JP2007099815A - Polyimide film and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyimide film that retains higher levels of heat resistance and flexibility and is excellent in mechanical strength and elastic modulus, has a recessed part of a prescribed pattern formed on one side and is useful as a solar cell substrate, a heat-radiation film, an electromagnetic-shielding film, a film for preventing dielectric loss, a mixed optical/electric substrate, etc. , that utilize the recessed part. <P>SOLUTION: The polyimide film has the recessed part of the prescribed pattern composed of one or a combination of a rectangle, a triangle, a circle, an arc and an oval having a depth of 1-15 μm and a width of 1-1,000 μm in the film thickness direction. In a method for manufacturing the polyimide film, a polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid is cast on a support, on which a convex structure of the prescribed pattern is previously formed, to obtain a polyimide precursor film, which is subsequently subjected to a heat treatment and/or imidation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyimide film having a predetermined pattern groove shape structure on one side and a manufacturing method thereof. More specifically, the present invention relates to a heat dissipation film in which a heat transfer material is loaded in a predetermined pattern groove shape structure, an LSI such as a CPU, and a plasma display panel. In addition, heat removal (heat dissipation) from heat generating parts such as LCD backlights, organic EL panels, and inverters is possible in an extremely narrow space, making it an effective heat dissipation means for miniaturization and thinning of these electronic components. Heat-resistant polyimide film that can be used for film, dielectric loss prevention film, etc., film substrate for optical waveguide circuit, film circuit substrate in which optical waveguide circuit and electric circuit coexist, or material for build-up layer of multilayer substrate. A substrate material in which an optical waveguide circuit and an electric circuit coexist on the layer, an optical waveguide circuit connector, Waveguide circuit and the electric circuit connector to coexist, and the polyimide film of the film substrate to be part of the MEMS, a manufacturing method thereof.

Conventionally, ceramics and metals have been used as base materials for electronic components such as flexible solar cells, information communication equipment (broadcast equipment, mobile radio, portable communication equipment, etc.), radars, high-speed information processing devices, and the like. Although a substrate made of ceramic has heat resistance, ceramics are not flexible and cannot be thinned, so the fields that can be used are limited.
For this reason, studies have been made to use a film made of an organic material as a base material for an electronic component, and a film made of polyimide has been proposed.

  The conventional polyimide film is excellent in heat resistance and tough, but in order to give a surface uneven structure, a prescription of adding insulating fine particles having a particle diameter of 0.1 to 1 μm has been adopted. I have to stay in it. Addition of a large amount of large particles has a significant effect on productivity, and it has been extremely difficult to efficiently provide a desired surface uneven structure.

  The present invention is excellent in heat resistance of polyimide film, retains tough properties, imparts an arbitrary surface uneven structure to the polyimide film at low cost, and imparts an arbitrary surface structure to a heat dissipation film or dielectric loss prevention film Another object of the present invention is to provide a polyimide film useful for substrates of solar cells and solar cells.

  As a result of intensive studies, the present inventors obtained a polyimide precursor film by casting polyamic acid on a support, and a method for producing a polyimide film obtained by heat-treating and / or imidizing the polyimide precursor film, A convex structure having a predetermined pattern is formed in advance on a support, a polyamic acid is cast on the support to obtain a polyimide precursor film, and the polyimide precursor film is heat-treated and / or imidized to form one surface of the film. However, it has been found that a polyimide film having a predetermined pattern groove shape structure having a depth of 1 μm to 15 μm and a width of 1 μm to 1000 μm in the film thickness direction can be obtained.

That is, this invention consists of the following structures.
1. Polyimide obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid on a support to obtain a polyimide precursor film, and a polyimide obtained by heat-treating and / or imidizing the polyimide precursor film A film, wherein one surface of the film has a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm to 1000 μm in the film thickness direction, one kind selected from a rectangle, a triangle, a circle, an arc, an ellipse, and a trapezoid It has concave portions of a predetermined pattern formed by a combination, the cross-sectional shape of the predetermined pattern portion is trapezoidal, the lower base of the trapezoid corresponds to the film surface, and the ratio of the pattern depth to the film thickness is 0.4. It is in the range of -0.005, The polyimide film characterized by the above-mentioned.
2. 1. A polyamic acid is obtained by reacting an aromatic diamine having a benzoxazole structure with an aromatic tetracarboxylic acid. The polyimide film as described.

