PCB Cleaner/washer suggestions

You state that you need a washer for �pcb washer/cleaner for misprints etc�

Is it only for misprints or is it also for post-reflow de-fluxing?

I would not suggest that you utilize one machine for both applications. Misprints should always be cleaned in a separate machine from populated boards. This prevents the transfer of loose solder balls from the misprint to a populated board.

Ultrasonic technology works best for misprints and stencils, spray-in-air (batch or online) is better for post-reflow de-fluxing.

With lead-free in your future, consider carefully. For stencils and misprints, lead-free is not an issue. It is just as easy to remove as 63/37. In post-reflow de-fluxing applications, lead-free is more difficult to remove and one should ensure that whatever machine they are considering is compatible with lead-free.

I hope this helps!

Mike Konrad Aqueous Technologies konrad@aqueoustech.com (909)944-7771 ext 29

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We use a Cyberclean 3000 model 32F for our stencils and misprints.We currently use no-clean, water-clean, and lead free. It's been working great for us for 4 years now...

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Here are some of the leading mfrs.:

http://www.pressureproducts.com

http://www.smartsonic.com

http://www.aqueoustechnologies.com

http://www.emcgti.com

http://www.jnjultrasonics.com

Using ultrasonics has proven to be most effective at dislodgeing those pesky spheres and cleaning them off the PCB.

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Thank you all for the info. I'll check all the links and related articles.

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The pre-solder cleaning of misprinted PCBs can be a completely different experience from a post-solder application.

While the paper that DaveF references is excellent, you may want to read the paper by Richard S. Clouthier, "SMT Stencil Cleaning: A Decision that Could Impact Production." Mr. Clouthier reviews the pros and cons of using various technologies for cleaning misprinted PCBs. A copy of the article may be obtained at: http://www.smartsonic.com/article.html

Regards, Bill Schreiber Smart Sonic Corporation bill@smartsonic.com http://www.smartsonic.com

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Hello JB,

Based on the double sided assemblies, the misprint cleaning process can demand the cleaning system to remove both raw solder paste from the misprinted side of the board, and, reflowed flux residues from the assembled side.

Recognizing and setting this as the requirement, the Austin American Technology development team conducted a study to select highest performing technology for the development of a misprint cleaning system. The findings were as follows:

Double sided Misprint assemblies � Spray in air systems demonstrated the ability to use of a diverse range of chemistries to effectively clean both sides, while not diminishing the mechanical energy contribution. At the time of AAT's study, ultrasonic energy allowed only a limited range of chemistries. Chemistries aggressive enough to remove reflowed flux residues diminished the ultrasonics mechanical energy contribution.

Dislodging and displacing raw solder paste � Spray in air effectively dislodged and displaced solder spheres away from a broad range of assemblies. Due to flushing and filtering associated with spray in air, dislodged solder paste were flushed away and the metal content filtered out of the active process solution. Ultrasonic energy effectively dislodged solder spheres, while it demonstrated less effectiveness in displacing the solder away from complex assemblies. AAT's in house test showed ultrasonic technology did not sufficiently carry the metal content away, rather, the dislodged spheres fell under components and into via's.

Spray in air technology also demonstrated higher marks in the technologies ability to rinse and dry complex assemblies, and, lends itself to simple and low cost of ownership maintenance procedures. While Austin American Technology offers both ultrasonic and spray in air systems, based on the results of the study, spray in air was chosen as the technology to integrate into the cleaning systems AAT offers for Misprint applications.

Hope this is useful information for your consideration of avaialable misprint cleaning technologies.

Shean Dalton www.aat-corp.com (512) 335-6400

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