Hi Cedric,

What's your latest pot analysis say?

Just as a personal note, in all my experience over the last 24-years, I've
only had a pot go bad because of low tin content, and it never looked like
that.

You send those pieces that you show in the pictures out for analysis and see
what comes back...

Steve

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Cedric ORAIN
Sent: Monday, January 17, 2011 2:57 PM
To: [log in to unmask]
Subject: [TN] Board failure due to fibber like fragments of alloy after wave
soldering

After wave soldering of boards with both SMD and PTH components, 18% of the
boards failed during ICT.
The failure is due to shorts between SMD pads. 

These shorts are caused by "fibber like" fragments entrapped in solder
joints. We are looking for root cause of this level of waste.

These fragments are very similar in aspect with dross that we found on the
top of the wave "head" after the pump stop. You can see dross picture in the
pictures posted here:

http://ipc-technet.groupsite.com/gallery/17663

The alloy is Sn63Pb37 and the flux is an alcohol based no-clean flux.
Soldering under air atmosphere. The design of the board is ok. Dross is
removed daily.

Did you ever encountered this kind of issue (I mean with such a rate of
defect)?
I'm wondering if the aspect of the dross shown in the picture is normal or
is it due to a pollution (metallic pollution: high Cu rate?? / organic
pollution : epoxy, fiber glass fragments ...). 

Thanks for your in advance for your help and support,

Best regards,

Cedric ORAIN



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