JP2001270033A - Method for manufacturing flexible metal foil laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flexible metal foil laminate having good product appearance and dimensional stability by laminating a polyimide and a metal foil. SOLUTION: The method for manufacturing the flexible metal foil laminate comprises the steps of supplying one or more combinations of each of a heat press bondable multilayer polyimide film and the metal foil to a double belt press, interposing a protective material between both outermost layers and a belt, heat press bonding, cooling and laminating them under pressurized state, and laminating the foil on at least one surface of a high heat resistant aromatic polyimide layer via a heat press bondable polyimide layer. In this case, the laminate does not have a product appearance fault and has the dimensional stability of |±0.10|% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a flexible metal foil laminate by a double belt press method, and more particularly, to a thermocompression-bondable aromatic polyimide layer on at least one surface of a highly heat-resistant aromatic polyimide layer. The present invention relates to a method for producing a flexible metal foil laminate having good product appearance and dimensional stability, which is an all-polyimide obtained by laminating a thermocompression-bondable multilayer polyimide film having a polyimide layer and a metal foil.

[0002]

2. Description of the Related Art Aromatic polyimide films are widely used for electronic devices such as cameras, personal computers, and liquid crystal displays. In order to use an aromatic polyimide film as a substrate material for a flexible printed board (FPC) or a tape-automated bonding (TAB), a copper foil is laminated using an adhesive such as an epoxy resin. The method has been adopted.

It has been pointed out that aromatic polyimide films are excellent in heat resistance, mechanical strength, electrical properties and the like, but are inferior in properties of polyimide due to poor heat resistance of adhesives. To solve such a problem,
All-polyimide substrates were developed by electroplating copper on a polyimide film without using an adhesive, applying a polyamic acid solution to a copper foil, drying and imidizing, or thermocompressing thermoplastic polyimide. I have.

A polyimide laminate in which a polyimide adhesive is sandwiched between a polyimide film and a metal foil using a vacuum press or the like is known (US Pat. No. 4,543,295). However, this polyimide laminate has a problem that a long one cannot be obtained, and a biphenyltetracarboxylic acid-based polyimide film having a low linear thermal expansion has a low adhesive strength and cannot be used.

Further, a flexible metal foil laminate in which a thermocompression-bondable multilayer polyimide film of a heat-resistant polyimide layer and a thermocompression-bondable polyimide layer and a metal foil are heat-pressed by a roll laminating method has been proposed. It was difficult to obtain a product with good appearance. For this reason, attempts have been made to use a metal having a specific hardness as a material for the roll, or to use a polyimide obtained from a specific aromatic diamine as a thermocompression bonding polyimide. However, the flexible metal foil laminate obtained by these methods also has insufficient product appearance, and when a flexible metal foil laminate having a small thickness is required, the uniformity and dimensional change rate in the width direction are sufficient. It is difficult to obtain a product, and the product yield deteriorates when an electronic circuit is formed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a flexible metal foil laminate in which a polyimide and a metal foil are laminated and which has good product appearance and dimensional stability.

[0007]

That is, the present invention provides:
When producing a flexible metal foil laminate from a thermocompression-bondable multilayer polyimide film and a metal foil in which a thermocompression-bondable polyimide layer is laminated and integrated on at least one surface of a high heat-resistant aromatic polyimide layer, a double belt press is used. Supply at least one combination of thermocompression-bondable multi-layer polyimide film and metal foil, interpose a protective material between both outermost layers and the belt, thermocompression-press under pressure, cool, and bond together to achieve high heat resistance A metal foil is laminated on at least one side of the aromatic polyimide layer via a thermocompression-bonding polyimide layer, and there is no defective product appearance and the dimensional stability is | ± 0.10 |% or less. Related to manufacturing method. In the above description, | ± 0.10 |% means that the absolute value is 0.10%.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be listed below. 1) The method for producing a flexible metal foil laminate, wherein the thermocompression-bondable multilayer polyimide film is formed by laminating a thermocompression-bondable polyimide layer on both sides of a highly heat-resistant aromatic polyimide layer. 2) The method for producing a flexible metal foil laminate, wherein the metal foil is an electrolytic copper foil, a rolled copper foil, an aluminum foil or a stainless steel foil. 3) The method for producing a flexible metal foil laminate, wherein the metal foil is a metal foil having a thickness of 3 μm to 35 μm. 4) The method for producing the flexible metal foil laminate, wherein the thickness of the polyimide layer is 7 to 50 μm. 5) A thermocompression-bondable multilayer polyimide film is obtained by laminating and integrating a thermocompression-bondable aromatic polyimide layer on at least one side, preferably both sides, of a high heat-resistant aromatic polyimide layer by a coextrusion-cast film forming method. A method for producing the flexible metal foil laminate. 6) The thickness of the flexible metal foil laminate is 15 to 120 μm
m. The method for producing a flexible metal foil laminate described above.

