A new electroforming technology in aid of pressure for LIGA process

New microelectroforming technique using air pressure assistance in the electrolyte is introduced. The theoretical model and experiments are reported in this paper. It shows that the pressurized electrolyte reduces hydrogen bubbles formation and defects existing on substrate surface. High pressure in the electrolyte limits bubbles formation in electroforming. It also results in good throwing power from the experimental samples observation. The edges of the electroformed workpiece using the pressurized method are smoother than the conventional electroforming. Metallurgical grains are finer when high pressures applied in the electrolyte based on SEM micrographs. The pressurized electroforming can increase the allowable current density, which can shorten plating time in the LIGA process. High growth rate due to a large applied current density results in large grains of electroforming microstructures, but the surface morphology of the pressurized electroforming is also improved comparing with the conventional method.