Anti-Shock Packaging Model Design For The Acoustic-Vibration Sensors System

The sensor –vibration sensors system has a bright and broad application prospect in the military field, and its package material and structure play key parts in the system packaging. In this paper many different kinds of anti-shock packaging models with different structure for the acoustic sensor in the system have been built by using of anti-shock pricinple. The modal analyses have been made to study on the structure and dimension effects on the anti-shock performance of the model so as to select the optimum packaging structure, and the optimum packaging model with the lowest natural frequencies has been gained by optimizing the dimension of the model and material parameters of the rubber. In the end, the anti-shock performance of the optimum model has been evaluated. Seven anti-shock models with different structure for the acoustic sensor have been designed, and six of them are traditinal models, whose natural frequencies are 10 ～1 Hz, which is in the range of vibration signal scope limitation10 ～1 Hz , and can easily lead to resonance vibration. The natural frequencies of the innovative double J-like anti-shock packaging model (10 ～ Hz) is far less than the traditional models with the same material parameters. The double J-like structure of anti-shock packaging model has been selected, and the dimension has been optimized, R=1.6mm,r=1.2mm,H=8mm. By modal analyses of the double J-like anti-shock packaging model with different rubber parameters, the optimized parameters have been gained young's modulusY=10 6 N ? m?2, poisson's ration μ=0.49, densityρ=1. 2 ×103kg?m?3. Modal, static and transient analyses have been made on the optimized model. The top three natural frequencies and their relative oscillating modes have been worked out by modal analyses. Left-right mode, f1=20.109Hz; back-forward, f2=69.614Hz; up-down mode, f3=82.705. The results of satic analyses showed that under the concentrated load the anti-shock structure could not be cracked, and can anti-shock quite effectively. The results of transient analyses showed that the model could effectively reduce the impulse force effects on the chip. The conclusion of this paper provides an important theoretic guidance for the packaging of the system.