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:
Feb. 20, 2024
Filed:
Aug. 05, 2021
Coorstek Kk, Tokyo, JP;
Yuji Fukasawa, Hadano, JP;
COORSTEK KK, Tokyo, JP;
Abstract
Provided is an alumina ceramic with a low secondary electron emission coefficient and suitable for components of a high frequency generator, a plasma generator and so on. The alumina ceramic contains alumina as a main component, and at least two kinds of elements selected from an alkaline earth metal and from an element belonging to period 3, 4 or 5. The alkaline earth metal and the element belonging to period 3, 4 or 5 have a higher first ionization energy than aluminum. An electronegativity difference between the alkaline earth metal and the element belonging to period 3, 4 or 5 is 0 or more and 0.6 or less. A ratio (x/y) of the grain boundary area (x) to the grain area (y) in the alumina ceramic is 0.0001 to 0.001.