The Natural Frequency Of The Micro Laminated Chip Test Research

In order to test the vibration characteristics of the stacked chip, the piezo-actuator was used as a base to excite the chip, and the vibration of the chip was recorded by using a Laser Doppler Vibrometer. By analyzing the changes in impedance of actuator and the dynamic responses of the chip, natural frequencies of it were obtained.The main works are as follows:1.The advantages and disadvantages of excitations and measurement technologies for microstructure were summarized. The piezoelectric base excitation and Laser Doppler Techniques were chosen to measure the dynamic characteristics of stacked chip and the vibration test platform was established.2.The white-noise, steady-state sinusoidal and fast sine sweep(chirp) excitations were used to excite the stacked chip. By comparing the three exciting methods, the white-noise was determined as the best option. Impedance analyzer was employed to measure the impedance of piezoelectric ceramics which was pasted on stacked chip. The results showed that the vibration characteristics of chip could also be tested by the analysis of the changes in impedance of PZT.3.Aiming at the interference caused by the base vibration, an experimental program that was dominated by optical measurement and assisted with impedance analysis was proposed. The difference between different algorithms for power spectrum estimation on random responses which caused by the white-noise excitation were studied. Using the welch algorithms to analyze the responses and assisting impedance analysis of PZT, natural frequencies of chip were obtained successfully after the interference were removed from the piezoelectric base vibration.This study provided some reference for testing the vibration of micro devices. The vibration characteristics of the stacked chip have certain guidance for optimizing the parameters of wire bonding on the cantilever.