Study on the Uniformity of Micro Electroforming Mold Insert Used in Micro Fluidic-Chip Fabrication

In the paper, a theoretical investigation was presented, which is used to explain the effect of pulse-reverse current on uniformity in micro-electroforming. And micro-electroforming experiments of two different pulse-reverse currents with gaps in positive direction were carried out correspondingly. The mold inserts used in micro fluidic-chip were micro-electroformed in these experiments, and its feature width is 90um. No backing process was adopted, which mainly consisted of three procedures. Two different pulse-reverse currents used in these experiments were pulse-reverse current with gaps in both positive and negative direction, and pulse-reverse current with gaps only in positive direction, respectively. The fundamental parameters of these experiments were summarized from lots of micro-electroforming experiments of pulse current. After experiments, comparisons were carried out between the results of pulse-reverse current experiments and pulse current experiment. Because negative current could erode the tips on electroforming surface, better uniformity was obtained in these experiments using pulse-reverse currents. The experimental results were consistent with the theoretical investigation.