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. 03, 1996
Filed:
May. 31, 1995
Osamu Yamagata, Kawashaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
There is provided a composite semiconductor device having a structure for bonding a wiring board to a package so as to satisfy both of the high thermal conductivity and low elasticity at the same time. The wiring board is fixed on the inner bottom surface of the ceramic package of alumina or the like on which a heat radiating plate is mounted by use of an adhesive agent. A plurality of semiconductor chips such as a CPU and memory are mounted on the wiring board. The chip is fixed on the wiring board by use of an adhesive agent of high thermal conductivity. As most part of the adhesive agent for fixing the wiring board on the package, an adhesive agent of low elasticity is used and an adhesive agent of high thermal conductivity is used in an area below a portion of the wiring board on which the chip is mounted. The stress caused in the interface by a difference between the thermal expansion coefficients of the wiring board and the package when heat is generated from the chip can be efficiently reduced by the adhesive agent of low elasticity since the adhesive agent of high thermal conductivity is applied only in the extremely limited area.