Nitto-denko Corporation

Yuichi Takayoshi

Kazushi Ichikawa

Toshiki Naito

Yasuhito Ohwaki

Toshihiko Sugimoto

Chiharu Miyaake

Mineyoshi Hasegawa

Yoshihiko Takeuchi

Akinori Itokawa

Yasuo Nakatsuka

Yasushi Tsuda

A wired circuit board that can provide improved reliability on connection between the terminal portions and the external terminals while ensuring high productivity and cost reduction, and a production method thereof. After a conductive patternincluding terminal portionsto connect with external terminalsof an electronic componentand criterion marksto determine presence or absence of an inhibitory portionthat may be formed due to formation of an insulating cover layerto inhibit connection between the terminal portionsand the external terminalsare formed on the insulating base layersimultaneously, the insulating cover layerto cover the conductive patternand an openingfrom which the terminal portionsand the criterion marksare exposed is formed. Thereafter, the presence or absence of the inhibitory portionis determined with reference to the criterion marksexposed from the openingof the insulating cover layer

Production method of a wired circuit board

Wired circuit board and production method thereof

A wired circuit board includes an insulating base layer, a conductive pattern formed on the insulating base layer, and an insulating cover layer formed on the insulating base layer for covering the conductive pattern. The conductive pattern includes terminal portions for connecting with external terminals. The insulating cover layer has an opening formed correspondingly for the respective terminal portions. A position determining zone for determining whether or not a margin of the insulating cover layer facing the opening is located in a proper position is provided in proximity of the terminal portions.

Wired circuit board and producing method thereof

An insulating substrate with metal foils on both sides thereof is prepared, and a through hole that passes through the metal foils and insulating substrate is formed. An electroless copper plating layer is formed on an inner surface of the through hole and a surface of each of the metal foils, followed by the formation of an electrolytic copper plating layer on the overall surface of the electroless copper plating layer. After removing the electrolytic copper plating layer except the portions on the inner surface and a peripheral region of the through hole, the metal foils are processed to form conductor patterns.

Method for manufacturing double-sided printed circuit board

A wired circuit board can control characteristic impedance at connection points between wires of a suspension board with circuit and terminal portions of the wired circuit board connected thereto with a simple structure, to improve signal transmission efficiency even for fine pitch wiring or for high frequency signals. The wired circuit board includes a relay flexible wiring circuit board formed by a first wired circuit board including a first metal substrate, a first insulating base layer, a first conductor layer and a first insulating cover layer which is substantially identical in layer structure with the suspension board with circuit and a second wired circuit board connected with the first wired circuit board for connecting with a control circuit board. Since the suspension board with circuit and the first wired circuit board are rendered substantially identical in layer structure, both characteristic impedances at these connection points can be matched.

Wired circuit board

A flexible wiring board including a gold pad having dynamic Vickers hardness of not less than 50 or having a ratio of amount of nickel in a surface of the gold pad (atomic weight %) to thickness of gold (&mgr;m) of not more than 5 or having both the dynamic Vickers hardness of not less than 50 and the ratio of amount of nickel in the surface of the gold pad (atomic weight %) to thickness of gold (&mgr;m) of not more than 5, to provide a flexible wiring board that can substantially ensure the connection reliability when the board is connected with a semiconductor device by wiring bonding.

Growing community of inventors

Osaka, Japan

Yuichi Takayoshi