Cal

> Concerns:
> - Ultrasonics damaging internals on IC's

Remote in the extreme. However, why not check with the component supplier(s)
....you might find that they use ultrasonic cleaning themselves.

> - Residues left after cleaning

Yes but this is something that you could measure. At least use an ionic
extract cleanliness tester but employ a Go/NoGo of around
0.2microgrammes/cm2 for your circuits.

> - Effects on Programmable IC's

Nah.

> - .....Just General over all reliability.

Justified and there are new SIR methods that may be used to characterise and
monitor your process. Not straightforward but usable and effective.

Why clean no-clean? This can prove more difficult than you imagine. A
conversion of solder paste/flux to a cleanable type might prove beneficial
and widen your process window with commensurate savings in whatever rework
you presently might do.

Hope this helps.
--
Regards Graham Naisbitt

Golf Quote of the week: I had a wonderful experience on the golf course
today. I had a hole in nothing. Missed the ball and sank the divot!

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> Hello All-
> Recently I was away on Holiday and when I came back....there was a Branson
> Utlrasonics system being used to clean our newly assembled PCB's. The
> machine is a standard ultrasonics (parts cleaner I call it) bath using a
> general cleaner/degreaser.
>
> Facts:
> Our process is:
> - No clean
> - double sided
> - mix technology
> - Discrete (tants, Chips resistors)
> - BGA's
> - QFPs
> - PLCC's
> - ASICS
> - Connectors
> - Headers
> - Electrolytic Caps
>
> Concerns:
> - Ultrsonics damaging internals on IC's
> - Residues left after cleaning
> - Effects on Programmable IC's
> - .....Just General over all reliability.
>
>
> I have huge concerns on the over all cleanliness and reliability. Any info
> supporting or declining this is of interest.
>
> Thanks in advance,
>
> Cal
>
> Caldon Driscoll
> Program Manager, Circuit Board Manufacturing
> CTDI
> 1373 Enterprise Drive
> West Chester, PA 19380
> 610-793-8098
> WWW.CTDI.COM
>
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