Given current market conditions for precious metals, avoiding gold is
a premium on making a device as inexpensively as possible. Gold
etching is pretty easy, as naturally is making gold ball bonds to gold
bond pads. I'm going to try to lightly wet etch my aluminum right
before bonding and see if that works. Also I can try an Ar sputter
etch of th he aluminum to clean off the bond sites. I have to be
careful not to etch off any thin, small devices (non-Al).

I'll keep consulting Harman's book. Anyone have a good source for an
inexpensive bond-pull tester? I'd like to quantify my bond strength.
Something for a small fab or lab.

Thanks,
Jon

On 1/26/09, Morten Aarøe  wrote:
> 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
>

Dr. Jon R. Fox
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