We have PCBs with blind vias. The fabrication process goes through two plating processes so the outer layers are quite thick. To offset this, the PCB supplier has proposed the use of 5 micron foil instead of 15 micron on the outer layers to reduce the thickness of the copper. Are there any drawbacks from using a thinner foil? Regards Edward Brunker Principal Process Engineer ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################