Novel High-g Accelerometer Geometry Requiring 90 Degree Contacting Techniques

摘要

This paper presents a novel silicon MEMS high-g accelerometer and its package solutions. It exhibits superior performance compared with commercially available transducers, but requires 90 degree contacting. It has a resonant frequency of more than 2.5 MHz, while having a sensitivity of about 0.2 μV/Vexc./g, which means a performance increase of about one magnitude over existing similar sensors. These high values are due to its unusual geometry, which causes the sensing direction to lie in the wafer plane. This means that the sensor can only be used to its full abilities, when 90 degree contacting is applied. Three solutions are presented that solve this problem on different levels, i.e. on cable, package and die level. They are based upon a machined bulk alumina ceramic, a thick nine layer LTCC ceramic and a non-contact direct write technique called aerosol printing, respectively. The latter, which works at the lowest, i.e. die, level, promises the best characteristics regarding size, cost and measurement performance.