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. 09, 1996
Filed:
Jan. 05, 1994
Seiji Nakahata, Itami, JP;
Takahiro Matsuura, Itami, JP;
Kouichi Sogabe, Itami, JP;
Akira Yamakawa, Itami, JP;
Abstract
An aluminum nitride sintered body comprising aluminum nitride crystals belonging to a Wurtzite hexagonal crystal system wherein the 3 axes a, b and c of the unit lattice of the crystal are defined such that the ratio b/a of the lengths of the axes b and a is 1.000 near the center of the crystal grain and lies within the range 0.997-1.003 in the vicinity of the grain boundary phase. Aluminum nitride sintered body is produced by sintering a molded body of a raw material powder having aluminum and nitrogen as its principal components at a temperature of 1700.degree.-1900.degree. C. in a non-oxidizing atmosphere having a partial pressure of carbon monoxide or carbon of not more than 200 ppm and then cooling the sintered body to 1500.degree. C. or a lower temperature at a rate of 5.degree. C./min or less. The aluminum nitride sintered body has a greatly improved thermal conductivity and, therefore, is suitable for heat slingers, substrates or the like for semiconductor devices.