JPH08230103A - Metal foil-laminated polyimide film - 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 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 polyimide film 2 of a metal foil-laminated polyimide film 1 is formed by coating at least one side of a high temperature-resistant aromatic polyimide substrate layer with a thin film formed by applying thereto a thermoplastic aromatic polyimide thin film by a coating method, and then drying and heating the laminate. The metal foil-laminated polyimide film 1 is formed by laying a metal foil on the thermoplastic aromatic polyimide thin film of the multilayer polyimide film 2 and then heating and pressuring them for lamination.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The metal foil laminated polyimide film of the present invention is a highly heat-resistant aromatic polyimide film having a thermoplastic aromatic polyimide layer on its surface, which has high dimensional stability and mechanical properties. At the same time, the adhesion between the thermoplastic aromatic polyimide layer and the highly heat-resistant aromatic polyimide film is strong, and the bonding between the highly heat-resistant aromatic polyimide film and the metal foil is thermosetting like an epoxy resin. Since it is bonded by thermocompression bonding of a thin layer of thermoplastic aromatic polyimide and metal foil without using any adhesive, it has high heat resistance with almost no oxidative deterioration like epoxy resin. I have. The metal foil laminated polyimide film of the present invention is a printed circuit board,
It is useful for TAB tapes, composite lead frames, etc.

[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 combining an aromatic polyimide film and a metal foil with "epoxy resin or the like". It was common to manufacture by laminating by heat-bonding via the "thermosetting adhesive of".

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, it is subjected to a working process such as soldering or the like, or However, there is a problem that it cannot be used in applications that are exposed to high temperatures, and a composite material having a metal foil and a heat-resistant film was expected to have higher heat resistance.

As a countermeasure against this, various studies have been conducted on heat-resistant adhesives. However, adhesives with 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 "adhesive-free composite materials" in which a metal layer is formed on an aromatic polyimide film support without using a thermosetting adhesive or the like have been studied.

For example, as a method for producing the "adhesive-free composite material", a composite material obtained by casting and film-forming a solution of an aromatic polyimide precursor (aromatic polyamic acid) on a metal foil,
Alternatively, a composite material in which a metal is plated on an aromatic polyimide film and / or vacuum deposited is proposed.

However, it is extremely difficult to sufficiently thicken the support layer in the above-mentioned composite material by the casting film forming method, or the solvent evaporation / removal step in the film forming step takes an extremely long time. There was a problem that productivity was low. In addition, it is difficult for the metal plating method and / or the metal vapor deposition method described above to sufficiently increase the thickness of the metal layer, and in this respect, the productivity is low.

Furthermore, recently, a laminate produced by using a thermoplastic polyimide for laminating a thermoplastic polyimide and a metal foil, or for laminating a polyimide film and a metal foil (JP-A-62-53827). ,
JP-A-6-93238, JP-A-6-218880
Issue).

However, these laminates have insufficient heat resistance, dimensional stability and mechanical properties of the thermoplastic polyimide, and are relatively strict conditions (pressure, time) for laminating the metal foil and the multilayer polyimide film. Therefore, there is a problem in the reliability (reproducibility) of the metal foil laminated polyimide film obtained when manufactured by an industrial production speed. Therefore, the characteristics of the metal foil laminate using these thermoplastic polyimides are not satisfactory.

Further, in the multilayer extrusion molding method, "a multilayer extruded polyimide film in which a thin layer of thermocompression-bonding aromatic polyimide is laminated on a specific heat-resistant aromatic polyimide with at least one base layer integrally on one side" A laminate in which “metal foil” is thermocompression-bonded has been proposed (JP-A-4-33847-8). However, when a multilayer extrusion die is used, the workability of casting a polyamic acid solution and the laminate It is not easy to satisfy both physical properties.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is that a support made of an aromatic polyimide film having high heat resistance and a metal foil are integrally bonded and laminated with a high adhesive force. It is intended to provide a metal foil laminated polyimide film in which a support made of only and a metal foil are laminated with polyimide.

