Nippon Steel Corporation

Osamu Kitamura

Tomohiro Uno

Yasuhide Ohno

Eiichi Takeuchi

Yasuhiro Suzuki

Hiromu Fujii

Tadakatsu Maruyama

Tosiharu Kikuchi

Tetsro Ohashi

Seizo Mineyuki

Hisao Kuribayashi

Gold-alloy bonding wire

A method of producing soft fine metal spheres for semiconductor packaging from a material selected from soft metals and soft alloys. A plurality of fine wires made of the material are arranged in parallel on a flat base plate. Each of the wires has a diameter of not more than 100 .mu.m. The fine wires are cut into wire chips having an equal mass relative to each other and a chip length/chip diameter ratio between 5 and 100 by utilizing a cutting jig having cutting edges which are arranged at a constant pitch. The resulting wire chips are arranged so that the chips are spaced apart a minimum distance sufficient to prevent the chips from merging when melted. The resulting spaced-apart wire chips are heated to a temperature up to but not exceeding 100.degree. C. above the melting point thereof, thereby forming the chips into molten spheres. The resulting molten spheres are cooled, thereby forming solid spheres having a diameter within about 5% of a desired diameter.

Method of producing fine metal spheres of uniform size

This invention provides a thin gold-alloy wire for a semiconductor device capable of improving long term reliability of bonding with an electrode and capable of simultaneously accomplishing reduction of a wire bend and wire flow at the time of resin molding and high looping. The thin gold-alloy wire contains 50 to 3000 ppm by weight of Mn and the balance comprising gold and unavoidable impurities. Further, the thin gold-alloy wire comprises any of the following combinations 1, 2, 1+2, 2+3 and 1+2+3 when element groups to be added are classified into the following groups 1 to 3:

Thin gold-alloy wire for semiconductor device

Palladium alloy thin wire for wire bonding semiconductor elements

In the continuous casting of steel, it has been possible to produce killed steel industrially, but semikilled and rimmed steel have not been successfully produced due to rimming action occurring in the oscillating mold. The present invention involves a concept of suppressing the nuclei of bubbles which will later grow into CO bubbles. In order to suppress the nuclei of bubbles and to form a non-defective solidification layer of a continuously cast strand, the present invention provides a combination of: a free oxygen concentration of from 50 to 200 ppm in the molten steel; a concave shape at the short sides of the mold; a propulsion forces of the molten steel directed along the long sides of the mold in directions opposite to one another; subjecting a solidification interface to an electromagnetic flow having a speed of from 0.1 to 1.0 m/sec, and; solidifying the molten steel at the solidification interface under the influence of the electromagnetic flow, until a non-defective solidification layer without blow holes is obtained.

Process for continuous casting of a slightly deoxidized steel slab

Growing community of inventors

Kawasaki, Japan

Osamu Kitamura