JP2008296405A - Polyimide film laminate with flexible metallic foil lamination having high reliability in adhesion with acf - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible printed circuit board having high reliability in adhesion with an anisotropic conductive film. <P>SOLUTION: A laminate of a flexible metallic foil lamination polyimide film and an anisotropic conductive film is provided, wherein in patterning performed so that the proportion of a polyimide surface exposure is 30-80% in the flexible metallic foil lamination polyimide film in the part in contact with the anisotropic conduction film, the initial adhesion is ≥0.8 kN/m and, after the processing at 85°C with 85 RH% for 250 hours, the adhesion between the flexible board and the anisotropic conductive film is ≥0.6 kN/m. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

   The present invention relates to a heat-resistant flexible metal foil laminated polyimide film laminate obtained by thermocompression bonding of an anisotropic conductive film (hereinafter referred to as ACF), a polyimide film exhibiting excellent adhesion, and a thin film metal sheet.

In recent years, there has been a demand for technological advances such as downsizing and high functionality as electronic devices become more sophisticated. In addition, electronic components constituting them are required to have higher performance in electrical characteristics, mechanical characteristics, heat resistance, and the like. Furthermore, in order to mount a semiconductor chip or the like in a limited volume, a flexible blind substrate in which a metal layer including a copper foil and a polyimide film are laminated is used as an electronic circuit substrate.
Flexible printed circuit boards (hereinafter referred to as FPCs) manufactured by processing flexible printed circuit boards are used as electronic circuits for mobile phones, hard disks, liquid crystal displays, node personal computers, digital cameras, and the like. ACF is used as one of materials for connecting electronic components such as chips.
Therefore, a high adhesive strength reliability is required between the ACF and the FPC for a long period of time, and Patent Document 1 discusses the adhesive strength between the ACF and the FPC, and further the adhesive strength reliability between the two. Is required.
JP 2002-363284 A

  An object of this invention is to provide the metal foil laminated polyimide film laminated body which has a high adhesive force between ACF and FPC, and has a polyimide film with the high retention rate of adhesive force.

As a result of intensive studies to solve the above problems, the present inventors have made the present invention. That is, the present invention is as follows.
Polyimide at the portion where the flexible metal foil laminated polyimide film (a) is in contact with the anisotropic conductive film (b), which is a laminate of the flexible metal foil laminated polyimide film (a) and the anisotropic conductive film (b). The flexible substrate is patterned so that the surface exposure ratio is 30 to 80%, the adhesive force between the flexible substrate and the anisotropic conductive film is 0.8 kN / m or more, and the flexible substrate is processed after 85 ° C. and 85 RH% for 250 hours A laminate having an adhesion force between the anisotropic conductive film and the anisotropic conductive film of 0.6 kN / m or more.
A laminate of a flexible metal foil laminated polyimide film (a) and an anisotropic conductive film (b), wherein the flexible metal foil laminated polyimide film (a) has a thermocompression bonding polyimide resin layer, and the thermocompression bonding A laminate comprising a porous polyimide resin layer containing an alicyclic acid dianhydride and / or an alicyclic diamine.

  When the flexible metal foil laminated polyimide film (hereinafter referred to as a flexible substrate) of the present invention is patterned such that the polyimide surface exposure ratio is 30 to 80%, the adhesive surface with the anisotropic conductive film is 85 ° C and 85RH% for 250 hours. It is a laminated body in which the adhesive force between the flexible substrate and the anisotropic conductive film after processing is 0.6 N / m or more. In addition, a thermocompression bonding polyimide resin is used for the flexible substrate, and the thermocompression bonding polyimide resin layer has an alicyclic acid dianhydride and / or an alicyclic diamine. Provided is a flexible metal foil laminated polyimide film having a high adhesive strength reliability between a flexible substrate and an anisotropic conductive film.

In the present invention, when patterning is performed so that the polyimide surface exposure ratio of the bonded portion between the flexible substrate and the anisotropic conductive film is 30 to 80%, the adhesive force between the flexible printed substrate and the anisotropic conductive film is 0.8 kN. Heat resistant flexible metal foil laminated polyimide film structure, characterized in that the adhesive strength between the flexible printed circuit board and the anisotropic conductive film is 0.6 N / m or more after treatment at 85 ° C. and 85 RH% for 250 hours Is the body.
Moreover, it is a laminated body of a flexible metal foil laminated polyimide film (a) and an anisotropic conductive film (b), and the flexible metal foil laminated polyimide film (a) has a thermocompression bonding polyimide resin layer, The thermocompression-bonding polyimide resin layer has a alicyclic acid dianhydride and / or an alicyclic diamine.

