Silicon nitride ceramic heater
US5998049A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1994 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Nov 8, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/9607
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A silicon nitride ceramic heater comprising a base body of silicon nitride ceramics, and a heating element embedded in the body, the ceramic heater being characterized in that the element further comprises, as a main ingredient, at least one of carbides, nitrides or silicides selected from the metal group consisting of W, Mo, Re, Cr, Ti, Ta, Ni and Co, and not more than 75 vol % of the BN content in combination with the main ingredient. This composition can reduce the difference in thermal expansion coefficients between the heating element and the silicon nitride ceramics and can thus prevent the heating element from being cracked by thermal stress. Consequently, the silicon nitride ceramic heater is superior in durability and can maintain high performance for a long time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.