Shaun

I suggest that you do not use tin/lead plated part with gold socket.  The 
contact interface will become unstable and contact integrity will be 
compromised.  The circuit will experience intermittent and/or open after a 
while, depending on the operating condition.  Tin/lead WILL form oxide and 
cause contact resistance to increase to the undesirable level.  This effect 
will be greatly accelerated by contacting gold due to the galvanic effect.  
In fact, any dissimilar metal contact is not recommended.  Furthermore, 
micro-motions between the contact interface will probably move (smear) gold 
and tin/lead around, which does not help in this situation.     

Kuan-Shaur Lei, Ph.D.
Senior Member of Technical Staff
Advanced Technology Department
Compaq Computer Corporation
(281) 518-8099 (phone)
e-mail: [log in to unmask]



Date: Mon, 2 Dec 1996 08:29:54 -0600
From: [log in to unmask] (SDalton)
To: [log in to unmask]
Subject: Gold migration into tin/lead
Message-ID: <[log in to unmask]>
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     Has anyone heard of problems with seating a tin/lead leaded part into 
     a gold socket?  I have heard concerns that the gold will migrate into 
     the tin/lead even though it is only a mechanical connection.  I would 
     appreciate any input you can give me on this issue.  
     
     Thanks,
     
     Shaun Dalton
     [log in to unmask]
     


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