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:
Sep. 18, 1984
Filed:
Dec. 28, 1981
Ralph I Larson, North Reading, MA (US);
Aavid Engineering, Inc., Laconia, NH (US);
Abstract
Efficient dissipation and uniform spreading of heat from electronic solid-state devices by their associated heat-sink structures is promoted by thin broad-area thermally-conductive mountings built up from layers of a special form of substantially pure flexible and compressible flat graphite sheet material and a bonding-and-filling coating. At least one such 5-10 mil thickness layer of Grafoil flexible sheet, involving a crushable compressed mass of expanded graphite particles which are plate-like and oriented essentially parallel with the sheet surfaces, is intimately connected with a very thin bonding-and-filling coating substantially fully along its broad-area surfaces, and the latter coating is bonded at elevated temperature and pressure into a self-adhering relationship with surfaces of a heat-sink device intended to be disposed opposite surfaces of an electronic semiconductor device from which excess heat is to escape. The coating is applied while in a liquid condition, in quantity sufficient to be effective to fill minute interstitial spaces appearing along the heat-sink surfaces and yet not so thickly as to prevent numerous point contacts from being made at sites of minute surface irregularities of the graphite sheet material and the heat-sink device. Mechanical fastening of a semiconductor device atop the prepared mounting layers of the heat-sink device compresses the crushable graphite sheet material so that voids are minimized and low thermal impedance can be realized between the heat sink and semiconductor device.