benzonitrile, xylene, solvent naphtha, and dioxane.

When carrying out the polymerization reaction, the concentration of all the monomers in the organic polar solvent is 5 to 40% by weight, especially 6 to
It is preferably 35% by weight, more preferably 10 to 30% by weight.

The above-mentioned polymerization reaction of the aromatic tetracarboxylic acid component and the aromatic diamine component is carried out, for example, by mixing them in the above organic polar solvent at a substantially equimolar ratio and
It can be carried out by carrying out the reaction for about 0.2 to 60 hours at a reaction temperature of 00 ° C or lower, preferably 10 to 80 ° C.

The organic polar solvent solution of the aromatic polyamic acid used for the production of the highly heat-resistant aromatic polyimide film in the present invention has a rotational viscosity measured at 30 ° C. of about 10 from the viewpoint of workability. 20,000 poise, especially 3
It is preferably in the range of 0 to 15,000 poise, and more preferably in the range of 50 to 12,000 poise. Therefore, it is desirable to carry out the above polymerization reaction until the resulting organic polar solvent solution of the aromatic polyamic acid has a viscosity in the above range.

In the present invention, it is necessary to use a low log viscosity thermoplastic aromatic polyimide layer,
This makes it possible to obtain a metal foil-laminated polyimide film having high adhesiveness and high reliability. The thermoplastic aromatic polyimide has a logarithmic viscosity of 0.1 to 1.2 obtained by polymerizing and imidizing an aromatic tetracarboxylic dianhydride component and an aromatic diamine component in an organic polar solvent.
(N, N-dimethylacetamide, 30 ° C., 0.5 g /
100 ml), glass transition temperature (Tg) is 200 to 3
It is preferably 00 ° C.

As the aromatic tetracarboxylic acid component, pyromellitic acid dianhydride and benzophenonetetracarboxylic acid dianhydride can be used.
4'-biphenyltetracarboxylic dianhydride, 2,
3 ′, 3,4′-biphenyltetracarboxylic dianhydride and the like are preferable, and as the aromatic diamine component, diaminodiphenyl ethers, di (aminophenoxy) benzenes, bis (aminophenoxyphenyl) sulfones,
Bis (aminophenoxyphenyl) propanes are preferred.

As a thermoplastic aromatic polyimide, an aromatic dicarboxylic acid anhydride or a derivative thereof or an aromatic monoamine is reacted with the amine or dicarboxylic acid at the end of the aromatic polyamic acid (precursor) for the purpose of improving fluidity. A both-end-sealed polyimide that is sealed and imidized is particularly preferable. As the aromatic dicarboxylic acid anhydride, phthalic anhydride is preferable. Moreover, aniline is mentioned as an aromatic monoamine.

Particularly, as the thermoplastic aromatic polyimide, an aromatic tetracarboxylic dianhydride or its derivative containing 30 mol% or more of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride or its derivative. And the general formula I

Embedded image (Provided that X is O, CO, C (CH ₃ ) ₂ or SO ₂ and when two or more are present, they may be the same or different, and n is an integer of 0 to 4) The compound and the aromatic dicarboxylic acid anhydride or its derivative or the aromatic monoamine are polymerized in an organic polar solvent and imidized to obtain a logarithmic viscosity of 0.1 to 1.2.
(N, N-dimethylacetamide, 30 ° C., 0.5 g /
100 ml), glass transition temperature (Tg) is 200 to 30
A 0 ° C. non-adhesive type both-end-capped aromatic polyimide is preferred.

The non-adhesive type low-logarithmic-viscosity thermoplastic aromatic polyimide does not adhere to a high heat-resistant aromatic polyimide film by a known coating method, and a laminate having high adhesive strength cannot be obtained. However, a multilayer extruded polyimide having high productivity and high quality can be obtained by the multi-layer extrusion in the present invention to obtain a laminate having high adhesive strength with a highly heat-resistant aromatic polyimide film, and further, the adhesion with a metal support is reduced. It is particularly preferable because a film can be obtained.

