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:
Jan. 15, 1985
Filed:
Jan. 05, 1981
Hiroshi Suzuki, Hitachi, JP;
Goro Tanaka, Fujisawa, JP;
Akio Nishikawa, Hitachi, JP;
Junji Mukai, Hitachi, JP;
Mikio Sato, Hitachi, JP;
Daisuke Makino, Hitachi, JP;
Yoshiaki Wakashima, Kawasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Chemical Company, Ltd., Tokyo, JP;
Abstract
In a semiconductor memory device comprising semiconductor memory elements having such a degree of integration in memory circuits as to produce soft errors by incident .alpha.-rays derived from a packaging material and a package which packages the memory elements and is made from the packaging material, when an .alpha.-rays shielding layer made from a resinous material, which may contain one or more high-purity fillers, containing a total amount of 1 part per billion or less of uranium and thorium is interposed between the memory elements and the package, the generation of soft errors is reduced remarkably.