JP4345188B2 - Flexible metal foil laminate and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flexible metal foil laminate by a double belt press method and a method for producing the same, and more specifically, thermocompression bonding having a thermocompression-bonding aromatic polyimide layer on at least one surface of a highly heat-resistant aromatic polyimide layer. The present invention relates to a flexible metal foil laminate which is an all polyimide obtained by laminating a conductive multilayer polyimide film and a metal foil and has good product appearance and dimensional stability, and a method for producing the same.
[0002]
[Prior art]
Aromatic polyimide films are widely used as applications for electronic devices such as cameras, personal computers, and liquid crystal displays.
In order to use an aromatic polyimide film as a substrate material such as a flexible printed board (FPC) or tape-automated bonding (TAB), a copper foil is bonded using an adhesive such as an epoxy resin. The method is adopted.
[0003]
Aromatic polyimide films are excellent in heat resistance, mechanical strength, electrical characteristics, etc., but it has been pointed out that the heat resistance of adhesives is inferior so that the characteristics of the original polyimide are impaired.
In order to solve such problems, copper is electroplated on the polyimide film without using an adhesive, or a polyamic acid solution is applied to the copper foil, followed by drying, imidization, or thermocompression bonding of thermoplastic polyimide. An all-polyimide substrate has been developed.
[0004]
Further, there is known a polyimide laminate in which a polyimide adhesive is bonded in a sandwich between a polyimide film and a metal foil using a vacuum press machine (US Pat. No. 4,543,295).
However, in this polyimide laminate, there is a problem that a long one cannot be obtained, and a low heat linear expansion biphenyltetracarboxylic acid type polyimide film has a low adhesive strength and cannot be used.
[0005]
In addition, a flexible metal foil laminate in which a thermocompression-bonding multilayer polyimide film of a heat-resistant polyimide layer and a thermocompression-bonding polyimide layer and a metal foil are thermocompression-bonded by a roll laminating method has been proposed. It was difficult to obtain a good one.
For this reason, attempts have been made to use a metal having a specific hardness as the material of the roll, or to use a material obtained from a specific aromatic diamine as a thermocompression bonding polyimide.
However, the flexible metal foil laminate obtained by these methods also has an insufficient product appearance, and when a thin flexible metal foil laminate is required, the uniformity in the width direction and the dimensional change rate are sufficient. It is difficult to obtain a product, and the product yield deteriorates when an electronic circuit is formed.
[0006]
[Problems to be solved by the invention]
The objective of this invention is providing the flexible metal foil laminated body which laminated | stacked polyimide and metal foil, and the product external appearance and dimensional stability are favorable, and its manufacturing method.
[0007]
[Means for Solving the Problems]
  That is, this invention is a flexible metal foil laminate having a metal foil on one or both sides of a highly heat-resistant aromatic polyimide layer through a thermocompression-bonding polyimide layer and a highly heat-resistant aromatic polyimide layer and a metal foil. Is a method of manufacturing
The thickness of the metal foil is 3 μm to 35 μm,
The highly heat-resistant aromatic polyimide layer is an aromatic polyimide produced from a component containing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and para-phenylenediamine,
Aromatics produced from components comprising 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, para-phenylenediamine and 4,4′-diaminodiphenyl ether Polyimide,
Alternatively, an aromatic polyimide produced from a component containing pyromellitic dianhydride, paraphenylenediamine and 4,4′-diaminodiphenyl ether,
The thermocompression bonding polyimide layer is a thermoplastic polyimide that can be thermocompression bonded at a temperature of 300 to 400 ° C.
Highly heat-resistant aromatic polyimide having a total polyimide layer thickness of 7 to 50 μm, a high heat-resistant aromatic polyimide layer thickness of 5 to 40 μm, and a thermocompression bonding polyimide layer thickness of 2 to 10 μm Using a thermocompression-bonding multilayer polyimide film in which a layer and a thermocompression-bonding polyimide layer are directly laminated,
Double belt pressThermocompression bonding polyimide filmTwo or more combinations of metal foil and metal foil are supplied, and the temperature of the heat-bonding zone of the double belt press is 20 ° C. higher than the glass transition temperature of the thermo-compression bonding polyimide layer and is under pressure at a temperature of 400 ° C. or lower. Thermocompression bonding, followed by cooling to a temperature lower by 20 ° C. or lower than the glass transition temperature of the thermocompression-bondable polyimide layer under pressure with a cooling zone, and simultaneously bonding two or more pairs, a highly heat-resistant aromatic polyimide layer It is related with the manufacturing method of the flexible metal foil laminated body characterized by laminating | stacking and metal foil through the thermocompression-bonding polyimide layer.
