The heavy components on a cell phone PCB are reinforced with spot applications of adhesive to the PCB. Filling the entire cell phone with epoxy wouldn’t help.

The heavy components on a cell phone PCB are reinforced with spot applications of adhesive to the PCB. Filling the entire cell phone with epoxy wouldn’t help. The parts that break on drops are external like the screen. This SD card was enclosed in a sealed metal container so it wasn’t exposed to water.