A process and apparatus for treating a metal foil to enhance its ability to be bonded to a substrate comprise immersing the metal foil in an electrolytic cell having an electrolyte bath solution containing copper and applying a current having regularly recurring pulses and preferably flowing in only one direction to the cell. The current causes a dendritic layer of copper to be deposited on at least one surface of the metal foil at a first current density and bonded thereto at a second current density. The process and apparatus are particularly suited for treating copper foil.