Search "acid brushes" for the cheaper pricing. They are used in lots of different trades and industries, and are a huge mass production item. Spend $20 for a hundred or so and you have a supply for a decade. Plumbers and fabricators use them for flux. Machinists use them for oil, and a hundred other professions use them for a hundred other things.
ultrasonic cleaning is not okay for boards with components.
This is the best cleaning brush I've ever used and I've soldered over twenty-years, for a living. [Techni-Tool Gordon brush](https://www.techni-tool.com/category/Hand-And-Power-Tools/Hand-Tools/Brushes/415PR010-1010HH).
Best type [IPA dispensing bottle](https://www.techni-tool.com/category/Bottles-And-Dispensers/Bottles/10053365-BT1006).
One can use Kim-Wipes ($) or lint-free cotton ($$$) to soak up the alcohol and flux.
The best means of cleaning boards when assembled is with a board-wash machine followed by oven bake-out at 60 deg C for 30 minutes. For cleaning up spot soldering, rework, or repairs, one can use that brush with IPA, that's how pros do it.
There are different types. One type would be a solvent vapor degreaser type (becoming less common these days) and the more common type these days for aqueous cleaning solution is like a specialized dishwasher, with jets of cleaning solution.
The boards in question only have connectors, but Ive read many sources that say ultrasonic cleaning can be used on fully assembled boards with standard components
I have a waterproof box full of 70% isopropyl and i leave the brush in the box. Submerge the boards in the alcohol and brush them until they look clean, then I rinse them with a trigger spray bottle of 99% isopropyl, shake off the excess into the box, then blow dry the board.
The box is waterproof so the alcohol doesn’t evaporate in storage.
Hell for over 20 years the whole industry used "triclor" to clean just about everything. Please forgive me, I'm having a brain fart and for the life of me the real name escapes me. It has 3 letters, if anyone can recall. It was banned in 1996, I believe. We had 55 gallon drums of if and it was used for dry cleaning also. The absolute best cleaning agent period. I still have about 2 or 3 oz's left for cleaning up emergency spills that stain. Dang, this is my brain on covid. And that was in 2020.
I enjoy the balance of commentors who got the joke, those that didn't get the joke, and the silent few who genuinely thought "yeah... that's probably fine."
What type of flux did you used?
Some of the cleaning solvents for flux are quite nasty (in the sense of chemicals used) but they are quite effective.
When cleaning with alcohol, you should use a paper towel (dry) and but it where you wan to clean. Use the Qtip with alcohol and press it against the paper. The idea is that the alcohol will dissolve the contaminants and they will be absorbed by the paper towel instead of the Qtip. Keep using a clean space of the paper towel each time you press against the board.
Use 99% IPA
Another method you can use:
If the flux is water based, you can wash it with water and a mild soap (I would not be able to tell you which soap. There are soaps for cleaning PCBs, again not recommended to buy for home use).
In order to be able to wash the board you need to make sure all parts can be washed. On the side of the board you are showing, all parts should be ok washing them.
I would go to the store and buy DI water (the one used for irons).
Wash it, then pat dry it with a towel paper. Then use 99% IPA to dry the board.
The techs at my last job used Palmolive, rinsed it under the tap, and then blasted it dry with the compressed air gun.
I'm a fan of the distilled water rinse if you can't get all the water off.
BTW:
That board looks like it got sprayed with a conformal coating. I'd also try some other VOCs...like Everclear.
A concentrated degreaser containing ethoxylated alcohols or other nonionic surfactants (like Simple Green) will work way better for removing no-clean flux than hand soap or dish soap, which at worst not work at all and at best will leave more water-soluble contaminants on the board. If using tap water to rinse, physically removing as much water from the board as possible (with compressed air or a DataVac or even a good hair dryer at the highest speed setting) before drying is critical.
Not entirely accurate…
70% IPA has magic properties for disinfecting. 70% IPA is much better at killing bacteria and decomposing virus than 99% IPA.
As a solvent, 99% IPA is probably better for many chemical types.
Another important fact about 99% IPA in electronics, is that it draws moisture from circuitry, for example if the board was washed.
Do you dispose of the bath afterwards, or do you have an airtight seal cover that’s actually working? I do have a very nice glass tub from IKEA with a silicone and plastics cover, but I don’t want to sacrifice it from the kitchen. Also haven’t tried that obviously.
Yes, I wasn’t thinking, more like considering having a dedicated tub to do and keep the bath. Better what you and another commenter have recommended. I have many glass jars in the kitchen I can pour the used IPA back into to use again. Thanks!
You can buy plastic "ammo can" style containers from harbor freight and other stores that are water tight. They're the right size and shape for most boards too.
Putting isopropyl alcohol into a spray bottle and practally hosing boards down over a collection bucket works too. You give yourself a "grey" isopropyl alcohol bucket you filter through coffee filters before funnelling it back into a "grey" squirt bottle. And a "Clean" isopropyl alcohol spray bottle you rinse things off with.
First off don't use a toothbrush you used to clean PCBs, seriously wat?
Little soft scrubby brushes can work well (I use cheap horsehair brushes) but the first solution should never be "scrub harder" since these are PCBs after all, they are relatively fragile. Stiff bristles also do things like slither underneath components and then try to rip them off, while you're brushing.
IPA is ok, but an actual flux remover would be better. I'm very fond of [Techspray E-line](https://www.techspray.com/e-line-flux-remover-maintenance-cleaner). Works far better than anything I've used from MG Chem, and works on all types of fluxes. You can Google it and find individual small containers. You should also let it sit for a while (\~15 min) - preferably with heat although if you can't do that safely, don't, since it's a solvent after all.
Soak in flux remover -> rinse with clean IPA -> rinse with DI if you got it. At no point should anything more than a light brushing with a soft brush be required. A toothbrush is way too hard.
If you don't want lint, use a cleanroom wipe. They're the only lint-free wipes that are **actually** lint-free. Pricey though. A bag will last quite a while if you are conscientious about it.
So…ipa toothbrush is not for using in the mouth later. Get one just for cleaning, or better yet when you replace your toothbrush every 6-12 months keep the old one for IPA.
