I just join with the electronic manufacturing because previous one resigned and my job is take care ESD control. I have some questions need to clarify about electrical/pneumatic screwdriver. So the pervious guy set the specification for electrical/pneumatic screwdriver per below. Are these specification correct? Could you please advise?
Electrical screwdriver
Resistance electrical screwdriver 's body to ground less than 2 ohm
Resistance electrical screwdriver 's tip to ground less than 10 Kohm
Leakage voltage between tip and ground less than 1 Vac (during bit rotation)
Pneumatic screwdriver
Resistance pneumatic screwdriver 's tip to ground less than 1 Mohm
Hello Natthawee,
There are no formal specifications for hand tools such as electrical/pneumatic screwdrivers. There are specifications on isolated conductors. In this case, the tip of the screwdriver is not considered an isolated conductor, based on the the tip to ground resistance, so this requirement is fine. You will not find this in any of the ESD Association documents at this time.
Thank you for your answer. As I understood the resistance requirement limit still can use the resistance tip to ground less than 10 Kohm.
But please advice for tip voltage leakage requirement, Is there ESD/EOS risk for electrical hand tools?
Because I have a plan to revise document for requirement.
Thank you.
The only leakage requirement that is specified is for soldering/desoldering tools. In ANSI/ESD S20.20 that is a qualification requirement only, not a compliance verification requirements. The requirement for soldering irons is a tip voltage of less than 20 millivolts. The reason for this was an issue found a long time ago that the heating element in a soldering iron could generate some voltage and current when the heat was cycled. The issue was improper grounding or no grounding of the tip of the soldering iron.
Again, for any other hand tool, specifications do not exist for tip voltage.