  Moreover, this invention relates to the flexible metal foil laminated body manufactured from the manufacturing method of the said flexible metal foil laminated body. Note that | 0.10 |% means that the absolute value is 0.10%.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention are listed below.
1) The manufacturing method of the said flexible metal foil laminated body by which metal foil is laminated | stacked on both surfaces of a highly heat-resistant aromatic polyimide layer through the thermocompression-bonding polyimide layer.
2) The manufacturing method of the said flexible metal foil laminated body whose metal foil is electrolytic copper foil, rolled copper foil, aluminum foil, or stainless steel foil.
3) The manufacturing method of the said flexible metal foil laminated body whose metal foil is metal foil of thickness 3 micrometers-35 micrometers.
4) The manufacturing method of the said flexible metal foil laminated body whose whole thickness of a polyimide layer is 7-50 micrometers.
5) A thermocompression-bonding multilayer polyimide film is obtained by laminating and integrating a thermocompression-bonding aromatic polyimide layer on at least one surface, preferably both surfaces of a highly heat-resistant aromatic polyimide layer by a coextrusion-casting film forming method. A method for producing the flexible metal foil laminate.
[0009]
As a structure of the flexible metal foil laminated body of this invention, the following various combinations are mentioned, for example. In the following description, TPI-F indicates a thermocompression-bonding multilayer polyimide film, TPI indicates a thermocompression-bonding aromatic polyimide layer, PI indicates a high heat-resistant aromatic polyimide layer, and the description in [] indicates thermocompression-bonding. The structure of a conductive multilayer polyimide film is shown.
Configuration of one set unit constituting two or more sets of flexible metal foil laminates:
(1) Metal foil / TPI-F [TPI / PI]
(2) Metal foil / TPI-F [TPI / PI / TPI]
(3) Metal foil / TPI-F [TPI / PI / TPI] / Metal foil
When combining two or more sets from (1) to (3), the combinations may be the same or different.
[0010]
The flexible metal foil laminate of the present invention is preferably manufactured by laminating two or more sets of a thermocompression-bonding multilayer polyimide film and a metal foil, and simultaneously laminating them by thermocompression-cooling under pressure with a double belt press. can do.
[0011]
The thermocompression-bonding multilayer polyimide film of the present invention is preferably, for example, after laminating a thermocompression-bonding aromatic polyimide precursor solution on one or both sides of a highly heat-resistant aromatic polyimide precursor solution dry film, or more preferably. The thermocompression-bonding aromatic polyimide or its precursor solution is laminated on one or both sides of the highly heat-resistant aromatic polyimide precursor solution by the coextrusion-casting film forming method, and then dried, imidized and thermocompression bonded. It can obtain by the method of obtaining a conductive multilayer polyimide film.
[0012]
The high heat-resistant aromatic polyimide of the thermocompression-bonding multilayer polyimide film is preferably 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter sometimes simply referred to as s-BPDA). ) And paraphenylenediamine (hereinafter sometimes abbreviated as PPD) and optionally 4,4′-diaminodiphenyl ether (hereinafter also abbreviated as DADE) and / or pyromellitic acid. It is produced from dianhydride (hereinafter sometimes abbreviated as PMDA). In this case, the PPD / DADE (molar ratio) is preferably 100/0 to 85/15. Moreover, it is preferable that s-BPDA / PMDA is 100: 0-50 / 50.
Highly heat-resistant aromatic polyimide is produced from pyromellitic dianhydride, paraphenylenediamine, and 4,4'-diaminodiphenyl ether. In this case, the DADE / PPD (molar ratio) is preferably 90/10 to 10/90.
Furthermore, high heat-resistant aromatic polyimides include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), pyromellitic dianhydride (PMDA), paraphenylenediamine (PPD) and 4 , 4'-diaminodiphenyl ether (DADE). In this case, it is preferable that BTDA in acid dianhydride is 20 to 90 mol%, PMDA is 10 to 80 mol%, PPD in diamine is 30 to 90 mol%, and DADE is 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.
Moreover, you may introduce | transduce substituents, such as a fluorine group, a hydroxyl group, a methyl group, or a methoxy group, into the aromatic ring of the said aromatic tetracarboxylic dianhydride or aromatic diamine.
[0013]
As the above-mentioned highly heat-resistant aromatic polyimide, in the case of a single-layer polyimide film, those that cannot be confirmed at a glass transition temperature of less than 350 ° C. are preferred, and in particular, the coefficient of thermal expansion (50 to 200 ° C.) ( MD, TD, and the average of all of these are usually displayed as MD values because there is little difference between them.^-6~ 25x10^-6What is cm / cm / degreeC is preferable.
The synthesis of this highly heat-resistant aromatic polyimide can be accomplished by randomly polymerizing, polymerizing, blending or preliminarily synthesizing two or more kinds of polyamic acid solutions as long as the ratio of each component is within the above range. This can be achieved by any method in which the solution is mixed to obtain a copolymer by recombination of the polyamic acid.
[0014]
As the thermocompression bonding polyimide in the present invention, any thermoplastic polyimide that can be thermocompression bonded at a temperature of about 300 to 400 ° C. may be used. Preferably, 1,3-bis (4-aminophenoxybenzene) (hereinafter sometimes abbreviated as TPER) and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter referred to as a- And may be abbreviated as BPDA).
The thermocompression bonding polyimide is manufactured from 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane (DANPG) and 4,4′-oxydiphthalic dianhydride (ODPA). The
Alternatively, it is prepared from 4,4'-oxydiphthalic dianhydride (ODPA) and pyromellitic dianhydride and 1,3-bis (4-aminophenoxybenzene).
Also, from 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, or from 3,3′-diaminobenzophenone and 1,3-bis ( 3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride.
[0015]
Other tetracarboxylic dianhydrides such as 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4- It may be replaced with dicarboxyphenyl) propane dianhydride or the like.
Further, other diamines such as 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, 2,2-bis, as long as the physical properties of the thermocompression bonding polyimide are not impaired. (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 di- having a plurality of benzene rings, such as 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane Mine, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane and other aliphatic diamines, bis (3-aminopropyl) tetra It may be replaced by a diaminodisiloxane such as methyldisiloxane.
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 sealing the amine terminal of the thermocompression-bonding aromatic polyimide In particular, phthalic acid may be used.
[0016]
The thermocompression bonding polyimide reacts with each of the above components, and optionally other tetracarboxylic dianhydrides and other diamines in an organic solvent at a temperature of about 100 ° C. or less, particularly 20 to 60 ° C. Thus, a polyamic acid solution can be used, and this polyamic acid solution can be used as a dope solution.
The thermocompression bonding polyimide reacts with each of the above components, and optionally other tetracarboxylic dianhydrides and other diamines in an organic solvent at a temperature of about 100 ° C. or less, particularly 20 to 60 ° C. Thus, a polyamic acid solution can be used, and this polyamic acid solution can be used as a dope solution.
In order to obtain the thermocompression-bondable polyimide in the present invention, the total amount of acids (as the total moles of tetracarboxylic dianhydride and dicarboxylic acid) used in the organic solvent is diamine (as the number of moles). Is preferably 0.92 to 1.1, particularly 0.98 to 1.1, and especially 0.99 to 1.1, and the amount of dicarboxylic acid used is tetracarboxylic dianhydride The ratio to the molar amount is preferably 0.00 to 0.1, particularly preferably 0.02 to 0.06.
[0017]
Further, for the purpose of limiting the gelation of polyamic acid, phosphorus stabilizers such as triphenyl phosphite and triphenyl phosphate are 0.01 to 1% based on the solid content (polymer) concentration during polyamic acid polymerization. It can be added in the range of. For the purpose of promoting imidization, a basic organic compound-based catalyst can be added to the dope solution. For example, imidazole, 2-imidazole, 1,2-dimethylimidazole, 2-phenylimidazole and the like are 0.01 to 20% by weight, particularly 0.5% with respect to the polyamic acid (solid content). It can be used at a ratio of -10% by weight. Since these form a polyimide film at a relatively low temperature, they are used to avoid imidation becoming insufficient.
For the purpose of stabilizing the adhesive strength, an organoaluminum compound, an inorganic aluminum compound or an organotin compound may be added to the thermocompression bonding aromatic polyimide raw material dope. For example, aluminum hydroxide, aluminum triacetylacetonate, or the like can be added in an amount of 1 ppm or more, particularly 1 to 1000 ppm as an aluminum metal with respect to polyamic acid (solid content).
[0018]
The organic solvent used for the production of the polyamic acid is N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, for both high heat-resistant aromatic polyimide and thermocompression aromatic polyimide. , N-dimethylacetamide, N, N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam, cresols and the like. These organic solvents may be used alone or in combination of two or more.
[0019]
In the production of the above-mentioned thermocompression-bonding multilayer polyimide film, it is preferable to use a coextrusion-casting film forming method, for example, thermocompression-bonding aromatics on one or both sides of the polyamic acid solution of the above-mentioned high heat-resistant aromatic polyimide A method in which a polyimide precursor solution is coextruded and cast onto a support surface such as a stainless steel mirror surface or a belt surface to be semi-cured or dried at 100 to 200 ° C. can be employed. When a 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-bonding multilayer polyimide film. This semi-cured state or an earlier state means that it is in a self-supporting state by heating and / or chemical imidization.
[0020]
The coextrusion of the polyamic acid solution that gives the high heat-resistant aromatic polyimide and the polyamic acid solution that gives the thermocompression-bonding aromatic polyimide can be performed by, for example, JP-A-3-180343 (Japanese Patent Publication No. 7-102661). ) Can be fed to a two-layer or three-layer extrusion die and cast on a support.
A polyamic acid solution that gives a thermocompression-bonding aromatic polyimide is laminated on one or both sides of the extrudate layer that gives the high heat-resistant aromatic polyimide to form a multilayered film-like product, and is dried, followed by thermocompression bonding. Heat to a temperature below the temperature at which deterioration occurs above the glass transition temperature (Tg) of the aromatic polyimide, preferably 300 to 500 ° C. (surface temperature measured with a surface thermometer) (preferably this temperature). Drying for 1 to 60 minutes) and drying and imidizing to produce a thermocompression-bonding multilayer polyimide film having a thermocompression-bonding aromatic polyimide on one or both sides of a highly heat-resistant (substrate layer) aromatic polyimide. Can do.
[0021]
The thermocompression-bondable aromatic polyimide according to the present invention has a glass transition temperature of 180 to 275 ° C., particularly 200 to 275 ° C. by using the acid component and the diamine component. Is not liquefied at a temperature not lower than the glass transition temperature and not higher than 300 ° C., and the elastic modulus is usually 275. It is preferable that the elastic modulus at 0 ° C. holds about 0.0002 to 0.2 times the elastic modulus at a temperature near room temperature (50 ° C.).
[0022]
In the present invention, the thickness of the high heat resistant (base layer) polyimide layer is preferably 5 to 70 μm, particularly preferably 5 to 40 μm. If the thickness is less than 5 μm, problems arise in the mechanical strength and dimensional stability of the thermocompression-bondable multilayer polyimide film produced. Moreover, even if it becomes thicker than 70 μm, there is no particular effect, which is disadvantageous in terms of high density.
In the present invention, the thickness of the thermocompression-bondable aromatic polyimide layer is preferably 2 to 10 μm, particularly about 2 to 8 μm. If it is less than 2 μm, the adhesive performance is lowered, and even if it exceeds 10 μm, it can be used, but it is not particularly effective, but rather the heat resistance of the flexible metal foil laminate is lowered.
The thermocompression-bonding multilayer polyimide film preferably has a thickness of 7 to 75 μm, particularly 7 to 50 μm. If it is less than 7 μm, it is difficult to handle the prepared film, and if it is thicker than 75 μm, there is no particular effect, which is disadvantageous for increasing the density.
[0023]
According to the coextrusion-casting film forming method, the high heat-resistant polyimide layer and the thermocompression bonding polyimide on one or both sides thereof are cured at a relatively low temperature without causing deterioration of the thermocompression bonding polyimide. A thermocompression-bonding multilayer polyimide film that has completed imidization and drying of the self-supporting film can be obtained, which is preferable.
[0024]
Examples of the metal foil used in the present invention include metal foils such as copper, aluminum, iron, and gold, or various metal foils such as alloy foils of these metals, preferably rolled copper foil and electrolytic copper foil. It is done. As the metal foil, one having a surface roughness which is not so large and not too small, preferably Rz is 7 μm or less, particularly Rz is 5 μm or less, particularly 0.5 to 5 μm is preferable. Such metal foils, such as copper foils, are known as VLP, LP (or HTE).
