A new polishing method for complex structural parts: Moist particle electrolyte electrochemical mechanical polishing (MPE-ECMP)

Abstract

The improvement of the surface quality of complex structural parts is a major challenge. Electrochemical mechanical polishing (ECMP) plays an important role in the polishing of wafers due to its high material removal rate. However, electrochemical mechanical polishing of the surface of complex structures, such as the bevels of turbine blades, has been little investigated. This paper proposes a new method, moist particle electrolyte electrochemical mechanical polishing (MPE-ECMP), for polishing the surfaces of complex structural parts. Using a sulfonated cation exchange resin as a moist particle electrolyte (MPE), polarization curves are measured using linear scanning voltammetry (LSV) and a selected potential of 1.0 V vs. Hg|Hg2SO4 over a 1 h polishing period. The elemental changes on the copper surface are examined by energy dispersive spectroscopy (EDS) and those on the MPE surface are studied using X-ray photoelectron spectrometry (XPS) to explain the material removal mechanism. The results show that the surface roughness of copper is reduced from the initial Sa = 433.48 nm to Sa = 21.83 nm, a reduction of 95.0%, that no copper oxides are generated during the MPE-ECMP process and that the MPE adsorbs released Cu2+. It is demonstrated that MPE-ECMP has good surface finishing properties for beveled surfaces, and provides an effective approach for surface polishing of complex structural parts.

Keywords

• Moist particle electrolyte electrochemical mechanical polishing
• Complex structural parts
• Copper