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.

2008/11/23 ANIRBAN SARKAR 

> Hey Jie,
>
> Thanks very much for the advice. I can replace Titanium by chromium.
> Will the suggested Ni etchant attack Silicon substrate?
> Thanks
> Anirban

--
Best regards,
Yours sincerely
Fei Wang