微加速度开关在高冲击环境中的防护技术研究

Research on shield methods of micro acceleration switch under high impact

加速度开关是感受加速度并输出开关信号的一类惯性器件。基于MEMS技术研制的微加速度开关需要感受的加速度值远低于其承受的环境冲击加速度值。在高冲击环境中,微加速度开关自身的防护成为一大难题。分析了高冲击环境下器件的失效机理,从材料、结构和封装等方面介绍了3种防护措施,即,采用韧性金属材料替代脆性硅材料制作开关芯片、采用缓冲材料灌封开关芯片和引线、采用不锈钢制作封装壳体,3种措施成功地解决了微加速度开关自身的高冲击防护问题,试验证明防护措施十分有效。

The acceleration switch is a kind of inertial device that can sense impact acceleration and output on-off signal. The micro acceleration switch is fabricated by MEMS technology. The preset switch threshold is much less than it should suffer from the environmental impact, Survival becomes a big problem when the micro acceleration switch itself is subjected to high impact acceleration. Failure principle of devices under high impact is analysed. Three kinds of shield methods are presented in some respects of material, structure and package, such as adopting the tough metal instead of the brittle silicon to fabricate the switch chip, adopting buffer material to wrap the switch chip and leading wire,adopting the stainless steel to fabricate the package shell structure. The shield problem is solved via the three kinds of methods. Test shows all kinds of shield methods are effective.