Preparation and Performance Test of Soldered Stators of Ultrasonic Motor

Abstract In order to obtain the optimal reflow parameters, a Sn-52In solder was adopted to join a PZT8 piezoelectric ceramic to a copper stator elastic-body, which matched with rosin organic flux. Modal testing was carried out to evaluate the vibration performance of the soldered stators. The results show that when the reflow parameters were 140°C, 115 s, and 100 N pressure, the soldered stators had the best vibration performance. The soldered stators can generate a B09 mode shape which is required by the TRUM-60 ultrasonic motor. Moreover, the coincidence of the two phase modal frequencies of soldered stators can fully meet the requirement of ultrasonic motors and there is no interference frequency near the operating modal frequency (around 40 kHz). With an electrical excitation of 80 Vpp, the amplitude of the soldered stators was 2.5 μm, which can reach the level of vibration of bonded stators with adhesives. Therefore, the soldering process could be expected to solve the problem of aging of the adhesive layer, thereby improving the service life of ultrasonic motors to a certain extent.