Laser Applications in Power Management IC Packaging

Power management integrated circuits (power management ICs or PMICs or PMU as unit) are integrated circuits for power management. A power management integrated circuit (PMIC) is used to manage power on an electronic devices or in modules on devices that may have a range of voltages. Two major issues have to be resolved in packaging PMIC, ie., thermal management and larger lead wire which incur problems of deflashing and bonding. In this paper, we presented some procedures and results when handling these issues by different laser modalities. A high power CW green laser was used to direct copper bonding and a medium power pulsed UV laser was used for deflashing. In both applications of laser the prerequisite is how to avoid damaging the he substrate or surrounding PI polymer since ablative irradiation is necessary.