Analysis of Fringe Effect of MEMS Comb Capacitor with Slot Structures

摘要

For a super high precision MEMS sensor with the comb capacitor structure, the fringe effect of capacitors can not be neglected. In this paper, directing at the comb capacitor structure with slot holes, the effects of the non-overlap parts of comb capacitor, the distance between two slot holes in comb electrodes and slot depth aspect ratio on sensing capacitance are simulated by 3D finite element method of ANSOFT Maxwell software. The results show that when the width H and thickness t of sensing electrode plate are fixed, the fringe effect becomes larger for a smaller length L. The fringe effect is very small as non-overlap length is between 100 μm and 180 μm for 500 μm≤L≤1200 μm. The capacitance error caused by the fringe effect is the smallest for the slot distance 35 μm, slot depth 25 μm and slot width 20 μm. The error of sensing displacement caused by the fringe effect of the comb capacitor is 0.61% obtained by MATLAB Simulink.View full textDownload full textKeywordsMEMS, comb capacitor, fringe effect, slotRelated var addthis_config = { ui_cobrand: "Taylor & Francis Online", services_compact: "citeulike,netvibes,twitter,technorati,delicious,linkedin,facebook,stumbleupon,digg,google,more", pubid: "ra-4dff56cd6bb1830b" }; Add to shortlist Link Permalink http://dx.doi.org/10.1080/10584587.2011.576920