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:
Jun. 14, 2005
Filed:
Mar. 26, 2003
Akira Morozumi, Nagano, JP;
Tadashi Miyasaka, Nagano, JP;
Katsumi Yamada, Nagano, JP;
Eiji Mochizuki, Nagano, JP;
Akira Morozumi, Nagano, JP;
Tadashi Miyasaka, Nagano, JP;
Katsumi Yamada, Nagano, JP;
Eiji Mochizuki, Nagano, JP;
Fuji Electric Co., Ltd., , JP;
Abstract
A semiconductor device can be formed with fewer voids in the solder bonding a laminate of a silicon chip, an insulator substrate, and a metal base, with a solder layer positioned between the layers. After placing the laminate in a furnace, it is evacuated and then pressurized with hydrogen gas, and then heated to melt the solder. While maintaining the heat, the furnace is again evacuated to remove voids in the solder, and then the furnace is positively pressurized again with hydrogen gas to prevent holes produced by the voids traveling in the solder, and to obtain a uniform solder fillet shape. Thereafter the laminate is rapidly cooled to obtain a finer grain solder to increase the rate of creep to quickly remove the warping of the laminate to the original state.