In the present invention, the polyimide film is preferably a heat-resistant polyimide film in which a thermocompression bonding polyimide resin layer is laminated on one side or both sides of a non-thermoplastic polyimide film.
Further, the heat-resistant polyimide film is a structure in which a heat-resistant polyimide adhesive layer is laminated on one side or both sides of a heat-resistant polyimide base film, and the alicyclic acid dianhydride and / or alicyclic type is formed on the heat-resistant polyimide. It is desirable to have a diamine.
The heat-resistant polyimide film in the present invention can be produced by applying a thermocompression bonding polyimide solution to one side or both sides of a non-thermoplastic aromatic polyimide film and drying the solvent by heating.

  The method for producing the non-thermoplastic aromatic polyimide film is not particularly limited, but is polymerized in a known organic polar solvent using aromatic tetracarboxylic dianhydride or its derivative and aromatic diamine. It can be obtained by casting on a stainless steel belt, removing the solvent by high-temperature drying, and imidizing. Examples of such acid dianhydrides and aromatic diamines include, but are not limited to, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as aromatic tetracarboxylic dianhydride Examples thereof include pyromellitic dianhydride and aromatic diamine such as p-phenylenediamine and / or diaminodiphenyl ether.

Organic polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylurea, γ-butyrolactone, dimethyl sulfoxide, hexamethylphosphoramide, dimethyl sulfone, tetramethylene Examples include sulfone, dimethyltetramethylene sulfone, diglyme, and triglyme. These organic polar solvents can also be used by mixing with other organic solvents such as toluene, benzonitrile and xylene.
The non-thermoplastic aromatic polyimide film preferably has a thickness of 5 to 125 μm. The non-thermoplastic aromatic polyimide film may be subjected to a surface treatment in order to improve the adhesive force with a thermocompression bonding polyimide layer laminated in a later step, but is not particularly limited. Examples of the surface treatment include plasma treatment, corona treatment, treatment with silane coupling agents, buffing, sand blasting, wet blasting, UV ozone treatment, and the like.

Moreover, a commercially available polyimide film can also be used for the non-thermoplastic polyimide film. For example, Upilex (registered trademark) S, Upilex (registered trademark) SGA, Upilex (registered trademark) SN (manufactured by Ube Industries, Ltd., trade name); Kapton (registered trademark) H, Kapton (registered trademark) V, Kapton (registered) Trademark) EN (trade name, manufactured by Toray DuPont Co., Ltd.); Apical (registered trademark) AH, Apical (registered trademark) NPI, Apical (registered trademark) NPP, Apical (registered trademark) HP (trade name, manufactured by Kaneka Corporation) ), Apical (registered trademark) FP (manufactured by Kaneka Corporation, trade name), and the like.
As a lamination method of the thermocompression bonding polyimide laminated on one side or both sides of this non-thermoplastic aromatic polyimide film, a known coating method can be used. That is, although it can carry out using a blade coater, a knife coater, a comma coater, an impregnation coater, a gravure coater, a reverse roll coater, etc., it is not particularly limited thereto.

  A thermocompression bonding polyimide is obtained by imidizing a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine component, but an alicyclic acid dianhydride or alicyclic in the molecule. By having a diamine, a heat-reactive component in ACF and a high adhesive force can be obtained in the reaction of ACF with heat and pressure. Examples of alicyclic acid dianhydrides include, for example, bicyclo (2,2,2) oct-7-ene-1-methyl-2,3,5,6 tetracarboxylic dianhydride, 5- (2 , 5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2 dianhydride, 1,5-cyclooctanediene-1,2,5,6 tetracarboxylic dianhydride, And bicyclo (2,22) oct-7-ene-2,3,5,6 tetracarboxylic dianhydride. Among these, bicyclo (2,2,2) oct-7-ene-2,3,5,6-tetracarboxylic dianhydride is particularly preferable.

