I have not tried with any specific Nickle etchant. I used Au etchant (KI) once to etch out the electroplated nickel and it worked pretty well. As the Ti, H2O2 could be a good choice. Both of the two solution are safe for silicon substrate. Sorry for typing mistake.:) Best regards, Fei 2008/11/28 汪飞> I have not tried with any specific Nickle etchant. I used Au etchant (KI) > once to etch out the electroplated nickel and it worked pretty well. As the > Ti, H2P2 could be a good choice. Both of the two solution are safe for > silicon substrate. > -- Best regards, Yours sincerely Fei Wang