# Silver colored fingers????



## Paige (May 6, 2007)

In the midst of my cutting my gold fingers, I have come across a large number of boards whose fingers are a silver color. It doesn't look like silver. Does anyone have any guess as to what metal would be substitututed for gold? Palladium?


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## lazersteve (May 6, 2007)

The 'silver' is tin/lead solder.


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## goldsilverpro (May 7, 2007)

I have run across Rhodium fingers. In the late '60's, early '70's, there were several companies using it. I have heard that rhodium has been used more recently than that on fingers. If I remember right, the rhodium had a slight bluish cast to it. To test for it, dissolve the copper and nickel underneath and the rhodium will flake off, like gold.

I have also heard that a white Au/Pd alloy has been used.

In any case, you won't find silver on fingers. Silver migrates between the circuit traces in the board material and causes partial shorts.


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## lazersteve (May 7, 2007)

To test just mix up a batch of acid peroxide (2 parts HCl + 1 Part H2O2).

Soak the fingers in question for 5-10 minutes. If the 'silver' color disappears the coating is not Rhodium or white gold. 

Steve


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## Paige (May 7, 2007)

Thank you all for your input.

Paige


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## Destroyer (Jun 10, 2007)

I had the same problem I boxed them up and shipped them back to who I got them from. If that is an option I would try it, if they sold it to you based on Gold content.


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## Charlena (Jun 12, 2007)

ok i decided to wait and do more homework on the chips themselves to see if i can get the exacts as to whats on them....
what about SIPPs
you know pre-fingers memory?
what would those silver colored pins have on them...anyone?




lazersteve said:


> To test just mix up a batch of acid peroxide (2 parts HCl + 1 Part H2O2).
> 
> Soak the fingers in question for 5-10 minutes. If the 'silver' color disappears the coating is not Rhodium or white gold.
> 
> Steve


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