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:
Apr. 04, 2000
Filed:
May. 07, 1997
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
There is disclosed a composite material for an electronic part which has high thermal conductivity in a laminated direction, and also has low-thermal expansion characteristics. The composite material, used for a heat sink or a heat spreader, includes high-thermal conductivity layers of copper or a copper alloy and low-thermal expansion layers of a Fe--Ni alloy which are alternatively laminated to form a multi-layer structure having not less than 10 layers and preferably not less than 50 layers. Any two adjacent ones of the high-thermal conductivity layers, having the low-thermal expansion layer interposed therebetween, are continuous with each other through a plurality of through holes formed through the low-thermal expansion layer. This composite material can be produced by a method in which thin sheets of copper or a copper alloy and thin sheets of a Fe--Ni alloy (having a plurality of through holes) are alternatively stacked, and this stack is sealed in a vacuum not higher than 10-3 Torr, and the stack of layers is subjected to a bonding treatment at a temperature of 700 to 1,050.degree. C. under a pressure of not less than 50 MPa to provide a laminated structure, and this laminated structure is rolled into a sheet with a predetermined thickness.