[0012]

That is, the present invention provides:
In 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, a low logarithmic viscosity thermoplastic aromatic polyimide is integrally formed on at least one surface of a high heat-resistant aromatic polyimide layer. The present invention relates to a metal foil laminated polyimide film in which a thermoplastic polyimide layer of a multilayer polyimide film laminated on a metal foil and a metal foil are laminated and then laminated by heating and pressing.

The present invention will be described below in detail with reference to the drawings. In FIG. 1, a metal foil laminated polyimide film 1 is a low heat resistant aromatic polyimide film of a multilayer polyimide film 2 in which a low logarithmic viscosity thermoplastic aromatic polyimide is integrally laminated on one surface of a high heat resistant aromatic polyimide film. The layer and the metal foil 3 are laminated. In FIG. 2, a metal foil laminated polyimide film 1 is a thermoplastic polyimide layer of a multilayer polyimide film 2 and a metal foil in which a low logarithmic viscosity thermoplastic aromatic polyimide is laminated on both sides of a high heat resistant aromatic polyimide film. 3 is laminated on both sides thereof.

In the multilayer polyimide film used in the present invention, a thin film B made of a thermoplastic aromatic polyimide having a low logarithmic viscosity is integrally laminated on at least one surface of a base layer A made of a highly heat-resistant aromatic polyimide film. It is a multi-layered polyimide film.

The above-mentioned highly heat-resistant aromatic polyimide film is obtained by polymerizing, casting, drying, imide from aromatic tetracarboxylic dianhydride or its derivative and aromatic diamine in an organic polar solvent by a method known per se. Obtained. In particular, as a highly heat-resistant aromatic polyimide film, 30 mol% or more, particularly 50 mol% or more of a biphenyltetracarboxylic acid component (especially 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride) and 50 Aromatic polyimide obtained by polymerization and imidization from a phenylenediamine component (particularly p-phenylenediamine) of mol% or more, heat resistance of the obtained multilayer polyimide film and metal foil laminated polyimide film,
It is preferable in terms of mechanical strength, linear expansion coefficient and dimensional stability. The other balance (if two kinds of tetracarboxylic dianhydride and / or diamine are used) is pyromellitic dianhydride as the aromatic tetracarboxylic dianhydride and diaminodiphenyl as the aromatic diamine. Ether is preferred.

The above organic polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide,
Examples thereof include amide solvents such as N-methyl-2-pyrrolidone and N-methylcaprolactam, dimethyl sulfoxide, hexamethylphosphamide, dimethyl sulfone, tetramethylene sulfone, dimethyl tetramethylene sulfone and ethylene glycol. These organic polar solvents can also be used in admixture with other organic solvents such as benzene, toluene, benzonitrile, xylene, solvent naphtha, and dioxane.

The high heat-resistant aromatic polyimide film preferably has a thickness of 9 to 150 μm. The high heat resistant aromatic polyimide film is preferably one whose surface is treated with plasma, or whose surface is treated with an aminosilane coupling agent at the stage of a polyamic acid film, dried and heat treated.

The multilayer polyimide film in the present invention is produced by applying a thermoplastic aromatic polyimide solution to at least one surface of a highly heat-resistant aromatic polyimide film: coating and heat treatment for drying. can do.

The application of the thermoplastic aromatic polyimide solution to the surface of the above-mentioned highly heat-resistant aromatic polyimide film can be carried out by various coating methods known per se, such as a blade coater and a knife coater. Impregnation coater, comma coater
It can be carried out by using a water, a roll roll coater, a gravure coater, or the like.

The thermoplastic aromatic polyimide solution in the coating solution comprises an aromatic diamine component and an aromatic tetracarboxylic acid component, each component being contained so that the aromatic polyimide has a low logarithmic viscosity and is thermoplastic. It can be obtained by selecting and polymerizing in the organic polar solvent.

