[mems-talk] How to etch Chrome in Copper/Chrome Metalization?

[Michael D Martin]

Hi all, 
   I need to etch a chrome adhesion layer from a chrome/copper
metalization for a flex circuit board application and am having
difficulty removing the chrome. Using a chromic acid based chrome etch
the copper goes into solution before the chrome. Surely this is a common
problem in the flex circuit board industry, so has anyone heard of a
work around for this? Is there another chrome etch for this
metalization? 

Thanks, 
    Mike Martin 
    U. of Louisville