Nitto-denko Corporation

Tadao Ohkawa

Yasuhito Ohwaki

Takashi Oda

Toshihiko Omote

Shigenori Morita

Yasufumi Miyake

Shuichi Wakaki

A wired circuit board having improved adhesion between the conductive pattern and an insulating layer to prevent a plating solution from remaining between a metal plating layer and the insulating layer. The invention prevents ionic impurities in the plating solution from remaining as residual or ionic contamination, thereby preventing a short circuit from developing when electric current flows through the circuit under a high temperature and high humidity environment. Lower end portions of the terminal portions that are formed on an insulating base layer and lower end portions of side surfaces and metal plating layers that cover the terminal portions are embedded in the insulating base layer in a flexible wired circuit board.

Method of producing a wired circuit board

A wired circuit board is provided for controlling characteristic impedance at connection points between the read wire and write wire of a suspension board with circuit and terminal portions of the wired circuit board connected thereto. The invention provides improved signal transmission efficiency for fine pitch wiring or for high frequency signal. A conductive board is adhesively bonded to an insulating base layer of the wired circuit board at one side thereof opposite to the other side on which a suspension-board-side connection terminal portion is formed having a first terminal portion that connects with a read wire of the suspension board and a second terminal portion that connects with a write wire of the suspension board. An opening is provided adjacent to one of the first terminal portion and the second terminal portion and a stiffener board is adhesively bonded to the conductive board via an adhesive layer.

Wired circuit board for controlling characteristic impedances of a connection terminal

Wired circuit board

To provide a suspension board with circuit that enables its terminals to be bonded to the other terminals with sufficient strength with simple structure, to ensure sufficient bonding reliability, the suspension board with circuit includes a suspension board , a base layer formed on the suspension board , and a conductive layer formed on the base layer and a cover layer with which the conductive layer is covered, wherein external connection terminals to be bonded to terminals of a read/write board are formed without the suspension board and/or the base layer being formed.

Suspension board with circuit

To provide a circuit board, having a circuit pattern of adequate high-frequency characteristics, for transmitting high-frequency electric signals at high speed, a circuit board, including a base layer formed of insulating material and a conductive layer formed on the base layer in the form of a specified circuit pattern, is so constructed that an air layer is made to lie between lines of wire of the circuit pattern or is so constructed that the lines of wire are covered with the cover layer but land portions of the base layer extending between the lines of wire are not covered with the cover layer. This construction of the invention enables dielectric constant between the lines of wire to be reduced and, as a result of this, the capacitance between the lines of wire can be reduced to provide improved high-frequency characteristics of the circuit pattern.

Growing community of inventors

Osaka, Japan

Tadao Ohkawa