Bonds to aluminum pads are always going to be problematic, unless done
immediately, as Al oxidizes quite quickly. Aluminumoxide/Alumina is very
tough, and - of course - insulating. In my lab, we usually add a gold
layer to the top of the aluminum bonding pads to avoid oxidation and
ease bonding. Is this an option for you, or are you trying to avoid gold
in your process entirely?

// Morten

Jon R. Fox wrote:
> I'm trying to make reliable aluminum bond pads (99.999% Al) to gold
> ball and wedge bonds. Where is a good source of information on the
> recommended best practices for pad thickness and processing to make
> good bonds with gold wire?
>
> Any advice will be happily accepted. I've had good luck with gold pads
> on many projects, but Al has been hard.
>
> Thanks,
> Jon