Hello, We build connectors/sockets using laminates w/o copper and our connectors often are large and low profile. Since we promise 0.006" max flatness and coplanarity, warp and twist problems have to be monitored and controlled. There are a couple of things we have learnt. 1. weave/glass orientation in the laminate needs to be controlled 2. lamination presses do make a difference - Edge effects do lead to problems. Regards, Prashant --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------