On Tue, Aug 21, 2012 at 3:07 PM, Neil wrote: > After seeing some flaky soldermask over the years, I'm scared to do this > do to possible shorts. > > -Neil Yes, I wouldn't say it's ideal but If I had solder mask that wasn't insulating traces then I would be worried about using the PCB at all. Also: QFNs are on the surface of the board, so they can trap cleaning solvents or flux from the manufacturing process. It's another reason why you have to be careful with assembly. Another point: vias can suck heat away from QFN pads making them difficult to solder. When I'm autorouting a board I put a nice big rectangle under and around QFNs on the via-restrict layer. --=20 Martin K. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .