[EE]: Ultrasonic cleaner suitable for cleaning assembled PCBs?

[Philip Pemberton]

Just out of curiosity, is anyone using an ultrasonic cleaner to clean
assembled PCBs?

Specifically, I'm after something that can remove rosin-based fluxes, and
general muck, without damaging the components on the PCB. We're talking mixed
through-hole and SMD -- a few TQFPs, but no BGAs. The boards are typically
around Eurocard size (160x100mm) or smaller.

At the moment, my cleaning "procedure" (if you can call it that) involves
about 1/8th of a can of >90% isopropyl (Servisol IPA170), a stiff toothbrush
and a large amount of scrubbing, followed by a water rinse, then another IPA
rinse to get rid of the water. Total time about 15 minutes for a densely
populated Eurocard...

Maplin are advertising this thing:
http://www.maplin.co.uk/Module.aspx?ModuleNo=225671
at £25, and they claim it'll do PCBs, among other things. What I'm worried
about is if it'll damage the board or components, or (like a fair bit of
Maplin overpriced import junk) just plain not work at all...

Has anyone used one of these, or something similar, to clean PCBs? Did it
break anything?

I have heard they're good for regenerating old solder paste -- put some water
in the tank, throw the paste (syringe, needle and all) into the tank and hit
"start". Sounds like this might be useful, especially seeing as the shelf life
on the stuff isn't exactly stellar (the last batch I got had an expiry date of
the 27th of November -- the order arrived on the 12th). I'd be interested to
hear if that trick actually works...

Thanks,
--
Phil.
pic...@philpem.me.uk
http://www.philpem.me.uk/

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[John Chung]

I own an Ultrasonic cleaner. Use isopropyl solution for the
board. Cleaning should not damaged the circuit board at all since the
principal behind the machine is to generate tiny bubbles to clean the item
that is soaked in the machine with the solution.

I have not rejuvenate solder paste before so I can't say. It does excel in cleaning fountain pens!

Regards,
John

--- On Tue, 12/16/08, Philip Pemberton <pic...@philpem.me.uk> wrote:

[Clint Sharp]

In message <4947C384...@philpem.me.uk>, Philip Pemberton
<pic...@philpem.me.uk> writes

>Just out of curiosity, is anyone using an ultrasonic cleaner to clean
>assembled PCBs?
>

We used to when we reworked PC expansion cards back in the days when PCs
were worth money and a network card was worth repairing. Never had a
fail of a card after it was repaired that we could put down to the
ultrasonic tank. Admittedly they were all pretty coarse pitch PGA and
assorted SMD chips, no BGA in sight so YMMV.
--
Clint Sharp

[sergio masci]

On Tue, 16 Dec 2008, Philip Pemberton wrote:

> Maplin are advertising this thing:
> http://www.maplin.co.uk/Module.aspx?ModuleNo=225671
> at £25, and they claim it'll do PCBs, among other things. What I'm worried
> about is if it'll damage the board or components, or (like a fair bit of
> Maplin overpriced import junk) just plain not work at all...
>
> Has anyone used one of these, or something similar, to clean PCBs? Did it
> break anything?
>

I don't know if this cleaner will harm your PCB or not however you might
take comfort in the fact that this is not a "maplin only" item. I've seen
similar cleaners at Cookson (another UK company):

http://www.cooksongold.com/Jewellery-Tools/Ultra-7000-Mini-Ultrasonic-Cleaner-With-Digital-Timer-prcode-999-AJZ3

Regards
Sergio Masci

[Philip Pemberton]

John Chung wrote:
> I own an Ultrasonic cleaner. Use isopropyl solution for the
> board.

Basically the same stuff I use for cleaning PCBs by hand then.

> I have not rejuvenate solder paste before so I can't say. It does excel in cleaning fountain pens!

Might be useful for other things then...

Looks like I'm off to pick up an ultrasonic cleaner then. Thanks for the
feedback, guys!

[Jonathan Hallameyer]

>
> Looks like I'm off to pick up an ultrasonic cleaner then. Thanks for the
> feedback, guys!

At work we use http://www.microcare.com/pc-17-4-suprclean.aspx to
clean circuit boards, its really good, literally rinses flux off the
board, no scrubbing needed, though you can save on how much you use if
you do scrub.

Ultrasonic cleaners work great at cleaning PCBs, but they are banned
for use on NASA flight hardware. Our instructor explained it was
something along the lines of "Since ultrasonic wirebonding can be used
on IC's, ultrasonic cleaners cant be used on populated assemblies,
possibly affecting the wire bonds"

Overkill? For you, probably. For someone making something that will
waste billions of dollars, and up to decades of time if it fails?
Probably not.

Definitely get one though, an ultrasonic cleaner + IPA will work
wonders on a board, and most other stuff you throw in it.

--
Jonathan Hallameyer