Is there any consern with ESD when using air-compressor for cleaning with air-gun?

[David_]

Hello.

I was about to buy a air-compressor, one of those with large containers on them that turn on and stores some volume of compressed air that can then be used to blow things clean with a air-gun or whatever those tools are called.

I need such a tool for general cleaning of my work bench and hopefully circuit boards as opposed to cleaning them with a brush, I will get ESD safe brushes but still compressed air would be ideal, unless...

Unless, if the compressed-air striking the circuit board at both high speed and in high volume could have any ESD implications, I really have no idea and am simply looking for someone to elaborate on a hunch I have.

Could this cause ESD events/complications?
and if so are there any solution, maybe something like connecting the hole compressor to my work bench ESD ground system... Although I don't know why that would help since the thing that I got a hunch about was simply the friction of the air particles.

Regards

 

[c_mitra]

if the compressed-air striking the circuit board at both high speed and in high volume could have any ESD implications...

I would say absolutely none (or zero).

ESD is produced when two surfaces experience force sufficient to transfer one electron from one surface to another. In this case, the molecules must experience sufficient transfer of energy during collision to cause ionization. It cannot happen under the present conditions. However, consider a single dust particle that may have considerable kinetic energy to knock off electrons from the surface it hits. So, you need to filter the compressed air.

Friction of the air particles (or molecules) is a myth; they have collisions and these are all elastic collisions (inelastic collisions transfer energy to some internal degrees of freedom).

 

[andre_luis]

Ideally, there should be no concern in this regard, but if the air aspirated to the compressor entry has contamination of suspended dust and if the equipment produces static electricity at any part of its inner body due to friction with that particles, I do not think we could to state that it is strictly unlikely to happens damage to sensitive electronic components, indeed not due to ESD itself, but due to charged particles, therefore for this application in particular I would not consider at all useless to think of providing some level of earthing in the compartment right before the nozzle of the air compressor such as a grounded metal mesh or something else, despite not being sure of the effectiveness of this.

 

[Kajunbee]

A good moisture separator also. You don't want to give it a bath when you squeeze the trigger.

 

[Relayer]

If you're wearing any nylon garments, there is a risk of your body creating a charge, and if you were to
hold the metal nozzle (unlikely), then you could discharge electrostatic voltage to the PCB via legs of
components.
Have you ever wondered why on certain days you go to touch the door handle of a car, only to get
zapped by ESD? Its usually due to nylon garments or you just previously walked on carpet with nylon
fibers within it.
Regards,
Relayer

 

[Kajunbee]

It also seems like humidity also has and effect on static build up. I noticed that after a cold front would pass through and the temp and humidity dropped my truck door would zap me so hard it hurt. I'm not sure if it was the lower humidity the cold are a combination of the two but it sure was annoying.

- - - Updated - - -

There are anti static blow off guns and ionizing guns on the web.

 

[c_mitra]

... I noticed that after a cold front would pass through and the temp and humidity dropped my truck door would zap me so hard it hurt. ...

In fact the temp has no role in the static build up; but lower temp means lower humidity and that means lesser dissipation of charges. Water molecules are easily ionized and hence can carry away charges more happily.

It is not the truck that zapped you, most likely you collected lots of static and it got discharged via the truck (that has conducting tyres). The voltages can be as high as 20kV but the total charge is small and the effect is usually harmless.

 

[BradtheRad]

I read something about the need to use a horsehair brush nozzle, if you want to avoid static charge when vacuuming electronic devices. If it's a brush made from plastic fibers, you risk static buildup as air rushes at high speed. Your compressor blowing air may or may not generate the same effect but it might affect your choice of materials for hose and attachments.

 

[c_mitra]

I read something about the need to use a horsehair brush nozzle, if you want to avoid static charge when vacuuming electronic devices. If it's a brush made from plastic fibers, you risk static buildup as air rushes at high speed. Your compressor blowing air may or may not generate the same effect but it might affect your choice of materials for hose and attachments.

I agree completely and you should vacuum without using a brush. If you have done some wet cleaning, the vacuum-ing will help it dry faster. Blow compressed air using the smallest nozzle