High-precision thermistor chip for medical body temperature measurement and preparation method thereof

Abstract

The invention discloses a high-precision thermistor chip for medical body temperature measurement and a preparation method of the high-precision thermistor chip. A resistor body of the high-precisionthermistor chip is formed by sintering transition metal oxide powder, wherein the transition metal oxide powder is prepared from the following components in percentage by mole: 43 to 54 mol percent ofmanganous-manganic oxide Mn3O4, 42 to 53 mol percent of cobaltosic oxide Co3O4 and 3 to 12 mol percent of ferric oxide Fe2O3. The preparation method comprises the steps of ball milling, drying, presintering, secondary ball milling, drying, powdering, ingot pressing, sintering, cutting, electrode feeding, scribing and the like. The resistivity rho of the prepared thermistor chip is 550-750 ohm.cm,and the B value of the prepared thermistor chip ranges between 3900K and 3950 K; the resistance precision reaches + / -0.3%, and the annual drift rate of the resistor body is less than 0.5%; the thermistor chip prepared by the invention has the characteristics of good resistance stability, strong repeatability, low resistance drift rate and the like, and is universally suitable for the applicationfields of high sensitivity and high stability.

Description

technical field [0001] The invention relates to the technical field of thermistors, in particular to a high-precision thermistor chip for medical body temperature measurement and a preparation method thereof. Background technique [0002] Thermistors are a type of sensitive components, which are divided into positive temperature coefficient thermistors (PTC) and negative temperature coefficient thermistors (NTC) according to different temperature coefficients. NTC (Negative Temperature Coefficient) thermistor chips are generally sintered from transition metal oxide powder. These metal oxide materials have semiconductor properties, because they are completely similar to semiconductor materials such as germanium and silicon in terms of conductivity. When the temperature is low, the number of electrons in these oxides is small, and the resistance value of the NTC thermistor is high; as the temperature increases, the number of electrons increases, and the resistance value of the...

AI Technical Summary

Problems solved by technology

[0007] However, the existing NTC thermistor is affected by the performance of the raw material of the thermistor during use, the B value is small, and the test accuracy of the NTC thermistor needs to be improved

Moreover, the annual drift rate of existing NTC thermistors is generally high, the repeatability is not good, and the requirements for stability and service life cannot be well met.