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Question on ANSI/ESD-S20.20-1999

Ashok Dhawan

#4115

Question on ANSI/ESD-S20.20-1999 | 16 May, 2000

1) I had downloaded ANSI/ESD-S20.20-1999 from www.eosesd.org web site. I am not clear whether section 6.2.3.2 is correct. It states that " All process essential insulators that have electrostatic fields that exceed 2000 volts should be kept at a minimum distance of 12 inches from ESDS items." Should it not be 200 volts ( or 100 Volts) ? In the preface Section 2.0 Scope where the standard states that "......susceptible to damage by electrostatic discharge greater than or equal to 100 volts Human Body Model." Old revision ( 1994) of EIA-625 indicates 11.Methods for minimizing static charging as +/- 200 volts. That tells me there could be error in latest document of ANSI/ESD-S20.20-1999. Any user who is user of the document and can provide more info on that.This has created a lot of confusion as far as interpretation of document is concerned.

Ashok

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#4116

Re: Question on ANSI/ESD-S20.20-1999 | 16 May, 2000

Ashok: Hey guy ... snow starting to melt yet?

Keeping process insultaors with a charge of over 2kv a foot from ESDS items seems reasonable. The HBM assumes contact with the item, so it should have a lower potential.

You should double check with EOS/ESD crew.

Good luck Dave F

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Dave K

#4117

Re: Question on ANSI/ESD-S20.20-1999 | 17 May, 2000

2K at 12 inches seems high considering that degradation can take place at anything over 200v. If I recall correctly we required at least 3 feet of distance.

It's been a while since I've been an ESD coordinator. Thank god that chapter in my life is over. Not even the big bosses support you! (And that's at a major fortune 500 company)

DSK

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#4118

Re: Question on ANSI/ESD-S20.20-1999 | 26 May, 2000

Guys: Folk at EOSEAD told me two things on this: 1 Yes "All process essential insulators that have electrostatic fields that exceed 2000 volts should be kept at a minimum distance of 12 inches from ESDS items." is correct. 2 The latest revision to EIA 625 (now JESD 625) has an upper limit of 1000 volts for charged insulators.

Dave F

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