The structure of the flexible metal foil laminate obtained by the present invention includes, for example, the following various combinations. In the following description, TPI-F indicates a thermocompression-bonding multilayer polyimide film, TPI indicates a thermocompression-bonding aromatic polyimide layer, and PI indicates a high heat-resistant aromatic polyimide layer. 1 shows a configuration of a conductive multilayer polyimide film. Configuration of one set constituting flexible metal foil laminate: metal foil / TPI-F [TPI / PI] metal foil / TPI-F [TPI / PI / TPI] metal foil / TPI-F [TPI / PI / TPI] ] / Metal foil When two or more sets are manufactured from the above, any combination is possible. For example, the same configuration or a combination of different configurations may be used.

In the present invention, a protective material is interposed between the outermost layers and the belt when supplying at least one set of a double-belt press and a thermocompression-bondable multilayer polyimide film and a metal foil. Thermocompression bonding-cooling, laminating and laminating.

The thermocompression-bondable multilayer polyimide film according to the present invention may be obtained, for example, by laminating a thermocompression-bondable aromatic polyimide precursor solution on one or both sides of a high heat-resistant aromatic polyimide precursor solution dried film, or More preferably, after laminating a thermocompression-bondable aromatic polyimide or a precursor solution thereof on one or both sides of a precursor solution of a highly heat-resistant aromatic polyimide by coextrusion-casting film forming method, drying, imidizing. And obtain a thermocompression-bondable multilayer polyimide film.

The high heat-resistant aromatic polyimide of the thermocompression-bondable multilayer polyimide film is preferably 3,3 ',
4,4′-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated simply as s-BPDA) and paraphenylenediamine (hereinafter sometimes simply abbreviated as PPD), and optionally 4,4 ′. -Diaminodiphenyl ether (hereinafter sometimes abbreviated simply as DADE) and / or pyromellitic dianhydride (hereinafter sometimes simply abbreviated as PMDA). In this case, PPD / DADE (molar ratio) is 100/0
It is preferably ~ 85/15. Also, s-BPD
A / PMDA is preferably 100: 0-50 / 50. The high heat-resistant aromatic polyimide is pyromellitic dianhydride and paraphenylenediamine and 4,
It is produced from 4'-diaminodiphenyl ether.
In this case, DADE / PPD (molar ratio) is 90/10 to 1
It is preferably 0/90. Furthermore, high heat-resistant aromatic polyimides include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) and paraphenylenediamine (PPD) and 4 , 4'-Diaminodiphenyle-
Manufactured from Ter (DADE). In this case, BTDA in the acid dianhydride is 20 to 90 mol%, and PMDA is 10 to 90 mol%.
80 mol%, PPD in diamine 30-90 mol%, D
Preferably, the ADE is from 10 to 70 mol%. Other types of aromatic tetracarboxylic dianhydrides and aromatic diamines such as 4,4'-diaminodiphenylmethane may be used as long as the physical properties of the high heat-resistant aromatic polyimide are not impaired. Further, a fluorine group on the aromatic ring of the aromatic tetracarboxylic dianhydride or the aromatic diamine,
A substituent such as a hydroxyl group, a methyl group or a methoxy group may be introduced.

As the above-mentioned high heat-resistant aromatic polyimide, those which cannot be confirmed at a glass transition temperature of less than 350 ° C. in the case of a single-layer polyimide film are preferable, and particularly have a coefficient of linear thermal expansion (50 to 200). ° C) (MD, T
Both D and their average are usually represented by the value of MD because there is little difference between them. ) Is 5 × 10 ^-6 to 2
Those having a ^{concentration of} 5 × 10 ⁻⁶ cm / cm / ° C. are preferred. In the synthesis of this highly heat-resistant aromatic polyimide, two or more kinds of polyamic acid solutions are synthesized in advance by random polymerization, block polymerization, blending or each polyamic acid if the proportion of each component is within the above range. Mixing the solution to obtain a copolymer by recombination of the polyamic acid,
This can be achieved by either method.

