Abstract: The flexible wiring board has a first wiring film and a second wiring film. Because the first wiring film has a larger thickness than the second wiring film, the sectional area and electrical resistance of the first wiring film can be enlarged because of the larger film thickness even in a case where the first and second wiring films have almost the same width. Therefore, a high current can flow through the first wiring film, although the wiring film has a small width. As a result, a high density of the flexible wiring board can be easily achieved.

Abstract: A recording material for back printing has a transparent substrate; an ink absorbing layer that is provided on the transparent substrate; and a porous ink transmitting layer that is provided on the ink absorbing layer and comprises a filler dispersed in a binder resin, where ink transmitting layer is crosslinked.

Abstract: In a flexible wiring board of the present invention, a first shield film is connected to a ground wiring at the bottom of an opening in a cover film. The first shield film is connected to a second shield film via a through-hole penetrating from the surface to the rear surface of a base film. Thus, the second shield film is connected to the ground wiring via the first shield film, whereby the wiring board can be wholly shielded.

Abstract: An object of the present invention is to provide an adhesive with which voids are less likely to occur and adherends are not curved. Adhesives of the present invention have excellent dispensability from nozzles of dispensers because the overall specific gravity of the adhesives is adjusted to 1.4 or more and 4.0 or less by adding a filler having a specific gravity of 3.0 or more and 9.0 or less. A highly reliable electric device 1 can be obtained because no voids are generated in an adhesive 12 or an adherend or a flexible wiring board 5 is not curved when the flexible wiring board and a semiconductor chip 11 are connected.

Abstract: A process for mounting a semiconductor device and a mounting apparatus whereby electrodes of a fine-pitch semiconductor device and a wiring board can be surely connected to each other.

Abstract: The present invention aims to provide an adhesive composition showing high adhesion and cohesion as well as good heat resistance. Adhesive compositions of the present invention include an imide (meth)acrylate, a monomer having a glass transition temperature of −50° C. or less when it is homopolymerized, and a photoinitiator, wherein the content of the imide (meth)acrylate is 1-20 parts by weight per 100 parts by weight of the monomer.

Abstract: The present invention provides an adhesive film for producing an electric device having high reliability. Release agent layer of release film of the present invention is based on a fluorine compound with no silicone oil so that the adhesive force between substrate and release agent layer is enough high to provide an electric device having high reliability wherein release agent layer is not adhered when release film is separated from adhesive layer. The surface roughness of substrate of 3 &mgr;m or less limits irregularities on the side of adhesive layer from which release film has been separated and therefore, no bubbles occur between adhesive layer and semiconductor chip when semiconductor chip is pressed against adhesive layer. If the surface roughness of substrate is 1 &mgr;m or more, adhesive film also has high slitting performance.

Abstract: A method for connecting electrical components is provided. The method includes electrically connecting electrodes on two separate substrates with an anisotropic electroconductive adhesive layer. The thickness of the electroconductive adhesive layer prior to connection (X) is given by: 0.5×{(A1C1+A2C2)/(B+C)}≦X≦2×{(A1C1+A2C2)/(B+C)} where: A1 is a height of electrodes on a first substrate, B1 is a width of the electrodes on the first substrate and C1 is a width of an interelectrode space between the electrodes on the first substrate; A2 is a height of electrodes on a second substrate, B2 is a width of the electrodes on the second substrate and C2 is a width of an interelectrode space between the electrodes on the second substrate; and B+C=B1+C1=B2+C2.

Abstract: A double-sided flexible printed board is manufactured by the following steps of:

Abstract: An IC card 10A has a mica capacitor that comprises a mica film 1 and electrodes 6a, 6b formed on both sides thereof, where the mica film 1 serves as a mounting substrate for an antenna coil 2 and an IC chip 3, thereby reducing profile of an IC card and also reducing its cost of manufacture and to stabilize its resonance frequency.

Abstract: The present invention aims to connect metal films without forming any opening in a resin film. Against a first resin film 16 formed on a first metal film 12 are pressed bumps 21 on a second metal film 11 so that the bumps 21 are embedded into the first resin film 16. Either one of the first metal film 12 or the second metal film 11 or both is (are) patterned while the bumps 21 are in contact with the first metal film 12, and the first resin film 16 is heat-treated while the top of the first resin film is partially exposed to discharge the solvent or moisture from the exposed zone and cure the first resin film 16. After curing, the bumps 21 and the first metal film 12 may be ultrasonically bonded to each other. A second resin film and a third metal film may be further layered to form a multilayer structure.

