eeTimes eeTimes eeTimes
Forgot password Register
Print - Send - -

Technology News

Reliability of IEC 61000-4-2 ESD testing on components

August 10, 2008 | | 210001914
Testing using the IEC systems-level standard tends to provide ambiguous results for components; here's some info on understanding how to reconcile device-level checks with this spec, especially when it comes to the reliability of air discharge results.
Page 1 of 6

Testing for immunity to electrostatic discharge (ESD), from cell phones to computers, is usually done with the IEC 61000-4-2 standard.1 But IEC61000-4-2 is purely a systems-level test spec, not a spec for individual components. Components manufacturers are thus forced to define test plans without the guidance of a standard, and test results coming from different component manufacturers may differ considerably. So what does components testing to this standard mean? Here are the main issues to consider, particularly with respect to contact-discharge versus air-discharge results.

Contact-discharge testing
There are four recommended stress levels for contact discharge (conducting surfaces) and air discharge (insulating surfaces). Many systems are specified to pass at the highest defined levels in the standard (8 kV for contact discharge, and 15 kV for air discharge). In contact-discharge testing,2 the ESD gun is charged, the tip of the gun is placed against the object to be stressed and a relay inside the gun is closed, initiating the stress. IEC 61000-4-2 specifies a waveform for contact-level testing (Figure 1). The current waveform is characterized by an initial current spike with a rise time of 0.7 to 1.0 ns and specified currents at 30 ns and 60 ns. The current levels scale linearly with voltage from 2000 to 8000 volts. At 8000 volts, the peak current is 30 amps and the 30-ns and 60-ns current levels are 53, and 27 percent, of the peak current, respectively. Those familiar with component-level ESD testing will likely assume that contact discharge testing according to IEC 61000-4-2 is done similar to Human Body Model testing. The specified waveform is forced into one device pin, while one or more other pins are held at ground, which is the assumption made by manufacturers such as ON Semiconductor. The test that ON Semiconductor applies on its devices is to stress each pin 10 times positive and 10 times negative at each voltage.

1 | 2 | 3 | 4 | 5 | 6 | Next page

Please login to post your comment - click here
Related News
Technical papers
Do you find reference designs help speed your design cycle?