Improving the Thickness Uniformity of Micro Electroforming Layer by Megasonic Agitation and the Application

Abstract Throwing power can be used to quantitatively characterize the uniform distribution ability of electroforming layer thickness. From the perspective of throwing power, the effect of megasonic agitation on improving the thickness uniformity was studied under the experiment system of nickel containing electrolyte. Firstly, throwing power experiments were performed with different megasonic power densities. Experiment results show that throwing power increases with the increase in power density. When power density is 2.4 W/cm2, throwing power has a maximum value of 37.1% and increases 50.2% compared with the value of 24.7% obtained without megasonic. Then, the effect factors of throwing power, including electrolyte conductivity and cathodic polarizability, were investigated. The results reveal that megasonic has little effect on the cathodic polarizability, but it can increase the conductivity, which is conducive to improving thickness uniformity. Finally, to prove the feasibility of this method on micro metal devices, metal microfluidic chip molds were fabricated by megasonic micro electroforming. The result indicates that the thickness uniformity of the electroformed micro mold is improved by 43.4%.