Cleaning boards after working on them advice please

[No-Clean]

Some boards that come with no water damage for repair leave a little dirty from the flux used on them, regardless of a good cleaning with 99% alcohol and a brush I can still see that someone worked on the board and did not clean it well.

I have a Crest and Branson EC cleaner and have watched Louis video on how to use it, but that is for water damage boards, I want to just clean them fast to make sure the work we did looks decent.

Thanks in advanced!

 

[JohnB8812]

I use UC on anything with too much flux or corrosion. If it's a simple job like a PPBUS tantalum cap, I just be cautious of the amount of flux I use, and I use alcohol and a paper towel to clean it.

 

[No-Clean]

Thanks for all the tips, I already have the Ultrasonic Cleaner and I only want to clean boards that had lot of work done on them, JohnB8812 how long do you put it on the UC for and how do you dry it?

 

[JohnB8812]

I usually put them in the cleaner for 2 minutes on each side then use alcohol to displace the distilled water. Put back in for two minutes then dry with alcohol and heat. I use compressed air to blow out anything under the big BGA chips CPU/GPU/RAM, etc. Usually leaves minimal streaks and looks good. I do a final go over with alcohol and a paper towel for anything I miss.

 

[No-Clean]

JohnB8812 Thanks, that sounds good, will try later with a board that looks a little nasty after working on it.

 

[Milwaukee Mac Repair]

CLR+ light scrubbing. Dishwasher! Straight Methanol removes water perfectly. I own a great ultrasonic cleaner. I use it sparingly. Selectively. MEK is a great solvent!! HELLO! If the State of California bans it: it works and you need it. Cyanide vapors, Freon vapors..Carbon Tetrachloride...mmmmmm....There are dangerous chemicals that do the best job. Your dishwasher is made to clean stuff and not leave spots. hmm. Would you believe that your dishwasher is the BEST ever??!! A good ultrasonic cleaner will eat away at the end caps of SMD components like resistors, mlcc caps, etc. If corrosion has already eaten most of it away: ultrasonic cleaner should be your last choice.

 

[No-Clean]

Ok great, lots of info here and I agree on UC damaging boards, I already had one like that, but my problem was that I left the boards a little too long, I have a small boat that I had to do some repairs on it and had to use MEK, I will try that too before putting them on the UC, I was afraid that will damage some parts as that is a pretty strong solvent, but I have seen a few people use it on boards now.

 

[2informaticos]

If no sweep function available, change board position every 20-30s, to avoid hot spots; just push it 1-2cm.
Of course, depending of corrosion state, change board side up-down every 2-5min.

 

[No-Clean]

Thanks for al the tips, in the case of just cleaning flux from a clean board after doing some work I think it makes no sense to clean it on a ultrasonic cleaner and do all that extra work just to ensure the board leaves the shop looking like new, what I just discovered is that if I use 3M Quick Dry Contact Cleaner 16-102 and a brush to clean the edges of the chips as well as clean room wipers at the end the board looks like nothing happened and it takes me no more than 1-2 minutes to clean it well. Hope all this helps someone later on.

 

[KC Micro Tronix]

The dish washer is a great idea if I wasn't in a hurry. I guess I wont bother getting a ultra sonic machine. I have one for phones but it is crazy small