Co-planarity of IC-pins

The term „co-planarity“ discribes the proper seating of the tips of fine-pitch device leads on the copper pads on a PCB prior to solder process. The coplanarity is a critical dimension for the quality of the soldered joints, because no reliable and correct soldering can be done if there is a gap between the lead and the pad. In state of the art automatic assembly machines the co-planarity of components is measured during the assembling process. The component to be measured is passed over a triangulation displacement sensor which has a laser beam that scans the row of pins.