Patent ID: 7666471

Claim:
A method for metallizing a substrate comprising polyimide, said method comprising: (a) contacting the substrate with a surface treatment selected from the group consisting of plasma and corona discharge; (b) contacting the substrate with an etching solution comprising from about 190 to 385 g/l alkali metal hydroxide and from about 1 to 10 ppm ionic palladium; (c) contacting the substrate with an activating solution comprising ionic palladium and a chelator wherein the activating solution is alkaline in pH; (d) contacting the substrate with a reducing agent; (e) contacting the substrate with an electroless nickel plating bath wherein the electroless nickel plating bath comprises ammonium chloride; and (f) contacting the substrate with an electroless copper plating bath; wherein steps (b) and (c) comprise two separate steps with the etching solution and the activating solution being two separate solutions.