  In addition to the above alicyclic acid dianhydrides, other known tetracarboxylic dianhydrides may be used in combination for the purpose of adjusting various properties. For example, pyromellitic dianhydride, 4,4′-oxydiphthalic dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetra Carboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide Dianhydride, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2, 2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane Water, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 4,4′-bis (3 4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [(3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1 , 4,5,8-naphthalenetetracarboxylic dianhydride, 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid-1,4-phenylene ester dianhydride, etc. may be used in combination. .

Among these, pyromellitic dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride from the viewpoint of heat resistance Preference is given to anhydrides, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and bis (3,4-dicarboxyphenyl) ether dianhydride.
Examples of alicyclic diamines include isophorone diamine, 2,5-diaminomethyl-bicyclo [2,2,2] octane, 2,5-diaminomethyl-7,7-dimethylbicyclo [2,2,1]. Heptane, 2,5-diaminomethyl-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane 2,5-diaminomethyl-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxabicyclo [2,2,1] heptane, 2, 5-diaminomethyl-7-thiabicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-azabicyclo 2,2,1] heptane, 2,6-diaminomethyl-bicyclo [2,2,2] octane, 2,6-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2,6 -Diaminomethyl-7,7-difluorobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6- Diaminomethyl-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxybicyclo [2,2,1] heptane, 2,6-diaminomethyl- 7-thiobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-iminobicyclo [2,2,1] Heptane, , 5-Diamino-bicyclo [2,2,1] heptane, 2,5-diamino-bicyclo [2,2,2] octane, 2,5-diamino-7,7-dimethylbicyclo [2,2,1] Heptane, 2,5-diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2 , 5-Diamino-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diamino-7-oxabicyclo [2,2,1] heptane, 2,5-diamino- 7-thiabicyclo [2,2,1] heptane, 2,5-diamino-7-oxobicyclo [2,2,1] heptane, 2,5-diamino-7-azabicyclo [2,2,1] heptane, 2 , 6-Diamino-bicyclo [2, 2,1] heptane, 2,6-diamino-bicyclo [2,2,2] octane, 2,6-diamino-7,7-dimethylbicyclo [2,2,1] heptane, 2,6-diamino-7 , 7-difluorobicyclo [2,2,1] heptane, 2,6-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6-diamino-7,7- Bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diamino-7-oxybicyclo [2,2,1] heptane, 2,6-diamino-7-thiobicyclo [2,2,1 ] Heptane, 2,6-diamino-7-oxobicyclo [2,2,1] heptane, 2,6-diamino-7-iminobicyclo [2,2,1] heptane, 1,2-diaminocyclohexane, 1, 3-diaminocyclohexa 1,4-diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4 -Aminocyclohexyl) methane, bicyclo [2,2,1] heptanebismethylamine, 4,4'-diaminodicyclohexylmethane, 1,8-diamino-p-menthane, 1,4-cyclohexanebis (methylamine), 1 , 3-cyclohexanebis (methylamine), but is not limited thereto.

  Among them, isophoronediamine, 2,5-diaminomethyl-bicyclo [2,2,2] octane, 2,5-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2,5- Diaminomethyl-7,7-difluorobicyclo [2,2,1] heptane, 2,6-diaminomethyl-bicyclo [2,2,2] octane, 2,6-diaminomethyl-7,7-dimethylbicyclo [2] , 2,1] heptane, 2,5-diamino-7-oxabicyclo [2,2,1] heptane, 2,5-diamino-7-thiabicyclo [2,2,1] heptane, 2,5-diamino- 7-oxobicyclo [2,2,1] heptane, 2,5-diamino-7-azabicyclo [2,2,1] heptane, 2,6-diamino-bicyclo [2,2,1] heptane, 2,6 -Diamino-bi Chloro [2,2,2] octane, 2,6-diamino-7,7-dimethylbicyclo [2,2,1] heptane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diamino Cyclohexane is preferred.

  In addition to the above alicyclic diamines, other known aromatic diamines may be used in combination for the purpose of adjusting various properties. Examples of the diamine include paraphenylene diamine, metaphenylene diamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminobenzophenone, 3,4′-diaminodiphenyl ether, 4, 4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfoxide, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4 , 4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dichloro-4,4′-diaminobiphenyl, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-amino Phenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4 ′ -Bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-aminophenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3-amino-4-methylphenyl) propane, 1, -Bis (3-aminopropyldimethylsilyl) benzene, 3,5-diaminobenzoic acid, 3,3'-dihydroxy-4,4'-diaminobiphenyl, bis (aminomethyl) ether, bis (2-aminoethyl) ether Bis (3-aminopropyl) ether, bis (2-aminomethoxy) ethyl] ether, bis [2- (2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1,2-bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2 -Aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether, diethylene glycol bis (3-aminopropiyl) L) ether, triethylene glycol bis (3-aminopropyl) ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7- Examples include diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, and isophoronediamine.

