Over the years, engineers have produced smaller and smaller components, which operate at lower and lower voltages. Their goal is to reduce size, cost, and operational heat production. Those are worthy goals, but because of reduced component size, they present a smaller target with less resistance to power surges. This makes the parts more susceptible to damage from ESD.
The amount of damage and resulting problems caused by ESD can be divided into three categories:
- Catastrophic Failure: This is sometimes referred to as "frying" or "smoking" a part because of the heat (and sometimes the noise and smoke) generated during the failure. Mishandling and misapplication of a power source, cable, or test instrument are the most likely causes. Care in opening, installing, cabling, and testing are the best ways to prevent this type of ESD damage.
- Upset Failure: An ESD can produce an erratic fault in a component. This kind of problem is very difficult to detect and repair, because the failure is intermittent. It is easy to blame the operating system or a program operation for the data loss or system crash. The best way to diagnose and correct this type of problem is to remove and replace suspected parts until the failure stops appearing.
- Latent Failure: This type of failure weakens the actual transistor. The part will seem normal in most operations and will frequently pass quality control and conformance tests. Like upset failures, these can be very difficult to isolate.