Hi Wee:
                  You can look at the archives and we'll see this
subject has been covered. Plugged up vias on one side only is very
common. It prevents solder from being thieved from the pads. Board
Fabricators can tell a lot more about this subject.
        Regards,
        Ramon 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wee Mei
Sent: Wednesday, January 18, 2006 10:46 PM
To: [log in to unmask]
Subject: [TN] Plugged via issue

Hello,

Recently I took over the inspection of bare boards and noticed that the
vias are plugged with solder mask and some has small drop overflow on
the pad surface. Some of the SMD packages have via-on-pads with 0.3mm
diameter via.
I cam concerned about solder reliability. The via diameter is 0.3mm and
during fabrication, they are pluged with solder mask.

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