My company is doing a project with a lot of QFN. The question that we are not sure is how to properly solder a QFN on a PCB. QA says The alignment tab on the side of the QFN should have a physical solder from the board, like a leaded chip. After reflow the QFN do have contact with the board already but no solder on the alignment tab. So we have no manually solder. Does anybody who works with QFN have any input on how to treat soldering a QFN?