As the thermocompression-bondable polyimide in the present invention, any thermoplastic polyimide which can be thermocompression-bonded at a temperature of about 300 to 400 ° C. may be used. Preferably 1,3-
Bis (4-aminophenoxybenzene) (hereinafter referred to as TPE
Sometimes abbreviated as R. ) And 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter a-BPD)
Sometimes abbreviated as A. ) And manufactured from. Also,
As the thermocompression bonding polyimide, 1,3-bis (4
-Aminophenoxy) -2,2-dimethylpropane (D
ANPG) and 4,4'-oxydiphthalic dianhydride (O
DPA). Alternatively, it is produced from 4,4′-oxydiphthalic dianhydride (ODPA) and pyromellitic dianhydride and 1,3-bis (4-aminophenoxybenzene). Alternatively, 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride or 3,3′-diaminobenzophenone and 1,3-bis ( 3-aminophenoxy) benzene and 3,3 ', 4
It is prepared from 4'-benzophenonetetracarboxylic dianhydride.

As long as the physical properties of the thermocompression-bondable polyimide are not impaired, other tetracarboxylic dianhydrides, for example, 3,
It may be replaced by 3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride or the like. Further, other diamines such as 4,4′-diaminodiphenyl ether, as long as the physical properties of the thermocompression-bondable polyimide are not impaired,
4,4'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenoxy)
Benzene, 4,4'-bis (4-aminophenyl) diphenyl ether, 4,4'-bis (4-aminophenyl) diphenylmethane, 4,4'-bis (4-aminophenoxy) diphenyl ether, 4,4'-bis (4-
Aminophenoxy) diphenylmethane, 2,2-bis [4- (aminophenoxy) phenyl] propane, 2,
Flexible aromatic diamine having a plurality of benzene rings such as 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-diaminobutane,
6-diaminohexane, 1,8-diaminooctane,
Aliphatic diamines such as 1,10-diaminodecane and 1,12-diaminododecane, bis (3-aminopropyl)
It may be replaced by a diaminodisiloxane such as tetramethyldisiloxane. Dicarboxylic acids, such as phthalic acid and its substituted products, hexahydrophthalic acid and its substituted products, succinic acid and its substituted products and derivatives thereof, for blocking the amine end of the thermocompression-bondable aromatic polyimide In particular, phthalic acid may be used.

The above-mentioned thermocompression-bondable polyimide is obtained by mixing the above-mentioned components and, if necessary, other tetracarboxylic dianhydrides and other diamines in an organic solvent at a temperature of about 100 ° C. or less, especially 20 to 60 ° C. The solution is reacted at a temperature to form a polyamic acid solution, and this polyamic acid solution can be used as a dope solution. In order to obtain the thermocompression-bondable polyimide according to the present invention, the amount of the total moles of the acid (as the total moles of tetraacid dianhydride and dicarboxylic acid) in the organic solvent is based on the diamine (as the mole number). As a ratio,
Preferably 0.92 to 1.1, especially 0.98 to 1.1,
Among them, it is particularly 0.99 to 1.1, and the amount of the dicarboxylic acid used is preferably 0.00 to 0.1, particularly 0.0 as a ratio to the molar amount of the tetracarboxylic dianhydride.
A ratio such as 2 to 0.06 is preferred.

For the purpose of limiting the gelling of the polyamic acid, a phosphorus-based stabilizer such as triphenyl phosphite, triphenyl phosphate or the like is used in an amount of 0.01% based on the solid content (polymer) concentration during the polymerization of the polyamic acid. It can be added in the range of １1%. Further, for the purpose of accelerating imidization,
A basic organic compound-based catalyst can be added to the solution. For example, imidazole, 2-imidazole, 1,2
-Dimethylimidazole, 2-phenylimidazole, etc., in an amount of 0.01 to 20 with respect to the polyamic acid (solid content).
%, In particular from 0.5 to 10% by weight. Since these form a polyimide film at a relatively low temperature, they are used to avoid insufficient imidization. Further, for the purpose of stabilizing the adhesive strength, an organic aluminum compound, an inorganic aluminum compound or an organic tin compound may be added to the thermocompression-bondable aromatic polyimide raw material dope. For example, aluminum hydroxide, aluminum triacetylacetonate or the like can be added to the polyamic acid (solid content) at a ratio of 1 ppm or more, particularly 1 to 1000 ppm, as aluminum metal.

