JPH08244168A - Manufacture of metal foil laminate polyimide film - Google Patents

Abstract

PURPOSE: To bond a polyimide film with a metal foil firmly by overlapping a thermoplastic polyimide layer of a multilayer polyimide film formed by stacking integrally a thermoplastic aromatic polyimide layer of low logarithm viscosity on one surface of an aromatic polyimide layer of high heat resistance and then heating and fixing by pressure. CONSTITUTION: Thermoplastic aromatic polyimide solution of low logarithm viscosity or its precursor solution is applied at least to one surface of a self-supporting imide gelatinized film manufactured by cast applying the aromatic polyimide precursor solution of high heat resistance containing a dehydrating agent and a catalyst, and then heating and turning the solution into partial ring closure imide, and then dried and heat treated. A metal foil 20 is overlapped on a thermoplastic polyimide layer of a multi-polyimide film 10 formed integrally with the thermoplastic aromatic polyimide layer of low logarithm aromatic polyimide layer at least on one surface of the aromatic polyimide layer of high heat resistance thus formed, and heated and fixed by pressure by heating rollers 3 and 4 integrally, and a laminate thus formed is cooled by a cooling roll.

Description

Detailed Description of the Invention

[0001]

This invention relates to an aromatic polyimide film layer having a thermoplastic aromatic polyimide layer on its surface, which has extremely high heat resistance, dimensional stability and mechanical properties, Despite the fact that the aromatic polyimide itself has no performance as an adhesive, the adhesion between the thermoplastic aromatic polyimide layer after drying and imidization and the highly heat-resistant aromatic polyimide fill layer is strong, Furthermore, the bonding of the multi-layer polyimide film having a thermoplastic aromatic polyimide layer on the surface and the metal foil can be performed without using a thermosetting adhesive such as an epoxy resin, etc. Polyimide has a large adhesive strength with a metal foil at a practical level and has high heat resistance. The metal foil laminated polyimide film obtained by the method of the present invention is a printed circuit board, TA
It is useful for B 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, in the above-mentioned composite material, it is extremely difficult to make the support layer sufficiently thick, or
There has been a problem that the evaporation / removal process of the solvent in the film forming process takes an extremely long time and productivity is 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). Japanese Patent Laid-Open Nos. 6-93238 and 218880) have been proposed.

However, there is a problem in that the adhesiveness between the thermoplastic polyimide and the aromatic polyimide film is poor. 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. This method has problems that the number of plasma treatment steps 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 a minimum of base layers" 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 group polyimide has poor fluidity, it is necessary to perform thermocompression bonding under high pressure.

[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 to provide a method for producing a metal foil laminated polyimide film in which a support made of only polyimide and a metal foil are laminated by an aromatic polyimide layer.

[0012]

That is, the present invention provides:
The organic polar solvent solution of a highly heat-resistant aromatic polyimide precursor containing a dehydrating agent and a catalyst was cast and applied in a film form, and the obtained aromatic polyimide precursor was partially ring-closed and imidized, and volatilized. At least one side of a self-supporting gelled film containing a substance is coated with a solution of a thermoplastic aromatic polyimide having a low logarithmic viscosity or a solution of a precursor thereof, the resulting laminate is dried, and then a heat treatment step is included. A multilayer polyimide in which a low logarithmic viscosity thermoplastic aromatic polyimide layer is integrally laminated on at least one surface of a highly heat-resistant aromatic polyimide layer obtained by substantially completing solvent removal and imidization by subjecting to heat treatment. A method for producing a metal foil laminated polyimide film, which comprises stacking a thermoplastic polyimide layer of a film and a metal foil, and then thermocompression-bonding them to integrally laminate them. It relates to the law.

In the present invention, the aromatic polyimide precursor may be partially imidized, and the aromatic diamine component and the aromatic tetracarboxylic component are preferably mixed in an organic polar solvent at a ratio of about equimolar. It is preferably obtained by polymerizing in. Such an aromatic polyimide precursor 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, and 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 (aminophenoxybiphenyl-based diamine such as 4,4′-bis (3-aminophenoxy) biphenyl, bis [(aminophenoxy) phenyl] sulfone such as bis [(4-aminophenoxy) phenyl] sulfone, and the like. And they can be used alone or as a mixture.

