JP2010094983A - Laminated polyimide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated polyimide film facilitating handling of a polyimide film thin and excellent in heat resistance. <P>SOLUTION: The laminated polyimide film is formed by laminating the polyimide film, a thermoplastic resin layer, and a substrate film in this order. The laminated polyimide film has a composition in which, all temperatures at 5% weight reduction of the polyimide film, thermoplastic resin layer, and substrate film are ≥400°C, and peel strength between the polyimide film and substrate film is 0.01-1.0 N/cm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated polyimide film used during processing / manufacturing of a copper-clad laminate, a multilayer printed circuit board (hereinafter referred to as multilayer board), and a manufacturing method thereof. More specifically, a laminate in which a functional thin film layer such as copper is formed on a polyimide film on which a backing film having appropriate rigidity, thermal dimensional stability, and peelability is laminated, which is suitable for handling an extremely thin polyimide film. It relates to a polyimide film. Furthermore, the present invention relates to a polyimide film in which a backing film having rigidity, thermal dimensional stability, and peelability suitable for use in a flexible device manufacturing process in which solar cells, semiconductor circuits, sensors, and actuators are formed is laminated.

In recent years, with the advancement of technology of electronic devices such as mobile phones, the demand for thin multi-layer substrates using FPC (Flexible Printed Circuit), TAB, COF, and film has increased rapidly, and further downsizing of such devices. In response to light weight and high density wiring, thinning of FPC and the like is progressing. For this reason, thinning of a copper-clad laminate (CCL) for FPC or the like is also progressing at the same time, but this reduces the rigidity of the film itself and makes it difficult to process CCL.
As a method for improving workability in manufacturing FPC or the like, a method of giving rigidity as a whole by pasting a backing film in advance is used. At that time, a slightly tacky reinforcing film that can be easily handled at the time of processing and can be peeled and removed after the processing is finished is used. Conventionally, acrylic or rubber-based adhesive sheets have been used for this purpose. However, these sheets have a large adhesive force, and the adhesive force varies significantly with temperature and pressure. Depending on the processing conditions, it could not be used.
For example, in a flexible laminate with metal foil on only one side, coexistence of metal foil, thermoplastic polyimide layer, non-thermoplastic polyimide layer, and imidization accelerator to prevent warpage and decrease in production efficiency A flexible laminate (see Patent Document 1) obtained by laminating a polyimide resin backing layer obtained by converting the polyamic acid below in this order, and a polyester (A) and a polyimide ( A reinforcing polyester film containing B), having a thermal shrinkage rate of 0.25% or less, and a thermal expansion coefficient of 13 × 10 ⁻⁶ / ° C. to 50 × 10 ⁻⁶ / ° C. (see Patent Document 2) is proposed. Has been.
In addition, in the process of creating CCL, in the manufacturing methods other than the manufacturing method by casting on the copper foil, in particular, the handling of thin films by roll-to-roll is mostly performed, and the deposition and plating of copper thin films by sputtering Alternatively, application of adhesive, bonding of copper foil, thermocompression bonding, pressing, and the like correspond thereto. In these cases, it is necessary to transport the thin base film without wrinkles, distortion, or rubbing. In addition, even when a substrate is formed, depending on the thickness of the film, it may be difficult to cut, convey, and bond itself.
Furthermore, these backing films in the prior art often have insufficient heat resistance of the adhesive layer and the base film, and are often unable to withstand high temperatures during the formation (laminate) of the functional thin film layer.

JP 2005-186274 A JP 2003-101166 A

  The present invention is a polyimide film in which a backing film having heat resistance, moderate rigidity, thermal dimensional stability, and peelability suitable for handling ultra-thin polyimide films used during processing and manufacturing of FPC, etc., The present invention provides a functional thin film layer laminated polyimide film in which a functional thin film layer is formed on this laminated polyimide film and a method for producing the same.

That is, this invention consists of the following structures.
1. 0.5 μm to 12.5 μm thick polyimide film, 0.05 μm to 10 μm thick thermoplastic resin layer, 12.5 μm to 200 μm thick base film (hereinafter referred to as thermoplastic resin layer, base film 2) In the laminated polyimide film in which the layer film is referred to as the backing film), the 5% weight reduction temperature of the polyimide film, the thermoplastic resin layer, and the base film are all 400 ° C. or higher, and A laminated polyimide film, wherein the peel strength between the polyimide film and the substrate film is 0.01 N / cm to 1.0 N / cm.
2. 1. The thermoplastic resin layer is made of at least one resin selected from polyamideimide and polyimide, and is soluble in an organic solvent. Laminated polyimide film.
3. 1. The polyimide film is a polyimide film having a polyimide benzoxazole component, and the linear expansion coefficient is −10 ppm / ° C. to 10 ppm / ° C. Or 2. Laminated polyimide film.
4). 1. The base film is a polyimide film. ~ 3. Any laminated polyimide film.
5). 1. The substrate film is a polyimide film having a polyimide benzoxazole component, and the linear expansion coefficient is −10 ppm / ° C. to 10 ppm / ° C. ~ 4. Any laminated polyimide film.
6). 1. ~ 5. A functional thin film layered polyimide film in which a functional thin film layer having a thickness of 0.01 μm to 10 μm is laminated on the surface of one of the laminated polyimide films opposite to the surface on which the backing film is attached.
7). 5. The functional thin film layer is made of one or more selected from copper, nickel, and chromium. Functional thin film layer laminated polyimide film.

The laminated polyimide film of the present invention comprises a polyimide film having a thickness of 0.5 μm to 12.5 μm, a thermoplastic resin layer having a thickness of 0.05 μm to 10 μm, and a base film having a thickness of 12.5 μm to 200 μm (hereinafter referred to as thermoplastic). In the laminated polyimide film in which the resin layer and the two-layer film of the base film are referred to as a backing film), the polyimide film, the thermoplastic resin layer, and the base film have a 5% weight reduction temperature. All are 400 ° C. or higher, and the peel strength between the polyimide film and the base film is 0.01 N / cm to 1.0 N / cm, so when handling in various processes, especially at high temperatures, It is possible to reduce the occurrence of problems such as peeling, wrinkles, distortion, and rubbing.
Furthermore, when peeling the backing film from the laminated polyimide film or when laminating with another substrate, another backing film is formed by forming an adhesive layer or adhesive layer on the side of the polyimide film opposite to the side with the backing film. Laminating with the substrate makes it easy to peel the backing film and reduces the occurrence of wrinkles and distortion of the polyimide film, so it has extremely high heat resistance, flexibility and mechanical strength. Manufacture of a product using a polyimide film having a thickness can be easily and stably performed.
For this reason, it is industrially very useful as a functional thin film layer-laminated polyimide film that can be used for electrical and electronic parts that require fineness, lightness, shortness, and thinness such as thin FPC.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the pin sheet | seat which provided the stand in the width direction outer side of the pin which contacts the film in the pin tenter type film processing machine used at the time of the polyimide film used by this invention, (a) is a front view, (b) is a side view FIG. It is the schematic of the pin insertion part of the film in the pin tenter type film processing machine used at the time of the polyimide film manufacture used by this invention.

