基于电化学沉积的高深宽比无源MEMS惯性开关的研制

Development of High-Aspect Ratio Passive MEMS Inertial Switch Based on Electrochemical Deposition Technique

基于电化学沉积技术在金属基底上制作了一种新型的无源MEMS惯性开关。针对高深宽比、细线宽微电铸用光刻胶模具制作过程中,由于SU-8胶膜严重侧蚀导致的胶膜制作困难、质量低下的问题,进行了紫外光刻试验研究。试验研究了不同曝光剂量和后烘时间对SU-8胶光刻效果的影响,优化了光刻工艺参数。采用降低曝光剂量和延长后烘时间相结合的方法解决了高深宽比、细线宽SU-8胶膜制作困难的问题,制作出高质量的微电铸用光刻胶模具。最后,在上述试验结果基础上制作了一种高深宽比、无源MEMS惯性开关。其外形尺寸为3935μm×3935μm×234μm,其中最细线宽12μm,单层最大深宽比达10∶1,多层最大深宽比达20∶1。

Based on the electrochemical deposition technique, a new passive MEMS inertial switch was fabricated on a metal substrate. In view of the problems of poor quality caused by the serious lateral erosion of SU-8 in the process of making high-aspect ratio and fine-line micro electroforming molds, SU-8 UV lithography was studied. The effects of different exposure dose and PEB（post exposure bake） time on SU-8 UV lithography were studied experimentally, and the parameters of UV lithography were optimized. By using the method of reducing the exposure dose and prolonging the PEB time, the problem of poor quality of high-aspectratio and fine-line SU-8 electroforming mold was solved successfully. Finally, on the basis of the above experimental results, a passive MEMS inertial switch with high-aspect ratio was developed. The external dimensions are 3935μm×3935μm×234μm, of which the smallest line width is 12μm, the highest aspect ratio of the single layer is 10∶1, and the highest aspect ratio of the multi-layer is 20∶1.