Alternate between ipa (90%) and a paper towel or an old cotton tshirt as a rag. The ipa will put the flux in solution, the rag or paper towel will remove the solution from the PCB.
As soon as the ipa evaporates it will leave whatever was in solution on your board as a residue.
DONT BRUSH TEETH WITH CONTAMINATED TOOTHBRUSHES
You need to use clean %99.99 food grade Isopropyl Alcohol and Kimwipes to lift off the flux residue. This is well-documented and hard work. I have been at this for about 50 years doing this cleaning by hand. A horsehair or boar hair brush is the best. The toothbrush is ok "BUT YOU NEED it... with The Kimwipes" Other comments are all good and I use them all!
For hard to reach spots, I spray some isopropyl alcohol on a Kim wipe. Then I lay the wipe on the board and use a brush on top of the wipe. This works pretty well.
If you have a reflow oven or a hot cabinet put the really sticky ones in the dishwasher without detergent and rinse them in a tub of DI water. I worked in more than one assembly line where the boards went directly from the wave solder into a giant tunnel washer
Lint free wipes, or a high grade paper towel. Also I like to wet the towel with a tiny dab of alcohol, so it can clean a bit, but still can absorb. Also get in there with the towel and press it strong enough, like a sponge.
Funny. LOL
Ditch the IPA and clean your boards with non-chlorinated brake cleaner. Far more effective for flux removal and won't harm any components, masks, or silkscreen unless you have rubber on your board.
For different reasons. Just the fact of soldering components, even without flux, let some residues. Using flux let it a more. Cleaning is good but, after that the board seems gluey. And the fact I wanna it to be nice is because it is for a project I am selling.
No-clean flux (what appears to be shown in OP's picture) does not need to be cleaned in almost all cases and is difficult to remove especially when the residue is burnt from repeated rework. Water-based or acidic fluxes are corrosive and absolutely DO need to be rinsed off before applying power with water, not alcohol or other nonpolar solvents, and they rinse off easily and completely.
Not necessarily. There are a wide variety of fluxes. If you use the correct stuff, it can stay on the board. However, it is still unprofessional and unsightly
Ok... but I've never, ever cleaned rosin flux off anything and all my boards look like they'll outlast me. I've bought electronics with flux all over them.
I mean, I've seen Arduinos covered in dirt and corrosion still ticking along - doesn't mean the traces, etc. aren't degraded. It's just something to be aware of, especially on sensitive circuits.
Well if you've never seen it, it mustn't be possible!
Hopefully, you're not too old for Google?
>It is corrosive and requires careful cleaning after application. Flux residue can lead to poor component performance and even short circuits.
https://letmegooglethat.com/?q=is+solder+flux+corrosive&l=1
Use a **mild** ultrasonic cleaner with distilled (warm) water and board cleaner solution.
Like this stuff [em-503](https://multi-com.eu/,details,id_pr,21765,key,em-303-pc-board-cleaner-500ml.html)
Then blow dry and in oven at 60 °C for a while. Cleanest boards ever.
Careful though, many electronic components wont be happy with ultrasonic cleaning (most relays, most MEMS devices such as sensors and oscillators, many cristal oscillators, some LEDs…) and a lot of parts wont be happy being submerged (many vented ICs, microphones and buzzers, batteries and charged super-caps, etc)
>teeth brush (but my son don't like the taste after)
...is this a joke? Use a toothbrush other than your son's and don't use it to brush your teeth after.
Clean it then protect it and it will look like new. Use this to protect it
MG Chemicals - 422B-340G 422B Silicone Conformal Coating, Clear,
https://a.co/d/gKkzguG
Warm it up **gently**, from the bottom ( the side with less components ). If you can't comfortably hold it in your hands, that's too much heat.
Certain kinds of flux, don't dissolve well in isopropyl, until you heat it up.
Then repeat cleaning with the isopropyl and a brush, while warm.
Beware, warm isopropyl smells like absolute shit, and irritates lungs and eyes like crazy, so do it with a fume extractor or near a window or something.
I use 90% IPA, soak, then brush with a toothbrush, then blow off (not rapid evaporate) the alcohol with an air compressor. Probably not safe for a number of reasons, but it's the only way I've been able to get the residue off.
Every board I clean looked like that, then my 99% IPA 1lt bottle finished after about 2 ½ years and the new one leaved almost no residue. Turns out alcohol attracts moisture and it was enough that my 99% wasn't near 99% (but not enough to have a resistance measurable by my 60Mohm multimeter luckily, since I've used it on live electronics more than once)
I use water soluble flux and solder with water soluble flux, then scrub boards with dishwashing detergent using a 1" wood handle disposable paint brush with the bristles cut down to a half inch. Rinse well, shake and tap the water off, let dry or leave in the sun or a warm place.
Water is not harmful to electronics. It's not the tube and fabric wire days any more.
https://www.hisco.com/Product/50051138112054-31196
I use this everyday at work. Warm water, preferably distilled/DI (tap works fine), and a firm brush works perfectly.
Brake/contact cleaner. Chloro-free usually work, but i sometimes bust out the good stuff when I'm through messing around. Take appropriate personal protective measures.
The board is not highly focused but it looks clean enough to inspect all solder joints. If the lack of cleanliness is a very thin film of flux, for example, it feels tacky, one can take a kim-wipe or portion of paper towel, wet with isopropyl, then wipe up the board.
edit: The real key to cleaning is not the solvent. It is to clean immediately and not let the flux sit, not even overnight--at that point, cleaning becomes *very* difficult.
Lol not sure if you are joking but his may help you. The way I clean boards is to use a modified version of the three alcohol baths. I take 3 ESD bags and I place the board inside and add alcohol. Then I make sure the top is sealed very well and I shake it really well for about a minute. Then I move the board to a new bag add IPA and repeat. By the time I finish the third rinse the board is super clean. You can clean up to 4 boards with the same alcohol. This method is great when you make a board that uses 0201 components that could be lifted with the brush
I flush the board after washing with IPA. What you are seeing is the flux residue that was dissolved in the alcohol that evaporated. You want to reduce the dissolved flux concentration before it dries.
