Moisture Absorption Kinetics in Epoxy Molding Compounds
Epoxy molding compounds absorb moisture according to temperature-dependent diffusion rules, requiring strict MSL floor life management to avoid popcorning during reflow.
Dry Pack Packaging
Moisture Protection
Hermetic sealing of moisture-sensitive electronics prevents the absorption of atmospheric water during distribution and warehouse storage. The system of dry pack packaging combines a moisture barrier bag, a calculated desiccant charge, and a relative humidity indicator card to safeguard components. This assembly maintains the internal moisture levels well below the critical threshold where risk of reflow damage begins.
Barrier Integrity
Barrier bags used in this setup must meet strict standards for water vapor transmission rates and puncture resistance. Within a typical dry pack packaging flow, the pouch is heat-sealed under a partial vacuum to minimize the volume of trapped atmospheric air. The integrated humidity card provides a visual confirmation of the dry state when the pack is opened.
These elements work together to extend the shelf life of sensitive components.
Storage Standard
Metrology of this protective envelope involves weighing the package over long periods or analyzing the internal atmosphere of selected samples. This tracking reveals any micro-leaks in the heat seal or tears in the laminated aluminum layers of the pouch. The moisture transmission rate is measured at a reference temperature and humidity to ensure consistency with the specification.
These parameters dictate the formal expiration date of the pack.
Environmental Exposure
Environmental limits on the warehouse floor govern the maximum safe exposure time of the package prior to final assembly. Exceeding these storage limits requires that the components undergo a long baking process to drive out any moisture that has managed to seep through the barrier.