Design, Fabrication and Characterization of a 5x5 Array of Piezoresistive Stress and Temperature Sensors

This paper reports on the development and characterization of piezoresistive stress and temperature sensors fabricated on silicon-on-insulator (SOI) wafer. The sensor chip consists of a 5x5 array elements enabling the simultaneous measurement of the absolute temperature as well as in-plane stress components in a temperature compensated manner. Each cell comprises a p-type piezoresistor rosette paralleling to the [110] crystal direction of silicon, an n-type piezoresistor rosette along the [100] crystal direction and a temperature sensor. Design, fabrication and characterization of piezoresistive and temperature sensors are described in detail. Moreover, based on the flexible printed circuit board, the prepackaging technique of sensors is reported and the electrical connections between the testing sensors and external measuring devices are achieved, then the changes in resistance versus temperature changes are measured in our experiment, the results show that this approach can be used for the signal measurement of sensor before the second packaging and on-line measurement of packaging stresses.