The quality and reliability of multilayer boards are determined by the adhesion strength between the copper sheets and the epoxy-glass laminates. The adhesion properties of copper foil may be improved by mechanical or chemical roughening. The most efficient method is, however, to oxidize the copper surface.Oxidized copper layers have been tested by thermogravimetry. Subsequently the oxide layers have been tested by Auger and SIMS techniques. The results showed that the main constituent of the oxide layer produced in a sodium hypochlorite type electrolyte is Cu20.