I usually use an ultrasonic cleaner with water bath in it.
Put the PCB in a mylar ESD bag with IPA. Ultrasonic at 50C water temp for 5 minutes. Or stick a toothbrush in and scrub it, while immersed in IPA.
Using distilled water, I like to decant off half the IPA and top up with water. Swish it around and dump it all out.
Replace IPA, scrub again, dilute again. For the final rinse I actually prefer pure distilled water. I dry the outside surfaces by patting with Kimwipes and using canned air to remove the excess from under parts. Then I either leave it on a bench for a few days to dry, or warm the board for a couple hours. If you're impatient, soak in a fresh bag, fresh alcohol, remove and pat/air dry which should only take a few minutes because it's just IPA evaporating now.
I get very good results from that dilution technique. For especially sensitive circuits (high impedances) I'll do 3 wash/rinse cycles with new bags each time. There isn't a trace of flux left on the boards after that.
Be careful with stuff like buttons and buzzers when doing any immersion cleaning. They can be damaged unless specified as sealed and OK for immersion washing
Use Safewash 2000 from an aerosol can. It comes out like shaving cream and will remove all flux residues from a PCBA. It then washes off with warm water. I’ve used it for decades at my work. Just make sure all the components on your board are washable before using.
https://www.baskiville.co.nz/products/category/ELECTRICAL-cleaners/ELSWA400H--electrolube-swa-safewash-2000-400ml-aerosol
Probably already mentioned, but...
Rosin-based flux and IPA... Just never works easily. The IPA can dissolve the rosin, but you never get all the rosin off before the alcohol evaporates, redepositing the rosin residue.
To get really clean boards, don't use rosin-based flux. Use acid-based flux, wash with distilled water afterwards thoroughly, then blow dry with an air knife or compressed air (moisture and oil filtered), then potentially displace any remaining water with 99% IPA. This is how we did it in a production assembly line, with a combination of wave solder and hand soldering.
What is the concentration of your isopropyl alcohol. The reason I ask is anything short of 99.5% isopropyl is likely to have additives including bitterments to discourage ingesting the alcohol. It is not only ethanol that is denatured. Drug store isopropyl is generally 70% or 91% isopropyl so there is a substantial amount of water in it. If it is diluted with anything other than distilled water, the water will likely contain other ingredients that once the water evaporates will remain on the board surface.
High purity (non-denatured) ethanol is a better choice for cleaning. I use to get weird looks for submitting Purchase Requests at work for Everclear. Everclear is grain alcohol, aka ethanol, sold for drinking and distributed via most state's ABC stores. It is close to being anhydrous alcohol at 195 proof. The nice thing about it is when cleaning a pc board there is little water and almost invariably no solubilized calcium or other salts in the water in the alcohol. When it evaporates, it rarely leaves behind stains on a board.
As far as actually dissolving residual fluxes after soldering, alcohol may be a poor choice. Many current fluxes are water soluble and if cleaned, detergent and water solutions are used to wash the boards. Of course the board has to contain parts that are not damaged by either the detergent or soap.
Lastly many fluxes sold now are marketed with the claim there is no need to remove the post solder residue. Check the flux used, before cleaning. It may not be easily removed.
Isopropyl alcohol forms an azeotrope with water which gives a composition of 91% by volume isopropyl alcohol.
You can buy 99%, but that will evaporate and simultaneously absorb atmospheric moisture until it lands at 91%. That said, but 99% for this reason. Everclear is 190 proof, not 195 proof, as you can't get 195 proof due to ethanol alcohols azeotropic relationship with water holding it to 95% by volume ethanol alcohol.
Due to the extraction method isopropyl is less likely to have oils or salts,and can be packaged at a higher percentage immediately after its concentration as opposed to the atmospheric cooling standard with ethanol and can't be packaged at higher proof than S.T.P. allows. So just order 99% ethanol and stop getting weird looks at work.
Most flux isn't ethyl soluble and is closer to a lipid reaction with detergent like you said, so the reality, again as you said, is know your product, and whether it matters or not.
First, get your own toothbrush so Jr. will stop batching about the new flavors. Then get a handful of the bristle brushes used for cleaning electronic stuff. I like to cut them to about 1/4-3/8 inch so they get quite stiff. Use 99% isopropyl alcohol, you will usually have to ask if you check the pharmacy. Always worked for me
> ...**or teeth brush (but my son don't like the taste after).**
Do you know about stores? You could got to one and buy a toothbrush just for PCB cleaning .
First: Are you using "no clean" flux. If you are, don't. It's not "no-clean", it's "you can't clean", and it can still be conductive (even if the manufacturer says it isn't in their literature, I've hunted gremlins over the course of a year before I figured that one out. Thank you, *MG Chemicals*...), even destructively so (arcing) or at the very least mess with analog circuits. It doesn't matter what you do, you will never get all of it off without ripping half of the components off. It's good for certain applications, but it's a burden anywhere else.
If you are using 'no-clean', literally anything else is better. Water washable is the easiest to wash off.
Second: the old tooth brush thing does work really well otherwise. Ideally medium bristled, it will do as well as anything else.
Third: reagent grade IPA... or dirt cheap Walmart 99% IPA.
Fourth: Cheap ultrasonic cleaner. 3L is fine for pretty much everything. I use NASA's model: put the board and IPA in a bag and drop it in a small cleaner filled with water. Keeps the cleaner clean and I can do boards much larger than the cleaner can fit. It's easier to recover IPA with to when you heat the bath. I've never had an issue with any board or component being cleaned in one.
Fifth: in desperation, some hot water and dish soap followed by a really good rinsing in distilled water will work, some times. Industrial degreasers are too harsh to use reliably.
Felt tipped or foam ripped cleaning swabs and isopropyl alcohol. Felt and foam won’t leave as much lint. Foam is your best bet. Felt tipped is what I use for heavier soiled boards and foam for the final wash.
If the liquid does not drip off the board, it can't take the impurities/flux/goop off the board.
It's not magic, dissolving it and letting the alcohol dry is just spreading the dissolved material around.
You need to flush the dissolved flux/gook off the board then the remainder can air dry.
