Technet, My Mechanical Engineers just brought something to my attention that I would like to get some opinions/advise/info from the TechNet expertise. We have recently switched from HASL to OSP (Entek 106 I believe) finish for our boards. We run a ground plane around the perimeter of boards and backplanes to help with EMI shielding and grounding in general. Their concern is with the change to OSP finish, we are seeing bare copper now that is tarnishing/oxidizing and is this still an acceptable grounding contact where it bolts to the chassis or contacts a cardcage? Other Questions : 1. When the board is processed (IR) does the OSP get removed or does it remain, and is it conductive or an insulator? 2. What are the options for having the ground perimeter copper finished so it won't oxidize and will provide a conductive surface for acceptable ground/EMI contact? I would appreciate any comments/opinions/advise. Thanks..........DT ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################