A kind of manufacturing method of high precision ntc thermistor chip

Abstract

The invention discloses a method for manufacturing a high-precision NTC thermistor chip. The method comprises a step 1) of weighing corresponding metal oxides according to a chemical formula Mn3-x-y-zNixFeyCozQtO4, performing mixing ball-milling, low-temperature calcination, ball-milling crushing and high-temperature calcination, and obtaining thermal sensitive ceramic powder; a step 2) of performing ball-milling on the thermal sensitive ceramic powder, adding an organic binder, and performing drying, pelleting and sieving to obtain formed powder; a step 3) of performing dry pressing and isostatic pressing on the formed powder, and obtaining formed briquette; a step 4) of adding the formed briquette into an atmosphere furnace, performing sintering in the weak oxidizing atmosphere, and obtaining agglomerate; a step 5) of cutting the agglomerate into slices, coating the slices with silver or gold electrodes, performing heat treatment, cutting the slices into required sizes, and obtaining the high-precision NTC thermistor chip. The decomposition of FeMnNiO4 is restrained by controlling oxygen partial pressure in the sintering process, ingredient segregation is reduced by introducing low-temperature calcination before presintering, the production process is controlled easily, the chip resistance and B value pass rate are high, and the reliability is high.

Description

technical field

[0001] The invention relates to a manufacturing method of a high-precision NTC thermistor chip. Background technique

[0002] Negative temperature coefficient (NTC) thermistors refer to electronic ceramic materials whose resistance decreases with increasing temperature, and are widely used in temperature sensors to measure temperature. In recent years, with the rapid development of science and technology, people have higher and higher requirements for the temperature measurement accuracy and temperature control accuracy of NTC thermistor chips. Nickel element has the characteristics of reducing material resistivity and B value at the same time, and it is not easy to cause NTC thermistor aging like Cu element, so it can be conveniently added to the NTC thermistor formula as the main component to adjust the NTC thermal resistance. The resistivity and material constant B value of the varistor. However, due to the variable valence state of Ni, NiO will be decom...