The organic solvent used for the production of the polyamic acid is N-methyl-2 with respect to both the aromatic polyimide having high heat resistance and the aromatic polyimide having thermocompression bonding property.
-Pyrrolidone, N, N-dimethylformamide, N, N
-Dimethylacetamide, N, N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam, cresols and the like. These organic solvents may be used alone,
More than one species may be used in combination.

In the production of the thermocompression-bondable multilayer polyimide film according to the present invention, a co-extrusion-casting film forming method is preferably used, for example, thermocompression bonding to one or both surfaces of the polyamic acid solution of the above-mentioned heat-resistant aromatic polyimide. A solution of a hydrophilic aromatic polyimide precursor is co-extruded and cast on a support surface such as a stainless steel mirror surface or a belt surface to form a solution.
A method in which a semi-cured state or a dried state before that at about 200 ° C. can be adopted. When the cast film is processed at a high temperature exceeding 200 ° C., defects such as a decrease in adhesiveness tend to occur in the production of a thermocompression-bondable multilayer polyimide film. The semi-cured state or a state before that means that it is in a self-supporting state by heating and / or chemical imidization.

The co-extrusion of the polyamic acid solution giving the highly heat-resistant aromatic polyimide and the polyamic acid solution giving the thermocompression-bondable aromatic polyimide is described in, for example, JP-A-3-180343 (Japanese Patent Publication No. 102661
JP-A No. 2000-216, and a co-extrusion method described in Japanese Patent Application Laid-Open Publication No. HEI 9-260, which is applied to a two- or three-layer extrusion die, and cast on a support. On one or both sides of the extrudate layer giving the high heat-resistant aromatic polyimide, a polyamic acid solution giving the thermocompression-bondable aromatic polyimide is laminated to form a multilayer film-like material, dried and then heat-pressed Is heated to a temperature not higher than the temperature at which deterioration occurs above the glass transition temperature (Tg) of the aromatic polyimide, preferably 300 to 500 ° C. (surface temperature measured by a surface thermometer) (preferably this temperature). Drying and imidizing to produce a thermocompression-bondable multilayer polyimide film having a thermocompression-bondable aromatic polyimide on one or both sides of a highly heat-resistant (substrate layer) aromatic polyimide. Can be.

The thermocompression-bondable aromatic polyimide according to the present invention has a glass transition temperature of 180 to 275 ° C., particularly 2 ° C. by using the above-mentioned acid component and diamine component.
100 to 275 ° C., preferably dried under the above conditions.
It is imidized and does not liquefy at a temperature in the range of 300 ° C. to 300 ° C., which is obtained by substantially not causing gelation of the thermocompression-bondable polyimide, and the elastic modulus is usually 275 ° C. When the modulus of elasticity is around room temperature (50
C.) are preferably about 0.0002 to 0.2 times the elastic modulus at (.degree. C.).

In the present invention, high heat resistance (substrate layer)
The thickness of the polyimide layer is 5 to 70 μm, especially 5 to 50 μm
It is preferred that If the thickness is less than 5 μm, there is a problem in mechanical strength and dimensional stability of the formed thermocompression-bondable multilayer polyimide film. There is no particular effect even if the thickness is more than 70 μm, which is disadvantageous in terms of high density. In the present invention, the thickness of the thermocompression-bondable aromatic polyimide layer is 2
10 to 10 μm, particularly preferably about 2 to 8 μm. If it is less than 2 μm, the adhesive performance is reduced, and if it exceeds 10 μm, it can be used, but there is no particular effect, but rather the heat resistance of the flexible metal foil laminate decreases. The thermocompression-bondable multilayer polyimide film has a thickness of 7 to 75 μm, particularly 7 to 50 μm.
m is preferable. If the thickness is less than 7 μm, it is difficult to handle the produced film, and if the thickness is more than 75 μm, there is no particular effect, which is disadvantageous in increasing the density.

According to the co-extrusion-casting film forming method, the high heat-resistant polyimide layer and the thermocompression-bondable polyimide on one or both sides thereof are cured at a relatively low temperature to deteriorate the thermocompression-bondable polyimide. It is possible to obtain a thermocompression-bondable multilayer polyimide film in which the imidization and drying of the self-supporting film have been completed, without any need.

Examples of the metal foil used in the present invention include various metal foils such as copper, aluminum, iron, gold and the like, and alloy foils of these metals. Preferably, rolled copper foil, electrolytic copper foil And so on. As the metal foil, those having a surface roughness not too large and not too small, preferably having an Rz of 7 μm or less, particularly Rz of 5 μm or less, particularly 0.5 to 5 μm are preferable. Such a metal foil, for example, a copper foil, is known as VLP, LP (or HTE). The thickness of the metal foil is not particularly limited.
It is preferably not more than μm, particularly preferably 3 to 35 μm. When Rz is small, a metal foil whose surface is treated may be used.

