A new ultrasonic electrochemical potential activation method to enhance the adhesion strength between electroforming layer and Cu substrate

In Micro-Electro-Mechanical System (MEMS) area, micro metal devices can be fabricated by the micro electroforming process. However, due to the oxide layer of the substrate surface, the electroforming layer suffers from poor adhesion strength. In order to reduce the oxide layer of the substrate surface, the effects of the ultrasonic electrochemical potential activation method to reduce the oxide layer of the substrate surface are investigated originally. The electrochemical methods including the cyclic voltammetry method and the chronopotentiometric method were processed by an electrochemical station. The oxygen content of the substrate surface was measured by the EDS method. The adhesion strength between the electroforming Ni layer and the Cu substrate was measured by the scratch test. The experimental results show that comparing with the ultrasound free one, the ultrasonic electrochemical potential activation method can improve the hydrogen evolution reaction and reduce the Cu substrate surface oxide content. The results of this paper can provide a new ultrasonic electrochemical potential activation method to activate the oxide layer of the substrate surface, as well as to improve the interfacial adhesion performance.