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:
Oct. 26, 1999
Filed:
Aug. 25, 1997
Masahide Harada, Yokohama, JP;
Toru Nishikawa, Yokohama, JP;
Ryohei Satoh, Yokohama, JP;
Osamu Yamada, Hiratsuka, JP;
Takayuki Uda, Hadano, JP;
Mitsugu Shirai, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electronic device is solder bonded properly without using fluxes nor precise positioning with respect to a substrate. A bond pad with a size about twice the size of terminal pad of the electronic device is formed in a region on the substrate where the electronic device is to be mounted. After placing the electronic device of the substrate surface, the whole unit is heated in a nitrogen atmosphere to melt a bump formed on the terminal pad of the electronic device. The molten solder wets and spreads over the bond pads formed on the substrate, thereby establishing reflow soldering between the bond pads and the terminal pads. The position of the electronic device with respect to the substrate is spontaneously corrected due to a self-alignment function induced by wetting and spreading of the molten solder over the bond pad of the substrate.