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:
Mar. 23, 1999
Filed:
May. 28, 1996
Frank J Polese, San Diego, CA (US);
Vladimir Ocheretyansky, Santee, CA (US);
Other;
Abstract
High density heatsinks for microcircuit packages are formed by first mold-pressing a composite powder of free-flowing spray-dried particles of an inexpensive high thermal conductivity material having a high coefficient of thermal expansion (CTE) such as copper and at least one other low CTE material such as tungsten, the proportions of which are adjusted to match the CTE of the microcircuit material. The pressed compacts are sintered in order to achieve an homogeneous distribution of the melting copper throughout the structure. A multilevel embodiment of the heatsink comprises two bonded layers of metals or composites having their coefficients of thermal expansion adjusted to match those of the semiconductor material and of any supporting structures respectively, wherein the second layer in contact with the supporting structure has a high CTE and the other has a lower CTE. Another embodiment provides for bonding a composite heatsink to a high thermal conductivity pedestal which mounts the microcircuit device, using sintering to shrink an aperture engaged by the pedestal.