High Temperature Hygroscopic Swelling of Polymers in Electronic Packaging

Polymers used in electronic packaging can absorb moisture from the environment and swell, causing serious reliability and assembly issues. However, to this day, moisture swelling properties are not readily available - especially at high temperatures. This paper builds on a novel experimental concept that maintains specimens in a saturated state while measuring high temperature material swelling using digital image correlation (DIC). With this method, different materials such as dielectric build-up films (DBF), epoxy mold compounds (EMC) and solder resist (SR) were evaluated. The resultant hygro-swelling properties were compared against dynamic mechanical analyzer (DMA) measurements and other published data.