Abstract:
A process for avoiding blister formation between a metal layer which is electrolessly deposited on a surface of a ceramic substrate is claimed. The substrate is adhesion promoted with an alkali metal composition containing between 0.35 and 0.9 mole fraction alkali metal compound and water at a temperature equal to or in excess of 140°C and not exceeding 300°C, and preferably 240°C, for a time period between 1 and 200 minutes. Thereafter, the adhesion promoted ceramic surface is rendered receptive to electroless metal deposition and is coated free of blisters using an electroless metal deposition bath with an adherent, metal layer having a thickness greater than 5 µm.