The thickness of the metal foil is not particularly limited, but is preferably 70 μm or less, particularly preferably 3 to 35 μm.
Moreover, when Ra is small, you may use what surface-treated the metal foil surface.
[0025]
  In the present invention, it is necessary to supply two or more sets of a thermocompression-bonding multilayer polyimide film and a metal foil to a double belt press, and laminate them at the same time by thermocompression-cooling and bonding together under pressure. Even if it is a thin flexible metal foil laminate, the dimensional change rate measured for the film after heat treatment at 150 ° C. for 30 minutes (the metal foil with respect to the laminate before etching treatment is removed by etching and heat treatment at 150 ° C. for 30 minutes. Shows the dimensional change of the film)｜ 0.10 ｜%In the following, it has a dimensional stability of ± 0.001 to ± 0.10%, especially ± 0.001 to ± 0.08%, and visually observes the degree of flatness in the width direction and the occurrence of wrinkles. A flexible flexible metal foil laminate having a good product appearance determined as described above can be obtained.
[0026]
In the above manufacturing method, even if two or more sets of a thermocompression-bonding multilayer polyimide film and a metal foil are bonded together by thermocompression bonding under pressure at the same time, the roll laminating method has dimensional stability and product. A flexible metal foil laminate with good appearance cannot be obtained.
In addition, even with a double belt press, if only one set of a thermocompression-bonding multilayer polyimide film and a metal foil is simultaneously bonded by thermocompression-cooling under pressure with a double belt press, high dimensional stability is achieved. It is not easy to obtain a flexible metal foil laminate having an excellent product appearance.
[0027]
In the double belt press described above, the thermocompression-bonding multilayer polyimide film and the metal foil are preheated for about 2 to 120 seconds at a temperature higher than 100 ° C and lower than 250 ° C, preferably along an inlet drum leading to the double belt press. In addition, it is preferable to bond them by thermocompression bonding and cooling under pressure.
The double belt press is capable of performing high-temperature heating and cooling under pressure, and is preferably a hydraulic type using a heat medium.
[0028]
In the flexible metal foil laminate of 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 bonding polyimide and 400 ° C. or less, particularly 30% higher than the glass transition temperature. It is thermocompression bonded under pressure at a temperature not lower than 400 ° C. and not higher than 400 ° C., and subsequently cooled under pressure with a cooling zone, preferably at least 20 ° C. lower than the glass transition temperature of the thermocompression bonding polyimide, particularly 30 It can manufacture by cooling and laminating | stacking to the temperature lower than degreeC.
In the above method, when the product is a flexible metal foil laminate of a single-sided metal foil, a highly heat-resistant film that can be easily peeled, such as a high-heat-resistant film or metal foil having a Rz of less than 2 μm, preferably polyimide A heat-resistant resin film such as a film (Ube Industries, Upilex S) or a fluororesin film, or a rolled copper foil, which has a small surface roughness and good surface smoothness, is used as a protective material. You may interpose between a pressure-sensitive adhesive polyimide layer and another metal surface. After the lamination, the protective material may be removed from the laminate and wound up, or the protective material may be taken up while being laminated and removed during use.
[0029]
  In this invention, it is possible to achieve a take-up speed of 1 m / min or more, preferably by thermocompression-cooling and laminating under pressure using a double belt press, and the resulting flexible metal foil laminate is long. Even if the width is about 400 mm or more, especially about 500 mm or more, the adhesive strength is high (90 ° peel strength: 0.7 kg / cm or more, especially 1 kg / cm or more) Can be obtained, a flexible metal foil laminate having a good appearance can be obtained. In the present invention, the flexible metal foil laminate has a dimensional change rate of L, C and R (left end, center, right end in the film unwinding direction) in each width direction, and 150 ° C. × 30 minutes. After heating｜ 0.10 ｜%The dimensional stability is high.
[0030]
In this invention, the flexible metal foil laminate is supplied to the double belt press with the thermocompression-bonding multilayer polyimide film and the metal foil in a roll winding state, and the metal foil laminate film is obtained in a roll winding state. Can do.
