Question: We have boards with PEM® nuts being soldered during production. Has IPC established minimum soldering criteria for SMT PEM®s?
Answer: IPC has not addressed the specifics of PEM® nut soldering criteria. I would suggest using the criteria as defined in the Solder Connection Section of J-STD-001 or as defined in the Surface Mount Connector Section of the IPC-A-610.
This section describes the wetting of the solder to the physical part and the board itself. Keep in mind however, that a PEM® nut is inserted into the board with an interference fit, so it will be secure. The base of the PEM® nut should be on a non functional land/pad area on the PCB board to which it can be soldered and the securing hardware should originate on the opposite side of the PCB board.