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

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 dianhydrides are preferable, and in particular, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride is used alone or 30 mol% or more thereof and pyromellitic dianhydride 70 mol%. Preference is given to using a mixture with

In the present invention, as the aromatic polyamic acid, 30 mol% or more, particularly 50 mol% or more of 3,
3 ′, 4,4′-biphenyltetracarboxylic acid component (the balance is preferably pyromellitic acid component) and 50 mol% or more of p-phenylenediamine component (the balance is preferably 4,4 ′)
-Diaminodiphenyl ether) is particularly preferable because it has good dimensional accuracy in addition to the above-mentioned physical properties of the metal foil laminated polyimide film obtained.

In the present invention, it is preferable to add a phosphoric acid ester or a salt of a tertiary amine and a phosphoric acid ester to the above aromatic polyamic acid solution from the viewpoint of the film surface state and productivity. The amount of addition of these is 0. 1 with respect to 100 parts by weight of the aromatic polyimide or polymer.
It is preferably from 01 to 5 parts by weight.

As the organic polar solvent used in the above polymerization reaction, a solvent that uniformly dissolves each monomer component and the 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.

A layer of an organic polar solvent composition of an aromatic polyamic acid which is an aromatic polyimide precursor in the present invention,
That is, the organic polar solvent solution of the aromatic polyamic acid used for producing the aromatic polyimide gelled film has a rotational viscosity measured at 30 ° C. of about 10 to 20,000 poises, particularly 30 to 30 from the viewpoint of workability. It is preferably in the range of 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.

The aromatic polyamic acid solution produced as described above is allowed to contain a dehydrating agent and a catalyst,
The reaction is carried out at a temperature of 00 ° C. or lower, preferably in the range of 40 to 200 ° C., and the aromatic polyamic acid is subjected to ring-closing imidization so that the imidization ratio is preferably 20 to 80% to give a volatile substance. An aromatic polyimide gelled film having a content of 20 to 90% by weight is produced.

Examples of the dehydrating agent include organic acid anhydrides such as aliphatic acid anhydrides, aromatic acid anhydrides, alicyclic acid anhydrides, heterocyclic acid anhydrides or a mixture of two or more thereof. Can be mentioned. Specific examples of the organic acid anhydride, for example, acetic anhydride, propionic anhydride, butyric anhydride, formic acid anhydride, succinic anhydride, maleic anhydride, phthalic anhydride,
Examples thereof include benzoic anhydride, picolinic anhydride and the like. Acetic anhydride is particularly preferable.

Examples of the catalyst include organic tertiary amines such as aliphatic tertiary amines, aromatic tertiary amines, heterocyclic tertiary amines, and mixtures of two or more thereof. Specific examples of the organic tertiary amine include trimethylamine, triethylamine, dimethylaniline, pyridine, β-picoline, isoquinoline and quinoline. In particular, isoquinoline is preferable.

The order of adding and mixing the dehydrating agent and the catalyst to the aromatic polyamic acid solution is not particularly limited. For example, the catalyst and the dehydrating agent may be added in this order to the polyamic acid solution, or a mixture of the dehydrating agent and the catalyst may be added uniformly. In addition to the dehydrating agent and the catalyst, a third component such as a retarder (eg, acetylacetone) may be added.

The mixing amount of the dehydrating agent is preferably 0.5 mol or more per 1 mol of the amic acid bond of the aromatic polyamic acid component in the aromatic polyamic acid solution. If the mixing amount of the dehydrating agent is less than the above range, the rate of ring-closing imidization of the amic acid bond of the polyamic acid will be insufficient.

The amount of the catalyst mixed is preferably 0.1 mol or more per 1 mol of the amic acid bond of the aromatic polyamic acid. When the amount of the catalyst mixed is less than the above range, the imidization rate becomes slow.

As a method for producing an aromatic polyimide gelled film from the aromatic polyamic acid solution, a method known per se can be adopted. As such a method, for example, a solution of an aromatic polyamic acid containing the above-mentioned dehydrating agent and catalyst is first applied to the surface of a suitable support (for example, a roll made of metal, ceramic, plastics, or a metal belt). Cast on top, about 10
It is formed into a film having a uniform thickness (based on the solution layer) of about 2000 μm, preferably about 20 to 1000 μm, and then this film is heated to 200 ° C. using a heat source such as hot air or infrared rays.
By heating at the above temperature, preferably at a temperature of 40 to 200 ° C., the aromatic polyamic acid is subjected to ring-closure imidization, preferably at an imidization ratio of 20 to 80%, to partially gelate the aromatic polyamic acid. To produce a chemical film.

