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:
Nov. 21, 1995
Filed:
Oct. 31, 1994
Stuart E Greer, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A nodular metal paste (42) is used to temporarily attach the bumps (34) on a semiconductor die (32) to a substrate (38). The spherical nodules (44) composing the metal paste are dispensed onto contact pads (40) on the substrate, and then heated until they partially melt. The partial liquid region permits bonding of the individual metal nodules to the contact pads and to adjacent nodules. Subsequently, a bumped die is placed over the nodules and heated to a minimum temperature required to partially remelt to form a local tack joint. Because the metallurgical contact area between the paste nodules and the bumps is minimized, electrical contact can be sustained with a small cross-sectional area of connected material to create an electrically sound but physically weak link between die and the substrate. Once connected to the substrate, the die may be tested and burned-in, and removed afterwards with little damage to the bumps.