Terri, Don't mean to barge in like this but in the "good old" days of wine, roses, and the MX missile system as line was drawn in the sand, or rigid flex as it was. The MX never flew because it had a total of 79 layers of rigid flex circuitry. One supporting board had 22 layers and continually failed. It delaminated in several ways and areas. TMA analysis revealed delamination way below expectations due to the acrylic adhesive used then. Later, after the program was scrapped, folks like Marty Jawitz (anyone remember Marty) at Litton Guidance Systems came up with a requirement limiting all rigid flex designs to 11 layers. Have some pretty ugly pictures from that era. Probably you and others have answers overcoming the adhesive problem, cold flowing at room temperature (Tg of about 70 or so F.). Sure like to get updated on what those answers might be. MoonMan --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------