The NTC gold-electrode thermal chip produced by EXSENSE Electronic Technology Co., Ltd. has great reliability, good stability and high accuracy (accuracy can up to ±0.5%, ±1%, ±2%, ±3%), which is widely used in infrared thermopile, IGBT, optical communication module, etc. With the rapid development of electronic science and technology, the accuracy demand for temperature monitoring and temperature control of thermistor chip in the electronic industrial circuit is constantly improving, and the demand for thermistor chips with high accuracy and good performance stability is increasing day by day. Therefore, it is of great value to the development of NTC thermosensitive polymer composite miniature NTC thermistor chip, which is expected to replace the application of some linear or nonlinear thermistor in electronics industry.
Today, EXSENSE Electronics introduces a kind of miniature gold-electrode NTC thermistor chip, which has good stability, stable product performance and high resistance accuracy. The specific preparation methods are as follows:
One, material preparation
Fluorine rubber and conductive carbon black are proportionally weighed, fluorine rubber is dissolved with butyl acetate solvent, silane coupling agent is added, and conductive carbon black was added in the state of agitation. According to the need of resistance temperature coefficient value and resistance value of product to adjust the formula, until the conductive carbon black evenly dispersed in the fluorine rubber solution, the polymer composite material obtained.
Second, configure stretch forming material
The polymer composite slurry is stirred evenly to make the stretch forming material, the specific method is to add the appropriate amount of butyl acetate (quantified according to the viscosity), stirring for about 2 hours, filtering to obtain the stretch forming material.
Third, stretch forming and lamination
The thermistor polymer composite substrate is prepared by the process of stretch forming, gold-electrode printing and lamination, isostatic pressuring, hot-pressing and UV radiation cross-linking. Among them, it is possible to lamination, isostatic pressuring, then print the gold electrode for hot-pressuring and cross-linking; Or first, laminate the required thickness on the gold electrode, gold electrode is coated on the upper surface for isostatic pressuring, hot-pressing and cross-linking.
Four, product dicing
According to the technical requirements of the product, the thermistor polymer composite substrate is precisely diced, and miniature gold-electrode NTC thermistor chip of 3*3*0.3mm (dimensional tolerance<0.005mm) is obtained.
Fifth, electrical performance testing
The miniature gold-electrode NTC thermistor chip is sampled to examine, ensure good performance.
Compared with the NTC thermistor chip produced by the existing technology, this miniature gold-electrode NTC thermistor chip develops miniature thermistor chip by developing the molding process, surface treatment method and electrode formation method of NTC polymer composite material, so that the stability of resistance value and resistance temperature coefficient value is better. Moreover, the method of stretch forming is used to prepare the polymer composite substrate, the dispersity of conductive particles in polymer is better, the adhesion between polymer composite materials and gold electrode is stronger, and the negative temperature coefficient effect of the material is more stable, which is of great practical value to the industrial production of the miniature gold-electrode NTC thermistor chip.