JP4389337B2 - 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 laminated by a continuous laminating apparatus and a method for producing the same, and more specifically, a thermocompression-bonding aromatic polyimide on at least one surface of a highly heat-resistant aromatic polyimide layer. The present invention relates to a flexible metal foil laminate having high solder heat resistance, which is obtained by laminating a thermocompression-bonding multilayer polyimide film having a layer and a metal foil, 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 was electroplated on a polyimide film without using an adhesive, a polyamic acid solution was applied to a copper foil, dried and imidized, and a thermoplastic polyimide was thermocompression bonded. An all-polyimide substrate has also 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 flexible metal foil laminate in which a thermocompression-bonding multilayer polyimide film of a heat-resistant polyimide layer and a thermocompression-bondable polyimide layer and a metal foil are thermocompression-bonded by a roll laminating method has been proposed. It was difficult to obtain a product with a good appearance when the value was high.
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, due to the moisture contained in the polyimide, poor appearance due to foaming occurs in the laminated body after lamination, or the solder heat resistance is less than 280 ° C. because the foaming is caused by immersion in the solder bath when forming the electronic circuit. It is difficult to use as a lead-free solder substrate material, and the product yield also deteriorates.
[0006]
For this reason, a flexible metal foil laminate has been proposed in which a polyimide adhesive sheet is preheated in a separate process (outline), and after moisture-proof storage, a metal foil and a polyimide adhesive sheet are laminated. However, the method of performing the heat treatment in this outline is difficult to control the quality, and further absorbs moisture before the polyimide adhesive sheet is heat-bonded, so that the appearance of the flexible metal foil laminate is poor due to foaming. It cannot be completely eliminated and it is difficult to achieve high solder heat resistance.
[0007]
[Problems to be solved by the invention]
The object of the present invention is to laminate a heat-resistant multilayer polyimide film of a heat-resistant polyimide as a base layer and a thermo-compression-bonding polyimide film and a metal foil, and have a high solder heat resistance and a long length, and therefore a continuous laminating apparatus. It is providing the flexible metal foil laminated body formed, and its manufacturing method.
[0008]
[Means for Solving the Problems]
That is, the present invention has a solder heat resistance of 280 ° C. or higher, in which a metal foil is laminated on at least one surface of a highly heat-resistant aromatic polyimide layer via a thermocompression bonding polyimide layer by a continuous laminating apparatus. The present invention relates to a flexible metal foil laminate having no appearance defect due to foaming during lamination.
In addition, the present invention preheats in-line immediately before introducing a thermocompression-bonding multilayer polyimide film in which a thermocompression-bonding polyimide layer is laminated and integrated on at least one surface of a high heat-resistant aromatic polyimide layer into a continuous laminating apparatus. And it is related with the manufacturing method of the said flexible metal foil laminated body which heat-presses and bonds a metal foil and a thermocompression-bonding multilayer polyimide film.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention are listed below.
1) The said flexible metal foil laminated body by which metal foil is laminated | stacked through the thermocompression-bonding polyimide layer on both surfaces of the highly heat-resistant aromatic polyimide layer.
2) 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 flexible metal foil laminate described above, wherein the metal foil is a metal foil having a thickness of 3 μm to 35 μm.
4) The said flexible metal foil laminated body whose whole thickness of a polyimide layer is 7-50 micrometers.
5) Said flexible metal foil laminated body which has solder heat resistance of 300 degreeC or more.
6) 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 as described above.
[0010]
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.
(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 In the present invention, the thermocompression-bonding multilayer polyimide film and the metal foil are laminated by a continuous laminating apparatus.
[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 para-phenylenediamine (hereinafter sometimes abbreviated as PPD) and optionally 4,4′-diaminodiphenyl ether (hereinafter also abbreviated as DADE) and / or pyromerit. It is produced from acid dianhydride (hereinafter sometimes abbreviated simply 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.
High-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 high 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 preferable, and in particular, the linear expansion coefficient (50 to 200 ° C.) ( MD, TD, and the average of these are all preferably 5 × 10 ^{−6 to} 25 × 10 ⁻⁶ cm / cm / ° C.
The synthesis of this highly heat-resistant aromatic polyimide can be accomplished by randomly polymerizing, polymerizing, blending or preliminarily synthesizing two or more types 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 produced 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, , A flexible aromatic diamine having a plurality of benzene rings such as 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane; , 4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane and other aliphatic diamines, bis (3-aminopropyl) tetramethyldisiloxane And may be replaced by diaminodisiloxane.
