The rare event detection experiments have always been updated with the improved performance of the electronics. In the next phase of China Dark Matter EXperiment (CDEX), the electronics have been designed with detector crystal barely immersed in 6.5 m shielding thickness of liquid nitrogen. The flexible electronic substrate (FES) composed electronics are required to be with high adhesion, low-temperature resistance and low-background. Polytetrafluoroethylene (PTFE) is widely recognized with properties of low-background, high dielectric but with poor surface adhesion. Here we focus on the comparative behavior of ion implanted polymers with cross-linking or chain scission dominant effects, and analyse the surface adhesion mechanism of polymers, to lay an important foundation for achieving electronic substrates with high adhesion, low-temperature resistance, and low-background.