| 摘要 |
PURPOSE:To improve quality of a thermistor by holding a ceramic base body after a firing process or during the same process for a fixed time in a high temperature and to quickly cooling thereafter to normal temperature. CONSTITUTION:After temporarily firing a raw material, in which at least tow kinds of transition metal oxides are mixed at a fixed distribution ratio, the mixture is crushed for molding and firing. During the firing process, a ceramic base body is left for a fixed time desirably in a state of not less than 850 deg.C and quickly cooled to normal temperature directly thereafter. Rising temperature time and falling temperature time can be 5 to 15min each. In this way, a change ratio with time of specific resistance of the thermistor does not exceed + or -2% (85 deg.C, 1000hr) thus to improve quality. |
