Thermal analysis of printed circuit board degradation in a supercritical CO₂ environment

The bonding material used in printed circuit boards (PCBs), a brominated epoxy resin, should degrade in an oxygen-free environment when the temperature is 300 °C or above, and this is the theoretical basis for recycling PCBs via thermal decomposition. But in the supercritical CO₂ fluid environment, the epoxy resin should be incompletely pyrogenated at 260 °C. In this paper, a thermal analysis model of PCBs under high temperature and pressure is established, so the thermal stress that exists inside PCBs is described, and the results indicate that the thermal stress can promote the delamination and decomposition of PCBs in supercritical CO₂ environments.