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.
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 thermocompression-bonding multilayer polyimide film in the present invention, a coextrusion-casting film forming method, for example, a thermocompression-bonding fragrance on one side or both sides of the polyamic acid solution of the above-mentioned high heat-resistant aromatic polyimide, is preferable. Coextruded solution of group polyimide or its precursor, casted onto a support surface such as a stainless steel mirror surface or belt surface, and made into a semi-cured or dried state at 100-200 ° C. it can. 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 120 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. On the other hand, when the thickness is more than 120 μm, there are difficulties in removing the solvent and imidization.
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 125 μm, particularly 7 to 50 μm. When the thickness is less than 7 μm, it is difficult to handle the prepared film. When the thickness is greater than 125 μm, there are difficulties in removing the solvent and imidization.
[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 in which imidization and drying of the self-supporting film are completed can be obtained.
[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 75 μm or less, particularly preferably 3 to 35 μm.
Moreover, when Rz is small, you may use what surface-treated the metal foil surface.
[0025]
In the present invention, the thermocompression-bonding multilayer polyimide film and the metal foil are continuous laminating devices such as a roll laminator or a double belt press, and only the thermocompression-bonding multilayer polyimide film or thermocompression bonding is possible. A preheater such as a hot-air supply device or an infrared heater so that it can be preheated at about 150 to 250 ° C., particularly at a temperature higher than 150 ° C. and lower than 250 ° C. for about 2 to 120 seconds, just before the introduction of the multilayer polyimide film and the metal foil A flexible metal foil laminate can be obtained by preheating using, and thermocompression bonding.
The in-line means a device arrangement in which a preheating device is installed between a raw material feeding device and a crimping portion of a continuous laminating device and can be crimped immediately thereafter.
[0026]
And if it is not preheated in-line, it will absorb water from the atmosphere and the moisture contained in the polyimide will cause poor appearance due to foaming in the laminate after lamination, or foaming will occur during immersion in the solder bath when forming electronic circuits The product yield deteriorates. A method of installing the entire laminating apparatus in a furnace is also conceivable, but the laminating apparatus is practically limited to a compact one and is not practical due to limitations on the shape of the flexible metal foil laminate. Alternatively, even if pre-heat treatment is performed in the outline, moisture is absorbed again by the time of stacking, and appearance defects and a decrease in solder heat resistance due to the foaming cannot be avoided.
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.
[0027]
The flexible metal foil laminate of the present invention preferably has a temperature of a heat laminating zone of a roll laminate or double belt press of 20 ° C. or higher and 400 ° C. or lower than the glass transition temperature of the thermocompression bonding polyimide, In particular, it is thermocompression bonded under pressure at a temperature of 30 ° C. or higher and 400 ° C. or lower than the glass transition temperature. Especially in the case of a double belt press, it is subsequently cooled under pressure with a cooling zone, preferably thermocompression bonding. It can be manufactured by cooling and laminating to a temperature 20 ° C. or more lower than the glass transition temperature of polyimide, particularly 30 ° C. or more.
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.
[0028]
In the present invention, particularly by using a double belt press to laminate by thermocompression-cooling under pressure, the take-up speed can be preferably 1 m / min or more, and the obtained flexible metal foil laminate is: Long and wide, about 400 mm or more, especially about 500 mm or more, high adhesion strength (90 ° peel strength: 0.7 kg / cm or more, especially 1 kg / cm or more), and the surface of the metal foil is substantially wrinkled It is possible to obtain a flexible metal foil laminate having a good appearance that is not recognized.
Moreover, when a double belt press is used, the flexible metal foil laminate preferably has an average dimensional change rate of L, C, and R (left end, center, right end in the film unwinding direction) in each width direction. , MD, and TD are | ± 0.20 |% or less at room temperature (only after drying after etching) and 150 ° C. (heat treatment after etching), and the uniformity of dimensional change becomes high.
[0029]
In this invention, the flexible metal foil laminate is supplied to a roll laminate or a double belt press in a state in which the thermocompression-bonding multilayer polyimide film and the metal foil are rolled, and the metal foil laminate film is rolled. It can be obtained in a wound state.
