There are two different series of IPC specifications concerning boards: the 2221 and 2222 concern the design of the boards the 6011 and 6012 standards concern how the board is built and the properties obtained in fabrication. Also there is a covering standard for rigid board materials - 4101. You may want to go to _http://www.ipc.org/4.0_Knowledge/4.1_Standards/revstat1.htm_ (http://www.ipc.org/4.0_Knowledge/4.1_Standards/revstat1.htm) to see if you have the latest revision of a document in hand. --------------------------------------------------- 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 -----------------------------------------------------