It is preferable to add a phosphate ester or a salt of a tertiary amine, a phosphate ester and an amine to the thermoplastic aromatic polyimide solution or the precursor solution thereof, and to add titanium oxide, silicon dioxide or the like. You may add a filler. The filler may be added at any stage of the reaction.

The above-mentioned solution of the thermoplastic aromatic polyimide or the precursor thereof and the solution of the highly heat-resistant aromatic polyimide precursor have a polymer concentration in the above-mentioned organic polar solvent,
10 to 50% by weight, especially 15 to 45% by weight, 30
Those having a rotational viscosity measured at 0 ° C. of 10 to 50,000 poises, particularly 50 to 20,000 poises are preferable.

The metal foil used in the metal foil laminated polyimide film of the present invention is a conductive metal made of at least one metal or alloy selected from the group consisting of iron, aluminum, copper, gold and silver. It may be a foil, and particularly, the thickness is 5 to 100 μm, more preferably 1
A long electrolytic copper foil having a width of 0 to 60 μm and a width of 5 to 200 cm can be preferably mentioned.

The production of the metal foil-laminated polyimide film of the present invention is preferably carried out by directly (thermosetting) the "long metal foil" on the thin layer of the aforementioned "long multilayer extruded polyimide film". No adhesive, etc.)
The polymer is supplied between a pair of thermo rolls, and the temperature is higher than the glass transition temperature (Tg) of the thermoplastic aromatic polyimide and 230 to 400 ° C. (preferably 240 to 380).
C.) and a linear pressure between the heat rolls of 1 to 500 kg / cm (preferably about 2 to 300 kg / cm), and thermocompression bonding is performed continuously. The thermocompression bonding pressure in this case is 0.5 to 100 kg.
/ Cm ² , especially 1 to 80 kg / cm ² .

In the above-mentioned manufacturing method, the thermocompression bonding operation is carried out in an atmosphere of an inert gas such as nitrogen gas, neon gas, argon gas or the like in order to prevent thermal deterioration of the metal foil such as the copper foil. It is preferable that a metal foil (for example, a stainless steel foil, an aluminum foil or the like) for preventing thermal deterioration is superposed on the metal foil of (1) and subjected to thermocompression bonding at high temperature.

The above method can be continuously carried out using, for example, the apparatus shown in FIG. 3 and using a long multilayer extruded polyimide film and a metal foil.

As the above-mentioned method, using the apparatus shown in FIG. 3, the long double-layer extruded polyimide film 10 (high heat resistant substrate layer A and thermoplastic thin layer B) is fed from the raw material supply roll 7. And the thermoplastic thin layer B of the expander roll 11 and the guide roll 12
Via a pair of heat rolls 13 and 1 under tension
4 (elastic roll or metal roll) while supplying the long metal foil 20 from the raw material supply roll 6,
In a tense state, it is supplied between the pair of heat rolls via the expander roll 11 or the like, and both are directly overlapped with each other and thermocompression-bonded with the heat rolls 13 and 14 to be integrally laminated, and the lamination is performed. The body is preferably cooled through a chill roll (not shown) and finally by a take-up roll 15 a continuous take-up metal foil with a take-up speed of 1-200 cm / min, in particular 5-100 cm / min. It is preferable to manufacture the laminated polyimide film 1.

In the above method, when a long three-layer extruded polyimide film is used, the above-mentioned FIG.
The above three-layer extruded polyimide film 10 is supplied from the central raw material supply roll 7 in the apparatus of FIG.
Is simultaneously supplied, and the three members are superposed and supplied between the heat rolls 13 and 14, so that thermocompression bonding can be performed.

In the metal foil-laminated polyimide film obtained by the above method, the thin layer B and the above metal foil are directly thermocompression-bonded to each other, and their adhesive strength (90 ° -peeling method) is used.
Is at least 0.6 kg / cm or more, particularly about 0.7 to 5 kg / cm at room temperature, and the peeling interface is the interface between the surface of the thin layer B and the surface of the metal foil, and the base layer A Peeling does not substantially occur at the interface between the thin layer B and the thin layer B. Further, it is floated in a solder bath (about 288 ° C.) for 10 seconds and brought into contact with it, and swelling or peeling occurs on the thermocompression bonding surface. It has excellent heat resistance. The take-up roll 15 has a take-up core diameter of 25 cm so as not to apply stress to the metal foil laminated polyimide film.
It is preferable to use the above winding roll.