In the present invention, it is necessary to use a low log viscosity thermoplastic aromatic polyimide layer,
As a result, a metal foil laminated polyimide film having high reliability (reproducibility) can be obtained. The thermoplastic aromatic polyimide has a logarithmic viscosity of 0.1 to 1.2 (N, N
-Dimethylacetamide, 30 ° C, 0.5g / 100m
1), especially those having a low logarithmic viscosity of 0.2 to 0.6 are preferable.

As the thermoplastic aromatic polyimide, benzophenonetetracarboxylic dianhydride or pyromellitic dianhydride can be used as the aromatic tetracarboxylic acid component, but 3,3'4,4'- Biphenyltetracarboxylic dianhydride and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride are preferred. Among them, especially as an aromatic tetracarboxylic acid component, 2, 3,
It is preferable to use 3 ', 4'-biphenyltetracarboxylic dianhydride in the aromatic tetracarboxylic acid component in an amount of 30 mol% or more, particularly 50 mol% or more. As the aromatic diamine component, diaminodiphenyl ethers, bis (aminophenoxy) benzenes, bis (aminophenoxyphenyl) sulfones, and bis (aminophenoxyphenyl) propanes are preferable. Further, as a diamine component, 5 to 25 mol% of diaminosiloxane and 75 to
Those using 95 mol% of aromatic diamine are preferably used.

In order to increase the fluidity of the thermoplastic aromatic polyimide, it is preferable to use an aromatic dicarboxylic acid anhydride to block the amine or dicarboxyl group at both ends of the amic acid. As the blocking agent, phthalic anhydride is particularly preferable as the aromatic dicarboxylic acid anhydride, and aniline can also be used as the aromatic monoamine. Particularly, in this invention, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride or its derivative is used as the thermoplastic aromatic polyimide having a low logarithmic viscosity.
An aromatic tetracarboxylic dianhydride or a derivative thereof in an amount of not less than mol%;

Embedded image (Provided that X is O, CO, C (CH ₃ ) ₂ or SO ₂ , and when two or more are the same or different, n is an integer of 0 to 4) Logarithmic viscosity (N, N-dimethylacetamide, 30 ° C., 0.1%) obtained by polymerizing a diamine compound and an aromatic dicarboxylic acid anhydride or a derivative thereof in an organic polar solvent and imidizing them.
5 g / 100 ml) having a glass transition temperature (Tg) of 200 to 300 ° C. and a glass transition temperature (Tg) of 0.1 to 1.2 are preferably used.

A coupling agent such as aminosilane, epoxysilane, or mercaptosilane is preferably added to the thermoplastic aromatic polyimide solution for the purpose of improving the adhesiveness to the highly heat-resistant aromatic polyimide film. . A filler such as titanium oxide or silicon dioxide may be added to the thermoplastic aromatic polyimide solution. The filler may be added at any stage.

The above-mentioned thermoplastic aromatic polyimide solution is
The polymer concentration in the organic polar solvent is 5 to 50% by weight, particularly 7 to 40% by weight, and the rotational viscosity measured at 30 ° C. is 0.5 to 1000 poise, and particularly 0.7 to 300 poise. preferable.

The coating amount of the thermoplastic aromatic polyimide solution on the surface of the high heat resistant aromatic polyimide film is 2 to 100% by weight based on the weight of the polymer with respect to the high heat resistant aromatic polyimide film. , Especially 5 to 90% by weight
It is preferred that A laminate obtained by applying a thermoplastic aromatic polyimide solution onto the surface of the high heat-resistant aromatic polyimide film may be dried and heated at a temperature of 50 to 350 ° C. to obtain a multilayer polyimide film. it can.

The above-mentioned polyimide film having the thermoplastic aromatic polyimide layer provided on one side has a total thickness of 6 to 2
50 μm, particularly 8 to 200 μm, more preferably 10
It is about 150 μm.

In the present invention, the above-mentioned multilayer polyimide film is a thermoplastic aromatic polyimide film (thin layer B) on one side of a highly heat-resistant aromatic polyimide film.
It is a film of two-layer structure provided with, also on both surfaces a thin layer B of the highly heat-resistant aromatic polyimide film, and B ^'
It may be a film having a three-layer structure.