The present invention is described in detail below.
In the present invention, the polyimide constituting the polyimide film, and the polyimide constituting the film when the polyimide film is used as the base film are, for example, generic names of aromatic tetracarboxylic acids (anhydrides, acids, and amide bond derivatives). Obtained by reacting a polyamic acid solution obtained by reacting an aromatic diamine (collectively referred to as a class of amines and amide-bonded derivatives, hereinafter the same) with molding and imidization. For example, when forming a film as a layer, the film can be obtained by casting, drying, and heat treatment (imidization) to form a film.
The polyimide film is not particularly limited as long as the 5% weight loss temperature is 400 ° C. or higher, but the following aromatic diamines and aromatic tetracarboxylic acids (anhydrides) A combination is given as a preferred example.
A. Combination with aromatic tetracarboxylic acid having pyromellitic acid residue and aromatic diamine having benzoxazole structure.
B. A combination of an aromatic diamine having a phenylenediamine skeleton and an aromatic tetracarboxylic acid having a biphenyltetracarboxylic acid skeleton.
C. A combination of an aromatic diamine having a diphenyl ether skeleton and an aromatic tetracarboxylic acid having a pyromellitic acid residue.
In particular, A. A polyimide film having an aromatic diamine residue having a benzoxazole structure is preferred.

Specific examples of the aromatic diamine having the benzoxazole structure include the following. These aromatic diamines are preferably 70 mol% or more, more preferably 80 mol% or more of the total aromatic diamines.

  Among these, from the viewpoint of easy synthesis, each isomer of amino (aminophenyl) benzoxazole is preferable, and 5-amino-2- (p-aminophenyl) benzoxazole is more preferable. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.

  Furthermore, as long as it is 30 mol% or less of the wholly aromatic diamines, one or more of the diamines exemplified below may be used in combination. Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′-diamino Diphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dia Nodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4 , 4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4, 4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-amino) Phenoxy) phenyl] ethane, 1,1-bis [4- 4-aminophenoxy) phenyl] propane, 1,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, , 4-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl ] Butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-a Minophenoxy) -3-methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2- Bis [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexa Fluoropropane, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4 -Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-amino) Enoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1, 3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] Benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) ) Phenyl] propane, 3,4'-diaminodiphenyl sulfide, 2,2-bis [3- (3-aminophenoxy) phenyl -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1 , 2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-Amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} fe Sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethyl Benzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluoro) Phenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4 -Amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-dipheno Cibenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino- 4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4′-diamino-4 -Biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino-4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) Benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-bi) Phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- ( 4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine are halogen atoms, An alkyl group having 1 to 3 carbon atoms, an alkoxyl group, a cyano group, or an alkyl group or an alkoxyl group having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl group or alkoxyl group are substituted with halogen atoms. Examples thereof include substituted aromatic diamines.

The molecular structure of the aromatic tetracarboxylic acids is not particularly limited, and specific examples include the following. These aromatic tetracarboxylic acids are preferably 70 mol% or more, more preferably 80 mol% or more of the total aromatic tetracarboxylic acids.

  These aromatic tetracarboxylic acids may be used alone or in combination of two or more.

  Furthermore, one or two or more non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination as long as they are 30 mol% or less of the total aromatic tetracarboxylic acids. Examples of such tetracarboxylic acid anhydrides include butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, and cyclobutanetetracarboxylic acid. Acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3 5,6-tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3 -(1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride 1-ethylcyclohexane -(1,2), 3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane- 1- (2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] Heptane-2,3,5,6-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1 -(2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ', 4'-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane -2,3,5,6-tetracarboxylic dianhydride, Cyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid A dianhydride etc. are mentioned.

  The solvent used for polycondensation (polymerization) of the aromatic diamines and aromatic tetracarboxylic acids to obtain a polyamic acid can be used as long as it dissolves both the raw material monomer and the polyamic acid to be produced. Although not particularly limited, polar organic solvents are preferred, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, Examples thereof include dimethyl sulfoxide, hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the mass of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by mass, The amount is preferably 10 to 30% by mass.

  Conventionally known conditions may be applied for the polymerization reaction for obtaining the polyamic acid (hereinafter also simply referred to as “polymerization reaction”). As a specific example, in a temperature range of 0 to 80 ° C., 10 Stirring and / or mixing continuously for 30 minutes. If necessary, the polymerization reaction may be divided or the temperature may be increased or decreased. In this case, the order of adding both monomers is not particularly limited, but it is preferable to add aromatic tetracarboxylic acids to the solution of aromatic diamines. The viscosity of the polyamic acid solution obtained by the polymerization reaction is measured with a Brookfield viscometer (25 ° C.), and is preferably 10 to 2000 Pa · s, more preferably 100 to 1000 Pa · s, from the viewpoint of the stability of liquid feeding. It is. The reduced viscosity (ηsp / C) of the polyamic acid solution is not particularly limited, but is preferably 3.0 dl / g or more, and more preferably 4.0 dl / g or more.

  Vacuum defoaming during the polymerization reaction is effective for producing a good quality polyamic acid solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamine before polymerization reaction. Examples of the end capping agent include compounds having a carbon-carbon double bond such as maleic anhydride. The amount of maleic anhydride used is preferably 0.001 to 1.0 mole per mole of aromatic diamine.

  In order to form a polyimide film, which is one of the layers of the present invention, from a polyamic acid solution obtained by a polymerization reaction, a green film (a self-supporting precursor is formed by applying the polyamic acid solution on a support and drying it. Body film), and then the imidization reaction is performed by subjecting the green film to heat treatment. Application of the polyamic acid solution to the support includes, for example, casting from a die with a slit and extrusion by an extruder, but is not limited thereto, and conventionally known solution application means can be appropriately used.