3. Polyimide obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid on a support to obtain a polyimide precursor film, and a polyimide obtained by heat-treating and / or imidizing the polyimide precursor film A method for producing a film, wherein a convex structure having a predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse is formed on a support in advance, and polyamic acid is allowed to flow on the support. To obtain a polyimide precursor film, heat-treat and / or imidize the polyimide precursor film, and one side of the film has a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm to 1000 μm in the film thickness direction, A concave pattern of a predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse Method for producing a polyimide film characterized by obtaining a polyimide film having a.
4). 2. A polyamic acid is obtained by reacting an aromatic diamine having a benzoxazole structure with an aromatic tetracarboxylic acid. The manufacturing method of the polyimide film of description.

  The polyamic acid obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid according to the present invention is cast on a support to obtain a polyimide precursor film, and the polyimide precursor film is heat-treated and / or imidized. A method for producing a polyimide film obtained by forming a convex structure having a predetermined pattern made of one kind or a combination thereof selected in advance from a rectangle, a triangle, a circle, an arc, an ellipse on a support, and on the support Polyamide acid is cast to obtain a polyimide precursor film. The polyimide precursor film is heat-treated and / or imidized, and one surface of the film has a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm in the film thickness direction. A predetermined pattern consisting of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse of ~ 1000 μm. The polyimide film manufacturing method for obtaining a polyimide film having a concave portion of the film can be manufactured at a low cost without any hindrance to productivity, and a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm to 1000 μm. A concave structure of a predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse having an effective use of light rays in a solar cell, and the concave structure holds air inside It can be used for a dielectric loss prevention film and the like, and can exhibit an excellent effect in a heat dissipation film in which a heat conductive material is loaded in a predetermined pattern groove shape structure, and is extremely useful industrially.

In the production of the polyimide film of the present invention, a polymerization reaction is performed by first subjecting an aromatic diamine and an aromatic tetracarboxylic acid to a ring-opening polyaddition reaction in a solvent to obtain a polyamic acid solution, and then, from this polyamic acid solution, a polyimide The green film (or sheet) which is the precursor film is formed and then dehydrated and condensed (imidized).
In the present invention, among these aromatic diamines, aromatic diamines having a benzoxazole structure are particularly preferred diamines. Examples of the diamine having a benzoxazole structure particularly preferably used in the present invention include the following.

  Among these, amino (aminophenyl) benzoxazole isomers are preferable from the viewpoint of ease of synthesis. 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. In the present invention, it is preferable to use 70 mol% or more of the aromatic diamine having the benzoxazole structure. The present invention is not limited to the above items, and the following aromatic diamines may be used. Preferably, the diamines do not have the benzoxazole structure exemplified below as long as the total aromatic diamine is less than 30 mol%. Is a polyimide film using one or two or more 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′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone,

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-aminophenoxy) 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, 1,4-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-aminophenoxy) -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-hexafluoropropane. 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-aminophenoxy) 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} phenyl] sulfone, 1,4-bis [4- (4-Aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-Amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl ] Benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-sia) Phenoxy)-.alpha., alpha-dimethylbenzyl] benzene. 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 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′-dibi Phenoxybenzophenone, 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, , 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-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-bi) Phenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the aromatic diamine are halogen atoms, Some or all of the hydrogen atoms of the alkyl group or alkoxyl group having 1 to 3 carbon atoms, the cyano group, or the alkyl group or alkoxyl group are halo Aromatic diamines which are substituted with an alkyl halide group or an alkoxyl group having 1 to 3 carbon atoms and the like in emissions atoms.

