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:
Jul. 04, 2000
Filed:
Dec. 09, 1998
Gerald K Bartley, Rochester, MN (US);
Douglas A Baska, Oronoco, MN (US);
James D Bielick, Pine Island, MN (US);
Matthew A Butterbaugh, Rochester, MN (US);
Mark K Hoffmeyer, Rochester, MN (US);
Sukhvinder Singh Kang, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Aluminum heatsinks are plated with a solderable layer and are overplated with a solder release layer. The release layer comprises a tin-lead-indium alloy. The heatsinks are mounted on individual IC modules or banks of IC modules that are interconnected to a printed circuit card. A mechanically compliant, thermally conductive adhesive is used to join the heatsinks to the modules. An oxide formed on the release layer readily bonds with the thermally conductive adhesive. In the event that heatsinks need to be removed to repair or rework the modules, local heat may be applied to melt the release layer to remove a heatsink without need for use of significant applied torque and normal forces. Because the release layer has a low melting point that affords easy separation from the adhesive layer, both component delaminations and the partial reflow or melting of solder joints on adjacent components are eliminated from the heatsink removal process.