Description

Through-mask electrochemical machining is a non-conventional metal patterning technique which allows very high etching rates using non-hazardous electrolytes. Consequently, it represents a promising alternative to chemical etching processes in a variety of applications, particularly in the context of printed circuit board (PCB) production. Nevertheless, the process is currently lacking a comprehensive understanding of the underlying reaction mechanisms.

This thesis examines the dissolution process at the microscopic and mechanistic levels by in-situ analysis and polarization studies conducted under a range of varying parameters, electrolytes, and metals. The first in-situ evidence for the so far only postulated surface film is found. A model for the dissolution mechanism at high current densities involving the surface film is postulated. Additionally, significant advances in process development are achieved.