In the present invention, at least one combination of a thermocompression-bondable multilayer polyimide film and a metal foil is supplied, and a protective material (ie, two protective materials) is interposed between both sides of the outermost layer and the belt. It is necessary to apply thermocompression bonding under pressure-cooling and laminating and laminating, so that even a thin flexible metal foil laminate can be heated at 150 ° C.
The dimensional change rate of the film after the heat treatment for 30 minutes was measured (the metal foil was removed by etching from the laminate before the etching treatment, and the film was subjected to the heat treatment at 150 ° C. for 30 minutes to indicate the dimensional change of the film). .10 |% or less, especially ±
0.001 to ± 0.10%, especially ± 0.00
A flexible metal foil laminate having good product appearance is obtained by visually observing the degree of flatness in the width direction, the presence or absence of wrinkles, and the presence or absence of scratches having dimensional stability of 1 to ± 0.08%. be able to.

As the protective material, any material can be used as long as it is non-thermocompressible and has good surface smoothness.
For example, a metal foil, particularly a copper foil, a stainless steel foil, an aluminum foil, or a highly heat-resistant polyimide film (UPIREX S manufactured by Ube Industries, Kapton H manufactured by Toray DuPont) having a thickness of about 5 to 125 μm is used. Preferred examples are given. By interposing the protective material between the outermost layer of the constituent material and the belt, even if the total thickness of the constituent material is thin, the product appearance in which the metal foil and the thermocompression-bonding polyimide film are laminated has a good flexible metal appearance. A foil laminate can be obtained. In particular, by laminating a metal foil and the thermocompression-bondable multilayer polyimide film, a flexible metal foil laminate having good product appearance and good dimensional stability can be obtained.
In the above manufacturing method, even when using a double belt press, thermocompression bonding without interposing a protective material between the outermost layer of the thermocompression-bondable polyimide film and the metal foil and the belt, and cooling- Even if they are laminated, it is not easy to obtain a flexible metal foil laminate having high dimensional stability and good product appearance.

In the above-mentioned double belt press, the thermocompression-bonding multilayer polyimide film and the metal foil are preferably placed at a temperature higher than 100 ° C. and 250 ° C. or lower, for example, along an inlet drum leading to the double belt press. It is preferable to preheat for about 120 seconds, and then bond by thermocompression-cooling under pressure. The double belt press is capable of performing high-temperature heating-cooling under pressure, and is preferably a hydraulic type using a heat medium.

In the flexible metal foil laminate according to the present invention, the temperature of the thermocompression bonding zone of the double belt press is preferably 20 ° C. higher than the glass transition temperature of the thermocompression-bondable polyimide.
Thermocompression bonding under pressure at a temperature higher than 400 ° C. or higher, especially at a temperature higher than 30 ° C. and lower than 400 ° C. above the glass transition temperature, followed by cooling under pressure with a cooling zone, preferably thermocompression bonding The polyimide can be manufactured by cooling at a temperature lower than 20 ° C. or lower, particularly 30 ° C. or lower than the glass transition temperature of polyimide to a temperature of about 25 ° C. or higher and laminating. In the above method, when the product is a single-sided metal foil flexible metal foil laminate, a highly heat-resistant film easily peelable, for example, a high heat-resistant film or a metal foil having an Rz of less than 2 μm, preferably polyimide A heat-resistant resin film such as a film (Ube Industries, Ltd., UPILEX S), a fluororesin film, or a rolled copper foil, and a metal foil having a small surface roughness and a good surface smoothness are bonded to a thermocompression bonding polyimide. It may be interposed between the layer and another metal surface. After the interposed film or metal foil is laminated,
It may be removed from the laminate and rolled up, or may be rolled up as it is laminated and removed at the time of use.

In the present invention, by combining a protective material between a press surface and a metal foil and thermocompression bonding under pressure using a double belt press, cooling and laminating, a long length is obtained. The width is about 400mm or more,
In particular, even if the width is about 500 mm or more, the adhesive strength is large (90 ° peel strength: 0.7 kg / cm or more, especially 1 kg / cm or more), and wrinkles and scratches are substantially observed on the metal foil surface. It is possible to obtain a flexible metal foil laminate having a better appearance as much as possible. In the present invention,
In the flexible metal foil laminate, the dimensional change rate is an average of L, C, and R (left end, center, right end in the film unwinding direction) in each width direction, and after heating at 150 ° C. for 30 minutes | ±
0.10% | or less, and high dimensional stability.