  The tetracarboxylic acid used in the present invention is preferably an aromatic tetracarboxylic anhydride. Specific examples of the aromatic tetracarboxylic acid anhydride include the following.

これらのテトラカルボン酸二無水物は単独で用いてもよいし、二種以上を併用してもよい。本発明においては、全テトラカルボン酸二無水物の３０モル％未満であれば下記に例示される非芳香族のテトラカルボン酸二無水物類を一種又は二種以上、併用しても構わない。

These tetracarboxylic dianhydrides may be used alone or in combination of two or more. In the present invention, one or two or more non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination as long as they are less than 30 mol% of the total tetracarboxylic dianhydrides.

  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, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and the like. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  The solvent used when polymerizing an aromatic diamine (monomer) and an aromatic tetracarboxylic acid (monomer) to obtain a polyamic acid can be used as long as it dissolves both the monomer as a raw material 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 an aromatic tetracarboxylic acid (anhydride) to the aromatic diamine solution. The mass of the polyamic acid in the polyamic acid solution obtained by the polymerization reaction is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and the viscosity of the solution is measured with a Brookfield viscometer (25 ° C.). From the viewpoint of the stability of liquid feeding, it is preferably 10 to 2000 Pa · s, and more preferably 100 to 1000 Pa · s.
The reduced viscosity (ηsp / C) of the polyamic acid in the present invention is not particularly limited, but is preferably 2.0 dl / g or more, more preferably 3.0 dl / g or more, still more preferably 5.0 dl / g or more. preferable.

Vacuum defoaming during the polymerization reaction is effective for producing a high-quality polyamic acid organic solvent solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamine before a 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 mol per mol of aromatic diamine.
In order to form a polyimide film from the polyamic acid solution obtained by the polymerization reaction, a green film is obtained by coating the polyamic acid solution on a support and drying, and then subjecting the green film to a heat treatment. A method of imidization reaction may be mentioned.

The support to which the polyamic acid solution is applied only needs to have sufficient rigidity to form the polyamic acid solution into a film, and the surface is metal (more preferably, stainless steel that does not rust and has excellent corrosion resistance), plastic Or a drum-like rotating body.
A method using a polymer film having appropriate rigidity is also a preferred embodiment.
The surface of the metal support may be plated with metal such as Cr, Ni, or Sn.
The support surface has a height of 1 μm to 50 μm depending on the concave portion of a predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle and an ellipse having a depth of 1 μm to 15 μm to be applied to the polyimide film to be produced. A convex structure having a predetermined pattern consisting of one or a combination selected from a rectangle, a triangle, a circle, and an ellipse is provided, and the surface convex structure on the support may be provided on the entire support. Alternatively, it may be applied partially, or may be applied directly to the drum or belt-like rotating body support, or a film or metal applied may be bonded together. The depth of the concave structure is preferably 1 μm to 15 μm, and the cross-sectional shape is preferably a trapezoidal shape with the film surface as the bottom surface.
In the present invention, the cross-sectional shape of the predetermined pattern portion is trapezoidal, the bottom of the trapezoid corresponds to the film surface, and the ratio of the pattern depth to the film thickness is within the range of 0.4 to 0.005. It is preferable that this makes it easy to peel the film from the support, and the resulting film does not have a significant deterioration in mechanical strength.
The concave portions of the predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse having a depth of 1 μm to 15 μm to be applied to these polyimide films may be a continuous pattern, or each of them is independent. Multiple patterns may be used.
Application of the polyamic acid solution to the support includes, but is not limited to, casting from a slit base, extrusion through an extruder, squeegee coating, reverse coating, die coating, applicator coating, wire bar coating, etc. Conventionally known solution coating means can be appropriately used.

