Holiday Greetings to one and all, I have an 8 layer FR-4 board that was supposedly built IAW IPC-6011, Class 3 and IPC-6012, Class 3. The board itself appears to be like any other board, .062" thick, no unusual ground plane layers etc. After wave soldering this assembly severely warped. Looking at the bare boards, they are also warped, but can be shaped into a straight position by bending a little. (I shouldn't have to do this.) Not being up to date on board fabrication techniques, was there anything in the fab process that could lead to a warped board? We're talking a 3/16" warp over an 8" length.. Or was there something at my assembly end that is introducing the warp. The boards were run in a titanium picture frame pallet. Your thoughts and ideas are greatly appreciated. Bill Kasprzak Moog Inc., Electronic Assembly Engineering --------------------------------------------------------------------------------- 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 the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------