Confusion about distilled/deionized water for circuit board cleaning

[caphair]

I've been reading up on distilled and deionized water and I've come across conflicting information.

If compared to regular tap water there are little to no minerals, why are they used to clean circuit boards? Is it because they're "hungry" for ions so they actually strip away any corrosion caused by mineral deposits?

That's my take on it and it got me wondering if that then makes distilled/di water corrosive if it's accidentally used on electronics when not intended to as a cleaning agent?

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

Water is known as the universal solvent because of it's molecular shape. Oxygen in the middle and two hydrogen on the outside. That doesn't make it a problem except for salt and sugar. Why you use it is distilled water has no minerals to leave behind when it evaporates. Just like using any ultra pure solvents.

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

I came across this on a site which tells about the uses for deionised water
"Ultrasonic cleaning tanks – deionised water is extremely active cleaner and will pull ions from any surrounding metal, including stainless steel. As deionised water contains no ions of its own, it will always look to draw from its immediate surroundings and even the atmosphere"

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

So it makes it sound like the water is "stripping" the metals clean, thus my confusion

[Longbow]

Re: Confusion about distilled/deionized water for circuit board cleaning

More to the point is that you do not want to place any circuit board in water unless you are faced with certain death if you don't try something. Spills of corrosive liquids can sometimes be removed by careful brushing in warm water, IF the spill is very recent. But odds are not in your favor. Placing the board in an ultrasonic cleaner is insanity. Are you going to put your reputation on the line by doing something like that? I wouldn't.

Ultrasonic cleaning is for jewelry.

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

I've never done it but I've read about others doing so to clean water damage corrosion or flux etc.

That's what got me investigating why distilled water was often mentioned in this process

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

Well, I used to use an ultrasonic cleaner quite a bit in a laboratory years ago for circuit boards. It used trichlorotriflouroethane instead of water. Ha, spell checks got nothin' for that one. Anyway, you could use distilled water as well I suppose. With our cleaner you had to be careful because it would ruin some plastics. Any connectors you used you had to sacrifice one by dipping it in there before trusting the board to it.

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

So distilled water is used because it doesn't leave a residue behind? It has nothing to do with it cleaning contaminants because it "strips" them away due to its "hunger" for ions? Here's another excerpt from another site

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

As your excerpt says ultra pure is used in the semi conductor business because it leaves no contamination. If your looking to strip things, it's best to use something specific instead of water. The chemical we used was meant mostly for flux. It dissolved flux very well. Water would not. Yes water can strip steal, it's called rust. Those sites are being disingenuous. We used to use freon to clean tape residue in tape recorders. It removed the brown residue very well. In the days of digital tape you had to keep the heads clean. I never lost a tape because I cleaned the path before each use. I watched more lazy people chew up several tapes from a dirty tape path.

I've got a glass bottle here I got in the mid eighties. I use it on cassette deck heads. Works great. Trichlorotriflouroethane. Works great on tape paths, much better than alcohol.

[stj]

Re: Confusion about distilled/deionized water for circuit board cleaning

freon is best - too bad it's banned by environuts because of lies made by the usg.

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

It's still used in some ways. Trichlorotriflouroethane or freon 113 is used by the military for cleaning stuff. Freon is also used to pressurize waveguides in high power imaging radar systems. It keeps down the arcing in the waveguide. It's just illegal in your new car and refrigerator and AC system. If it was designed for the old freons you can still use it if you can find it.

[stj]

Re: Confusion about distilled/deionized water for circuit board cleaning

have you seen the price? even 20years ago it was priced like liquid silver!

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

I'm still confused why distilled water is used as a final wash of circuit board manufacturing. Does it strip flux etc or?

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

No, not really. It's cheaper, leaves no residue, and just gives a physical flush of all solder particles, dust, dirt, and grime. At least I would guess. I'm not an engineer. I don't work for the manufacturer. Just an old soldering iron jockey.

[stj]

Re: Confusion about distilled/deionized water for circuit board cleaning

pcb manufacturing uses water-based and soluable fluxes.

[caphair]

Re: Confusion about distilled/deionized water for circuit board cleaning

pcb manufacturing uses water-based and soluable fluxes.

Ah now it makes sense. So why do people use distilled water for water damaged boards? I can't see how it'd be a strong solvent for removing corrosion

[eccerr0r]

Re: Confusion about distilled/deionized water for circuit board cleaning

distilled water won't add additional salts to a water damaged board, that's about it...
It will wash ionic compounds created or left there where other solvents would leave behind.

[keeney123]

Re: Confusion about distilled/deionized water for circuit board cleaning

When you deionized water I would say that you lower the pH of water which makes it acidic which makes it corrosive to metals, but the mineral ion content is out of the water. Distilling takes other contaminates out of water. With that said when I worked on sub-micro particle analyzers our Chemist use to triple distill the water and deionize it. First she used sulfuric acid to clean the cuvettes. She then use triple distilled/deionized water to rinse out the cuvettes 25 times. She then filled the cuvette with the triple distilled/deionized water and then she put a 40nM sample into the cuvette using a filter to block out any larger particles than 40nM. She cap the cuvette and sealed the cap with tape. This was then put into a refrigerator. This sample had to be used for measurement with-in 3 days before the sample was no good as it would acquirer bacteria in it which would render it useless.

[stj]

Re: Confusion about distilled/deionized water for circuit board cleaning

most boards arent really "water" damaged,
it's milk, coffee, coke, piss, beer - the list is long.

your flushing the sticky mess off the board with the water.

[rhomanski]

Re: Confusion about distilled/deionized water for circuit board cleaning

Ha Ha Ha, that's funny. One night after a drunken party at college, I woke up in the top bunk and heard water hitting the floor. I rolled over and there was my roommate peeing on my other roommate in the dark. He woke up and started yelling. I rolled back over. They were both dicks anyway. Maybe the beer from the keg would cut the smell of pee?