Method for applying electrical conductors on a smooth vitreous surface and article

A metal coated dielectric substrate, e.g. a wafer thin circuit device, is produced by depositing on the cleaned substrate (e.g. alumina, glass, ceramic and plastics material), over the resistive and conductive areas of the circuit, an electroconductive metallic oxide material containing tin oxide and a suitable binder and filler. The resistive area is coated with an acid resist, the outer layer of uncoated oxide chemically or electrochemically reduced to tin, on to which Cu is deposited and the resist removed. The resist is preferably photosensitive and is applied to the entire area, the pattern being formed photographically. The oxide may be reduced in a mixture of Zn, Fe, Al, Ni, Co, Cd, Cr or Mn with hydrochloric or fluoboric acid. The Cu is deposited from an electroless plating bath containing KNa tartrate, CuSO4, NaOH, NaCo3 and formaldehyde. The substrate may be cleaned in an ultrasonically agitated bath of acetone, xylene or trichlorethylene.