The heating is carried out such that the gelled film has a volatile content of 20 to 90% by weight, preferably 25 to 85.
%, Particularly preferably up to an amount in the range from 30 to 75% by weight. The gelled film thus produced has a self-supporting property and can be peeled from the support.

The volatile matter content of the gelled film is a value determined by the following formula from the weight W ₁ before drying and the weight W ₂ after drying after drying the film to be measured at 420 ° C. for 20 minutes. is there. Volatiles content _{(wt%) = {(W 1 -W} 2) / W 1} ×
100

The higher the volatile content, the higher the surface tension of the gelled film, and the better the wettability when the coating solution is applied to the surface of the gelled film in the subsequent step. Therefore, the volatile content is within the above range. Among them, the larger one is relatively preferable. When the volatile content is larger than the above range, the self-supporting property of the gelled film is reduced and the coating solution cannot be uniformly applied in a later step, or the gelled film and the coating solution are too mixed to be separated from the coating solution. There are drawbacks such as difficulty in obtaining the desired thickness of the layer.

The gelled film produced without using a dehydrating agent and a catalyst has a problem that the gelling film has a low tensile strength when the coating solution is applied to the surface of the gelled film in a later step, and therefore the gelling film has a problem in running. May occur, or the wettability may be poor, resulting in uneven application.
Further, problems such as easy occurrence of solvent crazing occur, which makes uniform lamination difficult.

In the present invention, a coating solution comprising a thermoplastic aromatic polyimide solution or an aromatic polyimide precursor solution is applied to at least one surface of the aromatic polyimide gel film.

The thermoplastic aromatic polyimide or precursor solution in the coating solution is treated with the aromatic diamine component and the aromatic tetracarboxylic acid component by the method as described for the preparation of the gelled film of the aromatic polyimide. Can be obtained by selecting each component so that the aromatic polyimide has a low logarithmic viscosity and thermoplasticity, and polymerizing in the organic polar solvent.

In the present invention, it is necessary to use a thermoplastic aromatic polyimide layer having a low logarithmic viscosity,
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 (polymer-0.5 g / solvent 100 ml), particularly 0.1 to 0.
7, especially 0.2 to 0.6 are preferable.

As the thermoplastic aromatic polyimide having a low logarithmic viscosity, benzophenonetetracarboxylic dianhydride and pyromellitic dianhydride can be used as the aromatic tetracarboxylic acid component, and 3,3'4. , 4'-biphenyltetracarboxylic dianhydride, 2,3 ', 3,4'
-Biphenyltetracarboxylic dianhydride is preferable, and as the aromatic diamine component, diaminodiphenyl ethers, di (aminophenoxy) benzenes, bis (aminophenoxyphenyl) sulfones, and bis (aminophenoxyphenyl) propanes are preferable.

For the purpose of increasing the fluidity of the thermoplastic aromatic polyimide, it is preferable to use an aromatic dicarboxylic acid anhydride to block the amine at the terminal of the amic acid.
As the aromatic dicarboxylic acid anhydride, phthalic acid anhydride is particularly preferable. Further, it is also preferable that the terminal carboxylic acid of the polyamic acid is end-capped with an aromatic monoamine such as aniline.

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, 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 imidized to obtain a logarithmic viscosity of 0.1 to 1.2 (polymer-0.5 g / solvent 10).
0 ml), glass transition temperature (Tg) is 200 to 300 ° C.
The both end-capped aromatic polyimide is preferred.

The above-mentioned thermoplastic aromatic polyimide or precursor solution has a polymer (including raw material components) concentration in an organic polar solvent of 5 to 50% by weight, particularly 7 to 40% by weight, and is measured at 30 ° C. Those having a rotational viscosity of 0.5 to 1000 poises, particularly 0.7 to 300 poises are preferable. A filler such as titanium oxide or silicon dioxide may be added to the thermoplastic polyimide or the precursor solution thereof. The filler may be added at any stage of the polyamic acid polymerization.

In the present invention, the coating solution is applied to the surface of the gelled film by various coating methods known per se, for example, blade coater, knife coater, impregnation coater, reverse roll coater, kiss roll coater and the like. It can be done using the method used.

