Research of megasonic electroforming equipment based on the uniformity of electroforming process

Megasonic has obvious advantages in overcoming the limitations of electroforming process based on its low cavitation effect, high sound intensity and acoustic streaming. In this paper, megasonic was employed to achieve uniform electroformed layer in electroforming process. Impedance values, resonant frequencies were measured in order to get a high-efficiency megasonic source. Considering the directions of acoustic radiation and combining with other functional modules, an integrated megasonic electroforming equipment was designed and set up. Then, nickel was electroformed on copper substrates without megasonic wave, with single directional megasonic wave and with bidirectional alternating megasonic wave, respectively. The planeness value (PV) of electroformed layer is 15.03 μm without megasonic agitation, and the PV of electroformed layer is 15.36 μm with single directional megasonic wave radiation. Bidirectional alternating megasonic wave assisted electroforming has an outstanding performance on the uniformity of electroformed layer, which achieves the lowest planeness value (PV = 10.91 μm) of all the electroforming experiments. Besides, the bidirectional megasonic wave assisted electroforming can achieve better surface quality than other conditions too.