Title |
Driving Characteristics of the Scanning Mirrors to the Different width and Number of the Grooves on the Electrodes |
Authors |
박근우(Park, Geun-U) ; 김용권(Kim, Yong-Gwon) |
Keywords |
scanning mirrors ; grooved driving electrodes ; squeeze effect |
Abstract |
In this paper, using 500μm-thickness (100) silicon wafer, flat 65μm-thickness silicon mirror plates were fabricated through dry etching and wet etching, and 45μm-depth grooved driving electrodes were fabricated through UV-LIGA process. Four shapes of the driving electrode were fabricated: twenty four grooves of the 50μm-width, twelve grooves of the 100μm-width, six grooves of the 200μm-width, and no grooves on the driving electrode. Fabricated mirror plate size and spring size are 2400×2400×65μm3 and 500×10×65μm3, respectively. Mirror plate parts and driving electrodes were assembled into the scanning mirrors. Measured natural resonance frequencies were about 600Hz which have error within pm 2% to calculated value. Due to the squeeze effect in the narrow gap between the mirror plate and the driving electrode, measured resonance frequencies were reduced as raising the amplitude of the mirror plate. In a case of driving electrode without grooves, the resonance frequency was reduced largely, compared with a case of driving electrode with grooves. According to the experimental results, squeeze effect was smaller in the driving electrode with smaller-width and many grooves. Therefore, the driving electrode with smaller-width and many grooves was effective in low voltage and high speed operation. |