  The conditions for drying the polyamic acid coated on the support to obtain a green sheet are not particularly limited, and examples include a temperature of 70 to 150 ° C. and a drying time of 5 to 180 minutes. A conventionally known drying apparatus that satisfies such conditions can be applied, and examples thereof include hot air, hot nitrogen, far infrared rays, and high frequency induction heating. Next, in order to obtain a target polyimide film from the obtained green sheet, an imidization reaction is performed. As a specific method thereof, a conventionally known imidation reaction can be appropriately used. For example, there may be mentioned a method (thermal ring closure method) in which an imidization reaction proceeds by subjecting to a heat treatment after performing a stretching treatment as necessary using a polyamic acid solution containing no ring closure catalyst or a dehydrating agent. The heating temperature in this case is exemplified by 100 to 500 ° C. From the viewpoint of film physical properties, more preferably, a two-stage heat treatment in which the treatment is performed at 150 to 250 ° C. for 3 to 20 minutes and then treatment at 350 to 500 ° C. for 3 to 20 minutes. Is mentioned.

  Another example of the imidization reaction is a chemical ring closure method in which a polyamic acid solution contains a ring closure catalyst and a dehydrating agent, and the imidization reaction is performed by the action of the ring closing catalyst and the dehydrating agent. In this method, after the polyamic acid solution is applied to the support, the imidization reaction is partially advanced to form a film having self-supporting property, and then imidization can be performed completely by heating. In this case, the condition for partially proceeding with the imidization reaction is preferably a heat treatment for 3 to 20 minutes at 100 to 200 ° C., and the condition for allowing the imidization reaction to be completely performed is preferably 200 to 400 ° C. For 3 to 20 minutes.

  The polyimide film used in the present invention preferably has a thickness of 0.5 μm to 12.5 μm, more preferably 1 μm to 10 μm, still more preferably 2 μm to 7.5 μm. It is very difficult to form a polyimide film having a thickness of less than 0.5 μm. On the other hand, when the film thickness is thicker than 12.5 μm, it can be handled by a conventional general apparatus, and the effect of using the backing film is small.

  The polyimide film used in the present invention preferably has a linear expansion coefficient in the plane direction of −10 ppm / ° C. to 30 ppm / ° C., more preferably −10 ppm / ° C. to 20 ppm / ° C., and still more preferably −10 ppm / ° C. 10 ppm / ° C. If the linear expansion coefficient exceeds this range, distortion or wrinkles may occur during high-temperature exposure such as soldering, and the film may peel off due to a large deviation from the linear expansion coefficient of the thin film. Further, for example, when this multilayer polyimide film is bonded and laminated to a Si wafer, the deviation from the linear expansion coefficient of the Si wafer becomes large, and problems such as warpage and peeling are likely to occur.

The tensile strength at break of the polyimide film used in the present invention is not particularly limited, but is preferably 250 MPa or more, more preferably 300 MPa or more. If the tensile strength at break is lower than 250 MPa, film breakage is likely to occur during conveyance, and the yield may be reduced.
The tensile elongation at break of the polyimide film used in the present invention is not particularly limited, but is preferably 10% to 90%, more preferably 20% to 80%. When the tensile elongation at break exceeds these ranges, film breakage tends to occur during conveyance, and the yield may be reduced.
Moreover, although the tensile elasticity modulus of the polyimide film used by this invention is not specifically limited, 4.0 GPa or more is preferable, More preferably, it is 5.0 GPa or more.

  The base film constituting the backing film used in the present invention is a polyimide film, polyamideimide film, polyphenylene sulfide film, polyetheretherketone film, polyetherketone as long as the 5% weight loss temperature is 400 ° C. or more. Although it is not particularly limited, such as a ketone film, an aramid film, a liquid crystal polymer film, and a fluororesin film, a polyimide film is preferable, more preferably a polyimide film having a benzoxazole component disclosed in the section of the polyimide film, and a wire It is a polyimide film having an expansion coefficient of −10 ppm / ° C. to 10 ppm / ° C.

  As for the thickness of the base film which comprises the backing film used by this invention, 12.5 micrometers-200 micrometers are preferable, More preferably, they are 15 micrometers-200 micrometers, More preferably, they are 25 micrometers-200 micrometers. When the film thickness is thinner than 12.5 μm, the reinforcing effect as a backing film is poor, and handling properties are not improved. On the other hand, forming a heat-resistant film with a film thickness of more than 200 μm and a 5% weight loss temperature of 400 ° C. or more causes variations in the amount of residual solvent on the film surface and in the film formation / drying process, resulting in quality. It is very difficult because the physical properties are lowered. Further, since the raw material cost increases as the film thickness increases, it is not realistic to use a base film having a film thickness of 200 μm or more.

  If the thermoplastic resin layer constituting the backing film used in the present invention has a 5% weight loss temperature of 400 ° C. or more, polyimide, polyamideimide, polyphenylene sulfide, polyether ether ketone, polyether ketone ketone, aramid, Although not particularly limited, such as a liquid crystal polymer and a fluororesin, those composed of at least one kind of resin selected from polyamide imide and polyimide are easy to adhere to the base film and the polyimide film. It is preferable because it is easy to achieve both peelability.

  The thickness of the thermoplastic resin layer constituting the backing film used in the present invention is preferably 0.05 μm to 10 μm, more preferably 0.05 μm to 7.5 μm, and still more preferably 0.05 μm to 5 μm. If the film thickness is less than 0.05 μm, there is a possibility that a uniform backing film cannot be created due to problems such as coating failure. Moreover, adhesiveness becomes weak and there exists a possibility that a polyimide film and a backing film may peel during conveyance. On the other hand, if the film thickness is thicker than 10 μm, the backing film itself is warped and the handling property may be deteriorated.

  The 5% weight reduction temperature of the polyimide film used in the present invention, the thermoplastic resin layer constituting the backing film, and the base film is preferably 400 ° C. or higher, more preferably 425 ° C. or higher, and further preferably 450 ° C. or higher. If the 5% weight loss temperature is lower than 400 ° C., the high temperature process targeted by the present invention cannot be passed.