Preferably, from the viewpoint of heat resistance, 3,5-diaminobenzoic acid, 3,3′-dihydroxy-4,4′-diaminobiphenyl, bis (aminomethyl) ether, 1,4-bis (4-aminophenoxy) benzene 1,3-bis (4-aminophenoxy) benzene and 1,3-bis (3-aminophenoxy) benzene are preferred.
The alicyclic dianhydride and / or alicyclic diamine is preferably contained in the structure in an amount of 10 mol% or more in order to maintain the adhesive force with the ACF, and in order to maintain heat resistance, 60 mol% or less. It is preferable that More preferably, it is the range of 10-40 mol%.
Moreover, it is preferable that the terminal of this thermocompression-bonding polyimide resin is carboxylic acid or diamine. Thereby, the reaction of the ACF with the heat-reactive component is promoted, the adhesive force is improved, and a decrease in the adhesive force is suppressed when the film absorbs moisture.

As the thin film metal sheet used in the present invention, a known metal foil, alloy foil, or the like can be considered. Specifically, copper foil, stainless steel foil, aluminum foil, and the like are conceivable, but copper foil is desirable from the viewpoint of availability. The kind of copper foil is not particularly limited, and any of known electrolytic copper foil, rolled copper foil, and copper foil with carrier may be used.
Considering the production of copper foil patterns by the subtractive method or the like, the ten-point average roughness of the roughened copper foil surface is desirably 0.5 to 2.0 μm, and the thickness is desirably 3 to 20 μm.
As a method for forming the thin film metal layer on a heat-resistant polyimide film to obtain a laminate of the present application, the metal sheets are stacked on the heat-resistant polyimide film, and a continuous laminator such as a vacuum press, a roll laminator or a double belt press is used. It is possible to use a known and commonly used apparatus capable of applying the temperature, pressure and time necessary for bonding them.

In the present invention, it is expected that the polyimide surface exposure ratio on the surface to be bonded to the ACF increases as the polyimide surface exposure ratio increases. From the viewpoint of high functionality by increasing the density of the entire electronic component, 30 to 80% is preferable, preferably 50 to 80%, and more preferably 50 to 65%.
For the patterning of the metal wiring, a known method such as a subtractive method is used, but it is not limited thereto. The metal wiring width is preferably 10 μm or more and 150 μm or less, more preferably 10 μm or more and 50 μm or less, from the viewpoint of increasing the density of electronic components.
The ACF used in the present invention is obtained by dispersing conductive particles in a resin mainly composed of an epoxy resin or an acrylic resin in an adhesive film. Between the circuits to which this resin is connected, it is used by being thermocompression bonded at a predetermined temperature, pressure and time. As a result, electrical conduction between the circuits can be established through the conductive particles, and insulation between the wirings in the lateral direction can be maintained.

As a main component of ACF, it is desirable to use a known epoxy resin or acrylic resin, but is not limited thereto. Preferred examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, epoxy novolac resin, naphthalene type epoxy resin, and polyfunctional epoxy resin, but are not limited thereto.
As the conductive particle species dispersed in the ACF, metal particles made of gold, silver, copper, nickel, solder, and alloys thereof, or particles obtained by coating the above metal particles and plastic with a conductive layer are preferable. The conductive particle diameter is desirably 3 to 5 μm. If the particle size is too small, there is a possibility that the reliability of the adhesive strength is lowered due to the variation in the surface roughness of the wiring. On the other hand, if the particle size is too large, the possibility of a short circuit of the wiring increases, which is not recommended. Furthermore, silicon-based insulator particles may be dispersed in the ACF.

