Electrochemical Migration in Thick‐Film IC‐S

Abstract

The phenomenon of silver migration in conductor‐insulator systems is well known, but it is less known that several other metals can exhibit migration. This paper tries to give a short summary of the phenomenon as applied to thick‐film circuits. Tests have been made on different conductors used in thick‐film circuits. The dendrites formed by electrochemical migration were examined by scanning electron microscope, and also by wavelength‐dispersive analysis of the emitted x‐rays. By obtaining secondary and back‐scattered electron images, x‐ray maps and profiles, it can be determined which components cause migration in the conductor in question. Photos are presented illustrating the results. Thermal Humidity Bias test was also performed in controlled environmental chambers in order to get a comparison between different thick film systems.