Pads sit on top of the circuit board and make an electrical connection to the USB connector. The most common type of failures are lifted/torn pads. The USB connector is firmly attached to the circuit board which isn’t a problem for slight bumps but if the connector is bent with force, for example by dropping the flash drive while connected to a laptop it can break the connector or circuit board. SanDisk flash drives use a durable circuit board design to withstand the rigors of normal wear and tear however this durability can also be a flaw. They’re very well constructed from their firmware to their circuit board.
SanDisk Cruzer flash drives are built to last.