微機電技術於電容式近接感測器之設計與製作

Abstract

本篇論文之研究方向在於以微機電系統(MEMS)技術之表面微加工技術製作微型近接感測器。主要內容包含兩大範疇：(1)提出一新式微電容感測器之結構，利用電磁模擬軟體Ansoft – Maxwell來設計並模擬分析新結構之效能，嚴謹考量電極板各部分的電容效應，以改善簡化電容結構而造成的誤差；(2)微電容感測器之製程規劃與製作，並在結構製程後段同時考量了封裝之設計，以提昇此感測器量測時之可靠度。最後並架設量測平台以驗證電容的感測特性、探討量測誤差之形成原因，以提供後續相關研究之參考。此型以邊際效應原理之微感測器除設計為具有微米級之位置量測，以作為精密定位控制之迴授訊號，且體積小、批量製造成本便宜，並且為不限定待測物材質之非接觸量測特性，更增加了其廣泛的量測用途。

In this thesis, MEMS Technology is used to develop the micro proximity sensors. The sensors are designed to detect the position of objects with different electric properties, which include grounding conductors, floating conductors and dielectric materials. The content of the thesis mainly includes two parts - one discusses analysis and design of the new capacitance sensors to improve the property of the sensors, the other focuses on the fabrication and measurement. For the analysis purpose, the FEM software package - Ansoft Maxwell is used to analyze the electrostatic field distribution surrounding the electrodes and determine the fringe capacitance. Through masks design and process arrangement for Surface Micromaching Technology, several new types of Microsensors, including comb type, ring type, and honeycomb type, are manufactured. An additional concern on sensor packaging for practical applications is also discussed in the thesis. Finally, the measurement platform is set up to measure the fringe capacitance, which will be varying with different positions of target object. The error caused during the measurement is investigated and discussed in the thesis.