The coating amount of the coating composition on the surface of the gelled film is 2 to 100% by weight, particularly 5 to 5% by weight, based on the weight of the polymer (dried product) based on the gelled film.
It is preferably 90% by weight. The coating composition may be applied to only one side of the gelled film, or may be applied to both sides, depending on the structure of the laminate.

The laminate obtained by applying the coating solution to the gelled film was heated to 50 to 200 ° C.
After drying at a temperature of 300 ° C. or higher, preferably 30 ° C.
Subject to a heat treatment including a heat treatment step at a temperature of 0-500 ° C.

The above heat treatment does not necessarily have to be performed at 300 ° C.
It is not necessary to carry out the above, and the above-mentioned 300 ° C. or higher, preferably 300 to 50, in a part of the heat treatment step, preferably in the terminal part.
A heat treatment step at a temperature of 0 ° C. may be included. Thus, for example, first heat at around 200 ° C., then 400
There may be a mode in which the temperature is changed and the heating is performed in multiple stages of two or more stages, such as heating in the vicinity of ° C. Needless to say, the heat treatment can be performed in one step at a temperature of 300 ° C. or higher, preferably 300 to 500 ° C. without temperature change.

The multilayer polyimide film having the thermoplastic aromatic polyimide layer on one side has a total thickness of 6
To 250 μm, particularly 8 to 200 μm, more preferably 1
It is about 0 to 150 μm.

The metal foil laminated film obtained by the method of the present invention is a film having a two-layer structure in which the above-mentioned multilayer polyimide film comprises a base layer of aromatic polyimide and a thin layer of thermoplastic aromatic polyimide. Also,
It may be a film having a three-layer structure composed of the base layer A and the thin layers B and B ′ on both sides thereof. In this case, the metal foil laminated polyimide film has 5 layers.

In the above-mentioned five-layer metal foil laminated film, the thermocompression-bonding thin layers B and B ′ have almost the same thickness (the thin layer thickness ratio B / B ′ is 0.8 to 1). .2, especially 0.9-
Within the range of 1.1), the curling property of the metal foil laminated film becomes extremely small, which is optimal.

The metal foil used in the present invention may be a conductive metal foil made of at least one metal or alloy selected from the group consisting of aluminum, copper, iron, gold and silver, and particularly, , Thickness is 5-100μ
m, more preferably 10 to 60 μm and have a width of 5 to 2
A long electrolytic copper foil having a length of 00 cm can be preferably mentioned.

In the method for producing a metal foil-laminated polyimide film of the present invention, for example, preferably, a metal foil is directly applied to a thin layer of the above-mentioned multilayer polyimide film (a thermosetting adhesive such as epoxy resin is used). (No use at all), and the polymer is supplied between a pair of hot rolls, and the temperature is not lower than the glass transition temperature (Tg) of the thermoplastic aromatic polyimide and is 230 to 400 ° C. (preferably 240 to 380). C.) pressure bonding temperature, and 1-500 kg / cm, especially 2-3
It is carried out by continuous thermocompression bonding with a linear pressure between hot rolls of 00 kg / cm. The line pressure between the heat rolls is 0.5 to 100 Kg / cm as the thermocompression bonding pressure.
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 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 method can be carried out continuously, for example, using the apparatus shown in FIG. 1 and using a long multilayer polyimide film and a metal foil.

As the above method, using the apparatus shown in FIG. 1, a long two-layer polyimide film 10 from the raw material supply roll 7 (the base layer A of the gelled film and the thermoplastic aromatic polyimide solution or Consisting of a thin layer of precursor dried and heated, with thin layer B facing up)
Via expander roll 1, guide roll 2, etc.
In a tense state, while supplying between the pair of heat rolls 3 and 4 (elastic roll or metal roll), the long metal foil 20 from the raw material supply roll 6 is in a tense state via the expander roll 1 or the like. Then, it is supplied between the pair of heat rolls, and both are directly superposed, thermocompression-bonded by the heat rolls 3 and 4, and laminated integrally, and the laminated body is preferably a cooling roll ( (Not shown) to finally produce a metal foil laminated film which is continuously wound by a winding roll 5 at a winding speed of 1 to 200 cm / min, particularly 5 to 100 cm / min. Is preferred.

