Singulation Characteristics of Semiconductor Package Using Pulsed Fiber Laser and SHG:YAG Laser

A laser singulation method by the superposition of a pulsed fiber laser and an SHG:YAG laser (SHG: Second Harmonic Generation) was proposed to perform the high-quality processing of semiconductor packages, which are consisted of thermosetting epoxy-resin with silica as the molding compounds and a glass epoxy board with insulator coatings for the semiconductor package. The superposition of the pulsed fiber laser and SHG:YAG laser with a high pulse repetition rate led to a straighter kerf shape with a smaller kerf width under the same pulse energy condition. A smaller kerf width was achieved by controlling the time-delay between the laser pulses compared with synchronized laser pulses. The heat affected zone from the cut surface was reduced by the superposition of the pulsed fiber laser and SHG:YAG laser. Moreover, synchronized laser pulses led to a smaller heat affected zone compared with unsynchronized pulses.