SOLDER JOINT INTEGRITY IMPACT OF IMMERSION SILVER SURFACE FINISH THICKNESS FOR TIN/LEAD AND LEAD-FREE SOLDER PROCESSES

摘要

An Institute of Printed Circuits (IPC) Plating Processes subcommittee 4-14 test program was undertaken to assess how printed wiring board immersion silver plating thickness impacts solder joint integrity. The study compared typical immersion silver plating thicknesses against extreme immersion plating thicknesses for a set of standard electronic component types used on printed circuit boards. The investigation test results demonstrated that the immersion silver printed wiring board surface finish thickness in both a tin/lead and a lead-free soldering process did impact the solder joint integrity for a -55°C to +125°C thermal cycle temperature range. A recommendation was made to review the current IPC-4553 maximum immersion silver plating thickness value and consider implementing a maximum immersion silver surface thickness in the 15-30 micro-inch range