The peel strength between the polyimide film used in the present invention and the backing film is preferably 0.01 N / cm to 1.0 N / cm, more preferably 0.01 N / cm to 0.75 N / cm, and still more preferably 0. 0.02 N / cm to 0.75 N / cm. If the peel strength is less than 0.01 N / cm, the polyimide film and the backing film may be peeled off during transportation. On the other hand, if the peel strength is greater than 1.0 N / cm, the thermoplastic resin may be transferred to the polyimide film or abnormalities such as wrinkles and distortion may occur when the backing film is peeled after passing through the process.
Further, the peel strength between the polyimide film and the backing film after passing through a processing process such as plating is preferably 0.01 N / cm to 1.0 N / cm, and more preferably 0. 0, for the same reason as described above. It is 01 N / cm to 0.75 N / cm, more preferably 0.02 N / cm to 0.75 N / cm.

  In the thermoplastic resin layer constituting the backing film used in the present invention, it is considered that glue transfer occurs on the polyimide film due to application of pressure and heat during various processes. It is desirable that this glue transfer is small, but after peeling the backing film, by plasma processing such as atmospheric pressure plasma, vacuum plasma, reactive plasma, microwave plasma, mechanical processing such as polishing and grinding, light washing, If some amount of glue transfer can be removed, a level that is not observed at all by ESCA is not required.

As the functional thin film layer formed on the polyimide film surface in the present invention, an oxide thin film such as ITO (indium / tin oxide), copper, nickel, molybdenum, tungsten, gold, silver, chromium, titanium, aluminum, etc. In particular, a metal thin film, a semiconductor thin film such as silicon or germanium, a composite film or a laminated film thereof can be used, and among these, a metal layer composed of one or more selected from copper, nickel, and chromium can be preferably applied.
Here, the main component of copper is one containing a small amount of other elements in the copper thin film, or Cr, Ta, Ti, Hf, Mo, W, Re, Ni—Cr, SiCr, between the film and the copper thin film, A material containing TiCr, Cu—Mn—NiPd—Ag, Pd—Au—Fe, Cr—SiO, Cr—MgF ₂ , Au—SiO, tantalum nitride, partial tantalum nitride, titanium nitride, partial titanium nitride, or the like is shown. Of these, Ni—Cr, Ni—Co—Cr, and more preferably a NiCr target for sputtering having a purity of 99.9% or more is used. These include metals, oxides such as ITO, Si, and Al, and composite oxide thin films sandwiched between them as an underlayer. Among these, a laminate in which a copper layer is laminated using the NiCr layer as a base layer (intermediate layer) is particularly preferable.

  The thickness of the NiCr intermediate layer is required to be at least 5 nm so that copper particles do not substantially enter the polyimide layer by heat treatment at 150 ° C. for 24 hours in the atmosphere (diffusion suppression effect). About 50 nm is preferable. When the film thickness is less than 5 nm, the copper particles penetrate into the polyimide layer under such conditions and have no effect as a diffusion suppressing layer. On the other hand, if the film thickness is thicker than 50 nm, it takes time to form the NiCr intermediate layer, which is not preferable in terms of production efficiency.

  The method of forming the thin film is not particularly limited, but is a dry thin film forming method such as vapor deposition, sputtering, ion plating, MBE, plasma CVD, MOCVD, aerosol deposition method, formation of nano ink thin film by ink jet printing, plating, sol gel Methods, coatings and the like can be preferably applied. A sputtering method excellent in thin film adhesion and thin film controllability is a particularly preferable method. The sputtering method is not particularly limited, and methods such as DC magnetron sputtering, high-frequency magnetron sputtering, and ion beam sputtering are effectively used. Industrially, direct current sputtering is simple and sufficient film quality can be obtained.

  As a form of the thin film in the present invention, in addition to being laminated with a uniform thickness on the entire surface of the polyimide film, when there are moderate irregularities on the surface, or when a pattern for expressing the function is formed Is also included.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by a following example. In addition, the evaluation method of the physical property in the following examples is as follows.

1. Reduced viscosity of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone (or N, N-dimethylacetamide) so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. with an Ubbelohde type viscosity tube.

2. The thickness of the polyimide film The polyimide film to be measured was measured using a micrometer (Minetron 1245D, manufactured by Fine Reef).

3. Tensile elastic modulus, tensile break strength, and tensile break elongation of polyimide film The polyimide film to be measured is subjected to a tensile fracture test under the following conditions, and the tensile modulus, tensile break strength, and tensile break elongation are measured in the MD direction. It was measured.
Device name: Shimadzu Corporation Autograph Sample length: 100mm
Sample width: 10mm
Drawing speed: 50mm / min
Distance between chucks: 40 mm

4). Linear expansion coefficient (CTE) of polyimide film
For the polyimide film to be measured, the stretch rate in the MD direction and the TD direction is measured under the following conditions, and the stretch rate / temperature at intervals of 90 to 100 ° C., 100 to 110 ° C.,. Measurement was performed up to 400 ° C., and an average value of all measured values from 100 ° C. to 350 ° C. was calculated as CTE (average value).
Device name: TMA4000S manufactured by MAC Science
Sample length: 10mm
Sample width: 2mm
Initial load: 34.5 g / mm ²
Temperature rise start temperature: 25 ° C
Temperature rise end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

5). Glass Transition Temperature Viscoelasticity measurement (DMA) was performed under the following conditions for the thermoplastic resin and polyimide film to be measured, and the glass transition point was determined from the maximum value of the tan δ peak.
Device name: Rheogel-E4000 manufactured by UBM
Jig: Extension jig Sample length: 14mm
Sample width: 5 mm
Frequency: 10Hz
Temperature rising start temperature: 30 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Nitrogen

6.5% weight loss temperature Thermoplastic measurement (TGA) is performed on the thermoplastic resin and polyimide film to be measured under the following conditions, the weight of the sample at 150 ° C. is set to 100%, and the weight of the sample is 5 from that point. The temperature at which the% decrease is taken as the 5% weight loss temperature.
Device name: TG-DTA2000S manufactured by MAC Science
Bread: Aluminum bread (non-airtight type)
Sample weight: 10mg
Temperature rising start temperature: 30 ° C
Temperature increase rate: 20 ° C / min
Atmosphere: Nitrogen

<< Evaluation of backing film >> Peel strength The peel strength between the polyimide film and the backing film was determined by conducting a 90 ° peel test under the following conditions.
Device name: Autograph AG-IS, manufactured by Shimadzu Corporation
Sample length: 100mm
Sample width: 10mm
Measurement temperature: 25 ° C
Peeling speed: 50mm / min
Atmosphere: Atmosphere

<< Evaluation of backing film >> Adhesive layer remaining (glue transfer)
After the backing film is peeled off, it is visually judged whether the thermoplastic resin layer is completely left on the base film side, and if the thermoplastic resin layer is completely left on the base film side, ○, the thermoplastic resin The case where the layer is present on both the polyimide film side and the base film side is indicated by Δ, and the case where the thermoplastic resin layer is completely transferred to the polyimide film side is indicated by ×.

