无源MEMS压力开关的设计与制备

Design and fabrication of passive MEMS pressure switch

为了克服传统机械式和电子式压力开关的体积大、制作工艺复杂以及不易与后续电路集成等缺点,论文采用具有金属引线台阶覆盖能力的玻璃浆料封装技术进行了无源MEMS压力开关的设计和制备。设计的无源MEMS压力开关的整体结构方案主要包括硅盖板上的压力敏感膜、硅岛、上电极和微阻挡凸台以及玻璃基底上的玻璃浆料和下电极。通过仿真优化了压力敏感膜、硅岛和上下电极的关键尺寸。经过三次湿法腐蚀工艺流程制得了双阻挡凸台、硅岛和感压膜片。通过玻璃浆料热压工艺将硅盖片、玻璃基底和金属引线三者键合成一体,工艺结果显示双阻挡凸台的高度和感压膜片的厚度很好地控制在8μm和50μm,而且经测试,MEMS压力开关的阈值压力为125kPa。

In order to overcome the shortcomings of traditional mechanical and electronic pressure switches,such as the production process is complex and it is difficult to integrate with the follow-up circuit,bulky and so on,the design and preparation of passive MEMS pressure switch were developed by using glass frit encapsulation technology with metal lead coverage in this paper.The overall structure of the passive MEMS pressure switch was designed to include the pressure sensitive film,the silicon island and the upper electrode on the silicon cover and the micro-barrier bumps,the glass paste and the lower electrode on the glass substrate.The key dimensions of pressure sensitive film,silicon islands and upper and lower electrodes were optimized by simulation.After three wet etching processes,double barrier bump,silicon island and pressure sensitive film were fabricated.The silicon cover,the glass substrate and the metal lead were then bonded together as a whole by glass frit thermal-pressure bonding process.The results show that the height of the double-barrier bumps and the thickness of the pressure-sensitive film are well controlled at 8μm and 50μm,respectively.And the threshold pressure of the MEMS pressure switch is 125 kPa.