I don't mean to cause any undue concern. The issue is fairly simple . . . You can break glass and ceramic with sound but it is not likely if you are careful. But ultrasonic cleaning can break wire bonds, and wires, this is especially true in controls, ceramic ICs and the like were the wires are not encapsulated and subject to vibration. There are technologies that are effective in reducing this type of damage. Hope this relieves your fear. If you are still concerned then you have some homework to do. What frequency and power does you cleaner work at. What is a construction of the packages in question . . . stuff like that.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Howard Watson
Sent: Friday, October 26, 2001 11:46 AM
To: [log in to unmask]
Subject: Re: [TN] Cleaning paste when misaligned.


Mike and Guy,

We routinely clean the second side of misprint solder paste, but from what you are saying perhaps there could be a problem with damaging some components.  The components that we clean in the ultrasonic cleaner are mostly flat chip package, C lead diodes, and some SOT-23 and SOIC.  How do I verify which components can or cannot go in the cleaner?  Is there any test data out there to support this issue?  Though we clean very few misprints, I am a little concerned.  Thanks for your help!

Howard Watson
Manufacturing Engineer
AMETEK/Dixson


"Barmuta, Mike" <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>

10/26/01 09:02 AM
Please respond to "TechNet E-Mail Forum."

       
        To:        [log in to unmask]
        cc:        
        Subject:        Re: [TN] Cleaning paste when mis-aligned.



Cathy: This should not be a problem for the bare (unloaded) PCB. However if
you are doing a double sided reflow and   misprint the second side you need
to verify that the first side components are compatible with the ultrasonics
you are using.


Regards

Michael Barmuta

Staff Engineer

Fluke Corp.

Everett WA

425-446-6076

-----Original Message-----
From: Cathy Killen [mailto:[log in to unmask]]
Sent: Friday, October 26, 2001 7:30 AM
To: [log in to unmask]
Subject: [TN] Cleaning paste when mis-aligned.
Importance: High


Hello All & the mountain dew man.
Can a mis-printed PCB be washed in a ultrasonic bath to remove all paste
particles?
Is there any danger of damaging innerlayers of PCB?

Thanks in advance.

Cathy Killen
Training Instructor
Smtek Europe Ltd.
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