| NTC thermistor is a common thermal sensing device of the temperature sensors, and every technique during production process has many significant effects on the consistency and stability of the product. With the improvement of temperature sensors, the thermistor with better consistency of electrical parameter and higher environmental stability is highly needed. Thus it is very important and significant to investigate and optimize the key techniques.In this paper, the NTC thermistors of the Mn-Co-Ni-Cu series are taken as the main research objects and their key techniques are studied intensively. The main contents of our research are as follows:1. Different fabrication techniques of the powder/slurry and the molding techniques of the green body are investigated. The stability and the adaptability of the powder /slurry in different systems are characterized, and the properties of the obtained green body are also commented. Finally, the relatively better fabrication techniques of the green body are determined as follows: dispensing forming pattern was used in slurry D and overlapping forming pattern was used in slurry E.2. The forming properties of the NTC thermistors are studied under microwave conditions. And by means of the electrical measurement and the microstructure characterization of the sintered products, the quality of the forming status of the ceramics under different sintering conditions is evaluated and the optimal sintering conditions are finally determined: the optimal sintering condition of sample No. 0805 was at 900℃for 11 minutes and the heating rate was 80℃/min, and the optimal sintering condition of sample No. 1206 was at 850℃for 9 minutes and the heating rate was 100℃/min.3. The stability and the environmental adaptability of the NTC thermistors with same composition and different seal structure are discussed, and the best seal structure for the NTC thermistors is applied to improve the stability of the NTC thermistors in an industrial situation. |
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