<< Evaluation of backing film >> Peeled state When the backing film is peeled off, the polyimide film is visually checked for abnormalities such as wrinkles and distortions. A case in which an abnormality such as distortion is slightly observed is indicated by Δ, and a case in which an abnormality such as wrinkle or distortion is frequently observed is indicated by ×.

<< Evaluation of Backing Film >> Heat Resistance Each laminated polyimide film composed of a polyimide film, a thermoplastic resin, and a base film was subjected to heat treatment at 350 ° C. for 1 hour in an N ₂ atmosphere. From the appearance after the test, the case where peeling, blistering, or discoloration was not observed at all was rated as ◯, the case where peeling, blistering, or discoloration was slightly observed was marked as Δ, and the case where peeling, blistering, or discoloration was observed was marked as x.

[Production Example 1]
(Preparation of polyamic acid solution A)
The inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 223 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole and 4416 parts by mass of N, N-dimethylacetamide were added. 40.5 parts by mass of Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) (containing 8.1 parts by mass of silica), pyromellitic acid, which is prepared by completely dissolving the colloidal silica in dimethylacetamide. When 217 parts by mass of dianhydride was added and stirred for 24 hours at a reaction temperature of 25 ° C., a brown and viscous polyamic acid solution A was obtained. This reduced viscosity was 3.9 dl / g.

[Production Example 2]
(Preparation of polyamic acid solution B)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 200 parts by mass of diaminodiphenyl ether and 4170 parts by mass of N-methyl-2-pyrrolidone were added and completely dissolved, and then colloidal silica was added. 40.5 parts by mass of Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) dispersed in dimethylacetamide (containing 8.1 parts by mass of silica), 217 parts by mass of pyromellitic dianhydride were added, and 25 ° C. When the mixture was stirred at the reaction temperature of 5 hours, a brown viscous polyamic acid solution B was obtained. This reduced viscosity was 3.6 dl / g.

[Production Example 3]
(Preparation of polyamic acid solution C)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, 108 parts by mass of phenylenediamine and 4010 parts by mass of N-methyl-2-pyrrolidone were added and completely dissolved, and then colloidal silica was added. 40.5 parts by mass of Snowtex (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) dispersed in dimethylacetamide (including 8.1 parts by mass of silica) and 292.5 parts by mass of diphenyltetracarboxylic dianhydride were added. When the mixture was stirred at a reaction temperature of 25 ° C. for 12 hours, a brown viscous polyamic acid solution C was obtained. This reduced viscosity was 4.3 dl / g.

[Production Example 4]
(Preparation of polyamic acid solution D)
After replacing the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod with nitrogen, 930 parts by mass of 1,3-bis (4-aminophenoxy) benzene and 15,000 parts by mass of N, N-dimethylacetamide were added. 40.5 parts by mass (DMAC-ST30, manufactured by Nissan Chemical Industries, Ltd.) 40.0 parts by mass (including 8.1 parts by mass of silica), 4,4, obtained by dispersing colloidal silica in dimethylacetamide -When 990 parts by mass of oxydiphthalic anhydride was added and stirred at a reaction temperature of 25 ° C for 17 hours, a pale yellow and viscous polyamide acid solution D was obtained. This reduced viscosity was 3.1 dl / g.

[Production Example 5]
(Creation of polyimide film for edge reinforcement)
Using the polyamic acid solution A obtained in Production Example 1, a non-slip material surface of a polyethylene terephthalate film (A-4100, manufactured by Toyobo Co., Ltd.) was coated using a comma coater (coating width 1240 mm). And dried at 90 ° C. for 60 minutes. The polyamic acid film that became self-supporting after drying was peeled from the support and cut at both ends to obtain a green film having a thickness of 15 μm and a width of 1200 mm. The obtained green film was subjected to heat treatment with the apparatus shown in FIGS. 1 and 2 by gripping both ends with a pin tenter under the conditions of a pin sheet, a brush roll, a pressing roll, and a supporting jig as shown in parentheses below. The pins are arranged so that the pin interval is constant when the pin sheets are arranged, the pin height from the pin base is 8 mm, the pin sheet interval is 1140 mm, and the length of the pin sheet in the longitudinal direction is The length in the width direction is 95 mm, the length in the longitudinal direction of the table set outside the pin sheet in the width direction is 95 mm, the length in the width direction is 15 mm, and the periphery of the table is chamfered. did. In addition, the brush roll has a two-layer structure using two kinds of materials in the width direction, made of Conex with a strand diameter of 0.3 mm, and on the outside a metal element with a strand diameter of 0.5 mm. A line was placed.
(The pin sheet has a flat plate shape, the distance between the press roll and the film grip start portion is 150 mm, the support jig uses a tetrafluoroethylene bar, and the distance between the support jig and the film grip start portion is 170 mm)
The heat treatment settings for the tenter are as follows. The first stage is heated at 180 ° C. for 5 minutes and the heating rate is 4 ° C./second, and the second stage is heated at 460 ° C. for 5 minutes under the condition of two stages. And the imidization reaction was allowed to proceed. Then, it cooled to room temperature in 5 minutes, wound up in roll shape, and obtained the 10-micrometer-thick polyimide film A.
Separately, a polyamic acid solution D diluted 10-fold with N, N-dimethylacetamide was prepared, and coated on one surface of the obtained polyimide film A using a bar coater. Subsequently, the thickness of the easily-adhesive layer which dried for 10 minutes at 90 degreeC and obtained the easily-adhesive polyimide film A is 0.1 with respect to the thickness 1 of the polyimide film A. The resulting easy-adhesive polyimide film was slit to obtain a polyimide film for end reinforcement having a width of 35 mm.