Further, as one aspect of the present invention, the thermoplastic aromatic polyimide layer is provided on one side or both sides of the five-layer metal foil laminated film, and a metal foil or the like is further provided on the seven layers. Alternatively, a 9-layer metal foil laminated film is also included. The 7-layer or 9-layer metal foil laminated film preferably has a thickness (total) of 100 to 400 μm. When the metal foil laminated polyimide film of the present invention wound on a take-up roll is used, the winding curl (stress) is released by a method known per se for use.

[0042]

EXAMPLES Examples of the present invention will be shown below. In the following examples, parts indicate parts by weight.

The measurement test of each example was performed as follows. Logarithmic viscosity Logarithmic viscosity = natural logarithm (solution viscosity / solvent viscosity) / solution concentration The solution concentration was measured by dissolving 0.5 g of the polymer in 100 ml of the solvent. The glass transition point (Tg) was obtained by a differential scanning calorimeter (DSC) or a film sample was obtained by thermomechanical analysis (TMA). Adhesive strength The adhesive strength of the metal foil laminated film is IPC-TM- (2.
4.9. ) Of "90 ° -peeling method". Solder resistance IPC-TM-650 (2.4.13) according to the measurement method, the metal foil laminated film of the sample was placed on the metal foil side and the solder bath in a solder bath maintained at a temperature of 288 ± 5 ° C. Was floated for 10 seconds so as to contact with each other, and the presence / absence of swelling or peeling of the metal foil laminated film was visually determined (defective / defective). Rotational viscosity The viscosity was measured at 30 ° C. using Bismetron manufactured by Tokyo Metrology Co., Ltd. Reliability evaluation The same operation was repeated 10 times, and when all of the same results were obtained, the results were evaluated as good, and when the result was not good even once, it was evaluated as bad. Dimensional change rate A on the metal foil laminated polyimide film (copper clad board),
Two points B were marked, and the lengths of the intervals A and B were measured.
Further, the copper clad plate was subjected to the steps of etching the entire surface: washing with water: drying according to a conventional method, and then the distance between A and B was measured, and the dimensional change rate was obtained using the following formula. The smaller this value, the smaller the dimensional change and the better the dimensional accuracy. Dimensional change rate = [(L ₀ −L) / L ₀ ] × 100 (%) L ₀ ; length between A and B before etching L; length between A and B after etching

Reference Example 1 1020 parts of N, N-dimethylacetamide (DMAc) was used as a solvent in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, a reflux condenser, and a stirrer, and (a) aromatic tetracarboxylic acid. Acid component; 3, 3 ', 4,
4'-biphenyltetracarboxylic dianhydride (s-BP
DA) 83.85 parts (285 mmol) and 2,3
3 ', 4'-biphenyltetracarboxylic dianhydride (a
-BPDA) 83.85 parts (285 mmol), (b) aromatic diamine component; bis [4- (4-aminophenoxy) phenyl] sulfone (4-BAPS) 25.
9.5 parts (600 mmol), and (c) aromatic dicarboxylic acid component; phthalic anhydride (PA)
8.89 parts (60 millimoles), particle size of about 600Å
The DMAc solution of colloidal silica of was added so that the weight of the colloidal silica was 2 parts, and the mixture was stirred at 25 ° C. for 6 hours to obtain a solution of polyamic acid.