In the present invention, when the multilayer polyimide film is a film having a three-layer structure, the thin layer thickness ratio B is
/ B 'have almost the same thickness (thin layer thickness ratio B / B' is 0.
It is optimal that it is in the range of 8 to 1.2, particularly in the range of 0.9 to 1.1, since the curling property of the metal foil laminated polyimide film becomes extremely small.

The metal foil used in the metal foil laminated polyimide film of the present invention is a conductive metal foil made of at least one metal or alloy selected from the group consisting of aluminum, copper, iron, gold and silver. In particular, 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 metal foil laminated polyimide film of the present invention is preferably manufactured, for example, by directly superposing the metal foil on one or both sides of the thin layer of the above-mentioned multilayer polyimide film, and then forming the laminated body into a pair of heat layers. The temperature is higher than the glass transition point (Tg) of the thermoplastic polyimide, preferably between the glass transition points (T
g) a higher temperature and a pressure bonding temperature of 230 to 400 ° C. (preferably 240 to 380 ° C.), and 1 to 500 k
g / cm, in particular 2 to 300 kg / cm, and in particular 5 to 50 kg / cm relatively low line pressure between heat rolls,
It is carried out by continuous thermocompression bonding.

In the above-mentioned 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 foil, an aluminum foil, etc.) for preventing thermal deterioration be superposed on the metal foil, and then thermocompression bonding at a high temperature.

The above-mentioned method can be carried out continuously, for example, by using the apparatus shown in FIG. 3 and by using a long multi-layered polyimide film and a metal foil.

As the above method, using the apparatus shown in FIG. 3, a long two-layer polyimide film 10 (a high heat-resistant substrate layer A and a thermoplastic aromatic polyimide thin film) from a raw material supply roll 7 is used. Consists of layer B, its thermoplastic thin layer B
(Upwardly facing upward) through the expander roll 11, the guide roll 12, etc. in a tensioned state, and the pair of heat rolls 13
And 14 (elastic roll or metal roll), while the long metal foil 20 from the raw material supply roll 6 is passed between the pair of heat rolls in a tension state via the expander roll 11 or the like. It is supplied, and both are directly overlapped, thermocompression-bonded by the heat rolls 13 and 14, laminated integrally, and the laminated body is cooled preferably through a cooling roll (not shown). Finally, the take-up roll 15 takes up a take-up speed of 1 to 200 cm.
It is preferable to continuously produce a metal foil laminated polyimide film by continuously winding the metal foil laminated polyimide film at a rate of 1 / min, particularly 5 to 100 cm / min.

In the above method, when a long three-layer extruded polyimide film is used, the three-layer polyimide film 10 is supplied from the central raw material supply roll 7 in the apparatus shown in FIG. The metal foils 20 and 20 'are simultaneously supplied from the upper and lower raw material supply rolls 6 and 8, and the three rolls are overlapped to form the heat rolls 13 and 1.
By supplying during 4, it can be thermocompression bonded. 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, and the adhesive strength (90 ° -peeling method) thereof is at least 0. 6 kg / cm, particularly about 0.7 to 5 kg / cm, which is excellent in heat resistance with no swelling or peeling on the thermocompression bonding surface when floated in a solder bath (about 288 ° C.) for 10 seconds for contact. It is a thing.

The take-up roll 15 preferably has a take-up roll core diameter of 25 cm or more so as not to apply excessive stress to the metal foil laminated polyimide film. When the metal foil laminated polyimide film wound on the winding roll is used, it is preferable to release the curl by a method known per se before use.

Further, as another embodiment of the present invention, the above-mentioned thermoplastic aromatic polyimide layer is provided on one side or both sides of the five-layer metal foil laminated film, and a metal foil is further provided thereon to form 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. Further, as another aspect of the present invention, a five-layer laminated film in which a metal foil is laminated on one surface of a three-layer polyimide film and an IC (silicon) is laminated on the other surface is also included.

