Glass Ball Grid Array Arrangement and Characterization for Capacitive Proximity Sensor

In this paper, we proposed a novel capacitive sensor. It was constituted by the parallel enameled copper wires as the electrodes. This sensor can be used to detect the yield ratio of micro assembled glass ball grid array (GBGA). The vacancy of the GBGA causes the capacitance drop, so we can detect the yield ratio of the micro-assembly process of GBGA by monitoring the change of the capacitance. Additionally, we measured the capacitance variation of the relative displacement about the copper wires and the GBGA in longitudinal and transverse directions. The measurements of capacitance variation in longitudinal relative displacement have stepwise features. These features have not been seen in other capacitive proximity sensors.