Semiconductor ceramic composition
US8067325B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2007 |
| Grant date | Nov 29, 2011 |
| Priority date | — |
| Expiry date | Nov 25, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/9661
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
It is intended to provide a semiconductor ceramic composition containing no Pb, which is capable of shifting the Curie temperate to a positive direction as well as of controlling room temperature resistivity and having an excellent jump characteristic. Since the semiconductor ceramic composition in which a portion of Ba of BaTiO3 is substituted by Bi—Na has a crystal in which a central part and an outer shell part of a crystal grain are different from each other in composition, the composition is capable of improving control of room temperature resistivity and a jump characteristic, and therefore it is optimum as a material for a PTC thermistor, a PTC heater, a PTC switch, a temperature detector, and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.