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February 2008

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Subject:
From:
Drew meyer <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Drew meyer <[log in to unmask]>
Date:
Mon, 25 Feb 2008 14:02:36 -0600
Content-Type:
text/plain
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text/plain (26 lines)
Vladimir,

Not wrong in context.  I did not state one important fact.  After attempting to 
remove the gold the PCB manufacturer lays down another layer of nickel.  
Thus reflow consumes the second gold layer into the solder joint.  

On an inffectively stripped PCB, after reflow, you have the following.

From the pad up to the solder joint. 
copper, nickel, gold, nickel, intermetallic, solder

The gold interface between the nickel layers is very weak and yields at very 
low levels of stress.

Drew

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