Old school here, I still use thin rosin-core solder and a sharp tip to hand solder SMD parts on DIY prototypes and systems.
View attachment 249743View attachment 249744
Eutectic (Sn-Pb) solder is not a rarity in the industrial repair and manufacturing field.
The electronic ROHS is mainly about manufacturing commercial products. The industrial products I build use lead electronic solder because I want them to last and leaded products are much easier for hand soldering joint quality. In the last year I had a long discussion with the local OHA about our engineering soldering practices during a general inspection. I told them in no uncertain terms we would continue to use lead-based solder for repairs and for building systems for internal industrial use.

Back to cleaning.
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Use the brush on the wet solvent then remove the mixture before it dries too much.
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Back side residue cleaned
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Fully cleaned and tested boards.
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Thanks! That does make a difference. I have noticed if you really pour on the IPA it does help.
By the way, what make and model is your inspection scope? It appears to give a nice clear up close view of the board on a nice large monitor.

 

Thanks! That does make a difference. I have noticed if you really pour on the IPA it does help.
By the way, what make and model is your inspection scope? It appears to give a nice clear up close view of the board on a nice large monitor.

https://forum.allaboutcircuits.com/threads/camera-for-taking-pcb-pictures.169736/post-1511842

 

I have recently finished soldering all my components to a PCB. I then used spray Isopropyl Alcohol (99.9% pure anhydrous) and sprayed the board multiple times and then used an acid brush to try to get all the flux off the board. But I have found no matter how much I do this there remains a thin film of flux on the board (you can tell the board is slightly sticky). Is there a different chemical I should be using or a different technique? Thanks in advance.

Hi, You have to leave the PCB inside a Tuper so that both sides are submerged, only, then brush it and dry it with a hair dryer. Spray with flux and dry in the sun or with hot air. It is like new.

 

I tried clean PCBs with IPA and with different PCB cleaner sprays. Special spray works lot better than IPA but smells to much, you must do cleaning in well ventilated room. Those cleaners work better if you let PCB soak about half to one minute and then use spray and brush to remove flux. But now i use ultrasonic cleaner and special ultrasonic cleaner detergent for PCB. Some ultrasonic cleaners have so called "delicate" mode and pre-heating, so i preheat detergent up to 30 degrees (centigrade) and give 3 minutes ultrasonic "delicate" cleaning time. After that i flush PCB under lukewarm running water and then spray with DEI water. This method removes rosin flux completely and most of the SMD flux. And no bad fumes, PCB looks very clean. IMHO it is best method if you have tens or hundreds PCBs to clean.

 

NO OLVIDAR QUER EL ALCOHOL ISOPROPÍLICO ES ALTAMENTE TÓXICO (AUNQUE NO LO INDIQUE EN EL ENVASE), LUGAR AL AIRE LIBRE O VENTANAS ABIERTAS-SIEMPRE BIEN VENTILADO. MÁS INFORMACIÓN: https://www.nj.gov/health/eoh/rtkweb/documents/fs/1076sp.pdf

 

To save others from having to translate...

DO NOT FORGET THAT ISOPROPYL ALCOHOL IS HIGHLY TOXIC (ALTHOUGH IT DOES NOT INDICATE IT ON THE PACKAGING), OUTDOOR PLACE OR OPEN WINDOWS-ALWAYS WELL VENTILATED. MORE INFORMATION:

 

NO OLVIDAR QUER EL ALCOHOL ISOPROPÍLICO ES ALTAMENTE TÓXICO (AUNQUE NO LO INDIQUE EN EL ENVASE), LUGAR AL AIRE LIBRE O VENTANAS ABIERTAS-SIEMPRE BIEN VENTILADO. MÁS INFORMACIÓN: https://www.nj.gov/health/eoh/rtkweb/documents/fs/1076sp.pdf

Welcome to AAC!

May I mention a couple of items regarding forum etiquette?

Posting in ALL caps indicates shouting and is considered rude. I don’t think this was your intent.

Secondly, AAC is an English language only forum. If you’re unfamiliar with English, may I suggest using a language translation site before posting?

Thanks for your contribution. And once again, welcome!

 

Welcome to AAC!

May I mention a couple of items regarding forum etiquette?

Posting in ALL caps indicates shouting and is considered rude. I don’t think this was your intent.

Secondly, AAC is an English language only forum. If you’re unfamiliar with English, may I suggest using a language translation site before posting?

Thanks for your contribution. And once again, welcome!

It was not my intention, excuse me, I wrote it with capital letters to attract attention for being a security case. Isopropyl is highly toxic. It is not because of "arrogance". Regards. JCL

 

IPA is less toxic than methanol. Don't drink it either, over 10grams gets your poisoned. IPA is used for medical purposes widely nowadays (hand cleaner) with no harm.

 

At my first job, we used TCE (trichloroethylene), that usage has been banned.

 

IPA and a brush or Q-tip.

 

I've found IPA of any strength and a lint free qtip work well... However, I have found that this method smears some percentage of the flux around instead of removing it. I've switched to using IPA in an ultrasonic bath. No visual blemishes, boards get super clean, and fillets are shiny (if using lead-based solder).

Amazon.com : ultrasonic bath

 

I spray drugstore 99% isopropanol on the board, let it soak a while, then scrub with a toothbrush. If there are obvious thick lumps of rosin, break them up with a pointy thing. Then, blow the dirty IPA off the board and the brush with compressed air (preferably outdoors). Squirt some fresh IPA on the brush and blow it dry again to clean it. Now spray, scrub, and blow dry the board again; repeat if necessary. If I'm doing a bunch of boards (and someone else is paying for the alcohol), I'll lay the boards in a shallow metal tray and pour in enough to let them soak. If you don't have an air compressor... shaking off the dirty IPA and repeated rinses and blotting dry with paper towels should work.
For cleaning up a few pads after rework, a Q-tip and/or a small wad of paper towel dipped in IPA. Press, twist, discard. Repeat until satisfied.
But that time I spent a couple of weeks replacing thousands of capacitors (potentially damaged by improper lead bending), it was "no clean" flux and a squirt of conformal coating and call it good.

 

I have recently finished soldering all my components to a PCB. I then used spray Isopropyl Alcohol (99.9% pure anhydrous) and sprayed the board multiple times and then used an acid brush to try to get all the flux off the board. But I have found no matter how much I do this there remains a thin film of flux on the board (you can tell the board is slightly sticky). Is there a different chemical I should be using or a different technique? Thanks in advance.

washing up liquid and water then dry it properly . but dont leave it wet to rust im sure that will work.