Fellow Technetters, Occasionally we encounter a phenomenon of copper pads remaining after HASL. The copper pad is always a pad that is defined only by soldermask on a ground plane area. Usually it is square or rectangular and from .040" to .080" in dimension. Often small writing in the mask will also remain copper. We've checked: developer; strength, temp, spray pressures, rinse pressure, rinse temp developed the boards faster, slower, pad side up vs. pad side down We've checked: pre clean strength, temp, copper removal, tried faster ,slower , two times etc. new flux , old flux, spiked flux(HCL), longer solder dwell Is it possible that this is caused by the geometry of the pad? It creates a sort of inground pool with a mask border. Maybe it doesn't rinse or develop clean or maybe in the leveler it creates a vapor barrier that doesn't allow the solder contact with the copper. That job at the Ice Cream stand is looking better and better! Any input appreciated. Thanks Brett Austin Nationwide Circuits Inc. ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################