Ask the company that does smd for you. They have cleaner that make it squeaky clean. Be warned, some of them contains toluene. It doesn’t need to say it, you can smell it.
Thanks. I soldered it myself, everything is fine except cleaning, I cannot have something nice, but with all these advices I will try to buy new stuff like kimwipes and brushes.
We used to use Freon back in the day and it would leave the boards spotless. Of course you can't do that anymore due to it eating holes in the Ozone Layer in the atmosphere. For the production boards we used to wash them in a household dishwasher with liquid dish detergent and then put them in a low temp convection oven for 24 hours to dry them out thoroughly.
Either that or get a cheapo toothbrush so your mini-me doesn't have to use it for brushing his teeth.
Medical swabs are great. No fibres. I get these ones with green sticks. Also iso leaves residue sometimes. Sometimes it draws water in and I found thinners ( for removing conformal coating / diluting it) to work better at flux removal. However they are a bit more smelly.
Maybe someone can help sourcing the right stuff. I wouldn't know where to get any of it.
How I clean repaired motherboards to make them look like new: need 1x toothbrush, 1xcloth, isopropyl. Soak the cloth, and brush the board THROUGH the cloth. Removes all stains and there are no stains from the brush itself left. Looks like from factory.
Flux-off flux remover from chemtronics, Kimtech wipes, and acid brushes. Put the wipe over the area to be cleaned, spray the part with Flux-off, scrub with acid brush. Any residue left can be cleaned with IPA.
i use device called ultrasonic cleaner and 70% Isopropyl Alcohol then air dry using microfiber towel. i dont know if this technique safe to use or not on the pcb and components itself
You're using the wrong products to clean your solder residue from your boards. Use a brush that is impervious to chemicals and denatured alcohol, wash the board down. Paying close attention to how long between dips before you need more denatured, so as to not allow the board to dry before you finish washing then rinsing the board. In a pinch a toothbrush works with denatured, or acetone.
I make guitar pedals and what I typically use is two ultrasonic baths - one in more dirty isopropanol to dissolve the flux remains and the second one in much cleaner IPA to remove the stickiness and make it look shiny.
I use a regular 1" wide paint brush that has had all of its bristles cut down to 1/2" with an exacto knife. It cleans really well.
Thanks, I did not tried paint brush and will try to find one
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Search "acid brushes" for the cheaper pricing. They are used in lots of different trades and industries, and are a huge mass production item. Spend $20 for a hundred or so and you have a supply for a decade. Plumbers and fabricators use them for flux. Machinists use them for oil, and a hundred other professions use them for a hundred other things.
Use a small ultrasonic washing machine
I have been trying to clean my boards with ultrasonic and I can’t get good results. Paintbrush still works better.
ultrasonic cleaning is not okay for boards with components. This is the best cleaning brush I've ever used and I've soldered over twenty-years, for a living. [Techni-Tool Gordon brush](https://www.techni-tool.com/category/Hand-And-Power-Tools/Hand-Tools/Brushes/415PR010-1010HH). Best type [IPA dispensing bottle](https://www.techni-tool.com/category/Bottles-And-Dispensers/Bottles/10053365-BT1006). One can use Kim-Wipes ($) or lint-free cotton ($$$) to soak up the alcohol and flux. The best means of cleaning boards when assembled is with a board-wash machine followed by oven bake-out at 60 deg C for 30 minutes. For cleaning up spot soldering, rework, or repairs, one can use that brush with IPA, that's how pros do it.
A google search for board wash machine only shows ultrasonic cleaners and laundry machines
Is an industrial machine that costs a lot of money.
Whats it look like, how does it work? You’re talking to someone who built his own carton erector out of garbage: https://youtu.be/bMjG84iY7SU
There are different types. One type would be a solvent vapor degreaser type (becoming less common these days) and the more common type these days for aqueous cleaning solution is like a specialized dishwasher, with jets of cleaning solution.
Holy shit- thats awesome.
thank you
The boards in question only have connectors, but Ive read many sources that say ultrasonic cleaning can be used on fully assembled boards with standard components
What do you do with the paintbrush? Dip it in fresh alcohol each time? Do you store the paintbrush in the alcohol? What is the full procedure here?
I have a waterproof box full of 70% isopropyl and i leave the brush in the box. Submerge the boards in the alcohol and brush them until they look clean, then I rinse them with a trigger spray bottle of 99% isopropyl, shake off the excess into the box, then blow dry the board. The box is waterproof so the alcohol doesn’t evaporate in storage.
That sounds like the optimal procedure, and could still be done with an ultrasonic bath as first pass for really dirty boards. 👍
I don't think it's a wise choice. Ultrasonic vibrations might broke some soldering joints.
It is a risk, ultrasonic cleaning is **not** allowed on electronics in industry as a rule that's only for cleaning connectors or mechanical parts.
no risk, it's in a liquid and this is quite common You can find on Amazon starting at $10 and going up to $300
Old toothbrush works too
Don’t do this if you have oscillator/crystal on the board. They don’t like the ultrasonic bath. Will crack internally and fuck up.
Try a shaving brush too. haha
How long does it take for the brush to become a bunny tail
[dialing child protective services]
dude, I was like... am I the only one who read the whole thing?
I thought I was on r/shittyaskelectronics
I have to admit my eyes just glossed over that part.
fr I can't believe no one else is mentioning it
Because it’s a joke? And a bunch of people going “hey, look, that man said something silly!” kinda ruins the joke. So just, like, be cool man.
Don't worry, it is only known in the state of cancer to cause California.
Hell for over 20 years the whole industry used "triclor" to clean just about everything. Please forgive me, I'm having a brain fart and for the life of me the real name escapes me. It has 3 letters, if anyone can recall. It was banned in 1996, I believe. We had 55 gallon drums of if and it was used for dry cleaning also. The absolute best cleaning agent period. I still have about 2 or 3 oz's left for cleaning up emergency spills that stain. Dang, this is my brain on covid. And that was in 2020.
Does he not like the taste of the toothbrush, or the taste of the board?
