Hello, I would like to survey flex and PCB manufacturers who supply controlled impedance product as to how conformance to the specification is typically monitored. More specifically... 1. Is it customary to measure samples from every manufacturing lot? 2. Do you measure samples of the customer design? Or do you measure impedance test coupons that are included in the panel for the express purpose of impedance verification/monitoring? 3. Does IPC, or any other standards organization, provide any standards for impedance test coupon use and/or design? Which have been most useful? Thanks in advance for any assistance. Mark _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx --------------------------------------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------