Even within electrostatic breakdowns, device electrostatic breakdowns can be divided into 3 main types.
Occurs when the gate oxide film of a MOS transistor or other such devices breaks down.
This breakdown is not caused by discharge, but rather the difference in potential from the charge of the device.
Occurs when excess voltage is placed in the reverse-bias direction (The opposite direction from which current normally flows) of a PN joint, and the resulting heat causes the joint to break down.
However, breakdown may also occur even when running excessive current in the standard direction, not only in the reverse-bias direction.
Occurs when resulting heat from running excess current beyond that which is allowable, causes the pattern to fuse or become welded.