hi, encounter few cases PCB was delam after reflow, and the supplier was refuse that this is a PCB manufacturing defect as the fallout is low within one lot. the cost for this scrap is high after PCBA level, my query here are 1) is there any way to determine or confirm the incoming bare PCB is good before reflow? 2) i know baking before use is good, but the long cycle time is not allow me to do that, can i reflow the PCB using normal profile before printing? if the bare pcb having problem , it will shown after the reflow and the cost is much more lower, any side impact if i reflow the bare pcb before solder paste printing? 3) autually, what are the potential factors for SMT process or environment can contribute to this delam issue?
I suggest you to do some EDX ananlysis or maping and make a comparsion between the delam part and the good one. maybe some contamination or element used in the board manufacturing process stayed under the coating layer. If there is some difference between the good one and the delam part, you can prove something to the supplier. take more note to the substance used in the manufacturing process.