It is believed that there are three main types of charged bodies which cause electrostatic breakdown, the operator, equipment type, and the device itself.
A human body charged with static electricity will discharge upon making contact with an electronic device, such as an IC, resulting in electrostatic breakdown. When the charged object is a human body, the charge released is extremely large.
Equipment charged with static electricity will discharge upon making contact with a device. This may result in electrostatic breakdown.
The charge of the device itself is the cause of electrostatic breakdown.
Components in a charged state, upon contact with the machine frame or tooling, may result in static discharge.