# EPROM bonding wires



## solarnevo1 (May 26, 2017)

What kind of material is used in eprom for bonding wires? Tested with diluated nitric. Thin wires don't react with nitric? What kind of material can be? Aluminium is reacting with nitric. Platinum maybe?


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## g_axelsson (May 26, 2017)

Try a piece of aluminum in nitric and tell us what you found. :wink: 

Göran


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## goldsilverpro (May 26, 2017)

Probably 99+% of all bonding wires are: pure gold, aluminum, or copper. There are a few odd-ball ones out there but they seem to be quite rare.

Of these 3:

The yellow ones are always gold. An inch is worth from 0.5 to 1 cent per inch, depending on whether they are .0007" or .001" in diameter.

The white ones are aluminum. They are worthless.

I've never seen the copper bonding wires, except in pictures.
https://www.google.com/search?q=copper+bonding+wires&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZl8DugI7UAhVBzoMKHaHkDAYQ_AUICygC&biw=1138&bih=481


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## solarnevo1 (May 26, 2017)

Thanks for reply.


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## kurtak (May 27, 2017)

Aluminum does NOT react with nitric - it does react with HCl

In other words - nitric will not dissolve aluminum - HCl will

The point is - nitric is NOT the go to - test all - acid to determine if a metal is a precious metal (gold or PGM) or a base metal

Kurt


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## goldsilverpro (May 27, 2017)

Aluminum will react slowly with dilute nitric but it depends on the Al alloy. It doesn't react with strong nitric because an impervious aluminum oxide film forms on the surface of the Al due to the strong oxidizing action of the strong nitric. Al will, of course, react quickly with HCl or muriatic acid.


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