Thermal management solutions and design guidelines for silicon based photonic integrated modules

In this study, thermal design and thermal management for a low-cost photonic integrated circuits (PIC) platform is proposed and analyzed. The involved PIC platform is targeted for various applications including optical communications, optical interconnects, signal processing and sensing. The module considered in this study consists of a rigid PCB made of FR4 material and a silicon photonics ICs platform on which a laser diode chip, a driver chip, and a trans-impedance amplifier (TIA) chip are jointed using solder balls. A kovar case is chosen for the module. For the thermal design and thermal management, two objectives are involved in this study. The first one is to reduce the thermal resistance from junction to ambient and the other one is to reduce the thermal cross talk between the driver/TIA chips and laser source chip. The following accomplishments are achieved in this study. The overall junction to ambient thermal resistance is reduced to a certain level and meets the design target. The thermal cross effect between the driver/TIA chips and the laser source chip is reduced by cutting a slot in the silicon photonic platform and implementing separated heat spreaders for these chips.