The above polyimide film can be provided with a lubricant in the polyimide to give fine irregularities on the film surface to improve the slipperiness of the film (particularly the surface opposite to the surface imparting the surface irregular structure). .
As the lubricant, inorganic or organic fine particles having an average particle diameter of about 0.03 μm to 1 μm can be used. Specific examples include titanium oxide, alumina, silica, calcium carbonate, calcium phosphate, calcium hydrogen phosphate, calcium hydrogen pyrophosphate. , Magnesium oxide, calcium oxide, clay mineral and the like. As these polyimide films, unstretched films are preferably applied, but uniaxial or biaxially stretched films can also be used.
Here, the unstretched film refers to a film obtained without intentionally applying a mechanical external force in the surface expansion direction of the film by tenter stretching, roll stretching, inflation stretching, or the like.

  An example of a preferred embodiment of the present invention is a heat dissipation film. As an example, as the integration degree of the CPU increases, the heat generation therein becomes so large that it cannot be ignored, the wiring becomes thin, and the waste heat in the wiring also decreases. In order to increase the degree of integration, elements that consume the same power are becoming closer, and high-frequency use is required. Heat) is becoming difficult. Conventionally, as an LSI cooling method, an attempt has been made to attach a metal called a heat spreader to a chip and bring it into contact with a heat sink. However, this conventional cooling method cannot cope with the heat generation problem that becomes more serious as the design rule becomes finer and the operating frequency increases. For this reason, attempts have been made to make the heat sink water-cooled, but it cannot cope with a situation in which specific parts of the LSI such as the input / output circuit and the buffer circuit generate heat. For this reason, it is necessary to actively cool in a place close to the LSI chip. The use of Peltier elements is also considered, but it has not been put into practical use. As a method of giving the waste heat function as close as possible to the heat generation part of the LSI chip, attention is paid to the interposer that enters between the package substrate that receives the chip. The heat dissipation film used can be applied.

As an interposer, a plurality of films are formed by sputtering and then metallized by plating, and a pattern circuit formed thereon is bonded together. As an interposer, one layer is used for waste heat in addition to the necessary circuit, and a copper wiring pattern is made here. However, a recess such as a groove is formed in advance during film production, and a metallized pattern is created there. Therefore, a sufficiently thicker wiring can be made than other wirings.

  Examples of the heat radiation (heat radiation) film in the present invention include a method of filling and baking alumina sol (far-infrared radiation layer) in the concave portion of the film obtained by the present invention, and a method of filling and baking copper paste (heat transfer radiation layer). These may be combined to form the same film in the respective pattern recesses, different films may be formed, or different films may be stacked in the same pattern. The thickness of these heat radiation layers may vary depending on the heat radiation characteristics of the formed heat radiation layer itself, but is preferably 3 μm or more in order to obtain sufficient characteristics. This is because the far-infrared radiation characteristic is remarkably reduced when the layer thickness is less than 3 μm. The thickness of these layers is usually up to about 50 μm, and if it exceeds this, the bending resistance tends to be insufficient.

An adhesive layer may be laminated on the surface of the heat radiation film on the metal layer side.
The surface of the heat-dissipating sheet on the side of the pressure-sensitive adhesive layer may be affixed to electronic device parts and the like, and since the pressure-sensitive adhesive layer has adhesiveness, it can be adhered to the heat generating part of the electronic device component. And the thermal resistance in the meantime can be significantly reduced, and the heat conduction is done quickly.

  As an example of a preferred embodiment of the present invention, a highly transparent resin is placed in the concave portion of the film of the present invention to provide a light guide circuit and to form a circuit board having a conductive circuit from a separately formed conductive thin film. . For example, by forming transparent PAI (polyamideimide resin) in the concave portion of the film, it is possible to form a heat-resistant substrate member including a light and electrical mixed substrate optical waveguide, an optical transmission line, an optical connector, and a mixed optical and electrical connector. it can.

