UBC Theses and Dissertations
Investigation for improvement and application of MEMS-based micro-electro-discharge machining (M3EDM) Wang, Ningyuan
MEMS-based micro-electro-discharge machining (M3EDM) is a batch microfabrication technique utilizing planar electrode actuators to machine conductive materials. The low contrast pattern transfer issue in electroplating mold fabrication is firstly analyzed and improved by eliminating the contact gap and adding a rehydration step. The new method gives a better structure profile with near vertical sidewalls. The causes and mechanisms of spin coating non-uniformity and bonding voids are discussed, as well. The deformation on the foil electrode area where discharges occur is explained by abnormal heat shock, tool wear, material softening and discharge-brought reactive force. A feedback control circuit with pulse discrimination is developed to detect the harmful short pulse and prevent thermal shock. Nickel is proposed and tested as the new material for actuators owing to its higher mechanical and thermal resistance. The optimized nickel based electrodes together with the affiliation circuit are applied to cantilever MEMS contact switch fabrication. The photoresist melting in the photoresist sandwich structure is observed. A new reverse fabrication process is proposed and processed in order to minimize the photoresist melting. The method partially addresses the issue. The further directions for improvements and the potential application of the reverse process to reusable M3EDM devices are discussed.
Item Citations and Data
Attribution-NonCommercial-NoDerivatives 4.0 International