In the present invention, the flexible metal foil laminate is preferably supplied with a thermocompression-bondable multi-layer polyimide film, a metal foil and a protective material in a rolled state, respectively, to a double belt press, and pressurized under pressure. The laminate can be formed by thermocompression bonding and cooling, and the protective material can be separated and removed at the time of winding the product to obtain a continuous roll.

The flexible metal foil laminate obtained by the present invention is cut into a predetermined size as it is, or after being subjected to various treatments such as core winding, etching, and, if necessary, curling back, for electronic components. Can be used as a substrate. For example, it can be suitably used as a substrate for FPC, TAB, multilayer FPC, or flex-rigid substrate. In particular, a single-sided copper foil laminate (total thickness is 15 to 85 μm) or a double-sided copper foil laminate (total thickness is 25 μm) in which the thickness of a metal foil is 3 to 35 μm and the thickness of a thermocompression-bonding multilayer polyimide film layer is 7 to 50 μm. ~ 120 µm),
A heat-resistant adhesive (thickness: 5 to 50 μm, preferably 5 to 15 μm) selected from an epoxy-based adhesive or a heat-resistant polyimide-based adhesive such as thermoplastic polyimide, thermoplastic polyamide-imide, or polyimidesiloxane-epoxy.
μm, especially 7 to 12 μm) by bonding a plurality of flexible copper foil laminates so that the flexible copper foil laminate has 2 to 10 layers and satisfies high heat resistance, low water absorption, low dielectric constant, and high electric characteristics. A substrate can be suitably obtained. The flexible metal foil laminate according to the present invention includes not only the above-mentioned long one but also a long one cut into a predetermined size as described above.

[0032]

The present invention will be described in more detail with reference to the following examples. In each of the following examples, parts mean parts by weight. In each of the following examples, the evaluation of physical properties and the adhesive strength of the flexible metal foil laminate were measured according to the following methods.

Product appearance: Regarding the product appearance after lamination,
The degree of flatness, the presence or absence of wrinkles, and the presence or absence of scratches were visually judged and evaluated. ○: good flatness with no wrinkles or abrasions, good: △: slightly unevenness or slight wrinkles or abrasions, ×: non-uniform flatness or wrinkles or abrasions Dimensional stability: before heating 150 ° C for the dimensions of the laminate of
Dimensional change of laminate after heat treatment for × 30 minutes
The measurement was carried out according to C-6471 "Testing method for copper-clad laminate for flexible printed wiring boards", and the dimensional change rate in% was determined. ○: good dimensional stability when the dimensional change rate is | ± 0.10 |% or less; Δ: normal dimensional stability when the dimensional change rate is more than | ± 0.10 |% and less than | ± 0.12%, × Is poor in dimensional stability when the dimensional change rate is | ± 0.12 |% or more. Thermal expansion coefficient: measured at 50 to 200 ° C., 5 ° C./min (T
D, average value of MD). Glass transition temperature (Tg): Measured from viscoelasticity. Adhesive strength: 90 ° peel strength was measured and indicated as an average value.

Synthesis Example 1 of Dope for Production of Highly Heat-Resistant Aromatic Polyimide A reaction vessel equipped with a stirrer and a nitrogen inlet tube was charged with N-methyl-
2-Pyrrolidone was added, and paraphenylenediamine (PPD) and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s-BPDA) were further added at 1000: 9.
At a molar ratio of 98, the monomer concentration was 18% (% by weight, the same applies hereinafter). After completion of the addition, the reaction was continued for 3 hours while maintaining the temperature at 50 ° C. The obtained polyamic acid solution is a brown viscous liquid, and the solution viscosity at 25 ° C. is about 15
It was 00 poise. This solution was used as a dope.

Synthesis of Dope for Production of Aromatic Polyimide of Thermocompression Bonding-1 N-Methyl-methyl was added to a reaction vessel equipped with a stirrer and a nitrogen inlet tube.
2-Pyrrolidone was added, and 1,3-bis (4-aminophenoxy) benzene (TPE-R) and 2,3,3
3 ', 4'-biphenyltetracarboxylic dianhydride (a
-BPDA) in a molar ratio of 1000: 1000 to give a monomer concentration of 22%, and triphenyl phosphate was added in an amount of 0.1% by weight of the monomer. After completion of the addition, the reaction was continued for 1 hour while maintaining the temperature at 25 ° C. This polyamic acid solution has a solution viscosity of about 200 at 25 ° C.
It was 0 poise. This solution was used as a dope.