In the above method, when a long three-layer 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 raw material supply rolls 6 and 8, and the three members are overlapped and supplied between the heat rolls 3 and 4, so that thermocompression bonding can be performed. In the metal foil laminated film obtained by the above method, the thin layer B and the metal foil are directly thermocompression-bonded to each other, and the adhesive strength (90 ° -peeling method) thereof is at least 0 at room temperature. .6k
g / cm, particularly about 0.7 to 5 kg / cm, and the peeling interface is the interface between the surface of the thin layer B and the surface of the metal foil, and the interface between the base layer A and the thin layer B. Of the solder bath (approx. 288
It is excellent in heat resistance since it does not swell or peel off on the thermocompression-bonded surface after floating for 10 seconds at (° C.).

As the winding roll 5, it is preferable to use one having a winding 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 aspect of the present invention, the thermoplastic aromatic polyimide layer is provided on one 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.

[0057]

EXAMPLES Examples of the present invention will be shown below. In each of the following examples, “part” indicates “part by weight”, and the number in parentheses “” indicates a molar ratio. The measurement of each example was performed 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. It was determined with a Tg differential scanning calorimeter (DSC), or with a film sample 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, the metal foil side and the solder bath in the solder bath maintained at the temperature of 288 ± 5 temperature. 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) Repeated the same operation 10 times, all of which gave comparable results were evaluated as good (○), and ones that failed even once were evaluated as bad (×). did. 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, this copper clad plate was subjected to metal etching, water washing and drying steps 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 = [(L _O -L) / L _O] × 100 (%) L _O: length between before etching A, B L: length between A, B after etching

Reference Example 1 3600 parts of N-methyl-2-pyrrolidone (NMP) as a solvent was added to a reaction vessel equipped with a nitrogen inlet tube, a thermometer, a reflux condenser, and a stirrer, and (a) aromatic tetra Carboxylic 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.

Reference Example 2 To 2000 parts of the polyamic acid solution prepared in Reference Example 100 was added 100 parts of azeotropic dehydration toluene, and while stirring the nitrogen gas while stirring to distill off the produced water, about 175
The reaction was carried out at a reaction temperature of ˜180 ° C. for 8 hours to prepare a uniform polymer solution. A portion of this polymer solution was poured into methanol to precipitate the polymer, the aromatic polyimide powder was recovered, and the aromatic polyimide powder was washed with hot methanol three times and then dried. A plastic aromatic polyimide was obtained. The thermoplastic aromatic polyimide obtained as described above has a glass transition temperature Tg of 269 ° C.,
Logarithmic viscosity (NMP, 30 ° C.) was 0.38.

Reference Example 3 In the reaction vessel used in Reference Example 1, 3400 parts of N-methyl-2-pyrrolidone (NMP), 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 polyamic acid solution was prepared in the same manner as above, and then a thermoplastic aromatic polyimide was obtained in the same manner as in Reference Example 2. The thermoplastic aromatic polyimide obtained as described above,
The glass transition temperature (Tg) was 269 ° C and the logarithmic viscosity (NMP, 30 ° C) was 0.41.

Reference Example 4 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 polyimide was obtained. This thermoplastic polyimide is
Glass transition temperature (Tg): 240 ° C, logarithmic viscosity (NM
P, 30 ° C.) 0.37.

Reference Example 5 A thermoplastic polyamic acid solution was obtained in the same manner as in Reference Example 1 except that s-BPDA and DADE were used as the components (a) and (b). A part of this polyamic acid solution was heated at a reaction temperature of 175 to 180 ° C. for 4 hours in the same manner as in Reference Example 2 to obtain a polyimide powder. Collect this powder,
It was washed three times with hot methanol and dried. The logarithmic viscosity (p-chlorophenol, 50 ° C.) of this polyimide is 0.4.
It was 5.

Reference Example 6 A polyamic acid solution was prepared in the same manner as in Reference Example 5 except that the aromatic dicarboxylic acid component was not added. A part of this polyamic acid solution was treated in the same manner as in Reference Example 5 to obtain a polyimide powder. Logarithmic viscosity (p-
Chlorphenol, 50 ° C.) was 2.85.

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 then polyamic acid (s-type) was added. ) Was obtained. This polyamic acid polymer 10
To 0 parts, monostearyl phosphate ester ethanol-
0.1 part of a ruamine salt was added, stirred and dissolved to obtain a polyamic acid solution. The rotational viscosity of this solution was 1300 poise (30 ° C.). The viscosity was measured using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd.

