Ibiden Company Limited

Susuka National College of Technology

Suzuka National College of Technology

Osaka Lead Refinery Co., Ltd.

Takeo Oki

Naohiro Hirose

Honchin En

Kouta Noda

Tohru Nakai

Hideyuki Kanematsu

Yoshihiko Masuo

Tatsumasa Kobayashi

Isao Hiraki

Hirohiko Ohmura

The present invention has for its object to provide a process for manufacturing multilayer printed circuit boards which is capable of simultaneous via hole filling and formation of conductor circuit and via holes of good crystallinity and uniform deposition can be constructed on a substrate and high-density wiring and highly reliable conductor connections can be realized without annealing. The present invention is related to a process for manufacturing multilayer printed circuit boards which comprises disposing an interlayer resin insulating layer on a substrate formed with a conductor circuit, creating openings for formation of via holes in said interlayer resin insulating layer, forming an electroless plated metal layer on said interlayer resin insulating layer, disposing a resist thereon, performing electroplating, stripping the resist off and etching the electroless plated metal layer to provide a conductor circuit and via holes, wherein the electroplating is performed intermittently using said electroless plated metal layer as cathode and a plating metal as anode at a constant voltage between said anode and said cathode.

Printed wiring board and its manufacturing method

An electroplating process of electroplating an electrically conductive substrate is described. The process includes electroplating intermittently to a predetermined plating thickness using the substrate surface as a cathode and a plating metal as an anode at a constant voltage between the anode and the cathode by repeating application of a voltage between a cathode and an anode and interruption of the application alternately. It is described that a voltage time/interruption time ratio is 0.1 to 1.0, a voltage time is not longer than 10 seconds, and an interruption time is not less than 1 x 10seconds.

Electroplating process of electroplating an elecrically conductive sustrate

The present invention is directed to a process for manufacturing multilayer printed circuit boards which is capable of simultaneous via hole filling and formation of conductor circuit and via holes of good crystallinity, and by which uniform deposition can be constructed on a substrate and high-density wiring and highly reliable conductor connections can be realized without annealing.

A tin layer and a zinc layer are stacked sequentially on a given substrate to form a multilayered film composed of the tin layer and the zinc layer. Then, the multilayered film is heated to a given temperature to form a tin-zinc alloy film through the diffusion of the tin elements of the tin layer into the zinc layer.

Method for producing a tin-zinc alloy film

A tin layer and a zinc layer are stacked sequentially on a given substrate to form a multilayered film composed of the tin layer and the zinc layer. Then, a laser beam is irradiated onto the multilayered film to produce a tin-zinc alloy film through the inter-diffusion between the tin elements of the tin layer and the zinc elements of the zinc layer.

A tin layer and a nickel layer are stacked sequentially on a given substrate to form a multilayered film composed of the tin layer and the nickel layer. Then, the multilayered film is heated to a given temperature to form a tin-nickel alloy film through the diffusion of the tin elements of the tin layer into the nickel layer.

Method for producing a tin-nickel alloy film

A tin layer and a nickel layer are stacked sequentially on a given substrate to form a multilayered film composed of the tin layer and the nickel layer. Then, laser beams are irradiated onto the multilayered film to form a tin-nickel alloy film, having stable phases composed of equilibrium phases such as Ni Sn phase through the diffusion of the tin elements of the tin layer into the nickel layer.

A method of electrolytically collecting lead from ashes containing lead compounds, comprising the steps of adding the ashes to an aqueous solution of caustic soda, and subjecting the mixture to electrolysis in two stages, i.e., preliminary electrolysis and stationary electrolysis.

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Tsushima, Japan

Takeo Oki