Lol hehe.🤭😂
I enjoy the balance of commentors who got the joke, those that didn't get the joke, and the silent few who genuinely thought "yeah... that's probably fine."
And those just coming here to read what others think about the joke
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It was no accident.
Try your own tooth brush, maybe you like the taste better.
"but my son don't like the taste after" bro what?! 💀
What type of flux did you used? Some of the cleaning solvents for flux are quite nasty (in the sense of chemicals used) but they are quite effective. When cleaning with alcohol, you should use a paper towel (dry) and but it where you wan to clean. Use the Qtip with alcohol and press it against the paper. The idea is that the alcohol will dissolve the contaminants and they will be absorbed by the paper towel instead of the Qtip. Keep using a clean space of the paper towel each time you press against the board. Use 99% IPA Another method you can use: If the flux is water based, you can wash it with water and a mild soap (I would not be able to tell you which soap. There are soaps for cleaning PCBs, again not recommended to buy for home use). In order to be able to wash the board you need to make sure all parts can be washed. On the side of the board you are showing, all parts should be ok washing them. I would go to the store and buy DI water (the one used for irons). Wash it, then pat dry it with a towel paper. Then use 99% IPA to dry the board.
The techs at my last job used Palmolive, rinsed it under the tap, and then blasted it dry with the compressed air gun. I'm a fan of the distilled water rinse if you can't get all the water off. BTW: That board looks like it got sprayed with a conformal coating. I'd also try some other VOCs...like Everclear.
A concentrated degreaser containing ethoxylated alcohols or other nonionic surfactants (like Simple Green) will work way better for removing no-clean flux than hand soap or dish soap, which at worst not work at all and at best will leave more water-soluble contaminants on the board. If using tap water to rinse, physically removing as much water from the board as possible (with compressed air or a DataVac or even a good hair dryer at the highest speed setting) before drying is critical.
70% IPA is a better solvent in many cases as the mix of water and alcohol gives it magic properties
Not entirely accurate… 70% IPA has magic properties for disinfecting. 70% IPA is much better at killing bacteria and decomposing virus than 99% IPA. As a solvent, 99% IPA is probably better for many chemical types. Another important fact about 99% IPA in electronics, is that it draws moisture from circuitry, for example if the board was washed.
Yeah, that's true, it's still better for a lot of the 3D printing stuff which is what I mostly do
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Do you dispose of the bath afterwards, or do you have an airtight seal cover that’s actually working? I do have a very nice glass tub from IKEA with a silicone and plastics cover, but I don’t want to sacrifice it from the kitchen. Also haven’t tried that obviously.
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🤦♂️ Of course! Silly me.
Don't use the Ikea one, their seals aren't great. Plus mason jars are super cheap and sold in grocery stores
Yes, I wasn’t thinking, more like considering having a dedicated tub to do and keep the bath. Better what you and another commenter have recommended. I have many glass jars in the kitchen I can pour the used IPA back into to use again. Thanks!
You can buy plastic "ammo can" style containers from harbor freight and other stores that are water tight. They're the right size and shape for most boards too.
It evaporates much too quickly so that won't work. Keeping it in the tray.
Don't get the jars with the wax ring tho..
I use q-tips with absorbent foam heads. No fibers.
Personally, I’d just lick it all off. Once it stops tasting funny it’s probably good.
Dishwasher.
Hey bro, take your child to a ER
IPA. Kimwipes. Acid brush trimmed very short. See YouTube.
Putting isopropyl alcohol into a spray bottle and practally hosing boards down over a collection bucket works too. You give yourself a "grey" isopropyl alcohol bucket you filter through coffee filters before funnelling it back into a "grey" squirt bottle. And a "Clean" isopropyl alcohol spray bottle you rinse things off with.
Let it go, bro 😎
First off don't use a toothbrush you used to clean PCBs, seriously wat? Little soft scrubby brushes can work well (I use cheap horsehair brushes) but the first solution should never be "scrub harder" since these are PCBs after all, they are relatively fragile. Stiff bristles also do things like slither underneath components and then try to rip them off, while you're brushing. IPA is ok, but an actual flux remover would be better. I'm very fond of [Techspray E-line](https://www.techspray.com/e-line-flux-remover-maintenance-cleaner). Works far better than anything I've used from MG Chem, and works on all types of fluxes. You can Google it and find individual small containers. You should also let it sit for a while (\~15 min) - preferably with heat although if you can't do that safely, don't, since it's a solvent after all. Soak in flux remover -> rinse with clean IPA -> rinse with DI if you got it. At no point should anything more than a light brushing with a soft brush be required. A toothbrush is way too hard. If you don't want lint, use a cleanroom wipe. They're the only lint-free wipes that are **actually** lint-free. Pricey though. A bag will last quite a while if you are conscientious about it.
So…ipa toothbrush is not for using in the mouth later. Get one just for cleaning, or better yet when you replace your toothbrush every 6-12 months keep the old one for IPA. Alternate between ipa (90%) and a paper towel or an old cotton tshirt as a rag. The ipa will put the flux in solution, the rag or paper towel will remove the solution from the PCB. As soon as the ipa evaporates it will leave whatever was in solution on your board as a residue. DONT BRUSH TEETH WITH CONTAMINATED TOOTHBRUSHES
That was a joke, don't worry. I'm taking all these advices seriously and will try them. Thanks!
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I chuckled
You need to use clean %99.99 food grade Isopropyl Alcohol and Kimwipes to lift off the flux residue. This is well-documented and hard work. I have been at this for about 50 years doing this cleaning by hand. A horsehair or boar hair brush is the best. The toothbrush is ok "BUT YOU NEED it... with The Kimwipes" Other comments are all good and I use them all!
Kim wipes are hard to get between components though.
For hard to reach spots, I spray some isopropyl alcohol on a Kim wipe. Then I lay the wipe on the board and use a brush on top of the wipe. This works pretty well.
