Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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PCB cleaning

Murray Pulman

#11076

PCB cleaning | 12 June, 1999

We are using so called no-clean fluxws for our small batch production, however the results are not always very visualy pleasing with white powdery deposits being the norm. I would like advise on the best avenue to explore for a small batch cleaning system, chemicals etc.

Thanks

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Brian Ellis

#11077

Re: PCB cleaning | 13 June, 1999

Murray

"No-clean" fluxes/pastes should not normally give "white residues". Before exploring cleaning, which is costly for small production levels, I suggest you may care to find out why you have these residues.

To help you, can you please answer the following preliminary questions: are you using cored (solid) flux in wire, liquid flux in e.g. a soldering machine or reflowed solder paste? do you obtain the same results with different makes of flux? please describe your process and product briefly what is your soldering alloy and temperature? what kind of finish do you have on your PCB soldering pads? what kind of solder mask are you using? (if none, what kind of laminate? do you apply any liquids to the PCB after soldering? If so, what and why? do you have any abnormal reliability requirements? do your "white residues" appear always or intermittently? If latter, any known predisposing factors? is your product used or stored under humid conditions?

If you can answer these, I'll be in a much better position to help you, but I may ask a few other questions subsequently.

If you can get away with not cleaning, this is the ideal. If you do decide that cleaning is necessary, then I suggest you look at water-soluble products and water wash as first choice, if possible, but let's not rush into things.

You may care to explore http://www.protonique.com for some further technical data on the merits of cleaning or otherwise.

Best regards

Brian

| We are using so called no-clean fluxws for our small batch production, however the results are not always very visualy pleasing with white powdery deposits being the norm. I would like advise on the best avenue to explore for a small batch cleaning system, chemicals etc. | | Thanks |

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