Mark - I encountered this situation a number of years back and ended up using a higher Tg laminate to reduce Z expansion during the HASL and soldering processes. This change was preceeded by a considerable amount of expensive TMA testing, etc. Suggest you take a close look at your post solder microsections - are the outer pads tilted? Do the coupons or the circuit boards show signs of pad edge separations on the vias? Both of these conditions are indicators of heavy expansion. We are currently using vias drilled at .010" diameter in boards up to .085" thick and 14 layers and are not experiencing the problems you describe. Note that we are using laminates with a 180C or higher Tg. If I can be of assistance, my PX is 256.882.4536. Regards - Kelly ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################