Virtually any solder mask will bubble and flake when covering tin/lead. The solder melts under the mask and flows/puddles. During the melting, most adhesion to the liquid is lost. Since the mask should be fully cured by then, full strength adhesion is impossible, and non-adhesion can occur. I suspect that you also have solder balls/shorts on the sides of some traces, if you look hard enough. Go to HASL or OSP. Either option should eliminate this specific problem. ______________________________ Reply Separator _________________________________ Subject: [TECHNET] Solder mask material Author: JOHN OSULLIVAN <[log in to unmask]> at INTERNET