[0030]
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 of 15 to 85 μm) or a double-sided copper foil laminate (overall thickness of 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 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 copper foil laminates, 2 to 10 copper foil laminates are preferable, and a multilayer substrate that satisfies high heat resistance, low water absorption, low dielectric constant, and high electrical characteristics is suitable Can get to.
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.
[0031]
【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.
[0032]
Dimensional change rate: Measured according to “Test method for copper-clad laminate for flexible printed wiring board” of JIS C-6471.
Thermal expansion coefficient: 50-200 ° C., measured at 5 ° C./min (average value of TD, MD), cm / cm / ° C.
Glass transition temperature (Tg): measured from viscoelasticity.
Adhesive strength: 90 ° peel strength was measured.
Product appearance: The appearance of the product after lamination is evaluated by visually judging whether or not there is swelling due to foaming.
○ is good without foaming, △ is partly foamed, × foaming occurs on the entire surface Solder heat resistance: Immersion at 280 ° C or 300 ° C for 1 minute, and evaluated by visually judging whether there is any abnormality due to foaming ○ is foaming No, good, △ partly foamed, × foamed over the entire surface.
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.
[0034]
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.
[0035]
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 three-layer extruded polyimide films. Rolled up in a le.
The obtained three-layer extruded polyimide film exhibited the following physical properties.
[0036]
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)
Water absorption of film: 0.8% by weight (the same applies hereinafter)
Thermocompression-bonding multilayer polyimide film-2
Thickness configuration: 3 μm / 9 μm / 3 μm (15 μm in total)
Thermocompression-bonding multilayer polyimide film-3
Thickness configuration: 2 μm / 6 μm / 2 μm (total 10 μm)
[0037]
Comparative Example 1
The thermocompression-bonding multilayer polyimide film-1 and two roll-wrapped electrolytic copper foils (manufactured by Mitsui Kinzoku Mining Co., Ltd., 3EC-VLP, Rz 3.8 μm, thickness 18 μm) are bonded to metal. A flexible copper foil laminate using a laminar roll composed of a roll and an elastic roll and continuously crimped without 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 below.
Product appearance: ×
90 ° peel strength (average: 1.3 kg / cm)
Solder heat resistance: x at 280 ° C
[0038]
Comparative Example 2
After preheating to 200 ° C. in the outline, the flexible copper foil laminate was wound on a winding roll in the same manner as in Comparative Example 1 except that the thermocompression-bonding multilayer polyimide film-1 stored in a desiccator was used. I took it.
The evaluation result about the obtained flexible copper foil laminated body is shown below.
Product appearance: △
Solder heat resistance: △ at 280 ° C
[0039]
Example 1
The flexible copper of double-sided copper foil was the same as Comparative Example 1 except that the thermocompression-bonding multilayer polyimide film-1 and the copper foil were preheated by heating in hot air at 200 ° C. for 30 seconds in-line immediately before the laminating roll. The foil laminate was wound on a winding roll.
The evaluation result about the obtained flexible copper foil laminated body is shown below.
Product appearance: ○
Resistance to soldering heat: at 300 ° C
[0040]
Comparative Example 3
A double belt press is continuously supplied with thermocompression-bonding multilayer polyimide film-1 and an electrolytic copper foil (Mitsui Mining & Mining Co., Ltd.) having a thickness of 18 μm from both sides, and the temperature of the heating zone (maximum heating temperature) without preheating. ) 381 ° C., cooling zone temperature (minimum cooling temperature: 117 ° C.), and continuously laminated under heat pressure-cooling under pressure, flexible copper foil laminate (width: about 530 mm, the same shall apply hereinafter) ) To obtain a roll.
The evaluation result about the obtained flexible copper foil laminated body is shown next.
Product appearance: △
Solder heat resistance: △ at 280 ° C
[0041]
Comparative Example 4
In the same manner as in Comparative Example 3, except that the thermocompression-bonding multilayer polyimide film-1 preheated to 200 ° C. in outline and stored in a desiccator was used, the layers were continuously laminated under pressure and thermocompression under pressure. Then, the roll-wound flexible copper foil laminate was wound around the roll.
The evaluation result about the obtained flexible copper foil laminated body is shown below.
Product appearance: ○
Solder heat resistance: △ at 280 ° C
[0042]
Example 2
Thermocompression-bonding multilayer polyimide film-1 and copper foil were thermocompression bonded under pressure in the same manner as in Comparative Example 3 except that they were preheated by heating with 200 ° C hot air for 30 seconds in-line immediately before double belt pressing. -It cooled and laminated | stacked and wound up the flexible copper foil laminated body of a roll winding double-sided copper foil in the winding roll.
