Packaging High Temperature Electronics for Harsh Flight Environments

Today’s high-power photodiode is perhaps one of the high temperature electronics (HTEs) that requires the highest dissipated heat density. Herein, Phase Sensitive Innovations (PSI) propose to develop a uni- travelling carrier (UTC) photodiode package that has significantly higher saturation power than the current high-speed photodiodes based on hybrid integration of the photodiode structure on high thermal conductivity substrates and optimization of the thermal interface conductance (TIC). In phase I period, we will build a comprehensive thermal model for the high-power UTC photodiode structure. This model will be verified experimentally using a time domain thermal reflectance (TDTR) approach developed by our subcontractor in University of Delaware (UD). New interface materials such like TiN and TiB 2 will be studied to improve the TIC at the metal / dielectric substrate boundary. In addition, basic fabrication processes such as die bonding and wafer bonding will be studied for the hybrid integration of photodiode epi-structures with high temperature substrates (HTSs) such as diamond and SiC. Approved for Public Release | 22-MDA-11215 (27 Jul 22)