MEMS封装用局部激光键合法及其实现

Local Laser Bonding Method and Its Implementation on MEMS Chip Package

对常规激光键合在Si-玻璃键合工艺中因高温而引起的负面效应进行了分析，从而设计出芯片表面活化预键合与激光键合工艺相结合的方法。该方法已用于微电子机械系统（MEMs）样片封装实验中。实验过程是：先用一种特殊的化学方法形成亲水表面，然后将Si和玻璃置于室温下进行预键合，最后取波长1064nm、光斑直径500μm、功率70W的Nd：YAG激光器作局部激光加热。结果表明，该方法在不施加外力下能实现无损伤低温键合，同时拉伸实验也说明了样片键合强度达到2．6～3．0MPa，从而既保证了MEMS芯片的封装质量又降低了其封装成本。

It was analyzed that conventional laser bonding could alleviate adverse effect which was caused by the high temperature in silicon-glass bonding process. So a novel method that was the combination of surface activated pre-bonding and laser bonding was designed. This method was used for an experiment on micro-electro-mechanical system （MEMS） chip package. Firstly, a special chemical solution was used to generate hydrophilic bonding surface, then the silicon-glass pre-bonding was accomplished at room temperature. At last the selected laser with a wavelength of 1 064 nm was used and its focus spot diameter was 500 μm and power was 70 W. The experiment results show that the pre-bonding pairs are bonded locally and the bonding strength even reaches 2.6-3.0 MPa without any external pressure. With these characteristics, this method improves the package quality of MEMS productions and reduces their costs.