| Author |
Question About ESD
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| RoRsChAcH_4 2003-03-26, 10:35 am |
| I read the bible and now in the process of taking prep tests to find out any areas i need to study for. I came around this question and wanted to know your guys opinion.
ESD can be reduced by installing?
1. A UPS
2. A dehumidifier
3. Adequate grounding
4. Server Rack
The correct answer the book says is 2. But wouldnt a dehumidifier take moisture out of the air causing more static? Wouldnt a humidifier be the correct answer since it puts moisture in the air reducing static? Also i take the test April 5th!
 Cant wait to get this one out of the way! | |
| Supertech 2003-03-26, 11:09 am |
| Why does high humidity affect electrostatic devices? Simple: it makes surfaces conductive enough to "short out" the devices. Under high-humidity conditions, insulating surfaces can behave as a dead short, almost like metal, even though their resistance remains too high to easily measure.
A subject of debate. Optimum humidity is typically 30-60%. Dry winter conditions can also be ripe for ESD, but wet will get you in trouble quicker than dry. Humidity control is only one factor in the control of ESD and proper grounding and materials handling is paramount. | |
| RoRsChAcH_4 2003-03-26, 11:17 am |
| Thanks Super!!! That makes sense. I knew that high humidity caused moisture to build up on components which could short them out but i didn’t think that was ESD. I was on the line thinking that a short out from moisture wans't static discharge. But a short out is a short out either from moisture or static. Again thanks! | |
| tohrt 2003-03-27, 11:26 am |
| quote:
Originally posted by Supertech
Why does high humidity affect electrostatic devices? Simple: it makes surfaces conductive enough to "short out" the devices. Under high-humidity conditions, insulating surfaces can behave as a dead short, almost like metal, even though their resistance remains too high to easily measure.
A subject of debate. Optimum humidity is typically 30-60%. Dry winter conditions can also be ripe for ESD, but wet will get you in trouble quicker than dry. Humidity control is only one factor in the control of ESD and proper grounding and materials handling is paramount.
Not that I'm the definative authority on the subject, but that is the first time in a long time I've seen it explained properly.
Kudos Supertech
I just hate to see "someones opinion" on what an answer is when asked by another trying to learn the correct answer.
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| azimuth40 2003-03-27, 12:18 pm |
| This question keeps coming up. Here is a basic tutorial.
http://www.midwestesd.org/fundesd1.html
Make sure that you grab all six parts, although part 1 is the theory piece. This is by the ESD association whos members concern themselves with ESD in the manufacturing workplace, including preventing explosions.
After reading it you my find that the
question posed is kind of ambiguous unless it has multiple answers. Three seems a better canidate for best answer. The Association normally beats on grounding grounding and more grounding.
For ESD horror stories try here
http://www.esdjournal.com/
Another link specific to electronic devices is
http://www.static-sol.com/61340-5-1/welcome.htm | |
| azimuth40 2003-03-28, 2:22 pm |
| You might find this picture interesting to remember the next time you see a sales person handling your new bare DIMM at the same time he is ringing up your purchase. This is from Rohm Electronics and the chip appears to work (I imagine most of the time)  |
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