Stability of thick film piezoresistors under large pressure cycles at elevated temperature

The resistance change of ruthenium based metal-insulator-metal (MIM) thick film resistors with hydrostatic pressure exhibits excellent linearity, no hysteresis, a small temperature dependency, and an order of magnitude greater sensitivity than the longitudinal mode. The effect of long-term 10(6) hydrostatic pressure cycles (0 to approximately 21 MPa) at 135 degrees C on response linearity, sensitivity (span), and the resistance at zero pressure Ro (offset) have been established for a commercial MIM composition. No change in linearity, sensitivity, and offset was observed up to 10(4) cycles. After 10(6) cycles the offset and sensitivity changed by less than 1% and 0.5%, respectively. Other parameters remained unchanged. The results are analyzed in terms of conduction models of this system.