Mitsubishi Kinzoku Kabushiki Kaisha

Mitsubishi Materials Corporation

Mitsubishi Denki Kabushiki Kaisha

Naoyuki Hosoda

Naoki Uchiyama

Masaki Morikawa

Toshiaki Ono

Hideaki Yoshida

Masayuki Tanaka

Ryusuke Kawanaka

Tamotsu Mori

Kazumasa Hori

Noboru Sonoda

Fukuzo Kaneko

Ariyoshi Saito

Tokio Yanagida

A precious metal foil composite comprising a precious metal foil encased, by lamination, in a transparent polymeric sheet material. The composite cards produced from this composite material are used for practical purposes by encasing the above composite together with another component having opaque decorative patterns, and finally encasing the entire assembly in a secondary hard protective covering to provide the outermost protection.

Composite cards

A fine gold alloy wire of high tensile strength for bonding semiconductor elements is disclosed. The wire consists essentially of 0.0003 to 0.010 wt % of at least one rare earth element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, the balance being Au and incidental impurities. The wire does not present a deformed loop and has greater bond strength if it contains 0.0003 to 0.010 wt % of at least one rare earth element of the Cerium Group selected from the group consisting of La, Ce, Pr, Nd and Sm and 0.0001 to 0.0060 wt % of at least one element selected from among Ge, Be and Ca.

Fine gold alloy wire for bonding of a semiconductor device

A fine gold alloy wire of high tensile strength for bonding semiconductor elements is disclosed. The wire consists essentially of 0.0003 to 0.010 wt % of at least one rare earth element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu,Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, the balance being Au and incidental impurities. The wire does not present a deformed loop and has greater bond strength if it contains 0.0003 to 0.010 wt % of at least one rare earth element of the Cerium Group selected from the group consisting of La, Ce, Pr, Nd and Sm and 0.0001 to 0.0060 wt % of at least one element selected from among Ge, Be and Ca.

Fine gold alloy wire for bonding of a semi-conductor device

An inexpensive, very fine wire of high-purity copper is disclosed as an alternative to the fine gold wire which is currently used in the bonding of semiconductor devices. The very fine wire of high-purity copper is prepared from a copper ingot that contains 0-2 ppm of S, 0-2 ppm of Ag, 0-1 ppm of Se and 0-1 ppm of Te as incidental impurities with the total content of these and any other incidental impurities present being held at a level not exceeding 10 ppm. By subjecting it to an appropriate heat treatment, the wire acquires an elongation of 5-22%, a breaking strength of 14-33 kg/mm.sup.2, and a Vickers hardness of 38-50, the latter value being measured with respect to said high-purity copper in an ingot form. By reducing the amounts of these impurities to even lower levels, very fine wires are obtained that can be used in the bonding of a semiconductor device without abnormally shaped loops being formed or wire breakage being experienced and the characteristics of the wires can be adapted to specific conditions of use by performing an appropriate heat treatment.

Wire for bonding a semiconductor device

The present invention eliminates the problems associated with the use of oxygen-free copper and other high-purity copper materials as bonding wires. In accordance with one aspect of the present invention, at least one rare earth element, or at least one element selected from the group consisting of Mg, Ca, Ti, Zr, Hf, Li, Na, K, Rb and Cs, or the combination of at least one rare earth element and at least one elemented selected from the above-specified group is incorporated in high-purity copper as a refining component in an amount of 0.1-100 ppm on a weight basis, and the high-purity copper is subsequently refined by zone melting. The very fine wire drawn from the so refined high-purity copper has the advantage that it can be employed in high-speed ball bonding of a semiconductor chip with a minimum chance of damaging the bonding pad on the chip by the ball forming at the tip of the wire. In accordance with another aspect of the present invention, 0.5-3 ppm of a rare earth element and/or Y is further incorporated as an alloying component in the zone-refined high-purity copper.

The present invention eliminates the problems associated with the use of oxygen-free copper and other high-purity copper materials as bonding wires. At least one rare earth element, or at least one element selected from the group consisting of Mg, Ca, Ti, Zr, Hf, Li, Na, K, Rb and Cs, or the combination of at least one rare earth element and at least one elemented selected from the above-specified group is incorporated in high-purity copper as a refining component in an amount of 0.1-100 ppm on a weight basis, and the high-purity copper is subsequently refined by zone melting. The very fine wire drawn from the so refined high-purity copper has the advantage that it can be employed in high-speed ball bonding of a semiconductor chip with a minimum chance of damaging the bonding pad on the chip by the ball forming at the tip of the wire.

Wire for bonding a semiconductor device and process for producing the

A process for recovering or purifying selenium is disclosed. A selenium-containing material is reacted with carbon monoxide and ammonia or a primary or secondary amine to form a compound soluble in an aprotic solvent. The reaction product is subjected to the reverse reaction by heating it to liberate selenium, which is separated by filtration. The reaction is specific to selenium, and selenium can be separated from sulfur, tellurium, arsenic, halogen, etc. The used reagents can be recovered and used repeatedly.

Process for recovering or purifying selenium

Lead alloy soft solder containing radioactive particles used to make

Process for the flotation of anode slime from copper electrolysis comprising subjecting the anode slime, as a preliminary treatment, to attrition treatment in combination with a copper leaching treatment in a medium of an acid solution. The floated material obtained from the flotation is continuously subjected to three processes of roasting, melting and cupellation in a rotary furnace lined with refractory bricks for recovery of good quality silver anode.

Growing community of inventors

Osaka, Japan

Naoyuki Hosoda