Bob,
Dave is right. I couldn't have said it better (funnier, yes; better, no). WE have all developed special processes with an aid from aggressive home-brews (internally and/or externally applied) with our own rigorous version of parametric controls. This in of itself does not a production process make. A corollary would be like letting Doug loose with aggressive flux and a soldering iron.
Dewey

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: Thursday, February 20, 2014 1:08 PM
To: [log in to unmask]
Subject: Re: [TN] Acetone as a cleaning agent for PCBA's

Hi Bob - No, that specific amount in that type of procedure should not be an issue. But the fact that there is sufficient industry data showing that acetone attacks the butter coat, potentially attacks the laminate and that  I have alternative cleaning chemistries that do not cause possible damage is reason enough for me to not use acetone. I tend to try and design processes that are "Hillman proof" as sometimes materials get misused unintentionally. You are using a specific, controlled procedure but another person who is not as diligent or knowledgeable may use the acetone in a less than acceptable manner causing damage. Just a case of "risk versus reward" where I have alternatives that eliminate the risk.

Dave 



From:   "Robert Kondner" <[log in to unmask]>
To:     "'TechNet E-Mail Forum'" <[log in to unmask]>, 
<[log in to unmask]>
Date:   02/20/2014 01:59 PM
Subject:        RE: [TN] Acetone as a cleaning agent for PCBA's



Dave,

 Do you think using two drops on a Q-Tip for cleaning with the acetone evaporated in 5 seconds is going to hurt a board? 

Bob

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: Thursday, February 20, 2014 2:14 PM
To: [log in to unmask]
Subject: Re: [TN] Acetone as a cleaning agent for PCBA's

Hi Bob - Acetone has the potential of damaging your laminate (see Richard's
reply) and I would not recommend it as a cleaning solvent.

Dave



From:   Robert DeQuattro <[log in to unmask]>
To:     <[log in to unmask]>
Date:   02/20/2014 12:20 PM
Subject:        Re: [TN] Acetone as a cleaning agent for PCBA's
Sent by:        TechNet <[log in to unmask]>



Thanks all on the comments.

This is a picture of what the residue looks like from the acetone cleaning process.



[cid:[log in to unmask]]



Based upon the replies at this point to this thread, it appears:

1.       Using the acetone as they are seems acceptable for cleaning

2.       The boards we are supplying have some type of residue on them 
regardless of the results of the zero-ion testing.



Bob













-----Original Message-----
From: Mike Fenner [mailto:[log in to unmask]]
Sent: Thursday, February 20, 2014 12:56 PM
To: 'TechNet E-Mail Forum'; Robert DeQuattro
Subject: RE: [TN] Acetone as a cleaning agent for PCBA's



Hmm

I think I would like to know what their wiping procedure is and what they are hoping to achieve by doing it before making any firm comment.

Naturally nothing has changed in your place or theirs, but something has if this has just started to appear.

I would start from the premise that the boards can be no cleaner than the last thing that touched them.

Unless the acetone is being allowed to flush off the board the probability 

is that they are making the boards dirtier. If there is anything in the acetone or on the board and it dries in place then the board will be no cleaner than it was before (the soil might be redistributed slightly) and anything in the acetone or on operators gloves will be left on board. If they are applying the acetone to the wipe by holding it against the bottle 

then anything in the wipes will gradually accumulate in the bottle.

Quite likely they are just seeing a surface effect as you would get on any 

shiny surface wiped over like this. Think of cleaning a mirror. So it could be technique or the acetone is dissolving something from the wipe or 

softening the resist slightly. OR your boards are contaminated from packaging say and they are seeing partial removal. In this respect the boards could be ionically clean as measured by zero ion tester, but theoretically could have non ionic contamination.

So a lot of what ifs and maybes at this point.





Regards



Mike

-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Robert DeQuattro

Sent: Thursday, February 20, 2014 5:00 PM

To: [log in to unmask]<mailto:[log in to unmask]>

Subject: [TN] Acetone as a cleaning agent for PCBA's



I have a customer that uses acetone to wipe down their PCBA's upon receipt.

The assemblies we make for them are cleaned using a closed loop aqueous board washer then sampled for cleanliness with our zero-ion tester per J-std-001E guidelines.

Recently this customer commented that boards appeared dirty upon cleaning with the acetone.  Does anyone have any thoughts on this acetone cleaning process.

Thanks,



Bob



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