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:
Dec. 09, 2014
Filed:
Mar. 15, 2012
Masahiro Kida, Yatomi, JP;
Toru Hayase, Nagoya, JP;
Yuji Katsuda, Tsushima, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
An electrostatic chuck is provided with a ceramic substratein which an electrodeis embedded, an electrode terminalexposed at the bottom of a concave portiondisposed on the back surface of the ceramic substrate, a power feed memberto supply an electric power to the electrode, and a joining layerto connect this power feed memberto the ceramic substrate. The joining layeris formed by using a AuGe based alloy, a AuSn based alloy, or a AuSi based alloy. The ceramic substrateand the power feed memberare selected in such a way that the thermal expansion coefficient difference D calculated by subtracting the thermal expansion coefficient of the ceramic substratefrom the thermal expansion coefficient of the power feed membersatisfies −2.2≦D≦6 (unit: ppm/K).