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. 15, 1994
Filed:
Sep. 16, 1991
Applicant:
Inventors:
Hiroaki Sakai, Nagoya, JP;
Shinsuke Yano, Nagoya, JP;
Takao Soma, Nishikamo, JP;
Manabu Isomura, Nagoya, JP;
Assignee:
NGK Insulators, Ltd., , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
174 524 ; 361714 ; 257678 ; 257712 ;
Abstract
A ceramic package for containing a semiconductor chip including a heat radiating plate, a base plate for wiring, and a ceramic package for containing a semiconductor chip. The package contains a ceramic board, a ceramic cap and a metal lead frame. The heat radiating plate and the ceramic board are made of silicon nitride sintered body, which is characterized in that the number of grain boundaries per a 10 .mu.m straight line drawn in an arbitrary section of the sintered (polycrystal) body is 20 or fewer.