[0031]
The flexible metal foil laminate obtained by the present invention is used as an electronic component substrate after being rolled, etched, and optionally subjected to curl return, etc., and then cut into a predetermined size. it can.
For example, it can be suitably used as a substrate of FPC, TAB, multilayer FPC, or flex-rigid substrate.
In particular, a single-sided copper foil laminate (overall thickness is 15 to 85 μm) or a double-sided copper foil laminate (overall thickness is 25 μm) having a metal foil thickness of 3 to 35 μm and a thermocompression-bonding multilayer polyimide film layer thickness of 7 to 50 μm. To 120 μm), a heat-resistant adhesive (thickness 5 to 50 μm, preferably 5 to 15 μm) selected from epoxy-based adhesives, heat-resistant polyimide adhesives such as thermoplastic polyimide, thermoplastic polyamideimide, or polyimidesiloxane-epoxy. In particular, 7 to 12 μm), by bonding a plurality of flexible copper foil laminates, the flexible copper foil laminate has 2 to 10 layers, and satisfies a high heat resistance, low water absorption, low dielectric constant, and high electrical characteristics. Can be suitably obtained.
The flexible metal foil laminate of the present invention includes not only the above-mentioned elongated shape but also those obtained by cutting the elongated shape as described above into a predetermined size.
[0032]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
In each of the following examples, “part” means “part by weight”.
In each of the following examples, the physical property evaluation and the adhesive strength of the flexible metal foil laminate were measured according to the following methods.
[0033]
(1)Product appearance: The appearance of the product after lamination is evaluated by visually judging the degree of flatness and the presence or absence of wrinkles.
○ is flat and uniform and good, △ is slightly non-uniform or slightly flat, x is normal, and × is non-uniform or flawed
(2)Dimensional stability: The dimensional change of the laminate after heat treatment at 150 ° C. for 30 minutes relative to the size of the laminate before heating was measured according to “Testing method for copper-clad laminate for flexible printed wiring boards” of JIS C-6471. The dimensional change rate of the display was obtained in%.
○ is the dimensional change rate｜ 0.10 ｜%Good dimensional stability below, △ indicates dimensional change rate｜ 0.10 ｜%Bigger| 0.12 |%Less than dimensional stability is normal, × indicates dimensional change rate| 0.12 |%Dimensional stability is poor
(3)Thermal linear expansion coefficient: 50 to 200 ° C., measured at 5 ° C./min (average value of TD and MD), cm / cm / ° C.
(4)Glass transition temperature (Tg): measured from viscoelasticity.
(5)Adhesive strength: 90 ° peel strength was measured and expressed as an average value.
[0034]
Synthesis example 1 of a dope for producing highly heat-resistant aromatic polyimide
N-methyl-2-pyrrolidone is added to a reaction vessel equipped with a stirrer and a nitrogen introduction tube, and further, paraphenylenediamine (PPD) and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (s -BPDA) at a molar ratio of 1000: 998 so that the monomer concentration was 18% (wt%, hereinafter the same). After completion of the addition, the reaction was continued for 3 hours while maintaining 50 ° C. The obtained polyamic acid solution was a brown viscous liquid, and the solution viscosity at 25 ° C. was about 1500 poise. This solution was used as a dope.
[0035]
Synthesis of Thermocompression Aromatic Polyimide Manufacturing Dope-1
N-methyl-2-pyrrolidone is added to a reaction vessel equipped with a stirrer and a nitrogen introduction tube, and 1,3-bis (4-aminophenoxy) benzene (TPE-R) and 2,3,3 ′, 4 are added. '-Biphenyltetracarboxylic dianhydride (a-BPDA) was added at a molar ratio of 1000: 1000 to a monomer concentration of 22%, and triphenyl phosphate was added to a monomer weight of 0.1%. 1% was added. After completion of the addition, the reaction was continued for 1 hour while maintaining 25 ° C. This polyamic acid solution had a solution viscosity at 25 ° C. of about 2000 poise. This solution was used as a dope.
[0036]
Reference Examples 1-3
Using a film-forming apparatus provided with a three-layer extrusion die (multi-manifold die) for the above-mentioned highly heat-resistant aromatic polyimide dope and thermocompression-bonding aromatic polyimide production dope. 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 is peeled off from the support, the temperature is gradually raised from 200 ° C. to 320 ° C. in a heating furnace to remove the solvent and imidize to take up three types of long three-layer extruded polyimide films. Rolled up in a le.
