Hitachi, Ltd.

Renesas Electronics Corporation

Renesas Technology Corp.

Hitachi Chemical Company, Ltd.

Hiroaki Okudaira

Asao Nishimura

Tasao Soga

Tetsuya Nakatsuka

Hanae Shimokawa

Toshiharu Ishida

Yoshiharu Inaba

Hitoshi Yokono

Naoya Kanda

Jiro Ushio

Setsuo Ando

Osamu Miyazawa

Akira Tomizawa

Naoko Matsuura

Hiroshi Okamoto

Yasuo Morooka

Naoki Tanaka

Takashi Inoue

Shin-ichiro Umemura

Hitoshi Oka

Takeshi Shimazaki

Tetsuya Yamazaki

Masahiro Kayama

Masayoshi Naito

Nobuo Nakagawa

Yoshio Gobara

Takayoshi Sowa

Masako Fujisawa

Provided are a bonded structure by a lead-free solder and an electronic article comprising the bonded structure. The bonded structure has a stable bonding interface with respect to a change in process of time, an enough strength and resistance to occurrence of whiskers while keeping good wettability of the solder. In the bonded structure, a lead-free Sn&#x2014;Ag&#x2014;Bi alloy solder is applied to an electrode through an Sn&#x2014;Bi alloy layer. The Sn&#x2014;Bi alloy, preferably, comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn&#x2014;Bi alloy layer thereby obtaining an enough bonding strength.

Pb-free solder-connected structure

Pb-free solder-connected structure and electronic device

A method of producing an electronic device by connecting a lead of a semiconductor device with an electrode of a circuit board to form a bonded structure. In the bonded structure, a lead-free Sn&#x2014;Ag&#x2014;Bi alloy solder is applied to an electrode through an Sn&#x2014;Bi alloy layer. The Sn&#x2014;Bi alloy, preferably, comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn&#x2014;Bi alloy layer thereby obtaining an enough bonding strength.

Method of producing an electronic device having a PB free solder connection

A control system is for accelerating stabilization of a chaotic state of a controlled system into a desired periodic state. In the control system, the SOGY algorithm is extended to permit selection of a region on a chaotic attractor as a target, so that the SOGY algorithm can be successfully combined with the OGY algorithm for the purpose of stabilization of the controlled system in the periodic state. Also, the method of nonlinear prediction is introduced so as to secure the effectiveness of the SOGY algorithm. Further, an uncertainty of prediction is taken into consideration so as to eliminate unnecessary control and to improve the effectiveness of the SOGY algorithm.

Control system

The present invention relates to an electroless gold plating solution, a method of plating by using the same, and an electronic device plated with gold by using the same. According to the present electroless gold plating solution, the plating solution components contain no cyanide ions, the amount of a reducing agent used is small, and gold plating can be carried out without causing the gold plating on conducting paths having a fine interval between them to short-circuit the conducting paths. Therefore, according to the method of gold plating by using said electroless gold plating solution, a plating method that is safe in the plating work and in the treatment of its waste liquor can be accomplished. The method has a feature that the method can provide an electronic device on which parts can be mounted highly densely, and wherein the joint reliability to the parts is high.

Electroless gold plating solution, method of plating with gold by using

The present invention provides an electroless gold plating solution comprising essentially gold ions, a complexing agent, and a reducing agent, characterized by further containing a reduction promoter which has a function of giving electrons to an oxidant, the oxidant being produced from oxidation of the reducing agent with the gold ions being reduced, to change the oxidant to the original reducing agent. The present invention also provides a process for conducting electroless gold plating by bringing a substrate into contact with the electroless gold plating solution. The plating solution is excellent in the stability for gold plating of high deposition rate. Thus the present invention allows the electroless gold plating to be performed stably at a higher deposition rate.

Electroless gold plating solution and method for plating gold therewith

Electronic device plated with gold by means of an electroless gold

The present invention relates to an element comprising a superconductive material or a wiring formation technique. In a thin film wiring board in which a superconductive material is used as a conductor, annealing should be conducted at a high temperature in an oxygen atmosphere after formation of a film in order to convert the conductor portion into a superconductive material, which makes it necessary to use an inorganic oxide as the insulating film. This brought about a problem that the etching of the second and subsequent insulation layers causes a damage to the wiring and insulation layer provided thereunder. In the present invention, an over-etching preventing layer is provided on a wiring layer provided under the second and subsequent insulation layers in order to solve the problem in question. The present invention brings about an effect of realizing the formation of a multi-layered wiring layer by making use of a superconductive material.

Process for preparing superconductive wiring board

Disclosed is a magnetic recording medium in which an underlayer formed below a magnetic medium, in which a signal is written, is composed of a nickel alloy comprising 0.05 to 10 atom % of tungsten and 14 to 30 atom % of phosphorus. In this magnetic recording medium, the temperature for formation of magnetic medium and the temperature for formation of a protective film can be elevated over the levels adopted in the conventional techniques. Therefore, the magnetic characteristics and abrasion resistance can be improved. Furthermore, the magnetic recording medium is excellent in the mechanical strength and corrosion resistance. Accordingly, the reliability of the magnetic medium can be highly improved.

Magnetic recording medium having an amorphous, nonmagnetic

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Yokohama, Japan

Hiroaki Okudaira