There were a number of material supplier's papers published a few years back at the various flex circuit conferences (IPC and others). Most included a list something like "Why use adhesiveless?". Here was my list: Lower CTE for more reliable PTH. Excellent thermal resistance for elevated temperature processing and use, wire bonding applications, and multiple lamination cycles. Thinner for greater flexibility, shorter heat transfer path, and space savings. Excellent dimensional stability for finer geometry features, and tighter tolerances. Single dielectric for uniform response to, plasma, laser and chemical processing, as well as improved electrical properties. Inherent flame retardancy. Low water absorption. These advantages were typically offset by higher cost, so they are not a magic bullet to all your problems. Andy Magee - Flex Guru Senior Consultant - Bourton Group [log in to unmask] (815) 490-7593 ############################################################## 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 ##############################################################