Good morning all, Lately we have run into several situations where it appears the old tried and true polarity marking conventions for capacitors and diodes no longer apply on SMT parts. The customary silkscreen "+" to denote the anode end of the device appears to still be in use. However, the actual part marking (band, or dot, or chamfered edge or other polarity key) is now showing up on either the anode or the cathode, depending on how the OEM or supplier decides to mark the device. It has become necessary to question each polarized placement of a SMT diode or polarized capacitor when setting up assembly instructions or programming pick & place profiles. So, what happened to part marking convention in this regard? I don't believe any marking changes have taken place in the plated through hole world in regard to diodes and caps. But suppliers of the SMT versions of these devices are not necessarily following any marking conventions. They appear to simply mark the device in the manner they find acceptable, then define the marking (if you're lucky) in their data sheets. Doesn't help much once the parts are placed incorrectly and the inspection team thinks they are placed correctly per the visual part markings that have been a standard over the years. Is there any movement afoot to get some industry standardization of SMT part polarity markings in place? Maybe through SMTA? If so, I'd like to join the effort to make sure some standardization occurs in this area. Thanks for your feedback in advance! Dale Ritzen Quality Manager Austin Manufacturing Services --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 -----------------------------------------------------