Ultrasonic Cleaners and ESD

[badferday]

Hi all!

I'm looking at ultrasonic cleaners and can't seem to find one that is explicitely listed as ESD. The closest I found is a product that claims to be safe for circuit boards, but their photo doesn't show any boards with soldered on chips or other components I have not yet mastered removing and reattaching. So I wanted some input.

I have a few options.

1. Coat the pan with a material that is chemically inert, anti-static and heat resistant. I'll have to spot repair if it gets dinged. No biggie.
   
   
2. Ground the pan (304 stainless steel) through my ESD mat (https://www.ifixit.com/products/portable-anti-static-mat). I would do this by 1) installing a snap at another corner from the existing snap, 2) using the existing snap to ground to earth as I always do, 3) using the new snap to ground the pan to the mat. I figure with several decimetres of dissipative mat (10^7 - 10^9 Ω) between the two snaps, this would simulate placing the pan and its contents directly onto the mat. I could put the pan-side connection on the outer corner of the pan, or in the pan where the liquid would be, but I think in the pan is overkill... and I'm the queen of overkill!!
   
   
3. Chill out and just use the cleaner as stock. I know someone is going to suggest this, so I'm pre-empting that suggestion. Please don't. The way my mind is wired does not allow me to consider this option. Now if there is a concern about safety (to the circuitry) in suggestions 1 or 2, I am def interested in that.

I'm favouring approach #2, since it will mean I will also ground myself when I touch the outside of the pan, and [I think] that should act like a Farraday cage to ensure any static I have accumulated before touching the pan doesn't transfer to the board).

I know distilled water is considered isolative, but I dunno what conductive properties it may gain when I dissolve a cleaning agent in there, so I want to assume the cleaning medium is conductive.

Thoughts?

 

[max1zzz]

The cleaners should come pretty much wired for option 2 from the factory, the metal housing and steel pan of the unit will be connected to mains ground so as long as you are connected to a grounded outlet static buildup on the pan should not be a issue. If your still worried you can go with option 2 but given the metal pan is already ground to earth it would not have much of a effect as the existing ground path is lower resistance

Personally I wouldn't go with option 1 as it is likely any coating will not stick long term, with long enough exposure ultrasonic cleaners will take the silkscreen off chips so it is likely that over the long term any coating would just start flaking off

 

[phunguss]

I am not an electrical engineer, nor a professional circuit board repair person, so take it with a grain of salt. In the 40 years of handing all types of electronics with no ESD protection of any kind (I wear socks on carpet a lot), I have only personally experienced one single component failure due to ESD. The failure was an Ethernet controller on a wifi router for a F.I.R.S.T robotics build.

 

[badferday]

The cleaners should come pretty much wired for option 2 from the factory, the metal housing and steel pan of the unit will be connected to mains ground so as long as you are connected to a grounded outlet static buildup on the pan should not be a issue. If your still worried you can go with option 2 but given the metal pan is already ground to earth it would not have much of a effect as the existing ground path is lower resistance

Personally I wouldn't go with option 1 as it is likely any coating will not stick long term, with long enough exposure ultrasonic cleaners will take the silkscreen off chips so it is likely that over the long term any coating would just start flaking off

Oh, nice. I guess the only advantage of my approach would be slower dissipation, but I'm sure they've accounted for that in the design if they're saying it's safe for "circuit boards". They coulda just added "and integrated circuits" and called it a day, but I suppose an unpopulated circuit board wouldn't be in danger from ESD anyways.

And their customer support didn't know the answer.

Off to order mine now!

 

[badferday]

I am not an electrical engineer, nor a professional circuit board repair person, so take it with a grain of salt. In the 40 years of handing all types of electronics with no ESD protection of any kind (I wear socks on carpet a lot), I have only personally experienced one single component failure due to ESD. The failure was an Ethernet controller on a wifi router for a F.I.R.S.T robotics build.

I'm one of those possibility over probability types. Haha.

 

[badferday]

What y'all think about this one? I like the horizontal pan dimensions. Not so in love with how deep, but this is pretty much the best fit for compact mac lobos and ATX mobos. A bit too small for analog boards, but I can clean them in two parts I guess.

Ultrasonic Cleaning: Professional Ultrasonic Machine with Heater, Timer, and Dual Mode 15L

Experience advanced cleaning with our 360W Ultrasonic Cleaner. Perfect for makeup sponges, retainers, auto, and machine parts. Enjoy timed cleaning, adjustable heating, and protective modes. Get yours for effective, chemical-free cleaning!

www.creworksequipment.com

 

[Branchus]

What y'all think about this one?

That one looks pretty good to me. It has 360W of cleaning power, which means it will have 6 x 60W transducers. The rule of thumb is 25W per litre of liquid, so 360W is perfect for 15L. It has 600W heating power, which is a lot, so it should heat up nice and quickly. The price looks good too.