[Production Example 6]
(Preparation of polyimide film A1)
The polyamic acid solution A obtained in Production Example 1 was coated on a non-slip material surface of a polyethylene terephthalate film (A-4100, manufactured by Toyobo Co., Ltd.) using a comma coater (coating width 1240 mm), and 90 ° C. For 60 minutes. The polyamic acid film which became self-supporting after drying was peeled off from the support and cut at both ends to obtain a green film having a width of 1200 mm. While the polyimide film D having a width of 35 mm is superposed on both end portions on the obtained green film, a pin sheet, a brush roll, a pressing roll, and a supporting jig are used as shown in parentheses in the apparatus shown in FIGS. Under the conditions of the tool, both ends were held with a pin tenter and heat treatment was performed. The pins are arranged so that the pin interval is constant when the pin sheets are arranged, the pin height from the pin base is 8 mm, the pin sheet interval is 1140 mm, and the length of the pin sheet in the longitudinal direction is The length in the width direction is 95 mm, the length in the longitudinal direction of the table set outside the pin sheet in the width direction is 95 mm, the length in the width direction is 15 mm, and the periphery of the table is chamfered. did. In addition, the brush roll has a two-layer structure using two kinds of materials in the width direction, made of Conex with a strand diameter of 0.3 mm, and on the outside a metal element with a strand diameter of 0.5 mm. A line was placed.
(The pin sheet has a flat plate shape, the distance between the press roll and the film grip start portion is 150 mm, the support jig uses a tetrafluoroethylene bar, and the distance between the support jig and the film grip start portion is 170 mm)
The heat treatment settings for the tenter are as follows. The first stage was heated at 200 ° C. for 5 minutes and the heating rate was 4 ° C./second, and the second stage was heated at 450 ° C. for 5 minutes under the condition of two stages to advance the imidization reaction. The maximum wind speed in the tenter was 0.5 m / sec.
Up to the midpoint of the first stage of the tenter, the width of the pins at both ends was reduced by 2% to 98% of the initial width. In the second half of the first stage, the pin width is slightly widened to 99% of the initial width, expanded to 102% in the temperature rise interval, and further expanded to the middle point of the second stage to 103%, and thereafter constant Processed in width. Then, it cooled to room temperature in 5 minutes, the part where the flatness of the both ends of a film was bad was cut off with the slitter, and it wound up in roll shape, and obtained polyimide film A1 which exhibits 5 micrometers in thickness brown.
The evaluation results of the obtained polyimide film A1 are shown in Table 1.

[Production Examples 7 to 11]
(Preparation of polyimide films A2 to A6)
Polyimide films A2 to A6 were prepared in the same manner as in Production Example 6 except that the coating thickness was changed.
Table 1 shows the evaluation results of the obtained polyimide films A2 to A6.

[Production Example 12]
(Preparation of polyimide film B)
A polyimide film B was prepared in the same manner as in Production Example 6 except that the polyamic acid solution B obtained in Production Example 2 was used instead of the polyamic acid solution A.
The evaluation results of the obtained polyimide film B are shown in Table 2.

[Production Example 13]
(Preparation of polyimide film C)
A polyimide film C was prepared in the same manner as in Production Example 6 except that the polyamic acid solution C obtained in Production Example 3 was used instead of the polyamic acid solution A.
The evaluation results of the obtained polyimide film C are shown in Table 2.

[Production Example 14]
(Preparation of polyamideimide solution E)
After replacing the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod with nitrogen, 192 g of trimellitic anhydride, 211 g (80 mol%) of O-tolidine diisocyanate, 35 g of 2,4-tolylene diisocyanate, and 1 g of ethylenediamine was added, N-methyl-2-pyrrolidone was further added, and the mixture was reacted at 120 ° C. for about 1 hour, and further reacted at 180 ° C. with stirring for 5 hours. Next, while heating was stopped and cooling, N-methyl-2-pyrrolidone was further added and diluted to obtain a polyamideimide solution E having a solid concentration of 20% by mass.
The polymer of the obtained polyamideimide solution E had a glass transition temperature of 320 ° C. and a 5% weight loss temperature of 485 ° C. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Production Example 15]
(Preparation of polyamideimide solution F)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring bar was replaced with nitrogen, 1 mol of trimellitic anhydride, 1 mol of diphenylmethane diisocyanate and 0.01 mol of potassium fluoride were charged, and N, N-dimethyl was further added. Acetamide was charged and reacted at 90 ° C. with stirring for 3 hours. Next, while heating was stopped and cooling, N, N-dimethylacetamide was further added and diluted to obtain a polyamideimide solution F having a solid content concentration of 20% by mass.
The glass transition temperature of the polymer of the obtained polyamideimide solution F was 290 ° C., and the 5% weight loss temperature was 475 ° C. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Production Example 16]
(Preparation of polyimide solution G)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 73,56 g of 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 88 g of diaminopolysiloxane, 2,2 61.58 g of bis [4- (4-aminophenoxy) phenyl] propane and 1000 g of N-methyl-2-pyrrolidone were charged. After stirring at 60 ° C. for about 2 hours, the reaction was carried out with stirring at 200 ° C. for 3 hours while removing water. After the reaction, the reaction solution was added to 10 liters of water, precipitated for 30 minutes using a homomixer, and polymer powder was isolated by filtration. This polymer powder was washed twice at 80 ° C. for 1 hour using a homomixer in 5 liters of 2-propanol, dried with hot air at 120 ° C. for 5 hours, and then vacuum dried at 120 ° C. for 24 hours. Tetrahydrofuran was added to obtain a polyimide solution G having a solid content concentration of 20%.
The polymer of the obtained polyimide solution G had a glass transition temperature of 192 ° C. and a 5% weight loss temperature of 495 ° C. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Production Example 17]
(Preparation of polyimide solution H)
The inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer and a stirring rod was purged with nitrogen, and then 63.2 g of 4,4′-benzophenone tetracarboxylic dianhydride, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] propane 63.57 g, 62.11 g of bis (3-aminopropyl) polymethylsiloxane having a molecular weight of 750, and 315 g of xylene were charged. After reacting at 150 ° C. for about 1 hour, the reaction was carried out with stirring at 165 ° C. for 18 hours while removing water. After the reaction, the remaining xylene was distilled off under reduced pressure, and N-methyl-2-pyrrolidone was added to obtain a polyimide solution H having a solid concentration of 20%.
The polymer of the obtained polyimide solution H had a glass transition temperature of 186 ° C. and a 5% weight loss temperature of 366 ° C. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Production Example 18]
(Preparation of silicone solution I)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, it was _composed of a ratio of 1.1 mol of (CH ₃ ) ₃ SiO _1/2 units and 1 mol of SiO _4/2 units. 50 parts by mass of methylpolysiloxane resin containing 0.07 mol per 100 g, 50 parts by mass of raw rubber-like dimethylpolysiloxane having a degree of polymerization of 2,000 blocked with hydroxyl groups, 100 parts by mass of toluene, and 28% by mass of ammonia 0.5 mass of water was added, and the mixture was stirred at room temperature for 16 hours to conduct a condensation reaction. During this time, the generated water was removed out of the system by azeotropy. Thereafter, toluene was added so that the nonvolatile content was 40% by mass to synthesize a silicone condensate. 100 parts by mass of the obtained silicone partial condensate and 0.5 parts by mass of bis (4-methylbenzoyl) peroxide were mixed to obtain a silicone solution I.
The glass transition temperature of the polymer of the obtained silicone solution I was 190 ° C., and the 5% weight loss temperature was 250 ° C. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Production Examples 19 and 20]
(Creation of acrylic solutions J and K)
The inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then an alkyl (meth) acrylate monomer and ethyl acetate were charged and replaced and held until refluxed with stirring. Subsequently, 2,2′-azobisisobutyronitrile was added and reacted for a total of 8 hours. After completion of the reaction, toluene is added to dilute and cool to room temperature. Hexamethylene diisocyanate isocyanurate (Sumidule N-3300, Sumika Bayer) is used as a crosslinking agent for 100% of the solid content of the acrylic polymer. 1.4% (NCO equivalent / OH equivalent ratio is 1.2) was added to obtain acrylic solutions J and K having a solid content concentration of 20%. Here, the composition amount of the alkyl (meth) acrylate monomer, the amount of the crosslinking agent, and the evaluation results are shown in Table 3. Moreover, it confirmed that it had thermoplasticity from the attenuation | damping above the glass transition temperature of the storage elastic modulus: E 'of a viscoelasticity measurement.