The present invention will be described based on examples.
[Example 1]
A 2L glass separable three-necked flask equipped with a stainless steel vertical stirrer is equipped with a reflux condenser with a condenser tube with a ball on a trap with a nitrogen gas inlet tube and a stopcock. The reaction was performed in a nitrogen gas stream. 15.22 g (100 mmol) of 3,5-diaminobenzoic acid, 44.9 g (200 mmol) of bicyclo (2,2,2) oct-7-ene-2,3,5,6-tetracarboxylic dianhydride , 3.0 g (30 mmol) of gamma-valerolactone, 3.6 g (40 mmol) of pyridine, 300 g of N-methyl-2-pyrrolidone and 60 g of toluene were added thereto at 180 ° C. (bath temperature) with nitrogen gas being passed. Toluene and water azeotrope was removed, and 29.4 g (100 mmol) of 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 1,3- Bis- (3-aminophenoxy) 58.46 g (200 mmol) of benzene, 268 g of N-methylpyrrolidone and 40 g of toluene were added and reacted at room temperature for 1 hour while passing nitrogen gas. Then 180 ° C. (bath temperature) for 3 hours to obtain a heat-bondable polyimide varnish A having a reactive group due to heat in the molecule in the reaction while removing an azeotrope of water and toluene. Above reactions.

Varnish A was applied to a polyimide film (Kapton 80EN 20 μm) manufactured by Toray DuPont Co., Ltd., which was kept at 80 ° C., allowed to stand for 10 minutes, dried in an air-circulating drying furnace at a maximum temperature of 120 ° C. for 10 minutes, and then nitrogen. Drying was performed at 150 ° C. for 10 minutes, 180 ° C. for 10 minutes, and 260 ° C. for 30 minutes in a circulation type drying furnace to obtain thermocompression-resistant heat-resistant polyimide film B.
The roughened surface of a copper foil (USLP-SE, 12 μm) manufactured by Nihon Electrolytic Co., Ltd. is superimposed on the varnish A coated surface of the thermocompression-resistant heat-resistant polyimide film B, and heated at a temperature of 380 ° C. using a continuous laminator. A copper foil laminated polyimide film C was obtained by pressure bonding.
The copper foil laminated polyimide film C was patterned into a line and space of 50 μm / 50 μm by a subtractive method. On top of that, a Shin-Etsu Chemical coverlay (CN261) with a hole of 30 mm perpendicular to the direction of the copper foil and 10 mm parallel to the direction of the copper foil was pressed for 30 minutes at 160 ° C. and 4.9 MPa using a vacuum press. Subsequently, a coverlay layer was formed by curing at 150 ° C. for 4 hours. Next, 2 μm of electrolytic Ni plating and 0.05 μm of electrolytic Au plating are performed on the exposed portion of the copper wiring processed into a line and space of 50 μm / 50 μm (polyimide surface exposure ratio 50%) where the coverlay is not laminated, and the copper wiring The plating process was performed. Thus, a flexible printed wiring board D was obtained by punching with a 30 mm square mold including the plated portion.

Through the ACF (AC-4251FY-16) manufactured by Hitachi Chemical Co., Ltd., which is obtained by cutting the metal wiring part of this flexible printed wiring board D and ITO (indium-tin oxide) vapor-deposited glass to a width of 1.5 mm. Was temporarily pressure-bonded at a real temperature of 80 ° C. for 3 seconds and 1.0 MPa using a chemical equipment engineering (AC-SC120). Further, using a Nikka Equipment Engineering Co., Ltd. (AC-S100FM-U), actual pressure bonding is performed at 180 ° C., 15 seconds, 3.0 MPa, and flexible printed wiring board D and ACF are pressure bonded, and laminate E Got.
Of the 30 mm width of the laminated body E, the central portion was cut to a width of 10 mm, and a peel strength test was performed in the 90 ° direction using glass on which ITO was deposited as a base material. As a result, it was 0.95 kN / m. . The peeling interface was between the flexible printed wiring board and the ACF. Further, after the laminate E was exposed to high temperature and high humidity at 85 ° C. and 85 RH% for 250 hours, a peel test was similarly conducted in the 90 ° direction to find 0.75 kN / m. It can be seen that this laminate E maintains high adhesive strength even when exposed to a high temperature and high humidity environment for a long period of time, and has high adhesive strength reliability.

