| 摘要 |
Provided are a positive characteristic thermistor having high humidity resistance and a method for manufacturing the thermistor. A humidity resistance layer (17) made of glass or resin is formed in the region having no external electrodes (15, 16) arranged therein on the outer surface of a ceramic base body (12), while the density of the surface layer portion (18) in the ceramic base body (12) in contact with the external electrodes (15, 16) is set higher than the density of the remaining portion (19) other than the surface layer portion (18). For this purpose, a conductive paste used for forming the external electrodes (15, 16) is set to contain a ceramic material having a higher content of a donor element than the ceramic material contained in a raw ceramic base body. In a calcination process, the donor element contained in the conductive paste diffuses into the ceramic base body (12) on the basis of the difference in content rate and suppresses the grain growth of the ceramic in the surface layer portion (18) in contact with the external electrodes (15, 16), and thus forms the surface layer portion (18) to have a high density. |
