Copper electroless plating at low pH (7-9) using dimethylamine borane complex as a reducing agent is studied electrochemically by linear sweep voltammetry, cyclic voltammetry and chronopotentiometry in full electrolytes. We find that the mixed potential theory is not applicable to the described system. We show that both the working potential and the rate-controlling mechanism are dependent on the pH of the solution. The effects of altering the mechanism on the resulting film conductivity, morphology and adhesion are studied on copper films deposited onto a polyimide (PI) substrate. (C) 2011 Elsevier Ltd. All rights reserved.