To 500 parts of this polyamic acid solution was added 50 parts of toluene for azeotropic dehydration, and the mixture was allowed to react at a reaction temperature of about 165 ° C. for about 4 hours while blowing nitrogen gas and stirring to distill the produced water. To produce a uniform polymer solution. A part of this polymer solution was put into methanol,
A polymer was deposited, an aromatic polyimide powder was recovered, and the aromatic polyimide powder was washed with hot methanol and then dried to obtain a thermoplastic aromatic polyimide. The obtained polyimide had a Tg of 169 ° C. and an inherent viscosity of 0.38. This thermoplastic aromatic polyimide was used as a DMAc solution (30% by weight concentration, rotational viscosity 1100 poise).

Reference Example 2 To the reaction vessel used in Reference Example 1, 1010 parts of DMAc was added, and (a) as an aromatic tetracarboxylic acid component, 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride (s-
BPDA) 113.0 parts (384 mmol) and 2,
3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA) 113.0 parts (384 mmol), (b) aromatic diamine component; 1,4-diaminophenyl ether (DADE) 80.1 Parts (400 mmol) and 1,4-bis (4-aminophenoxy) benzene (APB) 116.9 parts (400 mmol), and (c) aromatic dicarboxylic acid component; phthalic anhydride (PA).
Reference Example 1 except that 9.48 parts (64 mmol) was added.
A polyimide solution (concentration: 30% by weight, rotational viscosity: 1300 poise) was prepared in the same manner as in.

Reference Example 3 Same as Reference Example 1 except that a-BPDA and 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) were used as the components (a) and (b). To obtain an aromatic polyimide solution (rotational viscosity 1200 poise).

Reference Example 4 The same procedure as in Reference Example 3 was repeated except that the aromatic dicarboxylic acid component was not added, imidization was not performed, and the polymer concentration was 18% by weight. 1200 poise) was prepared.

Reference Example 5 A polyamic acid solution (rotary viscosity) was prepared in the same manner as in Reference Example 4 except that s-BPDA and DADE were used as components (a) and (b), an aromatic dicarboxylic acid was added, and imidization was not performed. 1500 poise) was obtained.

Example 1 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and paraphenylenediamine (P
PD) and N, N-dimethylacetamide (DMA
Polymerization was carried out in c) to prepare an aromatic polyamic acid solution having a polymer concentration of 18% by weight and a solution viscosity of 1600 poise.

Using a solution prepared by adding 0.1 part of monostearyl phosphate ester triethanolamine salt to 100 parts of the polyimide polymer to the polyimide solution of Reference Example 1 and the above aromatic polyamic acid solution, Extruded from a two-layer extrusion die onto the upper surface of a smooth metal support for 2 m
Casting at a speed of / min, continuously drying with hot air at 140 ° C., solidified film (self-supporting film, solvent content:
35% by weight), the solidified film is peeled off from the support, and then gradually heated from 200 ° C. to 450 ° C. at a rate of 2 m / min in a heating furnace to remove the solvent and remove the polymer. It was imidized.

Then, by using the apparatus shown in FIG. 3, the long double-layer extruded polyimide film 10 is fed from the raw material feed roll 7 so that the thin layer B is on the upper side, while the raw material is fed. A long 35 μm cleaned electrolytic copper foil 20 is supplied from the supply roll 6, the both are superposed with the expander roll 11 and the like, and subsequently supplied to the heat rolls 13 and 14, and shown in Table 2. Thermocompression bonding was performed under the conditions to produce a metal foil-laminated polyimide film.

With respect to the above-mentioned metal foil laminated film, its adhesive strength (90 ° -peeling, room temperature), solder resistance and dimensional change rate were measured. The reliability was evaluated by repeating the same operation. The results are shown in Tables 1 and 2.

Example 2 A three-layer extruded polyimide film (7) having the thermoplastic polyimide layers (10 μm) of Reference Example 1 on both sides of the base layer A was prepared in the same manner as in Example 1 except that a three-layer extrusion die was used.
0 μm) was obtained. In the same manner as in Example 1 except that copper foil was supplied to both sides of this multilayer extruded polyimide film, a five-layer metal foil laminated polyimide film (140 μm) was obtained. The results are shown in Tables 1 and 2.