The evaluation result about the obtained flexible copper foil laminated body is shown below.
Product appearance: ○
Solder heat resistance: ○ at 300 ° C
[0043]
Example 3
Single-sided copper-clad laminate [protective material: polyimide film (Ube Industries, Upilex-S 25 μm) used] was used in the same manner as in Example 2 except that thermocompression-cooling was continuously performed under pressure with a double belt press. Then, a flexible copper foil laminate of roll-rolled single-sided copper foil was wound up on a take-up roll.
The evaluation result about the obtained flexible copper foil laminated body is shown below.
Product appearance: ○
Solder heat resistance: ○ at 300 ° C
[0044]
Examples 4-5
Use thermocompression-bonding multilayer polyimide film-2 and 12 μm thick electrolytic copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd.), or use thermocompression-bonding multilayer polyimide film-3 and 9 μm thick electrolytic copper foil (manufactured by Mitsui Kinzoku Mining Co., Ltd.) Except for the use, the same procedure as in Example 2 was followed by thermocompression-cooling and laminating under pressure, and laminating a flexible copper foil laminate of roll-wound double-sided copper foil onto the roll. I took it.
The evaluation result about the obtained flexible copper foil laminated body was equivalent to Example 2, and showed a favorable result.
Moreover, the flexible copper foil laminated body obtained in Examples 1-5 showed 90 degree peel strength equal to or higher than that of Comparative Example 1.
[0045]
【The invention's effect】
According to this invention, since it has the above-described configuration, the following effects can be obtained.
[0046]
According to the present invention, it is possible to obtain a flexible metal foil laminate, particularly a flexible metal foil laminate, having a long and wide appearance and good solder heat resistance.

Claims (11)

In a method for producing a flexible metal foil laminate having a metal foil on at least one surface, a high heat resistant aromatic polyimide layer and a metal foil are bonded by thermocompression bonding using a double belt press through a thermocompression bonding polyimide layer. Yes,
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,
After preheating for 2 to 120 seconds at a temperature of 150 to 250 ° C. in-line immediately before introducing the thermocompression-bonding multilayer polyimide film or the thermocompression-bonding multilayer polyimide film and the metal foil into the double belt press ,
The temperature of the thermocompression bonding zone of the double belt press is 20 ° C. or more higher than the glass transition temperature of the thermocompression bonding polyimide layer through the thermocompression bonding polyimide layer between the high heat resistant aromatic polyimide layer and the metal foil. Flexible metal foil that is thermocompression bonded under pressure at a temperature of ℃ or lower, and subsequently cooled to a temperature that is at least 20 ℃ lower than the glass transition temperature of the thermocompression-bondable polyimide layer. A method for manufacturing a laminate. The in-line preheating immediately before introducing a thermocompression-bonding multilayer polyimide film or a thermocompression-bonding multilayer polyimide film and a metal foil into a double belt press is performed using a preheater. A method for producing a flexible metal foil laminate. 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, 2. The method according to claim 1, wherein the product is produced from a component containing 3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride. The manufacturing method of the flexible metal foil laminated body of 2.   The method for producing a flexible metal foil laminate according to any one of claims 1 to 3, 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 4, wherein the flexible metal foil laminate is a flexible metal foil laminate in which metal foils are laminated on both sides.   The method for producing a flexible metal foil laminate according to any one of claims 1 to 5, wherein the total thickness of the polyimide layer is 7 to 25 µm. The method for producing a flexible metal foil laminate according to any one of claims 1 to 5, wherein the total thickness of the polyimide layer is 7 to 15 µm.
Manufacturing method.   The method for producing a flexible metal foil laminate according to any one of claims 1 to 7, wherein the metal foil is an electrolytic copper foil, a rolled copper foil, an aluminum foil, or a stainless steel foil.   The method for producing a flexible metal foil laminate according to any one of claims 2 to 8, wherein the preheater is selected from a hot air supply device and an infrared heater. The method for producing a flexible metal foil laminate according to any one of claims 1 to 9 , wherein the flexible metal foil laminate has a solder heat resistance of 300 ° C or higher. The flexible metal foil laminated body manufactured from the manufacturing method of the flexible metal foil laminated body in any one of Claims 1-10 .