Technical questions

Good morning

Do metallic accessories on an Esd mat that goes into contact with ESDS components and interact with previously grounded personnel meet the standar?

Should these devices be grounded directly using wire with a <1 Ohms range?

Example, accessories,brackets,etc.
Excelent day.

Hello Jgarcia4,

First of all, do these items come into contact with ESDS items by design or is this a question of if they accidently come into contact.

If these items are suppose to come into contact with an ESDS item, then you must evaluate them to see if they are a threat. First, can you ground them. I the resistance to ground of any conductive item is less than 1x10*9 ohms, they are not considered isolated conductors.

If these items are greater than 1x10*9 ohms and cannot be grounded, then you must ensure that they do not carry a voltage greater then +35 volts or less than -35 volts. The best way to measure this is to use a high impedance contact voltmeter as this will give the most accurate result. A non contact voltmeter could be used but the results may not be accurate.

Grounding the items with a wire would work and a voltage measurement would not be required.

good day
That’s right, these metal accessories come into contact with ESDS elements by design. because its function is to cut terminals.
The question is:
currently, we have the item in a mat, who have a resistance 1x10*8 (combinated the mat with the item/fixture), according with that, are we complying? or, it’s is necessary to use a ground connection of less than 1 ohm as you mentioned with a wire
thanks for the support

In the next version of ANSI/ESD S20.20, there are two definitions that will help. They are;
conductor. A material that measures less than 1.0 x 104 ohms point to point.
isolated conductor. A conductor that measures greater than or equal to 1.0 x 10
9 ohms from the contact point of the ESD sensitive (ESDS) item to ground.

If you measure less than 1x10*9 ohm to ground, the conductor is not an isolated conductor and meets the requirements of a grounded conductor.