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. 04, 1994
Filed:
Jan. 19, 1993
Kyung W Paik, Clifton Park, NY (US);
William A Hennessy, Niskayuna, NY (US);
Wolfgang Daum, Schenectady, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A method for attaching a chip to a substrate includes providing the substrate with an outer layer of an electrical conductor which is not wettable by solder and which has a window exposing an inner layer of electrical conductor that is wettable by solder. A solder preform is placed on the window exposing the inner layer, and the chip is placed on the solder preform. The substrate is then heated so as to melt the solder preform. To achieve planarity, the substrate is be positioned in a pressurizing chamber with a film overlay having higher pressure above the film overlay than underneath the overlay, and heated above the melting point of the solder.