[Example 1]
After diluting the polyamideimide solution E to a solid content concentration of 2.5%, the surface of the polyimide film A5 was coated using a micro gravure coater. Subsequently, a backing film A was obtained by performing heat treatment at 120 ° C. for 60 minutes and at 160 ° C. for 300 minutes. The thickness of the polyamideimide layer in the obtained backing film A was 1.0 μm.
Next, one surface of the polyimide film A1 and the polyamideimide E surface of the backing film A were bonded together, and thermocompression bonded at 300 ° C. and 5 MPa for 15 minutes to obtain a polyimide film A with a backing film. Table 4 shows the initial evaluation results of the peel strength, glue transfer, and peeled state of the obtained polyimide film A with backing film.
The obtained polyimide film A with backing film was put into a roll-to-roll sputtering machine, and after plasma treatment was performed on the polyimide film A1 surface of the polyimide film A with backing film, sputtering was performed. The plasma treatment and sputtering conditions are as follows. First, the surface of the polyimide film was treated with oxygen glow discharge. The processing conditions are O ₂ gas pressure 2 × 10 ⁻³ Torr, flow rate 50 SCCM, discharge frequency 13.56 MHz, output 250 W, processing time is 1 m / min because the film feed rate is 0.1 m / min and the effective plasma irradiation width is about 10 cm. The plasma irradiation time at the location is 1 minute. Thereafter, the NiCr underlayer thin film layer having a thickness of 15 nm was formed on the surface of the polyimide film A with the backing film that was taken out from the surface treatment apparatus by DC magnetron sputtering using argon gas with a NiCr alloy as a target. . The composition of the target NiCr alloy was Ni 80% by mass and Cr 20% by mass 3N purity. The degree of vacuum at the time of forming the thin film layer is 3 × 10 ⁻³ Torr. Then, a copper thin film layer having a thickness of 250 nm was immediately formed by DC magnetron sputtering using argon gas with copper as a target. The target Cu had a purity of 4N. Each target has a rectangular shape with a width of 12 cm in the film feeding direction and a width of 27 cm in the film feeding direction. Four rectangular targets are installed in the film feeding direction. Although the target is approaching by two, the distance between the target used for NiCr and the target used for Cu is separated, so that the sputtered NiCr atoms and the Cu atoms are in a vacuum. After mixing, the film does not reach the film, and the underlying NiCr thin film and Cu thin film do not cross each other, forming each thin film into a two-layer thin film. The thickness of the thin film was 20 nm for the NiCr layer and 200 nm for the Cu layer.
Note that the sputtering apparatus is a roll-to-roll system, and the film is moved from the roll to the unwinding chamber, the sputtering chamber, the spare chamber, and the winding chamber, and the surface treatment, NiCr layer creation, and Cu layer are sequentially performed. Creation is performed and then wound on a roll. Each chamber is roughly partitioned by a slit. In the sputtering chamber, the film is in contact with the chill roll, and is cooled by the temperature of the chill roll (−5 ° C.). A thin film is formed by metal particles from two Cu targets without using any target.
Next, the surface of the polyimide film A with backing film on which the sputtering was applied was further plated. That is, with the backing film still attached, a thick copper plating layer (thickening layer) having a thickness of 5 μm is formed on the sputtering surface using a copper sulfate plating bath, and subsequently at 80 ° C. for 1 minute. It dried and the functional thin film layer lamination polyimide film A with a backing film in which the target functional thin film layer was laminated | stacked was obtained. Table 4 shows the evaluation results after plating in the peel strength, paste transfer, and peeled state of the obtained functional thin film laminated polyimide film A with a backing film.
Next, the first backing film was peeled off to obtain a functional thin film layer-laminated polyimide film A in which the functional thin film layer was laminated on the polyimide film A1.

[Example 2]
A polyamideimide solution F was used in place of the polyamideimide solution E, and the conditions for thermocompression bonding were 320 ° C., 5 MPa, and 15 minutes.
The obtained evaluation results are shown in Table 4.

Example 3
A polyimide solution G was used in place of the polyamideimide solution E, and it was prepared and evaluated in the same manner as in Example 1 except that the thermocompression bonding conditions were 200 ° C., 5 MPa, and 60 minutes.
The obtained evaluation results are shown in Table 4.

[Examples 4 and 5]
It was prepared and evaluated in the same manner as in Example 1 except that the film thickness of the polyamideimide solution E was changed to 0.1 μm and 5.0 μm instead of 1.0 μm.
The obtained evaluation results are shown in Table 4.

