Vacuum cleaner on PCBs = disaster?

[atmfjstc]

I was watching a computer restoration video where this guy de-dusted the PCB using a can of compressed air, and I wondered, why doesn't he use a vacuum cleaner? Then I thought a bit more and it seems to me like a vacuum cleaner might be a serious ESD hazard. The nozzle is plastic, thus a dielectric, and it's being rubbed constantly by the air rushing past. Seems like a good possibility it would develop a static charge under these conditions.

My question is, has anyone ever cleaned a PCB with vacuum in practice? Or had the misfortune of zapping it in this manner? Or am I just overthinking things?

[hsn93]

for something like Tower PC .. i use blower from distance .. i dont know if its bad or good idea 

[ender4171]

Your thinking is correct.  Vacuums create a lot of static, though usually it becomes a problem more when you are actually moving material through the tube as opposed to just air.  Big commercial dust extractions systems usually have a ground wire running through the hose/piping to combat this.  I don't know what (if any) sort of grounding residential vacuums use, but I wouldn't trust it on a delicate PCB.  That said, there are electric blowers you can use instead of expensive (and hugely wasteful/environmentally unfriendly) canned air.  I use the MetroVac DataVac, and it is wonderful.

[CatalinaWOW]

Blowing the dust out has a lot of issues.  It just moves it somewhere else.  On the PC board, on your bench, in your lungs or just into the air to re-settle later.  You can somewhat control this by having a vacuum/dust collector/exhaust fan nearby, but it really never works all that well.

I haven't had a traceable ESD incident to using a vacuum, but that proves little as most ESD damage goes undetected anyway, or shows up days, weeks or months after the exposure as a weakened component finally bites the dust.

I agree that the vacuum can build charges easily.  When using my shop vacuum to pick up wood dust I frequently get shocked - often several times a minute.  For those who generate fine dust by sanding there is a real hazard of a dust explosion which is why serious dust collection systems have formal grounding schemes.  But I don't ever recall being shocked by the house vacuum I have used on PCBs.  There may be a conductive component in the plastic, the volume of air may be enough lower to prevent the problem, or the charge build up mechanism may depend on the heavy particle load I see in the shop.

If you are concerned it is really easy to set up a conductive nozzle of copper tubing or the like and ground that.  Any charge that builds up in the piping system is isolated from your PCB.

[GreyWoolfe]

If you want to vacuum your PC case out, there are ESD safe vacuums.  I have known field technicians that one was part of their field kit.  They are expensive though, easily into 100's of dollars for a quality unit.  Not something someone will have for casual use.  If I get froggy enough to clean my computers, I take them outside and use canned air to blow the crap out.

Catalina, never had that problem myself.  I have a Rigid 16 gal shop vac, this is my second one and I vacuum sawdust off the floor and my big tools without a problem.  I also live in Flori-DUH where there is always humidity, even in the winter.

[John B]

I take them outside and use an air compressor, definitely not something you want to do indoors. Those "air dusters" never seemed very ethical to me, just dumping hydrocarbons or HFCs into the *actual* air to blow dust around.

Also, a vacuum won't be able to move dust in all the little crevices, whereas a jet of air will be able to.

[CatalinaWOW]

Yep, the shock from the shop vac is not a consistent thing.  Drier air is involved and probably a couple of other variables.  But when it does happen it is a very unpleasant tingle felt through the forearms.  Every time it happens I think about ways to fix it, but am too busy at the moment.  And then I get a few uses when the problem doesn't occur.

[james_s]

When I want to clean dust off circuit boards I wash them in the sink with a bit of dish soap and a soft bristled brush, then rinse thoroughly with hot water and allow to dry overnight. Sounds crazy but it works fine, if you live somewhere with minerals in the water a distilled water or alcohol rinse is probably not a bad idea. Drying can be accelerated by warming in a low temperature oven or placing near a space heater.

[wizard69]

We use a variety of vacuum systems at work to move plastics around.   The static build up can be massive like ending people to the hospital massive.   We use ionizers of various types to negate the charge build up.   So yeah there is a real potential here to do significant damage with a static discharge.   One nasty with respect to charge built up on plastics is that simply grounding the plastic will not discharge the plastic completely due to its non conductivity.   Franky that was learned the heard way when ground wires did nothing to stop shocks form static discharge.

As somebody else has mentioned there re a variety of factors at play with charge build up as what you get away with one day might not work the next.   I might suggest though that metal hoses and extensions can still be found which can then be grounded to your chassis.

[paulca]

For cleaning a clogged up PC I just use a soft paint brush to loosen the dust and the vacuum to inhale the cloud that comes off.  Never had issues.

A technique which is probably less recommended, but again, never had issues, is to use the vacuum to spin the fans up, then stuff the paint brush into them while spinning to clean the blades.

[Zero999]

Irrespective of whether you're using a vacuum or compressed air, avoid spinning the fan, because it can generate high voltages (remember motors act as generators when spun fast) which can destroy the fan's internal BLDC driver circuitry, along with other components connected to it. Always keep the fan blades still with your fingers or a piece of wood (avoid metal, which can damage fan blades) whist cleaning with air.

[AVGresponding]

I've used a vac and a brush for decades without an issue, though I don't work with anything hugely sensitive.

Also as Zero999 says, hold the fan blades; in any case it makes them easier to dust off with the brush when they're still.

The UK is pretty damp most of the time so I expect that mitigates static issues for the average hobbyist...   

[xmetal]

I use a combination of a toner vac, brush and Giotto blower. The toner vac has ESD safe tools and pipe. They work well.

[tszaboo]

Not to mention the vacuum can remove those jumpers, and then your 486SX could suddenly run at a much slower frequency, and your second ISA card will have all sorts of issues. You can even lose a hard drive because of addressing problem on the IDE bus.

[paulca]

I did once hoover the bus select jumper out of an IDE drive.  Then I had to spend 20 minutes trying to find it in the dust bag as I had no replacement.