We have an application that requires fastening surface hardware through non-plated through holes in a multilayer PWB. A counterbore on the opposite side of the PWB is necessary so that the fastener does not protrude above the surface. For assembly reasons, the fastener needs to be retained in the PWB and successfully survive SMT reflow until the hardware is attached. We have tried PEM nuts and were not happy with the resulting laminate damage. The current thinking is to try tapping the non-plated through holes and inserting helicoils. I was wondering if anyone out there has successfully accomplished a similar design task? Also, I was wondering if there are board shops out there that have done this (i.e. tap/install helicoils)? To do this at module level would probably destroy the PWB solderability, etc.. Thanks in advance. Gerry *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************