Jon,

I would refer you to the classic book:

Wire Bonding in Microelectronics: Materials, Processes, Reliability,
and Yield
By George G. Harman

There is lots of information on many wire bonding techniques and
materials.  In particular, you may want to  read about the
intermetallics formed between Al and Au at high temperatures (purple
plague).

Brad


On Jan 23, 2009, at 12:54 PM, 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


Brad Cantos
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http://holage.com

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