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.
[Examples 1-3]
(Production of convex PET film)
On one side of a 100 μm thick polyethylene terephthalate (PET) film (trade name A-4100, manufactured by Toyobo Co., Ltd.), the following resin composition 1 was applied at a room temperature using an applicator, The PET film having a resin layer was prepared by applying the film so as to have a desired line height. A separately prepared plate was overlaid on the obtained resin layer and laminated at a pressure of 0.5 Mpa. After that, the resin is cured by irradiating UV of 0.5 J / cm ² from the top of the film, and the above plate is peeled and removed, and a convex shape is formed so that the line width and line height are predetermined. A PET film having a resin layer was obtained.
<Resin composition 1>
In a 500 cm ³ three-necked flask equipped with a thermometer, a condenser tube, and a nitrogen inlet tube, 200 cm ³ of toluene, 20 g of methyl methacrylate (MMA), 35 g of butyl acrylate (BA), 2 g of acrylamide (AM), bidoxyethyl methacrylate (HEMA) 5 g and AIBN 250 mg were added and stirred at reflux at 100 ° C. for 3 hours while bubbling with nitrogen. Next, 5 g of 2-methacryloyloxyethyl isociate (trade name Karenz MOI, Showa Denko KK) and 0.1 g of tin-dissolving medium were added and reacted at 80 ° C. for 2 hours. Thereafter, reprecipitation with methanol was performed, and the polymer as a reaction product was filtered and dried under reduced pressure to obtain a UV curable polyacrylic ester. To 100 parts by mass of the obtained polyacrylic acid ester (MMA / BA / AM / HEMA = 32/57/3/8, Mw = 30,000), 2-methyl-1 [4-methylthio] as a photopolymerization initiator 1 part by mass of phenyl] -2-morpholinopropan-1-one (trade name Irgacure 907, Ciba Geigy Co., Ltd.) and 150 parts by mass of toluene were added to obtain Resin Composition 1.

(Preparation of polyamic acid solution)
After the inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 500 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole was added. Next, 5000 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then 485 parts by mass of pyromellitic dianhydride was added and stirred at 25 ° C. for 48 hours. A polyamic acid solution was obtained.
(Manufacture of polyamic acid green film)
The polyamic acid solution is coated on a support in which the convex portion (line formation) polyethylene terephthalate (PET) film is bonded to a stainless steel belt, and is subjected to predetermined conditions using a continuous drying furnace having three zones. And dried. The polyamic acid film that became self-supporting after drying was peeled from the stainless steel belt to obtain a green film.
(Manufacture of polyimide (benzoxazole) film)
The obtained green film was passed through a continuous heat treatment furnace having three compartments and purged with nitrogen, and was heated to advance the imidization reaction to obtain a polyimide film.
A predetermined pattern in which concave portions having a predetermined width and depth were regularly arranged in parallel was formed on the surface of the obtained polyimide film in contact with the support.
Table 1 shows the convex shape on the used polyethylene terephthalate film and the evaluation of the concave portion of the obtained polyimide film.

[Examples 4 to 5]
Except for the adjustment of the following polyamic acid, a polyimide film was obtained in substantially the same manner as in Examples 1 to 3.
Table 1 shows the convex shape on the used polyethylene terephthalate film and the evaluation of the concave portion of the obtained polyimide film.
(Preparation of polyamic acid solution)
A container equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 4,4′-diaminodiphenyl ether was added. Next, after adding dimethylacetamide and completely dissolving it, pyromellitic dianhydride is added, and 4,4′-diaminodiphenyl ether as a monomer and pyromellitic dianhydride are in a molar ratio of 1/1. Polymerization in dimethylacetamide was performed so that the monomer charge concentration was 15% by mass, and the mixture was stirred at 25 ° C. for 6 hours to obtain a brown viscous polyamic acid solution. 15 parts by mass of acetic anhydride and 3 parts by mass of isoquinoline were mixed with 100 parts by mass of the obtained polyamic acid solution to obtain a polyamic acid solution.

