Nitto-denko Corporation

Nitro Denko Corporation

Yasuhito Funada

Jun Ishii

Toshihiko Omote

Tetsuya Ohsawa

Hitoki Kanagawa

Yasunari Ooyabu

Yasuhito Ohwaki

Hideyuki Usui

Kazumasa Igarashi

Masanori Ueno

Satoshi Tanigawa

Hirofumi Fujii

Yoshihiro Uetani

Masao Abe

Keisuke Kii

Akira Ohtani

Yoshihiko Takeuchi

Tetsuya Oosawa

A wired circuit board that can provide an enhanced adhesion of a metal supporting board at a marginal portion of an opening formed in the metal supporting board with a simple structure to prevent stripping of the metal supporting board. In a suspension board with circuit, in order to reduce a transmission loss of a conductive pattern, a metal foil embedded in an insulating base layer is formed in a pattern comprising a first metal foil portion and a second metal foil portion surrounding the first metal foil portion spaced apart therefrom, and an opening is formed in the metal supporting board so that a marginal portion of the opening is located in a space between the first metal foil portion and the second metal foil portion.

Wired circuit board

A wired circuit board includes a metal supporting board, an insulating layer formed on the metal supporting board, a conductive pattern formed on the insulating layer and having a plurality of wires, and a semiconductive layer formed on a surface of the insulating layer exposed from the conductive pattern so as to be in contact with the conductive pattern. The insulating layer is formed with a groove exposing the metal supporting board between at least two adjacent wires, and the semiconductive layer is in contact with the metal supporting board in the groove.

Wired circuit board having a semiconductive grounding layer and producing method thereof

A wired circuit board is provided which can reduce transmission loss with a simple layer structure and also features excellent long-term reliability by preventing the occurrence of an ion migration phenomenon between a metal foil and an insulating layer to improve the adhesion between the metal foil and the insulating layer and the conductivity of a conductor. A metal supporting board is prepared and a first metal thin film is formed on the metal supporting board by sputtering or electrolytic plating. A metal foil is formed on the first metal thin film by electrolytic plating. A second metal thin film is formed over the metal foil and the metal supporting board by electroless plating or sputtering. An insulating base layer is formed on the second metal thin film. A conductive pattern is formed as a wired circuit pattern on the insulating base layer. An insulating cover layer is formed on the insulating base layer to cover the conductive pattern.

The invention provides a wired circuit board that can prevent deterioration of a conductive pattern and short-circuiting of the conductive pattern. The wired circuit board is presented herein in the form of a suspension board with circuit which comprises an insulating base layer formed on a metal supporting board, a conductive pattern formed on the insulating base layer, a metal oxide layer formed on a surface of the conductive pattern and on a surface of the insulating base layer by sputtering, and an insulating cover layer, formed on the metal oxide layer, to cover the conductive pattern. According to this suspension board with circuit, since the metal oxide layer to cover the conductive pattern is formed by the sputtering, the metal oxide layer can be formed with a uniform thickness. Hence, the metal oxide layer can fully function as a barrier layer to the conductive pattern and, accordingly, deterioration of the conductive pattern and the short-circuiting of the conductive pattern can be prevented effectively.

A wired circuit board that can remove static electricity not only from an insulating base layer and an insulating cover layer but also from a terminal portion, to effectively prevent an electronic component mounted from being damaged by static electricity and also prevent stripping of a semi-conductive layer. In a suspension board with circuit including an insulating base layer formed on a metal supporting board, a conductive pattern formed on the insulating base layer, and an insulating cover layer, formed on the insulating cover layer, to cover the conductive pattern and form an opening, semi-conductive layer is formed in succession on an upper surface of the insulating base layer covered with the insulating cover layer, on a lateral side surface and an upper surface of the conductive pattern, and on a lateral side surface of the insulating base layer adjacent to the metal supporting board.

Wired circuit board and production method thereof

A suspension board with circuit that can allow precise adjustment of flotation (flotation angle) of even a small-sized slider to a magnetic disc even when the outrigger portions are reduced in rigidity. A gimbal portion of the suspension board with circuit is formed by a tongue portion for mounting a magnetic head thereon, and outrigger portions provided at both sides of the tongue portion, and an opening is formed in the insulating cover layerso that the conductor layer can be exposed therefrom in the outrigger portions. This can allow reduction in rigidity of the outrigger portions, and as such can allow precise adjustment of flotation (flotation angle) of the slider to the magnetic disc even when a small-sized slider is mounted on the gimbal portion.

Suspension board with circuit

An areafor mounting a magnetic head is formed on a metal board, a conductive layeris formed as a circuit pattern via an insulation layerinterposed outside this area and up to a metal board. A pattern endto be a connection terminal for connection with the terminal of the magnetic head is formed on the circuit pattern, an end faceof the pattern endis aligned with an end faceof the insulation layerdirectly beneath it or protruded in the terminating direction from the end face, thereby providing a structure preventing irradiation of a laser beam on the insulation layer.

