Browse Prior Art Database

Chip Cooling

IP.com Disclosure Number: IPCOM000081598D
Original Publication Date: 1974-Jul-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Campo, WA: AUTHOR [+2]

Abstract

This is a bimetallic heat conduction device that will improve the thermal performance of an integrated circuit chip package. A bimetallic stripper foil 10 is attached along one edge to the underside of the module cover 11. The bimetallic foil 10 is designed and located so that it does not contact the chip 12 throughout a normal operating temperature range.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 81% of the total text.

Page 1 of 2

Chip Cooling

This is a bimetallic heat conduction device that will improve the thermal performance of an integrated circuit chip package. A bimetallic stripper foil 10 is attached along one edge to the underside of the module cover 11. The bimetallic foil 10 is designed and located so that it does not contact the chip 12 throughout a normal operating temperature range.

When the chip 12 is powered, heat normally flows to the metal foil 10 by way of the substrate 13 and module cover 11. As the chip 12 temperature increases, the free end of the foil 10 approaches the chip 12 and makes contact with the chip 12 at or near some predetermined critical temperature as determined by the thickness, elastic modulus, and thermal expansion coefficient of the metals used in the foil. Once the foil 10 contacts the chip 12 there is a substantial reduction in the chip temperature and the chip-to-air thermal resistance, because of the conduction heat path introduced from the top of the chip 12 to the module 11 by way of the foil 10.

The foil 10 comprises two sheets of different metals having different thermal expansion coefficients and which have been welded or otherwise fastened together. The foil 10 thickness is such that the force exerted by the foil 10 on the chip 12 will insure good thermal contact, but will not unduly stress the chip 12 or the chip/module connections. Optionally, the chip 12 can be protected with a thin coating of suitable dielectric, if desired. To insure a...