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:
Sep. 08, 1998
Filed:
Dec. 28, 1994
Jun Monma, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kanagawa-ken, JP;
Abstract
A formed aluminum nitride piece is produced by applying a wiring layer-forming metal paste containing such a high melting temperature metal (wiring metal) as tungsten, for example, to an aluminum nitride green sheet and shaping one layer of the aluminum nitride green sheet now bearing the applied metal paste or superposing a plurality of such layers. In this case, a manganese component destined to densify tungsten is incorporated in at least either of the green sheet and the wiring layer-forming metal paste. The manganese component is either manganese as a simple metallic element or such a manganese compound as manganese oxide. Then, the formed aluminum nitride piece is fired to effect simultaneous sintering of an aluminum nitride and tungsten. Owing to the preparatory addition of the manganese component, a complex compound such as a complex oxide containing manganese and tungsten or a complex such as a eutectic alloy of manganese and tungsten is formed in the wiring metal layer. The wiring metal layer contains manganese at a ratio of not more than 2% by weight in addition to tungsten. Since the complex accelerates the granular growth of tungsten, a tungsten layer (wiring metal layer) densified to an extent of lowering the porosity thereof below 2% is obtained.