[0038]

EXAMPLES Examples of the present invention will be shown below. In the following examples, parts represent parts by weight, and the measurement of each example was carried out by the test method shown below. 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. Glass transition temperature (Tg ) It was determined by a differential scanning calorimeter (DSC) or a film sample was determined 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). Reliability (reproducibility) The same operation was repeated 10 times, and the ones that gave the same result in all cases were evaluated as good, and the ones that failed the test even once were evaluated as bad. Dimensional change rate A, B on metal foil laminated polyimide film (copper clad board)
2 points were marked and the lengths of the intervals A and B were measured. Further, according to a conventional method, this copper clad plate is entirely etched, washed with water,
After passing through the drying step, the distance between A and B was measured, and the dimensional change rate was calculated using the following formula. The smaller this value, the smaller the dimensional change and the better the dimensional accuracy. Dimensional change rate = [(L _O −L) / L _O ] × 100 (%) L _O : Length between A and B before etching L: Length between A and B after etching Tensile test, linear expansion Tensile strength, elongation and elastic modulus were measured by a method according to the coefficient ASTM D-882. The coefficient of linear expansion was measured at 50 to 300 ° C. at 5 ° C./min in the longitudinal direction of the sample film after the sample film was heat-treated at 400 ° C. Rotational viscosity The viscosity was measured at 30 ° C. using Bismetron manufactured by Tokyo Metrology Co., Ltd.

Reference Example 1 A reaction vessel equipped with a nitrogen inlet tube, a thermometer, a reflux condenser, and a stirrer was charged with 3600 parts of N, N-dimethylacetamide (DMAc) as a solvent, 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 colloidal silica was 2 parts, and the mixture was stirred at 25 ° C. for 6 hours to obtain a solution of polyamic acid (concentration: 10% by weight, rotational viscosity: 30 poise).

Reference Example 2 To 500 parts of the polyamic acid solution prepared in Reference Example 1 was added 50 parts of azeotropic dehydration toluene, and while stirring the nitrogen gas while stirring to distill off the produced water, the temperature was adjusted to about 165 ° C. After reacting for 4 hours at the reaction temperature, a uniform thermoplastic aromatic polyimide DMAc solution (10 wt%, rotational viscosity: 25
Poise) manufactured. A portion of this polymer solution was poured into methanol to precipitate a polymer containing silica, the aromatic polyimide powder was recovered, and the aromatic polyimide powder was washed with hot methanol and then dried. A thermoplastic aromatic polyimide was obtained. This thermoplastic aromatic polyimide had a Tg of 269 ° C. and an inherent viscosity of 0.36.

Reference Example 3 3980 parts of DMAc were added to the reaction vessel used in Reference Example 1, 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-diaminodiphenyl 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 polyamic acid solution was prepared in the same manner as. To 500 parts of this polyamic acid solution was added 50 parts of azeotropic dehydration toluene, and while stirring the nitrogen gas while stirring to distill off the produced water, the reaction was carried out at a reaction temperature of about 165 ° C. for 4 hours to obtain a uniform mixture. A DMAc solution of thermoplastic aromatic polyimide (10 wt%, rotational viscosity: 30 poise) was obtained. A portion of this polymer solution was poured into methanol to precipitate the polymer, polyimide powder was recovered, and the polyimide powder was washed with hot methanol and dried to obtain a thermoplastic aroma. A group polyimide powder (recovery rate: 95%) was obtained. The inherent viscosity of the obtained polyimide powder was 0.38.