In a 14% by weight solution of the obtained polyamic acid, 80.7 parts (0.63 mol) of isoquinoline, 510.5 parts (5.0 mol) of acetic anhydride and DMAc3050 were added.
Added parts. After extruding the obtained solution from the T die onto the rotating endless metal belt to form a coating film,
After supplying hot air of 65 ° C. to the surface and drying for 15 minutes, the formed gelled film having an imidization ratio of 48% was peeled from the metal belt. The weight loss on heating of this gelled film was 76% by weight, and the surface tension was 37 dyne / cm.

The polyamic acid solution prepared in Reference Example 1 was applied to one side of the gelled film previously formed with a knife coater at a speed of 5 m / min so that the weight of the polyamic acid solution was 6% by weight based on the dry matter. Coating was performed in various amounts, and the obtained laminate was dried in a hot air oven at 80 ° C. While holding this film with a pin tenter and continuously moving it in a high-temperature furnace, the film was heated at 200 ° C. for 3 minutes, and at 310 ° C. for 3 minutes.
Aromatic polyimide film (laminated film) with a thickness of 60 μm after heat treatment at 0 ° C for 3 minutes and then at 350 ° C for 3 minutes
I got

Then, by using the apparatus shown in FIG. 1, 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. Long 35 cleaned from roll 6
The electrolytic copper foil 20 having a thickness of 10 μm is supplied, the both are superposed with the expander roll 1 and the like, and subsequently, they are supplied to the hot rolls 3 and 4 in the furnace which are N ₂ gas purged, and the conditions shown in Table 1 are given. Was thermocompression bonded to produce a metal foil laminated polyimide film. The adhesive strength (90 ° -peeling, room temperature) and solder resistance of the metal foil laminated film were measured.
The results are shown in Tables 1 and 2.

Comparative Example 1 Imidization was carried out in the same manner as in Example 1 except that polyamic acid was produced without adding isoquinoline and acetic anhydride, and the coating film on the metal belt was dried with hot air at 100 ° C. for 15 minutes. A gelled film with a rate of 15% was produced. The gelled film obtained at this time had a volatile content of 45.5% by weight and a surface tension of 33 dyne / cm. This gelled film was coated in the same manner as in Example 1, but many fine cracks were generated in the gelled film, and a normal film could not be obtained.

Example 2 The same procedure as in Example 1 was carried out except that the polyimide solution prepared in Reference Example 2 was used and both sides of the gelled film were coated with a comma coater. A polyimide film was obtained. A 5-layer metal foil laminated polyimide film was obtained in the same manner as in Example 1 except that electrolytic copper foil was supplied to both sides of this 3-layer polyimide film. The results are shown in Tables 1 and 2.

Examples 3 to 4 Metal foil laminated polyimide films were obtained in the same manner as in Example 2 except that the polyamic acid solutions prepared in Reference Examples 3 to 4 were used. The results are shown in Tables 1 and 2.

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

Comparative Example 2 Reference Example 5 was prepared 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 obtained in 1. was coated with a comma coater so that it would be 20% by weight (40% by weight on both sides) based on the dry matter of the film, and the resulting laminate was 8
It was dried in a hot air oven at 0 ° C. While continuously moving inside the salani high temperature furnace, heat-treat at 200-350 ° C for 3 minutes,
An aromatic polyimide film (multilayer film) having a thickness of 70 μm was obtained. A metal foil laminated polyimide film was obtained in the same manner as in Example 5 except that this multilayer aromatic polyimide film was used. The results are shown in Tables 1 and 2.

Comparative Example 3 A metal foil laminated polyimide film was obtained in the same manner as in Comparative Example 2 except that the polyamic acid solution obtained in Reference Example 6 was used. The results are shown in Tables 1 and 2.

