Development of a high-resolution quartz resonator force and weight sensor with increased reliability

Test-analyze-and-redesign method is employed to develop a quartz crystal resonator (QCR) force and weight sensor with increased reliability for batch production. The sensor, which mainly consists of a QCR and a metal diaphragm structure, has the advantages of high resolution, digital output, and low cost. The failure mechanism of the single-diaphragm QCR sensor has been uncovered by experiments aiming at providing insight into the failure factors. In order to eliminate the failure stress and improve reliability, the sensor has been redesigned based on failure analysis results by designing a double-diaphragm structure. Life testing experiments for validating the effect of the corrective action show that reliability has been improved five times, and after redesign, the reliability satisfies the requirement of practical use. Accelerated life testing is performed to find acceleration factors and development stresses for batch production.