Examples 3 to 4 A solution prepared by adding 0.1 part of a monostearyl phosphate ester triethanolamine salt to 100 parts of a polyimide polymer in the polyimide solutions prepared in Reference Examples 2 to 3 was used.
A 5-layer metal foil laminate was obtained in the same manner as in Example 2 except that the pressure bonding conditions shown in Table 2 were used. The results are shown in Tables 1 and 2.

Comparative Example 1 The polyamic acid solution prepared in Reference Example 4 was used.
A metal foil laminated polyimide film was obtained in the same manner as in Example 2 except that thermocompression bonding was performed under the above conditions. The results are shown in Tables 1 and 2.

Example 5 DMAc448 was placed in a cylindrical polymerization tank having an internal volume of 10 liters.
0 part, PPD227.09 part (2.1 mol), 4,4 '
-Diaminodiphenyl ether 180.22 parts (0.9
Mol) and stirred at room temperature (about 30 ° C.) in nitrogen. To this solution, s-BPDA441.33 parts (1.5 mol) and pyromellitic dianhydride 327.18 parts (1.5 mol) were added, and stirred for 6 hours to obtain a solution of polyamic acid (rotary viscosity: 1700). Poise, 20% by weight) was obtained.

Using this polyamic acid solution and the polyimide solution of Reference Example 1, a three-layer extruded polyimide film was obtained in the same manner as in Example 2. Using this polyimide film, a metal foil laminated polyimide film was obtained in the same manner as in Example 2. The results are shown in Tables 1 and 2.

Example 6 The polyimide solution obtained in Reference Example 1 was applied to a 35 μm electrolytic copper foil, dried and then heated at 300 ° C. for 10 minutes to prepare a metal having a thermoplastic polyimide layer (10 μm) on one side. Got foil. A metal foil having a thermoplastic polyimide layer on one side thereof was thermocompression-bonded (350 ° C., 20 kg / cm) with the thermoplastic polyimide layer side on both sides of the metal foil laminated polyimide film obtained in Example 2. Stacked in 9
A layered metal foil laminated polyimide film was obtained. The results are summarized in Tables 1 and 2.

Example 7 Using the polyamic acid solution prepared in Reference Example 5, Table 2
A five-layer metal foil laminated polyimide film was obtained in the same manner as in Example 2 except that the above pressure-bonding conditions were used. The results are shown in Tables 1 and 2.

Example 8 A three-layer extruded polyimide film (thickness 70 μm) having thermoplastic polyimide layers (thickness 10 μm) on both sides prepared in Example 2 was cut into a 10 mm square and placed on a polyimide-coated Si chip. , And 42Ni on it
Arrange a comb-shaped lead frame made of Fe alloy,
Thermocompression bonding was performed at 30 kg / cm ² for 5 seconds. The peel strength of the obtained laminate was 1.0 kg / cm.

Comparative Example 2 Obtained in Reference Example 5 on both sides of an aromatic polyimide film (thickness 50 μm) obtained from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine. The polyamic acid solution was coated with a comma coater at a rate of 2 m / min so that the weight of the film was 20% by weight (40% by weight on both sides) based on the dry matter. It was dried in a hot air oven at ℃. Further, while continuously moving in a high temperature furnace, heat treatment was performed at 200 ° C. to 350 ° C. for 3 minutes to obtain an aromatic polyimide film (multilayer film) having a thickness of 70 μm. The same procedure as in Example 7 was carried out except that this multilayer aromatic polyimide film was used.
The results are shown in Tables 1 and 2.

The curl degree of the three-layer multi-layer extruded polyimide film produced in Examples 2 to 5 and Example 7 was 10 mm or less. Curling degree is 20 cm in length and 3.5 c in width
The sample film of m was placed on a flat substrate with a flat surface, and the height of the sample portion farthest from the flat substrate was measured by the "Toray method".

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

Since the present invention is configured as described above, it has the following effects.

The adhesive strength between the metal foil and the thermoplastic polyimide film (layer) is high, and peeling does not occur at the interface between the highly heat-resistant aromatic polyimide layer and the thermoplastic aromatic polyimide layer. In addition, the metal foil laminated polyimide film has good solder resistance.