The obtained three-layer extruded polyimide film exhibited the following physical properties.
[0037]
Thermocompression bonding polyimide film-1
Thickness configuration: 4 μm / 17 μm / 4 μm (total 25 μm)
Thermo-compressible aromatic polyimide Tg: 250 ° C. (the same applies hereinafter)
The elastic modulus at 275 ° C of the thermo-compressible aromatic polyimide is approximately 0.002 times the elastic modulus at 50 ° C (hereinafter the same)
Thermocompression-bonding multilayer polyimide film-2
Thickness configuration: 3 μm / 9 μm / 3 μm (15 μm in total)
Thermocompression-bonding multilayer polyimide film-2
Thickness configuration: 2 μm / 6 μm / 2 μm (total 10 μm)
[0038]
Comparative Example 1
One set of the thermocompression-bonding multilayer polyimide film-1 and two roll-wrapped electrolytic copper foils (Mitsui Metal Mining Co., Ltd., 3EC-VLP, Rz 3.8 μm, thickness 18 μm) A flexible copper foil laminate using a laminating roll made of a pressure-bonding roll and an elastic roll, and continuously crimped under heating at a metal side: 380 ° C. and an elastic side: 200 ° C. (Width: about 320 mm) was wound on a winding roll. All operations were performed in air, and cooling was performed by natural cooling.
The evaluation result about the obtained flexible copper foil laminated body is shown next.
Product appearance: ×
Adhesive strength Peel strength: Average: 1.2 kgf / cm
Product appearance: ×
Dimensional stability: ×
Dimensional change rate: -0.14%
[0039]
Comparative Example 2
The flexible copper foil laminate was wound up on a winding roll in the same manner as in Comparative Example 1 except that two sets of thermocompression-bonding multilayer polyimide film copper foil were thermocompression bonded.
The evaluation result about the obtained flexible copper foil laminated body is shown next.
Product appearance: △
Dimensional stability: ×
Dimensional change rate: -0.12%
[0040]
Comparative Example 3
  A double belt press is continuously supplied with thermocompression-bonding multilayer polyimide film-1 and one set of electrolytic copper foil having a thickness of 18 μm from both sides thereof, and the temperature of the heating zone (maximum heating temperature) is 380 ° C. (setting), At the cooling zone temperature (minimum cooling temperature: 117 ° C.)Flexible copper foil laminateA roll roll (width: about 530 mm, the same applies hereinafter) was obtained. The evaluation result about the obtained flexible copper foil laminated body is shown next.
Product appearance: ○
Dimensional stability: ×
Dimensional change rate: -0.12%
[0041]
Example 1
A flexible copper foil laminate of two sets of roll-wound double-sided copper foil is wound up in the same manner as Comparative Example 3 except that two sets of thermocompression-bonding multilayer polyimide film-1 and copper foil are laminated. Rolled up in a le.
This flexible copper foil laminate was composed of Cu / TPI-F / Cu and Cu / TPI-F / Cu and had a thickness of 18 μm / 25 μm / 18 μm.
The evaluation result about 2 sets of the obtained flexible copper foil laminated body is shown next.
Product appearance: ○
Dimensional stability: ○
Dimensional change rate: -0.08%
Adhesive strength: 1.3 kgf / cm
[0042]
Example 2
  Thermocompression-bonding multilayer polyimide film-1 and copper foil3PairLaminatedOtherwise, in the same manner as in Example 1, three sets of roll-wrapped double-sided copper foil flexible copper foil laminates were wound on a winding roll. This flexible copper foil laminate was composed of Cu / TPI-F / Cu, Cu / TPI-F / Cu and Cu / PI / Cu, and had a thickness of 18 μm / 25 μm / 18 μm. The evaluation result about 3 sets of the obtained flexible copper foil laminated body is shown next.
Product appearance: ○
Dimensional stability: ○
Dimensional change rate: -0.07%
Adhesive strength: 1.4 kgf / cm
[0043]
Examples 3-4
Use thermocompression-bonding multilayer polyimide film-2 and 12 μm thick electrolytic copper foil (made by Mitsui Kinzoku Mining Co., Ltd.) Other than the use, in the same manner as in Example 2, three layers of flexible copper foil laminates were wound around a take-up roll by continuous thermocompression-cooling and lamination under pressure.
