The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 1992
Filed:
Nov. 20, 1990
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A bump electrode structure of a semiconductor device comprises an electrode pad formed of an aluminum alloy, an insulating oxide layer covering only the peripheral edge portion of the electrode pad, an under-bump layer formed of an alloy of titanium and tungsten, and a bump electrode formed of gold. The titanium-tungsten alloy functions both as a barrier metal and as a bonding metal. The bump electrode rises substantially straight from the bonding surface of the under-bump layer, and its top portion has an area only substantially equal to that of the electrode pad. Fine V-shaped grooves are formed on the top surface of the bump electrode by anisotropic etching. Thus, the semiconductor device with fine electrode pad pitches is provided with a high-reliability bump electrode structure which ensures sufficient bonding strength between internal and external electrodes.