ASSESSMENT OF PACKAGING MEDIA USED IN LONG-TERM STORAGE OF ELECTRONIC COMPONENTS

Abstract

Companies that produce end-products with long-term sustainment requirements undertake long-term storage as one of the measures to overcome the problem of electronic component obsolescence. To protect the components from environmental degradation during storage, they are packed inside vacuum sealed moisture barrier bags along with desiccants and humidity indicator cards. The desiccants have a specific adsorption capacity at a particular temperature / relative humidity condition. They cannot absorb the moisture permeated through the moisture barrier bag beyond that capacity. The relative humidity inside the moisture barrier bag also changes during long-term storage. This thesis provides a methodology to estimate the time to reach the desiccant's adsorption capacity and to estimate the increase in relative humidity inside the moisture barrier bag. The methodology is based on the experimental results and the first principle physical equations used for moisture permeation and adsorption. Based on these estimations, companies can decide on replacement schedules for moisture barrier bags and desiccants, thus protecting the electronic components contained within moisture barrier bags from humidity-related reliability issues.