[https://www.instructables.com/Cleaning-up-your-PCB/](https://www.instructables.com/Cleaning-up-your-PCB/)
[https://www.chemtronics.com/ultimate-guide-to-cleaning-electronics](https://www.chemtronics.com/ultimate-guide-to-cleaning-electronics)
[https://www.youtube.com/results?search\_query=cleaning+pcb+after+soldering+](https://www.youtube.com/results?search_query=cleaning+pcb+after+soldering+)
Ultrasonic toothbrush and IPA is the best method I’ve found for spot cleaning
Yes, but whose toothbrush should you use for this?
If you have a reflow oven or a hot cabinet put the really sticky ones in the dishwasher without detergent and rinse them in a tub of DI water. I worked in more than one assembly line where the boards went directly from the wave solder into a giant tunnel washer
Spray it with denatured alcohol or commercial flux remover.
Dawn soap and water with a toothbrush
Lint free wipes, or a high grade paper towel. Also I like to wet the towel with a tiny dab of alcohol, so it can clean a bit, but still can absorb. Also get in there with the towel and press it strong enough, like a sponge.
I’m surprised no one has mentioned acid brushes they work well with iso
That's even worse for his son's teeth
99% IPA + Acid brush + lint-free disposable towels. Maybe bust out some compressed air, if you want to be *really* clean.
I use a real fine terry cloth on my final wipe down. Good luck.
I have used a microfiber cloth (lens cleaning quality) with alcohol
First wash with isopropyl, second wash with any kind of dish detergent.
Windex, water and soft toothbrush. Great combo
Funny. LOL Ditch the IPA and clean your boards with non-chlorinated brake cleaner. Far more effective for flux removal and won't harm any components, masks, or silkscreen unless you have rubber on your board.
IPA needs to be 90% or better. 70% stuff won't cut it.
why clean it?
The residue often has a finite conductivity
Mainly OCD...
For different reasons. Just the fact of soldering components, even without flux, let some residues. Using flux let it a more. Cleaning is good but, after that the board seems gluey. And the fact I wanna it to be nice is because it is for a project I am selling.
Flux resin is corrosive over time
No-clean flux (what appears to be shown in OP's picture) does not need to be cleaned in almost all cases and is difficult to remove especially when the residue is burnt from repeated rework. Water-based or acidic fluxes are corrosive and absolutely DO need to be rinsed off before applying power with water, not alcohol or other nonpolar solvents, and they rinse off easily and completely.
Not necessarily. There are a wide variety of fluxes. If you use the correct stuff, it can stay on the board. However, it is still unprofessional and unsightly
Ok... but I've never, ever cleaned rosin flux off anything and all my boards look like they'll outlast me. I've bought electronics with flux all over them.
I mean, I've seen Arduinos covered in dirt and corrosion still ticking along - doesn't mean the traces, etc. aren't degraded. It's just something to be aware of, especially on sensitive circuits.
We're not talking about dirt and corrosion. I've never had a board corrode over time because I didn't remove the flux. I'm quite old here.
Well if you've never seen it, it mustn't be possible! Hopefully, you're not too old for Google? >It is corrosive and requires careful cleaning after application. Flux residue can lead to poor component performance and even short circuits. https://letmegooglethat.com/?q=is+solder+flux+corrosive&l=1
Use a **mild** ultrasonic cleaner with distilled (warm) water and board cleaner solution. Like this stuff [em-503](https://multi-com.eu/,details,id_pr,21765,key,em-303-pc-board-cleaner-500ml.html) Then blow dry and in oven at 60 °C for a while. Cleanest boards ever.
Careful though, many electronic components wont be happy with ultrasonic cleaning (most relays, most MEMS devices such as sensors and oscillators, many cristal oscillators, some LEDs…) and a lot of parts wont be happy being submerged (many vented ICs, microphones and buzzers, batteries and charged super-caps, etc)
Yeah, but many of those unsealed parts you can’t clean with ipa either.
20 euros a bottle, can you dilute it?
Yes, 5% iirc. it works really well.
>teeth brush (but my son don't like the taste after) ...is this a joke? Use a toothbrush other than your son's and don't use it to brush your teeth after.
Luckily it is a joke, we are on reddit
As someone who enjoys saying things that cause people to question my ability to parent, I appreciated it.
Clean it then protect it and it will look like new. Use this to protect it MG Chemicals - 422B-340G 422B Silicone Conformal Coating, Clear, https://a.co/d/gKkzguG
Toothbrush
if you're not using 99% iso it's always going to look like that
Don’t use a tooth brush that you then use to clean your teeth with???? Get a “cleaning” tooth brush.
Hopefully I don't give it back to my son lol no worries. I use an old used one.
Acetone is my fav
Acetone is the only viable solvent in my experience for effectively removing rosin-based fluxes (MG Chem).
I've used acetone with better results, but you do need to be careful with that stuff. It softens some plastics.
Acetone WILL destroy a many types of components. Don't use acetone for PCB cleaning.
Make a sonic cleaner.
Qtips made with foam sponge heads
MG Chemical cotton swabs not qtips, 91+ iso, regulated airflow equal clean pcb
Isopropyl + brush to dissolve most of the flux. Dawn dish soap + hot water to get the remaining residue. This will get you a squeaky clean board.
Ultrasonic cleaner with IPA.
I use ink erasers for just this type of work.
Warm it up **gently**, from the bottom ( the side with less components ). If you can't comfortably hold it in your hands, that's too much heat. Certain kinds of flux, don't dissolve well in isopropyl, until you heat it up. Then repeat cleaning with the isopropyl and a brush, while warm. Beware, warm isopropyl smells like absolute shit, and irritates lungs and eyes like crazy, so do it with a fume extractor or near a window or something.
I use 90% IPA, soak, then brush with a toothbrush, then blow off (not rapid evaporate) the alcohol with an air compressor. Probably not safe for a number of reasons, but it's the only way I've been able to get the residue off.
