Porous film and multilayer assembly using the same

Abstract

To provide a porous-film layered product which has excellent porousness, has flexibility, and is excellent in handleability and formability; and a process for producing the layered product. [MEANS FOR SOLVING PROBLEMS] The porous-film layered product comprises a base and, superposed on at least one side thereof, a porous layer having many fine interconnecting pores having an average pore diameter of 0.01-10 [mu]m, and is characterized by suffering no interfacial separation between the base and the porous layer when examined in a tape peeling test by the following method. Tape peeling test A 24 mm-wide masking tape [Film Masking Tape No. 603(#25)] manufactured by Teraoka Seisakusho Co., Ltd. is applied to the surface of the porous layer of the porous-film layered product and press-bonded thereto with a roller having a diameter of 30 mm and a load of 200 gf. Thereafter, this sample is subjected to a T-peel test with a tensile tester at a peeling rate of 50 mm / min.

Description

technical field [0001] The present invention relates to a porous film laminate, which is laminated on at least one surface of a base material, and a method for producing the same, and a composite material using the porous film laminate, and a method for producing the same. porous layer. This porous film laminate can be used as a circuit board, heat dissipation material (radiator, heat sink), electromagnetic wave baffle or electromagnetic wave absorber, etc. by directly utilizing the pore characteristics of the porous layer or filling the pores with functional materials. Electromagnetic wave control materials, separators for batteries, capacitors (paper capacitors, plastic film capacitors, ceramic capacitors, mica capacitors, electrolytic capacitors, etc.), low dielectric constant materials, separators, cushioning materials, ink imaging sheets, test paper, insulation Materials, insulation materials, cell culture substrates, catalyst substrates (catalyst carriers) and a wide ra...

AI Technical Summary

Problems solved by technology

This dry layer inversion method is a method of volatilizing the solvent contained in the above-mentioned coating film and causing microphase separation. Therefore, there is a problem in that the resin (polymer compound) constituting the porous layer is limited to be soluble at a low temperature. Resins with a good solvent at the boiling point, high molecular weight compounds that are inherently insoluble and have a large molecular weight cannot be used

However, when the conductor wiring is finer pitched, when the copper foil is roughened, problems such as breakage or peeling of the wiring due to unevenness of the copper foil during etching occur.

On the other hand, when using copper foil that is not roughened, etching can be performed smoothly, but the adhesion strength between the insulator and the copper foil is lowered, and the entire wiring is easily peeled off.

[0008] In addition, the following problems will also arise: when the thickness of the copper foil is large, the central part of the thickness direction of the copper foil is cut along the direction perpendicular to the thickness direction during etching, and the cross-section of the wiring cannot be formed into a square; When the wiring breaks or peels off

However, although the fine wiring of the green sheet of the powder mixture is excellent in printability, it has the following disadvantages: it requires a firing process at a temperature around 1000°C, which is expensive, and the finished product is not flexible and brittle.

However, this method has disadvantages such as the need for a laser irradiation process, low productivity and high cost, the need for advanced technology for placing ink in the groove pattern, and lack of mass productivity.

However, in this technique, since the granular film is coated, the strength of the film is weak, and it is not durable as a wiring material.

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