Setting up a non-ESD area in a lab

Question

this question is regarding standards and/or best practice guidelines for ESD control in a professional lab environment.

We are currently tightening up our (admittedly too lax) ESD control in the labs, in preparation for an audit. We've had a chance to see the audit results from another one of our labs and are working on all the things they failed on.

One of the issues we have is how to manage non-ESD areas in a Lab. The lab itself is marked off as an ESD protected area, and has suitable flooring. The lab in question is our 'construction' lab, which has a few soldering benches and general tools/equipment. The majority of it will be ESD protected and grounded as appropriate, but there is going to be a mechanical rework bench in the corner which will not be ESD protected. The bench will be a metal frame, with a thick piece of ply on top so you can hammer/drill/bash/whatever.

Does anybody have an idea as to what best practice/standards would say about non-ESD working areas in an ESD room? Would it be sufficient to just mark out the area? It has the same dissipative floor tiles underneath, is that an issue? Would you ground the metal frame of the mech. workbench?

It terms of geography, the room is isolated from the rest of the office by walls, has ESD flooring throughout the room and ESD walkway to the other labs. In order to walk to the mech. working area, you would need to walk through the ESD protected area. It is likely that workers will swap between the mech. work bench and the ESD-safe soldering bench.

Any thoughts?

Answer 1

Just to complete the circle, we passed the audit and it was acceptable to have a non-esd area in an other ESD protected lab. The only requirements were that the area is suitably marked out (we have tape with arrows on which indicated which side was ESD protected), and that anything highly charged is a good distance from EPA work areas.

A side comment regarding ESD audits and protection is everybody has a different idea what is ESD good, and what is not, what is required and what is overkill. By sticking to a fixed, official standard (in our case IEC 61340), we avoided conflicts of so called common sense and had black and white standards to adhere to.

Also training is an on going thing which often organisations can improve, but the biggest issue we had is that ESD was not really considered except when directly handling sensitive products. We had to replace or refurb a lot of racking shelves, furniture, tools, workbenches etc because ESD was not considered when they were bought.

Answer 2

Earthing everything just provides a path for discharges. The whole idea is that you try and prevent discharge via/thru the sensitive equipment and this involves, amongst other precautions, a mindset i.e. if you go into the area there is no guarantee that your body hasn't accumulated a few hundred or thousands of volts. You have to train people not to touch anything sensitive - instead they should touch the grounded areas first then they are able to work on equipment or move it around. Use of earth wristbands helps of course but somebody bringing some equipment in and placing it on an ESD bench is more than likely not to have been able to put on a wrist strap and if they just "plonk" the circuit or module down on the bench then all the charge accumulated flows through the electrical item and it could suffer.

Training, training and training.

Answer 3

Beware of the flooring materials, which can create static ie no carpets! Also the overall environment should be air conditioned to ensure that humidity is kept fairly high. Static becomes a problem in very dry environments