Reference Example 4 2,3,3 ^' , ^4' -biphenyltetracarboxylic dianhydride (a-BPDA) was added to a glass flask equipped with a nitrogen inlet tube, a thermometer, a charging / discharging outlet and a stirrer. 48
Part (90 mmol), omega, omega ^'- bis (3-aminopropyl) polydimethylsiloxane (BAPS) (Shin-Etsu Silicon Co., Ltd., X-22-161AS) 16.8 parts (20 mmol), and N- methyl 2-Pyrrolidone (NMP) (300 parts) was charged and dissolved in a nitrogen stream, and then 2,2-bis [4- (4-diaminophenoxy) phenyl] propane (BAPP) (28.74 parts (7)
(0 mmol) was added, 50 parts of xylene was further added, and the mixture was stirred under reflux at 200 ° C. for 3 hours to remove water of reaction, to obtain a polyimide solution in which 18% by weight of polyimidesiloxane was dissolved. Next, the polymer liquid returned to room temperature is filtered under pressure, precipitated using ion-exchanged water and washed to obtain polyimide siloxane (yield: 95%, imidization ratio: 100).
%, Logarithmic viscosity: 0.54, Tg: 234 ° C.) were obtained. 100 parts of this polyimide and 200 parts of 2% by weight of γ-glycidoxypropyltrimethoxysilane and tetrahydrofuran (THF) with respect to the polyimide were mixed and dissolved to obtain a uniform thermoplastic aromatic polyimide solution (concentration: 33% by weight). %, Viscosity at 30 ° C .: 45 poise) was prepared.

Reference Example 5 Reference Example 2 was repeated except that a-BPDA and 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) were used as the components (a) and (b). Similarly, a thermoplastic aromatic polyimide solution was obtained.

Reference Example 6 As the aromatic tetracarboxylic acid component (a), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) 1 was added without adding the aromatic dicarboxylic acid component.
13.0 parts (384 mmol) and 2,3,3 ',
4'-biphenyltetracarboxylic dianhydride (a-BP
DA) 113.0 parts (384 mmol), (b) as aromatic diamine component, 1,4-diaminophenyl ether (DADE) 80.1 parts (400 mmol) and 1,4-bis (4-aminophenoxy). Benzene (AP
B) A polyamic acid solution was prepared in the same manner as in Reference Example 1 except that 116.9 parts (400 mmol) was used and the concentration of the polymer was 5% by weight.

Example 1 6200 parts of N, N-dimethylacetamide (DMAc) and 270.35 parts (2.5 mol) of p-phenylenediamine (PPD) were placed in a cylindrical polymerization tank having an internal volume of 20 liters, and nitrogen was added. The mixture was stirred at room temperature (about 30 ° C.). To this solution, 73.55 parts (2.5 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s-BPDA) was added, and the mixture was stirred for 6 hours and the polymer concentration was 18% by weight.
To obtain a solution of the aromatic polyamic acid. The rotational viscosity of this solution was 1600 poise (30 ° C.).

Using this polyamic acid solution, it is extruded onto the upper surface of a smooth metal support, cast, and continuously dried with hot air at 140 ° C. to obtain a solidified film (self-supporting film, solvent content: 35% by weight), and after peeling the solidified film from the support, in a heating furnace, 200 to 45
The temperature was gradually raised to 0 ° C. to remove the solvent and imidize the polymer to obtain an aromatic polyimide film (s-type). The thickness was 50 μm. The surface of this polyimide film was plasma-treated in an oxygen atmosphere.

The thermoplastic polyimide coating solution prepared in Reference Example 2 was applied to one side of the highly heat-resistant aromatic polyimide film previously obtained with a comma coater at a rate of 5 m / min, and the amount of the dried film was 20 on a dry matter basis. Coating was performed in an amount such that the weight% was obtained, and the obtained laminate was dried in a hot air oven at 80 ° C. Further, while continuously moving in a high-temperature furnace, heat treatment was performed at 200 ° C. for 3 minutes and 310 ° C. for 3 minutes to obtain an aromatic polyimide film (multilayer film) having a thickness of 60 μm.

Then, using the apparatus shown in FIG. 3, the long two-layer polyimide film 10 is fed from the raw material feed roll 7 so that the thin layer B faces upward, while the raw material is fed. A long copper foil 20 having a thickness of 35 μm is supplied from the roll 6, the both are overlapped with the expander roll 1 and the like, and subsequently, they are supplied to the heat rolls 3 and 4 in the N ₂ gas atmosphere, and shown in Table 1. Thermocompression bonding was performed under the conditions (50 cm / min) to produce a metal foil laminated polyimide film. About the above-mentioned metal foil laminated film, its adhesive strength (90 °
-Peeling, room temperature) and solder resistance were measured. The results are shown in Tables 1 and 2.

Example 2 A method similar to that of Example 1 except that a thermoplastic polyimide coating solution (Reference Example 2) was coated on both sides of a highly heat-resistant aromatic polyimide film with a comma coater. Similarly, a three-layer aromatic polyimide film having thermoplastic polyimide layers (10 μm) on both sides of the base layer A was obtained. A five-layer metal (copper) foil laminated polyimide film was obtained in the same manner as in Example 1 except that copper foil was supplied to both sides of this polyimide film. The results are summarized in Tables 1 and 2.

Example 3 A five-layer metal (copper) foil laminated polyimide was prepared in the same manner as in Example 2 except that the polyimide solution obtained in Reference Example 3 was used as the coating solution for the thermoplastic polyimide. I got a film. The results are summarized in Tables 1 and 2.

Example 4 An example except that the N, N-dimethylacetamide solution of N-phenyl-γ-aminopropylethoxysilane (silane compound concentration: 5% by weight) was applied to the surface of the solidified film in Example 1. A highly heat-resistant aromatic polyimide film was obtained in the same manner as described in 1. Further, without performing plasma treatment, a thermoplastic polyimide layer was provided on both sides in the same manner as in Example 2 to obtain a metal foil laminated polyimide film. The results are shown in Tables 1 and 2.

Example 5 The polyimide solution prepared in Reference Example 4 was coated without plasma treatment on both sides of a highly heat-resistant aromatic polyimide film, and heating after coating was carried out at 150 ° C. Was carried out in the same manner as in Example 2 to obtain a metal foil laminated polyimide film. The results are shown in Tables 1 and 2.

Example 6 A metal foil laminated polyimide film was obtained in the same manner as in Example 2 except that the polyimide solution (Example 6) prepared in Reference Example 5 was used. The results are shown in Tables 1 and 2.

Comparative Examples 1 and 2 A metal foil laminated polyimide film was obtained in the same manner as in Example 1 except that the polyamic acid solution prepared in Reference Example 6 was used and the pressure bonding pressure was set to the conditions shown in Table 1. Obtained. The results are shown in Tables 1 and 2.

Example 7 DMAc, 44 was added to a cylindrical polymerization tank having an internal volume of 10 liters.
80 parts, PPD227.09 parts (2.1 mol), 4,
180.22 parts (0.9 mol) of 4′-diaminodiphenyl ether was added, and the mixture was stirred in nitrogen at room temperature (about 30 ° C.). S-BPDA441.33 parts (1.5
Mol) and 327.18 parts (1.5 mol) of pyromellitic dianhydride and stirred for 6 hours to obtain a solution of polyamic acid. The rotational viscosity of this solution was 1700 poise (30 ° C.). Using the obtained polyamic acid, a highly heat-resistant aromatic polyimide film (m-type) was obtained in the same manner as in Example 1. Further, a metal foil laminated polyimide film was obtained in the same manner as in Example 2.
The results are shown in Table 1.

Example 8 35 μm of the thermoplastic polyimide solution obtained in Reference Example 2 was added.
After being applied to the electrolytic copper foil of No. 3, dried, and heated at 200 ° C. for 5 minutes, a metal foil having a thermoplastic polyimide layer (10 μm) on one surface was obtained. The metal foil having a thermoplastic polyimide layer on one side thereof was thermocompression-bonded (350 ° C., 40 kg / cm) with the thermoplastic polyimide layer side on both sides of the metal foil laminated polyimide film obtained in Example 7. By laminating, a 9-layer metal foil laminated polyimide film was obtained. The results are summarized in Tables 1 and 2.

