Patent ID: 7097713

Claim:
A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of: immersing the ceramic substrate coated with the metallic layer in an acid solution comprising hydrochloric acid at a concentration of about 31% by volume of the solution for a time to substantially remove the metallic layer therefrom; and annealing the ceramic substrate at a predetermined temperature sufficient to reduce pre-existing damage in the surface of the ceramic substrate by ramping the temperature using a heating ramp rate comprising: heating to a first temperature of about 302° F. at a first heating ramp rate said ramping the temperature of about 122° F./hour; maintaining the first temperature for about an hour; heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour; heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; maintaining the third temperature for about 7 hours; and allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.