When we made the switch to LPI, Dry film was too thick for the surface mount components to reach the pads. Although I'm sure that is not the case any more, I'll stick with what is already working. One advantage of LPI over dry film is rework. Occasionally we will need to cut and jump circuitry. You just can't cut through dry film mask, it's too tough. That's a good thing, but it's a trade off. By the way, we do specify our vias to be filled with LPI before the regular solder mask is applied. Larry Campbell Supervisor, PWB BFGoodrich, Avionics Systems >>> <[log in to unmask]> 11/11/97 05:41pm >>> Among the ways of sealing vias on LPI solder masked boards are a) filling the vias with LPI, and b) tenting the vias with dry film solder mask. We are on the brink of converting from dry film to LPI on all our PCB's. I would appreciate any comments on the relative merits/demerits of boards produced by these two processes. Our supplier recommends the dry film option. Our boards are sometimes in relatively harsh environments and are designed to operate from -40 C to +70 C. Thanks to those of you who responded to my inquiry on how to repair urethane conformally coated boards which have been contaminated with silicone prior to conformal coating. ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ############################################################## ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################