Reliability of hybrid encapsulation based on fluorinated polymeric materials

A new class of polymeric materials [1] synthesized from fluorinated precursors to produce network molecules of epoxies and polyurethanes has been analyzed as a hybrid encapsulation material. Using test structures, a microthin film (Au-Al2O3) moisture sensor and Auger/SIMS analysis, the moisture penetration kinetics for the fluorinated network polymeric materials (FNP) has been determined. It was determined that the activation energy for moisture penetration varied from 0.7 to 1.1 eV at relative humidity (RH) between 20-95 percent. Interdigitated test structures were utilized in order to study the migrative resistive short (MGRS) phenomenon in the hybrids encapsulated with the FNP material. The results show that for a surface ionic contamination level of 10¹⁴Na⁺/cm²on the encapsulant surface, RH of 95 percent and temperature cycle of +100 to -10°C migrative resistance shorts were not observed after 100 cycles of total duration of 4 h per cycle.