[Examples 6 to 10]
It produced and evaluated by the method similar to Example 1 except using polyimide film A2, A3, A4, B, and C instead of polyimide film A1.
The obtained evaluation results are shown in Table 5.

[Examples 11 and 12]
It produced and evaluated by the method similar to Example 1 except using polyimide film A4 and A6 instead of polyimide film A5 as a base film.
Table 6 shows the obtained evaluation results.

[Comparative Examples 1 and 2]
A polyimide solution H and a silicone solution I were used in place of the polyamide-imide solution E, and the conditions for thermocompression bonding were created and evaluated in the same manner as in Example 1 except that the conditions of thermocompression bonding were 200 ° C., 5 MPa, and 60 minutes. Table 7 shows the obtained evaluation results.
The polyimide solution H and the silicone solution I were poor in heat resistance, and could not pass through the process at 300 ° C. for 1 hour.

[Comparative Examples 3 and 4]
Instead of the polyamideimide solution E, an acrylic solution J and an acrylic solution K were used, and they were prepared and evaluated in the same manner as in Example 1 except that the thermocompression bonding conditions were 160 ° C., 5 MPa, and 60 minutes. Table 7 shows the obtained evaluation results.
The acrylic solution J and the acrylic solution K were poor in heat resistance, and could not pass through the process at 300 ° C. for 1 hour.

[Comparative Example 5]
Example 1 with the exception of using a film made of polyethylene terephthalate (A-4100, manufactured by Toyobo Co., Ltd., glass transition temperature = 80 ° C., 5% weight reduction temperature = 380 ° C.) instead of polyimide film A5 as the base film. A similar method was used for evaluation. Table 7 shows the obtained evaluation results.
The film made of polyethylene terephthalate was poor in heat resistance and could not pass through the process at 300 ° C. for 1 hour.

[Comparative Example 6]
As a counterfeit product of a general commercial backing film, a film made of polyethylene terephthalate (A-4100, manufactured by Toyobo Co., Ltd., glass transition temperature = 80 ° C., 5% weight loss temperature = 380) instead of polyimide film A5 as a base film. (° C.) was prepared and evaluated in the same manner as in Example 1 except that the acrylic solution J was used instead of the polyamideimide solution E, and the thermocompression bonding conditions were 160 ° C., 5 MPa, and 60 minutes. Table 7 shows the obtained evaluation results.
Both the acrylic solution J and the polyethylene terephthalate film were poor in heat resistance, and could not pass through the process at 300 ° C. for 1 hour.

[Comparative Examples 7 and 8]
It was prepared and evaluated in the same manner as in Example 1 except that the film thickness of the polyamideimide solution E was changed to 0.01 μm and 25 μm instead of 1.0 μm. Table 8 shows the obtained evaluation results.
When the film thickness of the polyamideimide solution E was 0.01 μm, the adhesiveness was poor, and peeling occurred during the passage of the process at 300 ° C. for 1 hour. On the other hand, at 25 μm, the adhesiveness was too strong, and when the backing film was peeled off after passing through the process, wrinkles and distortion occurred in the polyimide film. Moreover, the paste transfer of the thermoplastic resin was also seen.

[Comparative Examples 9 to 11]
It produced and evaluated by the method similar to Example 1 except using polyimide film A1-A3 instead of polyimide film A5 as a base film. Table 8 shows the obtained evaluation results.
As for these, the film thickness of the base film was too thin, and the effect of handling property improvement was not seen.

A polyimide film having a thickness of 0.5 μm to 12.5 μm, a thermoplastic resin layer having a thickness of 0.05 μm to 10 μm, and a base film having a thickness of 12.5 μm to 200 μm, which are laminated in this order. The 5% weight reduction temperature of the polyimide film, the thermoplastic resin layer, and the base film is all 400 ° C. or higher, and the peel strength between the polyimide film and the base film is 0.01 N / cm to 1.0 N. Since the structure is / cm, it is possible to reduce the occurrence of problems such as peeling, wrinkles, distortion, and rubbing when handling in various processes, especially when handling at high temperatures.
Furthermore, when the base film is peeled off from the laminated polyimide film or laminated with another base material, an adhesive layer or an adhesive layer is formed on the side of the polyimide film opposite to the side on which the base film is attached. When laminated with a backing film or substrate, the base film can be easily peeled off, and the occurrence of wrinkles and distortion of the polyimide film can be reduced, so that it has higher levels of heat resistance, flexibility, and mechanical strength. The manufacture of a product using an extremely thin polyimide film can be easily and stably performed.
For this reason, it is industrially extremely useful as a functional thin film layer-laminated polyimide film capable of dealing with electric and electronic parts that are required to be fine, light, short and thin, such as thin FPC, in a field where heat resistance is required.

1: Brush roll 2: Pin 3: Pin base 4: Base 5: Support jig 6: Pressing roll 7: Precursor film

Claims (7)

  0.5 μm to 12.5 μm thick polyimide film, 0.05 μm to 10 μm thick thermoplastic resin layer, 12.5 μm to 200 μm thick base film (hereinafter referred to as thermoplastic resin layer, base film 2) In the laminated polyimide film in which the layer film is referred to as the backing film), the 5% weight reduction temperature of the polyimide film, the thermoplastic resin layer, and the base film are all 400 ° C. or higher, and A laminated polyimide film, wherein the peel strength between the polyimide film and the substrate film is 0.01 N / cm to 1.0 N / cm.   The laminated polyimide film according to claim 1, wherein the thermoplastic resin layer is made of at least one resin selected from polyamide imide and polyimide, and is soluble in an organic solvent.   The laminated polyimide film according to claim 1 or 2, wherein the polyimide film is a polyimide film having a polyimide benzoxazole component and has a linear expansion coefficient of -10 ppm / ° C to 10 ppm / ° C.   The laminated polyimide film according to claim 1, wherein the base film is a polyimide film.   The laminated polyimide film according to any one of claims 1 to 4, wherein the base film is a polyimide film having a polyimide benzoxazole component and has a linear expansion coefficient of -10 ppm / ° C to 10 ppm / ° C.   A functional thin film layer having a thickness of 0.01 μm to 10 μm is laminated on the surface opposite to the surface on which the backing film is pasted of the laminated polyimide film according to claim 1. Characteristic functional thin film layer laminated polyimide film.   The functional thin film layer-laminated polyimide film according to claim 6, wherein the functional thin film layer comprises one or more selected from copper, nickel, and chromium.