The Transactions of the Korean Institute of Electrical Engineers C (대한전기학회논문지:전기물성ㆍ응용부문C)

The Korean Institute of Electrical Engineers (대한전기학회)
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A HIGH-ASPECT-RADIO COME ACTUATOR USING UV-LIGA SURFACE MICROMACHINING AND (110) SILICON BULK MICORMACHINING

UV-LIGA 표면 미세 가공 기술과 (110) 실리콘 몸체 미세 가공 기술을 이용한 큰 종횡비의 빗모양 구동기 제작에 관한 연구

  • Published : 2000.02.01
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Abstract

This paper reports a novel micromachining process based on UV-LIGA process and (110) silicon anisotropic etching for fabrication of a high-aspect-ratio comb actuator. The comb electrodes are fabricated by (110) SILICON comb structure considering the etch-rate-ratio between (110) and (111) planes and lateral etch rate of a beam-type structure. The fabricated structure was$ 400\mum \; thick\; and\; 18\mum$ wide comb electrodes separated by $7\mim$ so that the height-gap ratio was about 57. Also considering resonant frequency of the comb actuator and the frequency-matching between sensing and driving mode for gyroscope application, we designed the number, width, height and length of the spring structures. Electroplated gold springs on both sides of the seismic mass were $15\mum\; wide,\; 14\mum\; thick\; and \; 500\mum$ long. The fabricated comb actuator had resonant frequency ay 1430Hz, which was calculated to be 1441Hz. The proposed fabrication process can be applicable to the fabrication of a high-aspect-ratio comb actuator for a large displacement actuator and precision sensors. Moreover, this combined process enables to fabricate a more complex structure which cannot be fabricate only by surface or bulk micromachining.

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References

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