Wet etching of aluminum and aluminum alloy layers may be achieved using
slightly heated (35-45 deg C) solutions of phosphoric acid, acetic acid,
nitric acid, and water. Again, the nitric acid consumes some of the
aluminum material to form an aluminum oxide layer. This oxide layer is then
dissolved by the phosphoric acid and water, as more Al2O3 is formed
simultaneously to keep the cycle going.

http://www.semiconfareast.com/wetetch2.htm







wrote in message
...
hi buddies,
i recently found some interested aluminium etching photos ,
http://giore.4t.com/aluminium.htm

which created some special corrosion process.
and i would like to using this technic into my projects.
do someone know the formula to make such corrosion process??

Thanks for helping

pleex