Paymon,



I would be VERY curious to know how anyone could come up with the numbers from that kind of EDS analysis.



Regards,



Vladimir



----- Original Message -----

From: TechNet <[log in to unmask]>

To: [log in to unmask] <[log in to unmask]>

Sent: Thu Oct 09 09:57:20 2008

Subject: [TN] PCB pad non-wetting issues



Hello All,



 



We are experiencing a pad non-wetting issue for the though-hole

component pads ONLY! The PCB goes through few heat cycles with top and

bottom side assembly during at SMT process and then through-hole

assembly at wave process. The problem is found at Wave process. The Pb

solder does not wet to the through-hole component pads on the solder

side only! An SEM/EDS evaluation revealed high concentration of P in the

Nickel and Nickel/Tin intermetalic layer of 11% to 21%. I would like to

ask anyone if they have experienced a similar defect in the past. What

is the Root Cause?



 



Thank you in advance,



Paymon





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