Reference Examples 1 to 3 A three-layer extrusion molding die (multi-manifold type die) was prepared from the above-mentioned heat-resistant aromatic polyimide dope and the thermocompression-bondable aromatic polyimide production dope. Using the film forming apparatus provided, the polyamic acid solution was cast on a metal support while changing the thickness of the three-layer extrusion die, and continuously dried with hot air at 140 ° C. to form a solidified film. After the solidified film was peeled from the support, the temperature was gradually raised from 200 ° C. to 320 ° C. in a heating furnace to remove the solvent and imidize, and three types of long three-layer extruded polyimide films were wound up. Rolled up. The obtained three-layer extruded polyimide film exhibited the following physical properties.

Thermocompression-bondable multilayer polyimide film-1 Thickness constitution: 4 μm / 17 μm / 4 μm (total 25 μm) Tg of thermocompression-bondable aromatic polyimide: 250 ° C. (the same applies hereinafter) At 275 ° C. of thermocompression-bondable aromatic polyimide Has an elastic modulus of 5
Approximately 0.002 times the elastic modulus at 0 ° C. (the same applies hereinafter) Thermocompression-bondable multilayer polyimide film-2 Thickness configuration: 3 μm / 9 μm / 3 μm (15 μm in total) Thermocompression-bondable multilayer polyimide film-2 Thickness configuration: 2 μm / 6 μm / 2μm (total 10μm)

COMPARATIVE EXAMPLE 1 The thermocompression-bondable multilayer polyimide film-1 and two rolled electrolytic copper foils (3EC-Mitsui Metal Mining Co., Ltd.)
VLP, Rz of 3.8 μm, thickness of 18 μm), using a laminating roll consisting of a metal crimping roll and an elastic roll, continuously on the metal side: 380 ° C. Elastic side: The flexible copper foil laminate (width: about 320 mm) was press-bonded under heating at 200 ° C. and wound up on a take-up roll. All operations were performed in air, and cooling was performed by natural cooling. The evaluation results of the obtained flexible copper foil laminate are shown below. Product appearance: × Dimensional stability: × Dimensional change rate: -0.14% Adhesive strength Peel strength: Average: 1.2 kgf / cm

COMPARATIVE EXAMPLE 2 A thermocompression-bonding multilayer polyimide film-1 and one set of 18 μm-thick electrolytic copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd.) were continuously supplied from both sides thereof to a double belt press, and no protective material was used. The temperature of the heating zone (maximum heating temperature) is 380 ° C (setting), and the temperature of the cooling zone (minimum cooling temperature) is 117 ° C without preheating, and thermocompression-cooling is performed continuously under pressure. And laminated to form a flexible copper foil laminate (width: about 530m)
m, the same applies hereinafter). The evaluation results of the obtained flexible copper foil laminate are shown below. Product appearance: △ Dimensional stability: × Dimensional change rate: -0.12%

Example 1 A set of a thermocompression-bonding multilayer polyimide film-1 and a copper foil was overlaid on both sides with a 35 μm-thick electrolytic copper foil as a protective material such that all components had the same width to protect the configuration. Rolling a set of rolled double-sided copper foil flexible copper foil laminate in the same manner as in Comparative Example 2 except that the laminate was laminated as a material / copper foil / TPI-F / copper foil / protective material. Wound up. This flexible copper foil laminate had a structure of copper foil / TPI-F / copper foil and a thickness of 18 μm / 25 μm / 18 μm.
The evaluation results of the obtained flexible copper foil laminate are shown below. Product appearance: ○ Dimensional stability: ○ Dimensional change: -0.08% Adhesive strength: 1.3 kgf / cm

Example 2 Two sets of thermocompression-bondable multilayer polyimide film-1 and two copper foils on both sides thereof were overlaid with a 35 μm-thick electrolytic copper foil as a protective material on both sides so that all components had the same width. And the composition is protective material / copper foil / TPI-F / copper foil / copper foil / TPI-
Two sets of rolled double-sided copper foil flexible copper foil laminates were wound up on a roll in the same manner as in Example 1 except that F / copper foil / laminate was used as a protective material. This flexible copper foil laminate has a structure of copper foil / TPI-F / copper foil and copper foil /
TPI-F / copper foil with a thickness of 18 μm / 25 μm /
It was 18 μm. The evaluation results of the obtained flexible copper foil laminate are shown below. Product appearance: ○ Dimensional stability: ○ Dimensional change: -0.08% Adhesive strength: 1.3 kgf / cm

