What JaMi says about EMI testing has been my experience as well. The UL FCC CSA VDE, etc, etc ..., agency typically has a disclaimer in their documentation that indicates that the evaluation and licensing to use their approval sticker/logo on your product is only for the product submitted to be tested 'AS IS'. Any changes to the product, including changes to the board layer stacking after approval, would have to go through the agency for re-approval before making the change or shipping any product. Otherwise you would have to remove their logo and not advertise, sell, or ship your product with the label... that's where the legal stuff happens, they can bring suit for unauthorized use of their logo on your product etc.. etc... (Where's Judge Judy when you need her?) At any rate, any of us that have gone through agency approval are familiar with that requirement... and typically we get stopped at CCB for the changes to get routed to the agency for review and testing if needed. Some changes are not tested but approved on 'similar' design criteria, and that judgment is made by the agency reviewer or inspector. For some of you this is TMI - ( too much information ) but I'm sure it applies in some designers cases. (Is the Monday?) :) Bill Brooks -----Original Message----- From: JaMi Smith [mailto:[log in to unmask]] Sent: Monday, June 09, 2003 2:11 PM To: [log in to unmask] Subject: Re: [DC] Core thickness/emissions Alexis. Please see below. JaMi > ----- Original Message ----- > From: "Alexis Meehan" <[log in to unmask]> > To: <[log in to unmask]> > Sent: Monday, June 09, 2003 1:14 PM > Subject: Re: [DC] Core thickness/emissions > > . . . I have worked with many engineers who have approved > stackup changes such as this one. In those cases, the boards must have passed > EMI with a very wide margin so that a change in thickness would not affect that > particular test. Clearly, this is not the case with this particular board. . . . > While I will preface my response by stating the fact that not all PC boards require emissions testing, and that occasionally some companies and or engineers will perform emissions testing on something that is not required to have such testing performed, regulatorily speaking, that is the excepton to the rule, and the exception to the following statement. IT IS UNLAWFUL TO CHANGE THE STACKUP, OR ANYTHING ELSE ABOUT THE PC BOARD ONCE THE EMISSIONS TESTING HAS BEEN COMPLETED, UNLESS YOU PERFORM NEW EMISSIONS TESTING. PERIOD ! ! ! NO EXCEPTIONS ! ! ! ALEXIS, YOU NEED TO KNOW THIS ! ! ! ALEXIS, YOU NEED TO UNDERSTAND THIS ! ! ! ALEXIS, YOU NEED TO TELL THIS TO ANYONE WHO WANTS TO SUGGEST TO YOU THAT YOU MODIFY THE BOARD IN ANY MANNER WHATSOEVER, AFTER THEY HAVE GONE THRU EMISSIONS TESTING, WHETHER IT IS YOUR BOSS, OR AN ENGINEER, OR A BOARD HOUSE ! ! ! ANY CHANGE TO THE PC BOARD INVALIDATES THE EMISSIONS TEST ! ! ! PERIOD ! ! ! I apologize if this is rude or if this is unprofessional, but you just don't seem to get the point. It is not just bad design practice, or bad engineering practice, it is against the law. JaMi ---------------------------------------------------------------------------- ----- DesignerCouncil 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 DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- DesignerCouncil 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 DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil 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 ---------------------------------------------------------------------------------