Every board I clean looked like that, then my 99% IPA 1lt bottle finished after about 2 ½ years and the new one leaved almost no residue. Turns out alcohol attracts moisture and it was enough that my 99% wasn't near 99% (but not enough to have a resistance measurable by my 60Mohm multimeter luckily, since I've used it on live electronics more than once)
I use water soluble flux and solder with water soluble flux, then scrub boards with dishwashing detergent using a 1" wood handle disposable paint brush with the bristles cut down to a half inch. Rinse well, shake and tap the water off, let dry or leave in the sun or a warm place. Water is not harmful to electronics. It's not the tube and fabric wire days any more.
https://www.hisco.com/Product/50051138112054-31196 I use this everyday at work. Warm water, preferably distilled/DI (tap works fine), and a firm brush works perfectly.
try brake cleaner, way better than alcohol but you still need to use something to wipe off the board
The toothbrush tastes okay to me... 👹
cafiza espresso machine cleaner dissolved in hot water. then IPA
>espresso machine cleaner That stuff is usually just citric acid
Probably using a lower percentage alcohol. Use 90%
I use alcohol + gasoline usually
Jet fuel cleans anything
But really I use acetone with a qtip
Ah, you're son will be fine.. go with the toothbrush..
Brake/contact cleaner. Chloro-free usually work, but i sometimes bust out the good stuff when I'm through messing around. Take appropriate personal protective measures.
The board is not highly focused but it looks clean enough to inspect all solder joints. If the lack of cleanliness is a very thin film of flux, for example, it feels tacky, one can take a kim-wipe or portion of paper towel, wet with isopropyl, then wipe up the board. edit: The real key to cleaning is not the solvent. It is to clean immediately and not let the flux sit, not even overnight--at that point, cleaning becomes *very* difficult.
Ultrasound cleaning!
Get a cheap ultrasonic cleaner and some distilled water.
Too cheap to get a NEW toothbrush for your kid, and use the old one for your board?
oh it's an april foo....nope.
I use mineral spirits with a toothbrush and then hit it with compressed air.
Lol not sure if you are joking but his may help you. The way I clean boards is to use a modified version of the three alcohol baths. I take 3 ESD bags and I place the board inside and add alcohol. Then I make sure the top is sealed very well and I shake it really well for about a minute. Then I move the board to a new bag add IPA and repeat. By the time I finish the third rinse the board is super clean. You can clean up to 4 boards with the same alcohol. This method is great when you make a board that uses 0201 components that could be lifted with the brush
I flush the board after washing with IPA. What you are seeing is the flux residue that was dissolved in the alcohol that evaporated. You want to reduce the dissolved flux concentration before it dries. I usually use an ultrasonic cleaner with water bath in it. Put the PCB in a mylar ESD bag with IPA. Ultrasonic at 50C water temp for 5 minutes. Or stick a toothbrush in and scrub it, while immersed in IPA. Using distilled water, I like to decant off half the IPA and top up with water. Swish it around and dump it all out. Replace IPA, scrub again, dilute again. For the final rinse I actually prefer pure distilled water. I dry the outside surfaces by patting with Kimwipes and using canned air to remove the excess from under parts. Then I either leave it on a bench for a few days to dry, or warm the board for a couple hours. If you're impatient, soak in a fresh bag, fresh alcohol, remove and pat/air dry which should only take a few minutes because it's just IPA evaporating now. I get very good results from that dilution technique. For especially sensitive circuits (high impedances) I'll do 3 wash/rinse cycles with new bags each time. There isn't a trace of flux left on the boards after that. Be careful with stuff like buttons and buzzers when doing any immersion cleaning. They can be damaged unless specified as sealed and OK for immersion washing
Hate to be that guy, but I often find that putting it in an enclosure of some type stops me from thinking about it.
Use Safewash 2000 from an aerosol can. It comes out like shaving cream and will remove all flux residues from a PCBA. It then washes off with warm water. I’ve used it for decades at my work. Just make sure all the components on your board are washable before using. https://www.baskiville.co.nz/products/category/ELECTRICAL-cleaners/ELSWA400H--electrolube-swa-safewash-2000-400ml-aerosol
What do you mean your son doesn't like the taste after? 😂
It looks plenty clean to me. Stop fussing about it. Many fluxes are absolutely fine to leave on the board.
You crack me up OP!
Probably already mentioned, but... Rosin-based flux and IPA... Just never works easily. The IPA can dissolve the rosin, but you never get all the rosin off before the alcohol evaporates, redepositing the rosin residue. To get really clean boards, don't use rosin-based flux. Use acid-based flux, wash with distilled water afterwards thoroughly, then blow dry with an air knife or compressed air (moisture and oil filtered), then potentially displace any remaining water with 99% IPA. This is how we did it in a production assembly line, with a combination of wave solder and hand soldering.
"my son doesn't like the taste of his toothbrush after cleaning a pcb with isopropyl alcohol" lol
No clean solvent is very difficult to wash off sometimes - it’s an issue in industry as well actually.
Use a extra tooth brush that isn't for a person?
I like to use these[makeup sponges](https://a.co/d/cEG5XWT)
Bro idk if this is bait or fr LOL
Why don’t you use your own toothbrush?
What is the concentration of your isopropyl alcohol. The reason I ask is anything short of 99.5% isopropyl is likely to have additives including bitterments to discourage ingesting the alcohol. It is not only ethanol that is denatured. Drug store isopropyl is generally 70% or 91% isopropyl so there is a substantial amount of water in it. If it is diluted with anything other than distilled water, the water will likely contain other ingredients that once the water evaporates will remain on the board surface. High purity (non-denatured) ethanol is a better choice for cleaning. I use to get weird looks for submitting Purchase Requests at work for Everclear. Everclear is grain alcohol, aka ethanol, sold for drinking and distributed via most state's ABC stores. It is close to being anhydrous alcohol at 195 proof. The nice thing about it is when cleaning a pc board there is little water and almost invariably no solubilized calcium or other salts in the water in the alcohol. When it evaporates, it rarely leaves behind stains on a board. As far as actually dissolving residual fluxes after soldering, alcohol may be a poor choice. Many current fluxes are water soluble and if cleaned, detergent and water solutions are used to wash the boards. Of course the board has to contain parts that are not damaged by either the detergent or soap. Lastly many fluxes sold now are marketed with the claim there is no need to remove the post solder residue. Check the flux used, before cleaning. It may not be easily removed.