Example 3 The same procedure as in Example 1 was repeated except that three sets of the thermocompression-bonding multilayer polyimide film-1 and copper foils on both sides thereof were laminated.
A set of rolled double-sided copper foil flexible copper foil laminates was taken up on a take-up roll. The structure of this flexible copper foil laminate is copper foil / TPI-F / copper foil, copper foil / TPI-F
/ Copper foil and copper foil / TPI-F / copper foil, each having a thickness of 18
μm / 25 μm / 18 μm. The evaluation results of the obtained flexible copper foil laminate are shown below. Product appearance: ○ Dimensional stability: ○ Dimensional change rate: -0.07% Adhesive strength: 1.4 kgf / cm

Examples 4 to 5 Thermocompression-bondable multilayer polyimide film-2 and thickness 12 μm
m of electrolytic copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd.) or the same as in Example 3 except that a thermocompression-bonding multilayer polyimide film-3 and a 9 μm thick electrolytic copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd.) were used. Then, thermocompression bonding and cooling were continuously performed under pressure and laminated, and three sets of flexible copper foil laminates were wound on a winding roll. The evaluation result of the obtained flexible copper foil laminate was equivalent to that of Example 3 and showed good results.

[0044]

According to the manufacturing method of the present invention, the following effects can be obtained because of the above configuration.

According to the manufacturing method of the present invention, a flexible metal foil laminate having good product appearance and dimensional change rate of ± 0.10% or less and good dimensional stability can be obtained without increasing the size of the laminating apparatus. In addition, it is possible to manufacture while achieving both improvement in productivity and improvement in quality characteristics. In particular, according to the present invention, even when the product is thin, the appearance of the product is good and the dimensional stability can be improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 31/08 B32B 31/08 31/30 31/30 H05K 1/03 670 H05K 1/03 670Z // B29K 79:00 B29K 79:00 105: 22 105: 22 B29L 9:00 B29L 9:00 F term (reference) 4F100 AB01C AB04C AB10C AB17C AB33C AK49A AK49B AK49D BA02 BA03 BA04 BA07 BA10A BA10C BA10D BA13 EA022 EH201 EH461 EJ182 EJ422EJ422 JA20 JA20C JJ03A JL04 JL12B JL12D YY00 YY00C 4F204 AA40 AD03 AG03 AH36 FA11 FA16 FB02 FB11 FF01 FF05 FG02 FG08

Claims (7)

[Claims] 1. A method for producing a flexible metal foil laminate from a thermocompression-bondable multilayer polyimide film in which a thermocompression-bondable polyimide layer is integrally laminated on at least one surface of a highly heat-resistant aromatic polyimide layer and a metal foil. At least one combination of thermocompression-bondable multi-layer polyimide film and metal foil is supplied to a double belt press, and a protective material is interposed between both outermost layers and the belt. A metal foil is laminated on at least one surface of the high heat-resistant aromatic polyimide layer via a thermocompression-bonding polyimide layer.
A method for producing a flexible metal foil laminate having a content of 10% or less. 2. The method according to claim 1, wherein the thermocompression-bondable multilayer polyimide film is formed by laminating a thermocompression-bondable polyimide layer on both sides of an aromatic polyimide layer having high heat resistance. 3. The method according to claim 1, wherein the metal foil is an electrolytic copper foil, a rolled copper foil, an aluminum foil or a stainless steel foil. 4. The method according to claim 1, wherein the metal foil is a metal foil having a thickness of 3 μm to 35 μm. 5. The polyimide layer has a total thickness of 7 to 50 μm.
The production method according to any one of claims 1 to 4, wherein 6. A thermocompression-bondable multilayer polyimide film is formed by laminating a thermocompression-bondable aromatic polyimide layer on at least one side, preferably both sides, of a high heat-resistant aromatic polyimide layer by a coextrusion-casting film forming method. The production method according to any one of claims 1 to 5, which is obtained by conversion to an organic solvent. 7. A flexible metal foil laminate having a thickness of 15
The method according to any one of claims 1 to 6, wherein the thickness is from 120 to 120 µm.