Rudy, Because it was confined to the fine pitch areas, there may be a connection to residues but if the problem was solder mask residues, wouldn't the result be "non-wetting" with some visible areas of exposed copper? These boards were HASL'd by the supplier and they looked just fine. After they went through our IR process, some of the fine pitch pads do not stay fully wet with solder. No exposed copper can be seen, but on some of the finished solder connections ~20 - 30% of the pad surface refuses to allow the new solder to flow onto it. Generally these areas are from the outside of the pads inward. None were in the middle of the pad. At this point, I'm open to suggestions. Norm Dill [log in to unmask] ---------- From: TechNet-request To: TechNet Subject: Re: ASSY: Fine Pitch Dewetting? Date: Thursday, April 25, 1996 11:19AM Is it possible that the problem is coming from soldermask residues that the developer did not remove?? This would account for it not occuring in large pad areas, as the developer may have trouble getting into the very small areas. Rudy Sedlak RD Chemical ----------------------------- Original Post -------------------- Recently we have seen dewetting (~20 to 30%) that appears only on some of the fine pitch pads. Larger pads with various components on the same boards are ok. This has been seen on HASL boards from two different suppliers. There have been no reports of problems with our regular daily production lots. Any opinions would be welcomed.