Example 6 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 was added s-BPDA441.33 parts (1.5 mol) and pyromellitic dianhydride 327.18 parts (1.5 mol), and the mixture was stirred for 6 hours to obtain a solution of polyamic acid (m-type). Got The rotational viscosity of this solution was 1700 poise (30 ° C.). A monostearyl phosphate ester triethanolamine salt was added to and dissolved in the polyamic acid solution at a ratio of 0.1 part with respect to 100 parts of the polyamic acid polymer. In a 20% by weight solution of the obtained polyamic acid, isoquinoline 96.87 parts (0.75 mol), acetic anhydride 612.54 parts (6.0 mol) and D
2033 parts of MAc was added. The obtained solution was treated in the same manner as in Example 2 to obtain a gelled film. The weight loss on heating of the gelled film was 74% by weight, and the surface tension was 37 dyn.
It was e / cm. This gelled film was coated in the same manner as in Example 2 to obtain a 3-layer aromatic polyimide film having a thickness of 70 μm. This aromatic polyimide film was treated in the same manner as in Example 1 to obtain a metal foil laminated polyimide film. The results are shown in Tables 1 and 2.

Example 7 A metal foil laminated polyimide film was obtained in the same manner as in Example 2 except that the polyamic acid solution prepared in Reference Example 1 was used. The results are shown in Tables 1 and 2.

Example 8 The polyamic acid 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. 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.

The curl degree of the three-layer polyimide film produced in Examples 2 to 7 was 10 mm or less. The curl degree was measured by the "Toray method" in which a sample film having a length of 20 cm and a width of 3.5 cm was placed on a flat substrate and the height of the sample portion farthest from the flat substrate was measured.

[0079]

[Table 1]

[0080]

[Table 2]

[0081]

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, and peeling occurs at the interface between the aromatic polyimide film and the thermoplastic aromatic polyimide film (layer). Absent. In addition, 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 gentle condition, so that a highly reliable result can be obtained.

Further, when a polyimide containing a biphenyltetracarboxylic acid component of 30 mol% or more and a phenylenediamine component of 50 mol% is used as the aromatic polyimide, the linear expansion coefficient of the multilayer polyimide film is small and the dimensional accuracy is excellent. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of an example of an apparatus for carrying out the present invention.

[Explanation of symbols]

 1 Expander Roll 2 Guide Roll 3 Heat Roll 4 Heat Roll 5 Winding Roll 6 Raw Material Supply Roll 7 Raw Material Supply Roll 8 Raw Material Supply Roll 10 2 Layer (or 3 Layer) Polyimide Film 20 Metal Foil 20 'Metal Foil

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B32B 7/02 101 B32B 7/02 101 105 105 // B29K 77:00 B29L 9:00

Claims (6)

[Claims] 1. A solution of a highly heat-resistant aromatic polyimide precursor containing a dehydrating agent and a catalyst in an organic polar solvent is cast and applied in a film form, and then heated to partially ring-close imidize the aromatic polyimide precursor. The obtained, a self-supporting gelling film containing a volatile material, a solution of a thermoplastic aromatic polyimide having a low logarithmic viscosity or a solution of a precursor thereof is applied to at least one surface of the gelled film, and the obtained laminate is dried, Then, a low logarithmic viscosity thermoplastic aromatic polyimide layer is integrally laminated on at least one surface of the highly heat-resistant aromatic polyimide layer obtained by substantially completing solvent removal and imidization by subjecting it to a heat treatment including a heat treatment step. After laminating a thermoplastic polyimide layer of a multi-layered polyimide film and a metal foil, the metal foil laminated polyimide is characterized in that it is thermocompression bonded and laminated integrally. Film manufacturing method. 2. The linear expansion coefficient of the multilayer polyimide film is 1 × 10 ^{−5 to} 3 × 10 ⁻⁵ cm / cm / ° C.
A method for producing the metal foil laminated polyimide film described. 3. A thermoplastic aromatic polyimide having a logarithmic viscosity of 0.1 to 1.2 (polymer-0.5 g / solvent 100 m).
The method for producing a metal foil laminated polyimide film according to claim 1, wherein the glass transition temperature (Tg) in l) 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 method for producing a metal foil laminated polyimide film according to claim 1, wherein the transition temperature (Tg) is 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 imidized to obtain a logarithmic viscosity of 0.1 to 1.2 (polymer-0.5 g / solvent 10).
0 ml), glass transition temperature (Tg) is 200 to 300 ° C.
The method for producing a metal foil laminated polyimide film according to claim 1, which is a non-adhesive type both-end-sealed aromatic polyimide. 6. The method for producing a metal foil laminated polyimide film according to claim 1, wherein the metal foil is an electrolytic copper foil.