Example 9 A polyimide film (thickness 70 μm) having a thermoplastic polyimide layer (thickness 10 μm) on both sides prepared in Example 7
m) is cut into 10 mm square, placed on a polyimide-coated Si chip, and a comb-shaped lead frame made of 42NiFe alloy is placed on it, and the temperature is 310 ° C., 30 kg.
Thermocompression bonding was performed for 5 seconds / cm ² . The peel strength of the obtained laminate was 1.0 kg / cm.

Comparative Example 3 A metal foil laminated polyimide film was prepared in the same manner as in Example 1 except that the polyamic acid solution of Reference Example 1 was used as the coating solution without plasma treatment of the highly heat resistant aromatic polyimide film. Obtained. The results are shown in Tables 1 and 2.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

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

The adhesive strength between the metal foil and the thermoplastic aromatic polyimide film (layer) having a low logarithmic viscosity is high. Also,
The metal foil laminated polyimide film has good solder resistance.

Further, since the thermoplastic aromatic polyimide film having a low logarithmic viscosity is used, the thermocompression bonding with the metal foil can be performed under a mild condition, so that a highly reliable result can be obtained.

When a polyimide having a biphenyltetracarboxylic acid component of 30 mol% or more and a phenylenediamine component of 50 mol% is used as the highly heat-resistant aromatic polyimide, the coefficient of linear expansion of the multilayer polyimide film is 1 × 10. Since it is as small as ^{−5 to} 3 × 10 ⁻⁵ cm / cm / ° C., curling does not occur in the obtained metal foil laminated polyimide film, the dimensional change rate 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 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]

 1 Metal Foil Laminated Polyimide Film 2 Multilayer Aromatic Polyimide Film 3 Metal Foil 6 Raw Material Supply Roll 7 Raw Material Supply Roll 8 Raw Material Supply Roll 9 Furnace 10 2 Layer (or 3 Layer) Polyimide Film 11 Expander Roll 12 Guide Roll 13 Heat Roll 14 Heat roll 15 Winding roll 20 Metal foil 20 'Metal foil

Claims (6)

[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, wherein a thermoplastic polyimide layer of a multi-layered polyimide film in which a group polyimide is integrally laminated and a metal foil are laminated and then laminated by heating and pressing. 2. The linear expansion coefficient of the multilayer polyimide film is 1 × 10 ^{−5 to} 3 × 10 ⁻⁵ cm / cm / ° C.
The metal foil-laminated polyimide film described. 3. An aromatic tetracarboxylic acid dianhydride having a low logarithmic viscosity thermoplastic aromatic polyimide containing 30 mol% or more of 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride or a derivative thereof. Or a derivative thereof and a compound of the general formula I (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) Logarithmic viscosity (N, N-dimethylacetamide, 30 ° C., 0.1%) obtained by polymerizing a diamine compound and an aromatic dicarboxylic acid anhydride or a derivative thereof in an organic polar solvent and imidizing them.
The metal foil-laminated polyimide film according to claim 4, which is a polyimide having both ends sealed with 5 g / 100 ml) of 0.1 to 1.2 and a glass transition temperature (Tg) of 200 to 300 ° C. 4. A multi-layer polyimide film is preliminarily subjected to activation treatment for imparting adhesiveness to at least one surface of a layer of highly heat-resistant aromatic poimide, and then a thermoplastic aromatic polyimide solution having a low logarithmic viscosity is applied. The metal foil laminated polyimide film according to claim 1, which is obtained by applying and heat treatment for drying. 5. A multilayer polyimide film, wherein a solution of a low-logarithmic viscosity thermoplastic aromatic polyimide and a silane coupling agent added to at least one surface of a highly heat-resistant aromatic polyimide film is applied to heat treatment for drying. The metal foil laminated polyimide film according to claim 1, which is obtained by applying. 6. The metal foil laminated polyimide film according to claim 1, wherein the metal foil is an electrolytic copper foil.