Tim: This issue of solder spikes protruding from via usually occurs when the via is not cleared of solder (remains plugged) during HASL and then the via is capped or plugged with solder mask. If the solder mask plug is on the secondary side and that side is assembled first, then the solder will protrude from the primary side. The theory is that during the via solder mask cap process, air is entrapped between the mask plug and the solder. During reflow the air expands and the solder plug takes the path of least resistance and moves out the uncapped end of the via. The obvious fix is to change to OSP, or no via plugging, or the least desirable, have the fabricator increase the air pressure to assure that vias are not completely closed down with solder. Ryan ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################