How electro-static charges cause damage – Teledyne 6200E - Sulfides Analyzer User Manual

Page 266

A Primer on Electro-Static Discharge

Model 6200E Instruction Manual

266

M6200E Rev: A1

Table 12-1: Static Generation Voltages for Typical Activities

MEANS OF GENERATION

65-90%

10-25%

Walking across nylon carpet

1,500V

35,000V

Walking across vinyl tile

250V

12,000V

Worker at bench

100V

6,000V

Poly bag picked up from

bench

1,200V 20,000V

Moving around in a chair
padded with urethane foam

1,500V 18,000V

12.2. How Electro-Static Charges Cause Damage

Damage to components occurs when these static charges come in contact with an electronic
device. Current flows as the charge moves along the conductive circuitry of the device and the
typically very high voltage levels of the charge overheat the delicate traces of the integrated

circuits, melting them or even vaporizing parts of them. When examined by microscope the
damage caused by electro-static discharge looks a lot like tiny bomb craters littered across the

landscape of the component’s circuitry.

A quick comparison of the values in Table 12-1 with the those shown in the Table 12-2, listing

device susceptibility levels, shows why Semiconductor Reliability News estimates that
approximately 60% of device failures are the result of damage due to electro-static discharge.

Table 12-2: Sensitivity of Electronic Devices to Damage by ESD

DAMAGE SUSCEPTIBILITY

VOLTAGE RANGE

DEVICE

DAMAGE BEGINS

OCCURRING AT

CATASTROPHIC

DAMAGE AT

MOSFET 10

100

VMOS 30

1800

NMOS 60

100

GaAsFET 60

2000

EPROM 100

100

JFET 140

7000

SAW 150

500

Op-AMP 190

2500

CMOS 200

3000

Schottky Diodes 300

2500

Film Resistors

300

3000

This Film
Resistors

300 7000

ECL 500 500
SCR 500 1000
Schottky TTL

500

2500