Method for Mitigating Electrochemical Migration on Printed Circuit Boards

An effective method for preventing electrochemical migration (ECM) by adding carbohydrazide as an oxygen scavenger has been investigated on FR-4 printed circuit boards with Cu or Ag comb patterns by means of water drop testing, electrochemical testing, and surface analysis. The addition of carbohydrazide increased the mean time to failure by ECM in solutions with both low and high chloride concentrations, by delaying the formation and growth of dendrites. Also, the carbohydrazide decreased the kinetics of the oxygen reduction reaction evident in polarization curves. Thus, carbohydrazide retarded the ECM phenomenon by removing oxygen from solution, which suppressed the formation of dendrites.