The evaluation result about the obtained flexible copper foil laminated body was equivalent to Example 2, and showed a favorable result.
[0044]
【The invention's effect】
According to the manufacturing method of this invention, since it has the above configuration, the following effects can be obtained.
[0045]
  According to the manufacturing method of the present invention, the product appearance and the dimensional change rate are｜ 0.10 ｜%A flexible metal foil laminate having good dimensional stability can be produced in the following manner while improving productivity and improving quality characteristics without enlarging the laminating apparatus. In particular, according to the present invention, even when the product is thin, the product appearance is good and the dimensional stability can be improved.

Claims (8)

It is a method for producing a flexible metal foil laminate having a metal foil on one or both sides of a highly heat-resistant aromatic polyimide layer through a thermocompression-bonding polyimide layer with a highly heat-resistant aromatic polyimide layer and a metal foil. ,
The thickness of the metal foil is 3 μm to 35 μm,
The highly heat-resistant aromatic polyimide layer is an aromatic polyimide produced from a component containing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and para-phenylenediamine,
Aromatics produced from components comprising 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, para-phenylenediamine and 4,4′-diaminodiphenyl ether Polyimide,
Alternatively, an aromatic polyimide produced from a component containing pyromellitic dianhydride, paraphenylenediamine and 4,4′-diaminodiphenyl ether,
The thermocompression bonding polyimide layer is a thermoplastic polyimide that can be thermocompression bonded at a temperature of 300 to 400 ° C.
Highly heat-resistant aromatic polyimide having a total polyimide layer thickness of 7 to 50 μm, a high heat-resistant aromatic polyimide layer thickness of 5 to 40 μm, and a thermocompression bonding polyimide layer thickness of 2 to 10 μm Using a thermocompression-bonding multilayer polyimide film in which a layer and a thermocompression-bonding polyimide layer are directly laminated,
Supply two or more combinations of thermocompression-bonding multilayer polyimide film and metal foil to the double belt press, and the temperature of the thermocompression bonding zone of the double belt press is 20 ° C or more than the glass transition temperature of the thermocompression bonding polyimide layer. Two or more pairs are bonded together at the same time by thermocompression bonding under pressure at a high temperature of 400 ° C or lower, followed by cooling with a cooling zone to a temperature that is 20 ° C lower than the glass transition temperature of the thermocompression bonding polyimide layer. A highly heat-resistant aromatic polyimide layer and a metal foil are laminated via a thermocompression-bondable polyimide layer.   2. The flexible metal foil laminate according to claim 1, wherein the flexible metal foil laminate is a flexible metal foil laminate having no deterioration in uniformity in the width direction, no appearance defects due to generation of wrinkles, and excellent dimensional stability. Manufacturing method of foil laminated body. The metal foil is a metal foil having a thickness of 3 μm to 18 μm,
The manufacturing method of the flexible metal foil laminated body of Claim 1 or Claim 2 whose whole thickness of a polyimide layer is 7-25 micrometers. The thermocompression bonding polyimide layer is manufactured from a component containing 1,3-bis (4-aminophenoxybenzene) and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, Produced from a component comprising 3-bis (4-aminophenoxy) -2,2-dimethylpropane and 4,4′-oxydiphthalic dianhydride,
Produced from a component comprising 4,4′-oxydiphthalic dianhydride and pyromellitic dianhydride and 1,3-bis (4-aminophenoxybenzene),
Manufactured from a component containing 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, or 3,3′-diaminobenzophenone and 1, It is manufactured from the component containing 3-bis (3-amino phenoxy) benzene and 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride of Claims 1-3 characterized by the above-mentioned. The manufacturing method of the flexible metal foil laminated body of any one. The method for producing a flexible metal foil laminate according to any one of claims 1 to 4 , wherein the flexible metal foil laminate is a rolled product. The method for producing a flexible metal foil laminate according to any one of claims 1 to 5 , wherein the flexible metal foil laminate is a flexible metal foil laminate in which metal foils are laminated on both surfaces. The method for producing a flexible metal foil laminate according to any one of claims 1 to 6 , wherein the metal foil is an electrolytic copper foil, a rolled copper foil, an aluminum foil, or a stainless steel foil. The flexible metal foil laminated body manufactured from the manufacturing method of the flexible metal foil laminated body in any one of Claims 1-7 .