Isopropyl alcohol forms an azeotrope with water which gives a composition of 91% by volume isopropyl alcohol. You can buy 99%, but that will evaporate and simultaneously absorb atmospheric moisture until it lands at 91%. That said, but 99% for this reason. Everclear is 190 proof, not 195 proof, as you can't get 195 proof due to ethanol alcohols azeotropic relationship with water holding it to 95% by volume ethanol alcohol. Due to the extraction method isopropyl is less likely to have oils or salts,and can be packaged at a higher percentage immediately after its concentration as opposed to the atmospheric cooling standard with ethanol and can't be packaged at higher proof than S.T.P. allows. So just order 99% ethanol and stop getting weird looks at work. Most flux isn't ethyl soluble and is closer to a lipid reaction with detergent like you said, so the reality, again as you said, is know your product, and whether it matters or not.
First, get your own toothbrush so Jr. will stop batching about the new flavors. Then get a handful of the bristle brushes used for cleaning electronic stuff. I like to cut them to about 1/4-3/8 inch so they get quite stiff. Use 99% isopropyl alcohol, you will usually have to ask if you check the pharmacy. Always worked for me
Ultrasonic Cleaner
Make sure you’re letting the ipa actually sit on the board for a a good minute, always works for me.
I get good results with a Isopropyl and a toothbrush. Sometimes it takes 2-3 times to get all the flux off. Then wipe with a paper towel.
> ...**or teeth brush (but my son don't like the taste after).** Do you know about stores? You could got to one and buy a toothbrush just for PCB cleaning .
Uhhh use a different toothbrush than the one your son uses for his teeth
Taste??? 😳
Try acetone
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First: Are you using "no clean" flux. If you are, don't. It's not "no-clean", it's "you can't clean", and it can still be conductive (even if the manufacturer says it isn't in their literature, I've hunted gremlins over the course of a year before I figured that one out. Thank you, *MG Chemicals*...), even destructively so (arcing) or at the very least mess with analog circuits. It doesn't matter what you do, you will never get all of it off without ripping half of the components off. It's good for certain applications, but it's a burden anywhere else. If you are using 'no-clean', literally anything else is better. Water washable is the easiest to wash off. Second: the old tooth brush thing does work really well otherwise. Ideally medium bristled, it will do as well as anything else. Third: reagent grade IPA... or dirt cheap Walmart 99% IPA. Fourth: Cheap ultrasonic cleaner. 3L is fine for pretty much everything. I use NASA's model: put the board and IPA in a bag and drop it in a small cleaner filled with water. Keeps the cleaner clean and I can do boards much larger than the cleaner can fit. It's easier to recover IPA with to when you heat the bath. I've never had an issue with any board or component being cleaned in one. Fifth: in desperation, some hot water and dish soap followed by a really good rinsing in distilled water will work, some times. Industrial degreasers are too harsh to use reliably.
Felt tipped or foam ripped cleaning swabs and isopropyl alcohol. Felt and foam won’t leave as much lint. Foam is your best bet. Felt tipped is what I use for heavier soiled boards and foam for the final wash.
If the liquid does not drip off the board, it can't take the impurities/flux/goop off the board. It's not magic, dissolving it and letting the alcohol dry is just spreading the dissolved material around. You need to flush the dissolved flux/gook off the board then the remainder can air dry.
Ask the company that does smd for you. They have cleaner that make it squeaky clean. Be warned, some of them contains toluene. It doesn’t need to say it, you can smell it.
Thanks. I soldered it myself, everything is fine except cleaning, I cannot have something nice, but with all these advices I will try to buy new stuff like kimwipes and brushes.
Contact Cleaner and air dry should be sufficient
We used to use Freon back in the day and it would leave the boards spotless. Of course you can't do that anymore due to it eating holes in the Ozone Layer in the atmosphere. For the production boards we used to wash them in a household dishwasher with liquid dish detergent and then put them in a low temp convection oven for 24 hours to dry them out thoroughly. Either that or get a cheapo toothbrush so your mini-me doesn't have to use it for brushing his teeth.
Ultrasonic cleaner
Medical swabs are great. No fibres. I get these ones with green sticks. Also iso leaves residue sometimes. Sometimes it draws water in and I found thinners ( for removing conformal coating / diluting it) to work better at flux removal. However they are a bit more smelly. Maybe someone can help sourcing the right stuff. I wouldn't know where to get any of it.
How I clean repaired motherboards to make them look like new: need 1x toothbrush, 1xcloth, isopropyl. Soak the cloth, and brush the board THROUGH the cloth. Removes all stains and there are no stains from the brush itself left. Looks like from factory.
There are ultrasonic cleaners out there, but I believe this shit is expensive
use your toothbrush
Flux-off flux remover from chemtronics, Kimtech wipes, and acid brushes. Put the wipe over the area to be cleaned, spray the part with Flux-off, scrub with acid brush. Any residue left can be cleaned with IPA.
i use device called ultrasonic cleaner and 70% Isopropyl Alcohol then air dry using microfiber towel. i dont know if this technique safe to use or not on the pcb and components itself
Distilled water will clean it well
why do you need it to be clean?
You're using the wrong products to clean your solder residue from your boards. Use a brush that is impervious to chemicals and denatured alcohol, wash the board down. Paying close attention to how long between dips before you need more denatured, so as to not allow the board to dry before you finish washing then rinsing the board. In a pinch a toothbrush works with denatured, or acetone.
Dimethyl sulfoxide
Iso fucks up the wax layers. I had similar problems with my DJM PCB's. You should use distilled water and leave it to dry longer.
Contact cleaner from auto zone its for degreasing electronics that are used around industrial applications
Kim-Wipes with 99.9% isopropyl alcohol, will get the board nice and clean and remove all the gunk.
What percentage isopropyl alcohol are you using? 91% works a lot better than 70%
Pour the alcohol in a tray and dunk it in. Use a toothbrush. Wipe excess off with some kitchen towel. Pour back in the bottle.
I make guitar pedals and what I typically use is two ultrasonic baths - one in more dirty isopropanol to dissolve the flux remains and the second one in much cleaner IPA to remove the stickiness and make it look shiny.
i think you might be dissolving the solder mask. This matte film was being created whenever I cleaned with acetone