Abstract: The printed wiring board of the present invention is a printed wiring board produced by selectively etching a base film having a base metal layer and a conductive metal layer, which are formed on an insulating film, through plural etching steps comprising a conductive metal etching step and a base metal etching step to form a wiring pattern and then bringing the base film having the thus formed wiring pattern into contact with a reducing aqueous solution containing a reducing substance, wherein the amount of a residual metal derived from the etching solution on the printed wiring board is not more than 0.05 ?g/cm2. According to the present invention, the metal derived from the etching solution is removed by the use of a reducing substance-containing solution. Therefore, the water rinsing step in the production process can be shortened, occurrence of migration attributable to the residual metal can be prevented, and a printed wiring board having high reliability can be efficiently produced.

Abstract: A film carrier tape for mounting electronic components has a wiring with a wire pitch of 35 ?m or less. A method for manufacturing such film carrier tape is also disclosed. The film carrier tape for mounting electronic components is manufactured using a specific flexible conductor foil clad laminate as a wiring forming material. The flexible conductor foil clad laminate includes a base film and a conductor foil having a surface roughness (Rzjis) of a bonded surface of 2.5 ?m or less and a surface roughness (Rzjis) of a resist-side surface of 1.0 ?m or less. The flexible conductor foil clad laminate may be a flexible copper clad laminate in which a glossy-surface-processed electrolytic copper foil has a surface roughness (Rzjis) of a bonded surface of 2.5 ?m or less and a surface roughness (Rzjis) of a resist-side surface of 1.5 ?m or less and in which the copper foil is half etched as required to not less than half an original thickness.

Abstract: A wiring board with folding endurance includes an insulating film and a copper-containing wiring pattern on a surface of the insulating film, and includes an insulating resin coating layer formed on the wiring pattern such that terminals are exposed. The wiring board has any of the constitutions (A), (B), (C) and (D) below. (A) The wiring pattern includes copper particles having a mean crystal particle diameter in the range of from 0.65 to 0.85 ?m as determined by EBSP; not more than 1% of the volume of the wiring pattern is accounted for by copper crystal particles having a particle diameter of less than 1.0 ?m as determined by EBSP; and copper crystal particles that are [100] oriented in the longitudinal direction of a lead of the wiring pattern account for from 10 to 20% of the volume of the wiring pattern as determined by EBSP.

Abstract: An object of the invention is to provide a flexible copper clad laminate and the like in use of electro-deposited copper foil having lower profile and higher mechanical strength compared with conventional low profile electro-deposited copper foil having been supplied in the market. For attaining the object, a flexible copper clad laminate manufactured by laminating the electro-deposited copper foil to resin film, which is characterized in that a deposition surface of the electro-deposited copper foil comprises a low profile glossy surface having surface roughness (Rzjis) of not more than 1.5 ?m and brightness (Gs (60°)) of not less than 400 and the deposition surface and the resin film are bonded together is adopted. And, using the flexible copper clad laminate, it may ease manufacture of a flexible printed wiring board as a film carrier tape, such as a COF tape and the like, wherein the formed wiring has a fine pitch wiring with pitch being not more than 35 ?m.

Abstract: An object of the present invention is to provide a flexible printed wiring board, excellent in folding ability, obtained from a flexible copper-clad laminate using an electro-deposited copper foil. In order to achieve the object, there is provided a two-layer flexible printed wiring board having a wiring, formed by etching an electro-deposited copper foil, on a surface of a resin film layer, the wiring including only a steady-deposition crystal layer 2 formed by removing an initial-deposition crystal layer 1 formed at the time of the electro-deposited copper foil preparation. When the two-layer flexible printed wiring board has a cover film layer, preferably the deviation between the neutral line of the sectional thickness of the two-layer flexible printed wiring board and the central line of the wiring thickness of the two-layer flexible printed wiring board falls within 5% of the total thickness of the two-layer flexible printed wiring board.