Cleaning solutions for ultrasonic cleaning of electronics?

[champagneandchips]

For those who are using ultrasonic cleaners for boards (and other computer related components, if applicable): What sort of cleaning solutions are you using, if any? There seem to be quite a few that seem suitable for use on electronics. Bonus points if they're available in the US
Also, any other tips and tricks you can share (or pitfalls to avoid) for someone just starting to use this would be appreciated!

 

[davidg5678]

I'm using Branson EC and distilled water in my ultrasonic cleaner: https://www.proequip.com/product/ec-electronics-cleaner/

This chemical works pretty well, although it's a bit pricy. I started out using a combination of dish soap and isopropyl alcohol in my ultrasonic tank ---I later discovered that this was a terrible idea, so I'd really advise against it. The isopropyl alcohol is a fire hazard when used in the ultrasonic cleaner, and the dish soap leaves a terrible white residue on all of the circuit boards. I recommend using distilled water instead of tap water because tap water leaves a terrible residue on the PCB as well.

 

[Fizzbinn]

In the States here, I couldn't easily find Branson EC a year ago when I was setting up my VEVOR 30L Ultrasonic Cleaner (although perhaps I didn't do such a good job searching...). I ended up going with this which was available on Amazon:

Elmasonic 800 0102 Elma TEC Clean A1 Ultrasonic Cleaner Solution Concentrate for Electronics and Optics
https://www.amazon.com/gp/product/B0725WP9Z9/

It seems to work well although admittedly I don't have anything to compare against!

As far as tips I use distilled water with 6% cleaner solution and heat to 65 degrees C (from Elmasonic instructions). To clean boards I then do 5-9 minutes per side (longer the dirtier the board seems, pretty subjective). I then rinse by submerging in isopropyl alcohol in plastic tray to displace the water, and dry in my regular kitchen oven on a silicon baking pad, with the board raised up on a couple wooden chopsticks to let the air circulate underneath. I use the warming setting 150 degrees F for 10-15 minutes per side (longer the bigger the board). Finally I let the board sit for a day or so propped up perpendicular to a small fan blowing on it before testing it out.

I had originally been thinking I would have to change the water/solution very often, maybe every couple boards but heard from others that is not that case. I recall someone who seems to know what he's doing much more than me said he changed his when it become too cloudy to see or something like that.

Also, my cats do not like the Ultrasonic cleaner.

 

[Elemenoh]

I'm also using the Elmasonic at the moment. It looks like the size I got in June 2021 is not out of stock. I think I got 2L or so for ~$83. I dilute to 5-7% with reverse osmosis water since I have 5 stage filter at home already.

It really would be great to figure out what the basic composition of the detergent is so we can make an inexpensive home version. It can't be that complicated, right?

 

[The House of Moth]

I use Branson EC as well. The boards end up looking like new is all I can say. Don't know if that's because of Branson EC or because of the cleaner ¯\_(ツ)_/¯ but since it gets the job done, I'll continue to use it for now.

 

[champagneandchips]

Regarding temp and duration - I've had some mild crud on a PCB from SMD caps leaking. I did 9 minutes at 65 Celsius (one side only) and not much came off, and I had to give it a good scrub afterwards to get everything off. How long do you typically leave your PCBs in the cleaner? 5-10 minutes is what I've read elsewhere, and I'm trying to be cautious as to not add any more damage to the PCB, but it doesn't quite seem to cut it. Is that per side? Would that add to the clean factor significantly? Thanks!

 

[The House of Moth]

Regarding temp and duration - I've had some mild crud on a PCB from SMD caps leaking. I did 9 minutes at 65 Celsius (one side only) and not much came off, and I had to give it a good scrub afterwards to get everything off. How long do you typically leave your PCBs in the cleaner? 5-10 minutes is what I've read elsewhere, and I'm trying to be cautious as to not add any more damage to the PCB, but it doesn't quite seem to cut it. Is that per side? Would that add to the clean factor significantly? Thanks!

10 minutes each side. For nasty boards I always pre-scrub/clean. Results are better and the cleaner solution lasts longer.

 

[Kai Robinson]

In the UK - i buy this, in 5 litre bottles: https://www.allendale-ultrasonics.c...sonic-cleaner-solution-5-litre-cleaning-fluid

Works well enough - although it can struggle with Amtech 559 flux.

 

[pocketscience]

I've got a 10L cleaner coming and am going to try this stuff which is produced locally here in Sydney - specifically calls out PCB cleaning and use with ultrasonic cleaners. It's pretty cheap (AUD$15/L), plus I can pick it up from local electronics store - so no shipping.