Elucidating the large variation in ion diffusivity of microelectronic packaging materials

The risk of corrosion poses a challenge to meet the stringent reliability requirements microelectronic devices that are used in harsh environments. Microelectronic often encapsulated polymer packaging materials, which protect them from corrosion. These polymers are, however, not completely hermetic and thus allow small amounts ions moisture reach device, might cause circuitry. To improve predict it is important quantify ion diffusivity these materials. Previously reported values for vary by multiple orders magnitude single class material. Here, we investigate causes this discrepancy using three experimental methods: (i) saltwater immersion, (ii) diffusion cell measurements, (iii) transient electric current measurements. Several such as silicone, epoxy, polyamide, were tested cover broad spectrum microelectronics industry. We found discrepancies likely due strong dependence on both content within polymers, well salt concentration pH solutes. Furthermore, very low long measuring times, large errors contamination, leakage, or minor defects samples. • Reported diffusivities molding compounds magnitude. Three methods several materials study variation. Experimental conditions (e.g. temperature, pH, moisture) largely affect diffusion. H + was replace Mn 2+ cation increase Cl − polyamide. Ion epoxy resin above glass transition follows an Arrhenius relation.