Fundamental Research on Micro Electroforming of Metal Microstructures by Using Shielded Anode

Metal microstructures with high-aspect-ratio and complex features have become a real challenge for the microfabrication field. A novel metal micro-parts fabrication technology is presented in this paper. The anode which also serves as a mask is patterned by UV lithography, and used to confine the region of electrodeposition. With the increasing of the thickness of electrodeposition, the mask is detached from the substrate periodically. 3-Dimensional microstructures with limitless aspect ratio can be fabricated by this technology in principle. Immersion tests show that pyrophosphate bath is more appropriate for this technology than acid sulfate bath. Cell voltage is employed to monitor the electro forming process for it provides some process information such as flash deposition, shorting occurrence, et al. Two types of movement between the mask and the cathode have been carried out on the self-developed equipment to demonstrate its feasibility. Micro bars with vertical sidewall and micro structures with slanting profile have been produced.