Cleaning flux off after smd install, residue left on solder.

Rosin flux? For small runs I clean with IPA, then hot water and some detergent. (Awesome) Scrubbing with tooth brush. (For high impedance stuff I just leave the flux on.)

George H.

You clean your electronics with Beer??? IPA = India Pale Ale. If I were going to clean electronics or anything else with beer I would use IPA as I don't like the stuff. What they call hoppy, I call bitter.

Rick C.

No, the international phonetic alphabet.

This is also what I do, except I use methanol instead of isopropanol because I already stock it for other reasons. Toothbrush is key. Followed by hot soapy water. Finally a deionized water rinse and hot air dry.

This is for low-speed low-impedance circuits. Otherwise, you need to look into no-clean methods.

I used Methanol not isopropanol because it's what I have. The solder paste says no clean. Think I'm just going to leave it. Mikek

I use acetone for cleaning up low-speed boards that consist only of the solder-maksed PCB itself, passives, and surface-mount IC packages. I've never seen it damage any combination of those types of components and it sure cleans pretty aggressively.

I wouldn't use it for anything more complex than that as acetone attacks lots of plastics and resins, deffo keep it away from anything polystyrene, magnet wire, plastic trimmer pots, anything not HDPE, etc.

I absent-mindedly poured some in a styrofoam cup one time, that was fun to clean up.

It's hilarious that an "American-style malt liquors" i.e. high alcohol content hoppy lagers like Steel Reserve sometimes win awards at international beer festivals. They need to try drinking it sober I think. Bleerrrrcch....

Drugstore IPA is a disaster. Methanol or flux remover is the ticket.

Cheers

Phil Hobbs

We do lots of leakage-sensitive stuff, and our rule is to never expose those boards to water. We use rosin flux and a specific cleaning solvent.

The boards are dunked in boiling solvent for a minute, then sprayed with clean solvent.

IPA and lots of other things leave white residue. Water-wash fluxes will leave conductive, hygroscopic junk under parts.

You can just not clean RMA and get fA leakages, but it looks ugly.

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Drug store isopropyl alcohol has a significant water component and would no t be the best organic solvent, not to mention various other impurities that might be present. You can get it >99% pure commercially which will work b etter. But calling it a disaster is a bit overstated, no?

Rick C.

You're a digital guy, I'm primarily an analogue/mixed-technology guy. Drugstore IPA isn't going to hurt a processor much, but it'll render a low-level analogue board useless.

Cheers

Phil Hobbs

I made another go at it, I used acetone and an acid brush and then a second wash with methanol. Flux is gone, now I need to up my game on the printer, iron, soak, and etch, my printing left to many weak spots that partially etched. Mikek

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d not be the best organic solvent, not to mention various other impurities that might be present. You can get it >99% pure commercially which will wo rk better. But calling it a disaster is a bit overstated, no?

As opposed to what exactly?

Rick C.

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Sounds like a great reason to go with a commercial PWB maker rather than ho mebrew. I made PWBs some two decades ago and realized there was little poi nt. My time is much better spent on other engineering tasks that require t alent rather than a dogged determinism to get low level, finicky chemical-m echanical processes to work well enough to realize decent PWBs lacking silk screen or solder mask. Nope, I can honestly say that would be a huge waste of my time.

Rick C.

Just a home project. I used Paint to make the board layout, a bunch of squares. If I used a PCB program to make the board, I would need to learn the program to do the layout. I'm not opposed to learning another program. I have used two different ones over the years, but it has been 18 years since I used one to make a pcb. What's a free one to use for smd parts? Mikek

Kicad. It is a bit weird but of the free ones I think it is closest to reaching a critical mass of users necessary to motivate people to make it good.

As opposed to a clean solvent that actually dissolves flux properly. Acetone, methanol, flux remover. For protos I use HPLC-grade methanol--pricey but not a big hit in the quantities needed. It's what I use for lenses.

Cheers

Phil Hobbs