Jim, send me the stack-up specifics and I will check the model for you. I have 2 different modeling programs. At 07:28 AM 11/15/2005, you wrote: >Hello, > >If there are any impedance testing gurus out there I have a question for >you. We are testing an edge coupled offset strip line coupon. We modeled >the stack up to give us 100 ohms differential. When we test the coupon we >get around 130 ohms. We have done a microsection of the coupon and modeled >the coupon data and Polar says we should have 105 ohms, within tolerance. >We had a 4 panel lot and it is consistent across the board. The coupon is >constructed correctly. My question is, other than what I am seeing on the >microsection should I look for to find the culprit of the high reading? Any >help would be great. > >Jim Henderson >Colonial Circuits > >--------------------------------------------------- >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 >----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------