It is FR-4 in molded polycarbonate housing. ________________________________ From: [log in to unmask] [mailto:[log in to unmask]] Sent: Wednesday, August 09, 2006 7:44 PM To: James Verrette; [log in to unmask] Subject: Re: [TN] Routed edge tolerance Hi Jim, I do not know what kind of housing you are putting your PCB in, but from your outline description I am guessing some cast housing. You are also not giving us a clue about your application. You are also talking about punching instead of routing, so i am guessing CEM-3 instead of FR-4 as the PCB material. In that case, your routing tolerances are your least problem; much more worrisome are likely the different thermal expansions of the PCB and the housing as well as swelling of the CEM-3 with moisture absorption. GM ran into this with their windshield wiper controls: single-sided CEM-3 PCBs in some combination of routing and housing tolerances requiring press-fitting the PCBs. The result: windshield wiper failures for some of the more high-end [read: high-powered=running hotter] SUVs within as little as 1 year after sale due to solder joint failures caused by PCB warping-over 4 million vehicles were ordered by NHSTA to be recalled. Werner --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 -----------------------------------------------------