[Example 2]
When the printed wiring board D is thermocompression bonded to the ACF in Example 1, the type of ACF is ACF (CP9731SB 2.0 mm width) manufactured by Sony Chemical & Information Device Co. The laminate F was obtained by final press-bonding under conditions of 2 seconds, 1.0 MPa, and final pressing conditions of 180 ° C., 15 seconds, 3.0 MPa.
When the peel strength test in the 90 ° direction of the laminate F was conducted in the same manner as the laminate E, it was 0.81 kN / m. The peeling interface was between the flexible printed wiring board and the ACF. Further, after the laminate E was exposed to high temperature and high humidity at 85 ° C. and 85 RH% for 250 hours, a 90 ° peel test was conducted in the same manner, and the result was 0.63 kN / m. It can be seen that the laminate F maintains high adhesive strength even when exposed to a high temperature and high humidity environment for a long period of time, and has high adhesive strength reliability.

[Comparative Example 1]
A silica gel drying tube for absorbing water was attached to a 300-ml glass separable three-necked flask equipped with a stainless steel vertical stirrer. To this flask, 208.8 g of N-methyl-2-pyrrolidone (dehydrated) manufactured by Wako Pure Chemical Industries, Ltd. and 14.0 g of 1,3-bis- (3-aminophenoxy) benzene manufactured by Wakayama Seika Kogyo Co., Ltd. were brought to room temperature. After stirring and dissolving, 0.2 g of maleic anhydride manufactured by Wako Pure Chemical Industries, Ltd. was added, and after stirring for 5 minutes, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride manufactured by Mitsubishi Chemical Corporation 24.1 g was gradually added to the flask and stirred at room temperature for 8 hours.
Thereafter, 3.0 g (30 mmol) of gamma-valerolactone, 3.6 g (40 mmol) of pyridine, 60 g of toluene, and then at 180 ° C. (bath temperature) for 3 hours while removing the azeotrope of toluene and water. Varnish G was obtained.
A laminate H was obtained in the same manner as in Example 1 except that this varnish G was used. It was 0.85 kN / m when the 90 degree direction peel strength of this laminated body H with Hitachi Chemical Co., Ltd. ACF (AC-4251FY-16) was measured by the method similar to Example 1. FIG. The peeling interface was between the flexible printed wiring board and the ACF. Moreover, when the laminated body H was exposed to high temperature and high humidity for 85 hours at 85 ° C. and 85 RH% for 250 hours, a 90 ° direction peel test was conducted in the same manner as described above, and the result was 0.51 kN / m.
This laminate H has a low adhesive strength retention after long-term humidity control, and is inferior in adhesive strength reliability.

[Comparative Example 2]
When crimping the laminate H of Comparative Example 1, crimping was performed in the same manner as in Example 2 except that ACF (CP9731SB 2.0 mm width) manufactured by Sony Chemical Information Device Co., Ltd. was used as the type of ACF. A laminate I was obtained.
When the peel strength test in the 90 ° direction of laminate I was conducted in the same manner as in the above example, it was 0.53 kN / m. The peeling interface was between the flexible printed wiring board and the ACF. Further, when the laminate I was exposed to high temperature and high humidity for 85 hours at 85 ° C. and 85 RH% for 250 hours, a 90 ° peel test was performed in the same manner as described above, and the result was 0.26 kN / m.
This laminate I has a low initial adhesive strength and an adhesive strength retention rate after long-term humidity control, and is inferior in adhesive strength reliability.

  The flexible printed wiring board of this invention is a laminated body with high adhesive force reliability with an anisotropic conductive film. For this reason, it is useful for flexible substrate use for COF and COG.

Claims (2)

  A laminate of a flexible metal foil laminated polyimide film (a) and an anisotropic conductive film (b), wherein the flexible metal foil laminated polyimide film (a) is in contact with the anisotropic conductive film (b). Patterned so that the polyimide surface exposure ratio is 30 to 80%, and the adhesive force between the flexible metal foil laminated polyimide film (a) and the anisotropic conductive film (b) is 0.8 kN / m or more, and The laminated body whose adhesive force of this flexible metal foil lamination polyimide film (a) and this anisotropic conductive film (b) is 0.6 kN / m or more after a 85 degreeC85RH% 250-hour process.   A laminate of a flexible metal foil laminated polyimide film (a) and an anisotropic conductive film (b), wherein the flexible metal foil laminated polyimide film (a) has a thermocompression bonding polyimide resin layer, and the thermocompression bonding A laminate comprising a porous polyimide resin layer containing an alicyclic acid dianhydride and / or an alicyclic diamine.