Further, when the thermoplastic aromatic polyimide layer having a low logarithmic viscosity is used, the thermocompression bonding with the metal foil can be performed under a gentle (low pressure) condition, so that a highly reliable result can be obtained.

Further, as the highly heat-resistant aromatic polyimide, 3,3 ', 4,4'-biphenyltetracarboxylic acid component 30 mol% or more and p-phenylenediamine component 50 are used.
When the polyimide composed of more than mol% is used, the dimensional change rate of the metal foil laminated polyimide film is small and the dimensional accuracy is excellent.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a three-layer metal foil laminated polyimide film of the present invention.

FIG. 2 is a cross-sectional view showing an example of a five-layer metal foil laminated polyimide film of the present invention.

FIG. 3 is a schematic view of an apparatus for producing a metal foil laminated polyimide film.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 metal foil laminated polyimide film 2 multilayer extruded polyimide film 3 metal foil 6 raw material supply roll 7 raw material supply roll 8 raw material supply roll 9 furnace 10 2 (multi) layer extruded polyimide film 11 expander roll 12 guide roll 13 heat roll 14 heat Roll 15 Winding roll 20 Metal foil 20 'Metal foil

Claims (7)

[Claims] 1. A laminate in which a metal foil is bonded to at least one surface of an aromatic polyimide film by a thermoplastic aromatic polyimide layer, wherein a thermoplastic fragrance having a low logarithmic viscosity is provided on at least one surface of the highly heat-resistant aromatic polyimide layer. A metal foil laminated polyimide film, characterized in that a thermoplastic polyimide layer of a multilayer extruded polyimide film in which a group polyimide layer is integrally laminated and a metal foil are laminated and then heated and pressed to be laminated. 2. The linear expansion coefficient of the multilayer polyimide film is 1 × 10 ^{−5 to} 3 × 10 ⁻⁵ cm / cm / ° C.
A metal foil-laminated polyimide film as described above. 3. A thermoplastic aromatic polyimide having a logarithmic viscosity of 0.1 to 1.2 (N, N-dimethylacetamide, 3
At 0 ° C, 0.5 g / 100 ml), glass transition temperature (T
The metal foil laminated polyimide film according to claim 1, wherein g) is 200 to 300 ° C. 4. A highly heat-resistant aromatic polyimide containing 30 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic acid component and 50 mol% or more of p-phenylenediamine component, and glass. The metal foil-laminated polyimide film according to claim 1, which has a transition temperature (Tg) of 330 ° C. or higher. 5. A thermoplastic aromatic polyimide comprising biphenyltetracarboxylic dianhydride or a derivative thereof.
An aromatic tetracarboxylic dianhydride or a derivative thereof in an amount of not less than mol%; (Provided that X is O, CO, C (CH ₃ ) ₂ or SO ₂ , and when two or more, they may be the same or different, and n is an integer of 0 to 4) A diamine compound and an aromatic dicarboxylic acid anhydride or a derivative thereof are polymerized in an organic polar solvent and obtained by imidization,
Non-adhesive type both-end sealing with logarithmic viscosity of 0.1 to 1.2 (N, N-dimethylacetamide, 30 ° C., 0.5 g / 100 ml) and glass transition temperature (Tg) of 200 to 300 ° C. The metal foil-laminated polyimide film according to claim 1, which is an aromatic polyimide. 6. The metal foil laminated polyimide film according to claim 1, wherein the metal foil is an electrolytic copper foil. 7. A multilayer extruded polyimide film is obtained by extruding a highly heat-resistant aromatic polyimide precursor solution and a low logarithmic viscosity thermoplastic aromatic polyimide solution or a precursor solution thereof by a multilayer extrusion method. The polyimide film of a metal foil laminate according to claim 1, which is an aromatic polyimide film having a low logarithmic viscosity thermoplastic aromatic polyimide layer on its surface, which is produced by drying the resulting laminate and then subjecting it to a heat treatment including a heat treatment step. .