About shape measurement, such as a pattern in a table | surface, it performed with the measurement microscope Olympus STM6.
In order to investigate whether the pattern shape can be designed as designed, the convex shape on the support and the concave shape on the film surface were measured and compared. As an index of whether the shape of the cross section of the pattern is maintained in addition to the overall dimensions, the taper is defined and measured.
“Tapering” means a width value (W ₉₀ ) at a position of 90% of the groove (concave) depth (or the height of the convex part) in the cross section of the groove or convex part and the groove (concave part) depth ( or with 1.2 times the absolute value of the difference (W ₉₀ -W ₁₀₎ in 10% of the depth of the height) of the protrusion (width value at the position of height) and (W ₁₀₎ "taper Who "
The length, width, and height were measured at 10 locations, and the average was taken as the numerical value.
The taper droop was averaged by measuring five points on both sides of the groove (or convex portion).

[Comparative Examples 1-2]
A polyimide film was obtained in substantially the same manner as in Examples 4-5. Table 2 shows the evaluation of the convex portions (line formation) polyethylene terephthalate used and the concave portions of the obtained polyimide film.

比較例１は一部フィルムが破断した。比較例２では一部パターンが消失した。

In Comparative Example 1, the film was partially broken. In Comparative Example 2, some patterns disappeared.

  As described above, one surface of the film of the present invention is selected from a rectangle, a triangle, a circle, an arc, an ellipse having a depth of 1 μm to 15 μm and a width of 1 μm to 1000 μm in the film thickness direction, or a combination thereof. The polyimide film having a recess having a predetermined pattern is made of a heat-dissipating film, a solar cell, which retains its heat resistance, flexibility, mechanical high strength and high elastic modulus, and uses this recess. It can be used for substrates, dielectric loss prevention films, optical / electrical mixed substrates (electric circuit substrates including optical waveguides), electromagnetic wave shielding members, etc. As a method for producing this useful film, aromatic diamine and aromatic tetra A polyamic acid obtained by reacting with a carboxylic acid is cast on a support to obtain a polyimide precursor film. Or a method for producing a polyimide film obtained by imidization, wherein a convex structure having a predetermined pattern made of one kind or a combination selected from a rectangle, a triangle, a circle, and an ellipse is formed on a support in advance, and the support A polyimide precursor film is obtained by casting a polyamic acid on top of this, and the polyimide precursor film is heat-treated and / or imidized. Useful.

Claims (4)

  Polyimide obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid on a support to obtain a polyimide precursor film, and a polyimide obtained by heat-treating and / or imidizing the polyimide precursor film A film, wherein one surface of the film has a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm to 1000 μm in the film thickness direction, one kind selected from a rectangle, a triangle, a circle, an arc, an ellipse, and a trapezoid It has concave portions of a predetermined pattern formed by a combination, the cross-sectional shape of the predetermined pattern portion is trapezoidal, the lower base of the trapezoid corresponds to the film surface, and the ratio of the pattern depth to the film thickness is 0.4. It is in the range of -0.005, The polyimide film characterized by the above-mentioned. The polyimide film according to claim 1, wherein the polyamic acid is obtained by reacting an aromatic diamine having a benzoxazole structure with an aromatic tetracarboxylic acid. Polyimide obtained by reacting an aromatic diamine and an aromatic tetracarboxylic acid on a support to obtain a polyimide precursor film, and a polyimide obtained by heat-treating and / or imidizing the polyimide precursor film A method for producing a film, wherein a convex structure having a predetermined pattern made of one or a combination selected from a rectangle, a triangle, a circle, an arc, and an ellipse is formed on a support in advance, and polyamic acid is formed on the support. A polyimide precursor film is obtained by casting, and the polyimide precursor film is heat-treated and / or imidized, and one side of the film has a depth of 1 μm to 15 μm and a width (representative diameter) of 1 μm to 1000 μm in the film thickness direction. A predetermined pattern consisting of one or a combination selected from rectangle, triangle, circle, arc, ellipse Method for producing a polyimide film characterized by obtaining a polyimide film having a part. The method for producing a polyimide film according to claim 3, wherein the polyamic acid is obtained by reacting an aromatic diamine having a benzoxazole structure with an aromatic tetracarboxylic acid.