What to Look for From Your Board Supplier When Changing to an Alternate Surface Finish to HASL

Over the last five to eight years the use of HASL alternatives by the OEM’s and CM’s has increased dramatically,particularly in response to increasing board density and the need for a solderable planar surface that increases their yields at assembly. The chemical industry has responded to meet the needs of the OEM’s but unfortunately some of the product offerings and the manner in which they were installed were less than stellar. This paper outlines for the OEM / CM engineer/auditor some of the areas that should be examined in more detail than might otherwise happen. The information outlined should also be used for surface finish engineers at PWB fab houses that might be new to a finish and may possibly save them from some very late nights on a line trying to understand a problem.