We have a customer who wants us to run a board that uses a 256 pin BGA. The
problem is, he has placed vias for signal routing in the center of the BGA
pads.  The vias are plated with a 10mil finished size.  There is no solder
mask tenting these vias on the bottom of the PCB.  I realize this isn't
normally recommended, but as they already have the boards, re-layout isn't
an option.  My question is basically, what types of problems will I have?  I
know I may get wicking of solder through the PTH, but given the hole size,
how bad is it likely to be?  Anyone have any experience attaching BGAs to
this type of pad configuration?

Thanks in advance.


Rick Thompson
Ventura Electronics Assembly
2665A Park Center Dr.
Simi Valley, CA 93065

+1 (805) 584-9858 voice
+1 (805) 584-1529 fax
[log in to unmask]

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