Hi folks,
I am trying to etch gold away that is over a copper layer. Using HCl + HNO3 I
found out that the solution stops attacking the gold once it comes in contact
with the copper.
I then used Iodine and Iodide (I : KI) to etch the gold away and noticed that
there is a whitey layer created on top of the copper once the etching is over.
That layer can be manually removed (with use of a scalpel for example).
Is there any better etchant to use that does not attack the copper?

Thanks in advance

Nik Dee