Singulation of semiconductor package by superposition of pulsed fiber laser and green YAG laser

Abstract

The application of laser beam processing has been expected in the field of semiconductor devices because of its flexible cutting line and narrow kerf width. However, the deterioration of cutting quality would occur in the case of themosensitive materials due to the thermal damage, since the laser beam processing is mainly thermal process. Therefore, the laser singulation method by the superposition of pulsed fiber laser and green YAG laser was proposed to perform the high-quality processing for the semiconductor package, which is consisted of thermosetting epoxy-resin with silica for molding compounds and glass epoxy board for semiconductor package with insulator coatings. The superposition of pulsed fiber laser and green YAG laser with high pulse repetition rates led to a straighter kerf shape with smaller kerf width under the same pulse energy condition. The smaller kerf width could be achieved by controlling the time delay between both laser pulses compared with synchronized laser pulses. The heat affected zone in singulation process could be reduced by the superposition of pulsed fiber laser and green YAG laser. Moreover, the synchronized laser pulses could lead to the smaller heat affected zone compared with unsynchronized one.The application of laser beam processing has been expected in the field of semiconductor devices because of its flexible cutting line and narrow kerf width. However, the deterioration of cutting quality would occur in the case of themosensitive materials due to the thermal damage, since the laser beam processing is mainly thermal process. Therefore, the laser singulation method by the superposition of pulsed fiber laser and green YAG laser was proposed to perform the high-quality processing for the semiconductor package, which is consisted of thermosetting epoxy-resin with silica for molding compounds and glass epoxy board for semiconductor package with insulator coatings. The superposition of pulsed fiber laser and green YAG laser with high pulse repetition rates led to a straighter kerf shape with smaller kerf width under the same pulse energy condition. The smaller kerf width could be achieved by controlling the time delay between both laser pulses compared with synchronized laser pulses. The heat affe...