Abstract: An insulating sheet 13 is manufactured by attaching a buffer layer 21 and a resin film 23 using an adhesive layer 8 that is not adhesive at a normal ambient temperature. Since there is no need to use a release liner when manufacturing the insulating sheet 13, there is no release of a silicone component. Accordingly, when installing a hard disk printed wiring board, the printed wiring board and electronic circuits inside the hard disk will not be damaged by the released silicone.

Abstract: Process for producing a flexible wiring board by etching a metal foil halfway to form a thick film part and a thin film part, etching the thin film part in order to form a first wiring film having the thick film part and a second wiring film having the thin film part with the first wiring film having a larger thickness than the second wiring film. The sectional area and electrical resistance of the first wiring film can be enlarged, even in cases where the first wiring film and the second wiring film have almost the same width, because of the larger film thickness of the first wiring film.

Abstract: A flexible printed wiring board constructed by using elemental pieces at a low cost. The elemental pieces 81a to 81c according to the present invention are provided respectively with supporting films 24a to 24c on one face and adhesive resin films 19a to 19c on the other face. The supporting films 24a to 24c have connecting openings on the bottom face of which the surface of metal wiring circuits are exposed as lands 23a to 23c. On the other hand, conductive bumps 16a to 16c, which are connected respectively to the metal wiring circuits 14a to 14c, project on the resin films 19a to 19c. To construct a flexible printed wiring board 83 by using plural elemental pieces 81a to 81c, the tips of the conductive bumps 16b and 16c are brought into contact respectively with the lands 23a and 23b on the bottom face of the openings and contact-bonded under heating. Thus, the elemental pieces 81a to 81c are adhered to each other owing to the adhesiveness of the resin film 19b and 19c.

Abstract: An object of the present invention is to provide a winding apparatus adaptable to longer films with minimum design changes in existing apparatus.

Abstract: A double-sided flexible printed circuit board is manufactured by the following steps of: (a) forming a polyimide precursor layer on a first metal layer; (b) forming a second metal layer on the polyimide precursor layer; (c) patterning the second metal layer to form a second circuit layer or (c′) patterning the first metal layer to form a first circuit layer; and (d) imidating the polyimide precursor layer to form a polyimide insulating layer. The polyimide precursor layer is obtained by dissolving a polyamic acid or other polyimide precursor in N-methyl-2-pyrrolidone or the like and applying the resultant varnish to the first metal layer. The polyimide layer is then dried. The imidation ratio of the dried polyimide precursor layer is prevented from exceeding 50%.

Abstract: A flexible wiring board according to the present invention comprising growing metal bumps 16 using a mask film patterned by photolithography. Fine openings can be formed with good precision, therefore, fine metal bumps 16 can be formed with good precision because laser beam is not used to form opening in a polyimide film. After metal bumps 16 have been formed, the mask film is removed and a liquid resin material is applied and dried to form a coating, which is then cured into a resin film. The coating can be etched at surface portions during coating stage to exposed the tops of metal bumps 16.

Abstract: A process for manufacturing a flexible wiring board according to the present invention comprises growing metal bumps 16 using a mask film patterned by photolithography. Fine openings can be formed with good precision, therefore, fine metal bumps 16 can be formed with good precision because laser beam is not used to form openings in a polyimide film. After metal bumps 16 have been formed, the mask film is removed and a liquid resin material is applied and dried to form a coating, which is then cured into a resin film. The coating can be etched at surface portions during coating stage to expose the tops of metal bumps 16.

Abstract: In wiring board 1 of the present invention, a shield film 50 is connected to a specific wiring member (ground wiring) 17 at the bottoms of openings 14 in cover film 21 and the shield film 50 is wrapped from the side of cover film 21 to the side of base film 11. Therefore, shield film 50 can be placed at ground potential on not only the side of cover film 21 but also the side of base film 11, whereby wiring board 1 can be wholly shielded from the noise emitted from other electronic components. Ground wiring 17 is patterned to be wider than the other wiring members (signal wirings) 18, which allows a large current to pass and openings 14 to be made in a large diameter, so that cover film 21 can be easily aligned and more reliably connected to shield film 50.

Abstract: An adhesive material is used for connecting a protuberant electrode of an electronic component to a terminal electrode of a circuit board for carrying said electronic component through the adhesive material containing at least one curable resin and inorganic particles.