Another point in using press-in standoffs: Be sure to use these in laminate over .045 inch thick. Any less will bow the board during assembly and could fracture nearby joints or stress traces. Also, your assemblers should have the proper tooling. Without the proper support of the card during assembly, the standoffs can go in at odd angles; repair / realignment of these is next to impossible without messing up the hole. ---------- From: TechNet-request To: DesignerCouncil; TechNet; willli Subject: DES/FAB: PEMNUT FASTENERS IN FR4 FIBERGLASS -Reply Date: Thursday, July 11, 1996 8:25AM One word of caution when choosing your pad sizes and inner layer clearances, base them on the component diameter and not the specified hole size. The diameter of the part is normally some .015 larger than the finished hole size specified and should be taken into account in your design. Another problem that comes up is that many of these fasteners require a +.003, -.000 tolerance on the finished holes. When placing in nonplated holes this is not much of a problem. If using plated holes this tolerance is too tight for a large plated thru hole. We have been very successful using a +.004,-.001 finished hole size tolerance. [log in to unmask] *************************************************************************** * 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. * *************************************************************************** **************************************************************************** * The 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. * ****************************************************************************