LTCC based Passive Compensation Circuits for High Temperature Sensors

Abstract

A current research focus has been the high-temperature applications of LTCC based sensors. The field of sensors in Low Temperature Co-Fired Ceramics (LTCC) technology has grown dramatically over the last few years, bringing new possibilities for challenging electronics and packaging applications. Due to their high precision, low cost and high reliability at elevated temperatures and harsh environments, sensors manufactured using LTCC technology have been widely used in industrial fields in recent years. The error arising from the effect of temperature in harsh environments that results in measurement inaccuracy is a major problem associated with high temperature sensors. Different passive resistor temperature compensation techniques were verified experimentally under high temperature and pressure conditions. Finally, a high temperature LTCC based pressure sensor with integrated compensating circuit was manufactured and tested in the temperature and pressure range of 100 to 500 °C and 0 to 50 bar. This technique shows very promising results in the elimination of the zero-pressure offset and decreases the errors caused by temperature variations. Laser trimming is performed to reduce the measurement errors and achieve temperature compensation.