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:
Nov. 17, 2015
Filed:
May. 24, 2011
Yusaku Harada, Omuta, JP;
Katsunori Terano, Omuta, JP;
Takeshi Gotoh, Omuta, JP;
DENKI KAGAKU KOGYO KABUSHIKI KAISHA, Tokyo, JP;
Abstract
Disclosed is an aluminum nitride substrate for a circuit board, the substrate having aluminum nitride crystal grains with an average grain size of 2 to 5 μm and a thermal conductivity of at least 170 W/m·K. The aluminum nitride substrate does not include a dendritic grain boundary phase and has a breakdown voltage of at least 30 kV/mm at 400° C. Also provided is a method for producing the aluminum nitride substrate, including the steps of heating a raw material containing an aluminum nitride powder to 1500° C. at a pressure of at most 150 Pa, then increasing and holding the temperature at 1700 to 1900° C. in a pressurized atmosphere of at least 0.4 MPa using a non-oxidizing gas, then cooling to 1600° C. at a cooling rate of at most 10° C./min.