A wired circuit board and a producing method thereof are provided which can precisely form an insulating layer and reduce transmission loss with a simple layer structure and also features excellent long-term reliability by preventing the occurrence of an ion migration phenomenon between a ground layer and a positioning mark layer, and the insulating layer to improve the adhesion therebetween and the conductivity of a conductor. A metal supporting board is prepared and a first metal thin film is formed on the metal supporting board. A resist is formed in a pattern and a ground layer and a positioning mark layer are formed on the first metal thin film exposed from the resist at the same time. A second metal thin film is formed over the ground layer and the positioning mark layer, then the resist is removed. An insulating base layer is formed on the first metal thin film including the upper surface of the second metal thin film, thereafter, a conductive pattern is formed on the insulating base layer.

Wired circuit board and producing method thereof

A wired circuit board that can prevent inconsistency in characteristic impedance to allow effective transmission of electrical signals from a magnetic head to a control board portion. A wired circuit board is constructed so that a suspension board portion for supporting the magnetic head and a control board portion for controlling the magnetic head are formed to be continuous and integral with each other. To be more specific, a first conductor layer connected to the magnetic head in the suspension board portion and a second conductor layer connected to a preamplifier IC in the control board portion are formed from the same material and formed on a common insulating base layer simultaneously. Further, a common insulating cover layer to cover the first conductor layer and the second conductor layer is formed on the common insulating base layer.

A suspension board with circuit having a conductor layer formed in the form of a fine wiring circuit by an additive process, while providing a reduced risk of damage and breaking of the conductor layer in a flying lead portion. The suspension board with circuit comprises a supporting board, an insulating base layerformed on the supporting board, a conductor layerformed on the insulating base layer, an insulating cover layerformed on the conductor layer, and a flying lead portionin which a supporting-board-side opening, a base-layer-side opening, and a cover-layer-side openingare formed so that both sides of the conductor layercan be exposed therefrom. A reinforcing portionorfor reinforcing the conductor layerformed continuously from at least either of the insulating base layerand the insulating cover layeralong the longitudinal direction of the conductor layeris included in the flying lead portion

Suspension board having a circuit and a flying lead portion

There is provided a wired circuit board assembly that prevents breakage of the flexing portion of a wired circuit board supported by a support frame. In a wired circuit board support sheet, a plurality of wired circuit boards include a base insulating layer, a conductor pattern, and a cover insulating layer which are formed on a support board are supported by a support frame in such a manner that they are arranged and aligned in mutually spaced relation. Each of the wired circuit boards has a flexing portion formed by removing the support board to obtain a flexing property. In addition, second connecting portions are provided in spanning relation between the flexing portion and the vertical frame parts of the support frame.

Wired circuit board assembly

A wired circuit board that can provide a reduced transmission loss and an improved adhesion strength between a metal suspension board and a metal foil with a simple laminar structure, thereby ensuring improved long-term reliability. The wired circuit boardcomprises a metal suspension board, a thin metal filmformed on the metal suspension boardby sputtering or by electrolytic plating, a metal foilformed on the thin metal filmby electrolytic plating, an insulating base layerformed on the metal foiland the metal suspension board, and a conductive patternformed on the insulating base layeras a wired circuit pattern. The wired circuit boardmay include an insulating cover layerformed on the insulating base layerto cover the conductive pattern

In the vicinity of the exposed partA of the multiply formed plural wiring conductors, of the thicknesses of the insulating cover layermade of a polyimide layer, the thickness (T) of a part located at about the middle point between the adjacent wiring conductorsis made smaller than the thickness (T) of a part located on wiring conductor. Preferably, the difference in the thicknesses of a part located at about the middle point between the adjacent wiring conductors of the insulating cover layerand that of a part located on wiring conductor is made to fall within the range of 1&#x2013;5 &#x3bc;m. As a result, the insulating cover layer does not peel off easily.

Wiring circuit board and production method thereof

A photosensitive resin composition which, when exposed to light through a photomask and then developed, can form a pattern comprising a polyimide film having a thickness of 20 &#x3bc;m or larger with high resolution; and a use of the composition, in particular, a method of forming a pattern comprising the polyimide film. The photosensitive resin composition comprises (a) a poly(amic acid), (b) a specific 1,4-dihydropyridine derivative, and (c) a specific imide acrylate compound.

Photosensitive resin composition and use of the same

There are provided a circuit-forming substrate comprising a long stainless steel foil having formed on one surface or both surfaces thereof a polyimide resin layer wholly or partially, and a circuit substrate formed by using the circuit-forming substrate, wherein a conductor layer is finely patterned on the circuit-forming substrate. The circuit-forming substrate sufficiently satisfies low cost, high density and high reliability, scarcely causes warping of the substrate itself, and has excellent workability.

Growing community of inventors

Osaka, Japan

Yasuhito Funada