I have seen a few threads about delamination issues on IS410 laminate in RoHS applications. I have recently been running into a rash of issues on 4 different part numbers with a single PWB source. All the parts have been built fine in the past with no issues - there were no changes to process or mterials but we are now finding problems. Isola is giving us a major push about moisture in the boards but we don't bake anything in one of our facilities and have had no issues - the facility with the problems have been baking everything for 2 hours at 125 degrees. I saw many people changed sources or laminates or both but I was wondering if any definitive reasons have been found by anyone. The only definite similarity so far is the IS410 laminate with a resin to glass failure in the prepreg which happened to all be 7628 prepreg. I have changed a couple of the parts to 370HR and they seem to be working but I would like to have a better understanding of the problem if I can.
Any help is appreciated.