So, I have only ever spotlessly cleaned about 2 of the 60 or so keyboard PCBs I’ve built. It’s a huge pain in the ass for me.
I don’t use any additional flux on new boards when I solder, only the rosin flux in the core of my solder. But it does manage to make quite a few small sputters on the PCB.
For cleaning, I use 99% Isopropyl and a ton of cotton swabs to get all flux residue off the board. But yeah, that method takes me like at least an hour.
Is there an easier way? How do you clean the flux residue off of your boards after soldering?
I’ve done the whole Isopropyl Alcohol q-tip song and dance too. The only way to truly clean it, would be with a Ultrasonic cleaner, because flux, can make it’s way through the holes in the PCB and on to the other side. At that point, it’s bye bye lube.
So at this point, I’ve been reducing the amount of flux that I use, to hopefully minimize the amount that gets on the other side. A standard RA (rosin) flux should be sufficient for what we are doing. The only time I break out the tube of flux, is if I need to rework something, or if the board has sat for an extended period of time.
Yes, I should have stated that in the original post, but I am only using the rosin core flux that is in my soldier wire. I haven’t added any additional flux. But it does sputter and make small messes on the board as I build.
Um, I don’t clean PCBs after soldering. When a tiny drop of solder gets on the PCB, I flick it off. Never had issue with flux-related issues either. Lazy and lucky, I guess.
I’d be curious to know if it’s just my solder. I’ve always used the same stuff. The main mess I have is clear flux blobs. They are tiny, but you can see them if you get it at the right angle. (They’re also always crusted up on my thumb and pointer finger of my left hand ). Occasionally there will be some excess flux around a pin. Both come off easily with a few cotton swabs and patience. However, once you multiply that by 60 or 87, then it becomes a pain. It’s supposed to be “no clean” rosin core flux, but I’ve always heard you still need to remove it or it will corrode over the years. And that makes sense b/c flux is supposed to corrode… that’s part of it’s purpose.
I’ve went through the whole washing the back of the PCB with IPA a few times myself & agree it’s a time consuming pain in the ass. Really unless I have to clean it with IPA for some specific reason I usually just take a stiff bristled brush to the back of the PCB which knocks of most of the little flux sputters IME.
Chip brushes like that are usually really good for it. Although I’d go to a home depot or lowes in person to grab one if you do. Some of them have crazy stiff bristles & others are too soft to use for removing cooled flux.
Horse hair brushes and a couple good coatings of quality pcb cleaner(so much it drips off the pcb) will deliver a spotless pcb. Just gotta watch out for rosin bleed through on the otherside and on plate.
Oh man I am glad I am not the only one this happens to. It drives me crazy and I was curious how to clean it myself. But also, I never see the backside so I opt to be lazy and just leave it.
Electrical contact cleaner spray. It’s safe for any plastics or metals involved withe electronics, and you can get a can at any auto parts or hardware store. It’s super easy, comes with a straw for getting in the tight spots. Just spray, let evaporate, repeat if needed.
I use no clean flux and just leave it there. On the odd occasion I do clean a board I use spray isopropyl alcohol and an ESD safe brush. Just don’t spray it at your switches!
). Occasionally there will be some excess flux around a pin. Both come off easily with a few cotton swabs and patience. However, once you multiply that by 60 or 87, then it becomes a pain. It’s supposed to be “no clean” rosin core flux, but I’ve always heard you still need to remove it or it will corrode over the years. And that makes sense b/c flux is supposed to corrode… that’s part of it’s purpose.