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Mix of Lead free & Leaded washing in same machine

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#67134

Mix of Lead free & Leaded washing in same machine | 27 August, 2012

Hi, my supplier is using the same Aqueous machine to clean the boards for 2 different customers. My product uses the chemistry of leaded clean flux meanwhile the other product uses the chemistry of lead free with no clean flux, however that product requirement is to clean the boards thru chemical wash. The Aqueous machine is loaded with a chemical called EnviroGold. We too requested for chemical wash and this is the chemical wash provided by our supplier. The issue is we're seeing high fallout on the boards manufactured by this supplier at the system level test. For confirmation sake we did ionic contamination test on few boards and it all failed the ionic test. So i'm worried do the cleaning process using the same machine of both the chemistry (leaded with clean flux & lead free with no clean flux) will actually affect the ionic reading of the PCBA or any effect of contamination? The boards look really clean when inspected visually thru microscopes however the ionic reading show otherwise. I need some advise and help here folks...Thank you

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#67181

Mix of Lead free & Leaded washing in same machine | 31 August, 2012

Hi there, is there any SME in cleaning process for PCBA can help me out on the problem i have. More boards manufactured from this supplier failing at our system test. And currently we're in line down situation. Please help

Thank you Ilanhovan

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#67186

Mix of Lead free & Leaded washing in same machine | 31 August, 2012

First off - There should be no issue with washing your OA/water soluble boards with the other customer's no clean units provided that the recipe being used has been validated to effectively clean each product.

If your supplier is using a batch system, the wash time, temp and number of rinses should be something they can show are based on study or at least MFG'r recommendation for the cleaning solution.

Has the supplier verified that their machine is functioning properly? Spray bars spinning? Wash solution is within correct % range? Chamber is not overloaded causing shadowing?

Does your product have difficult to clean areas? Low standoff components such as BGAs, LGAs, QFNs, jam nut receptacles?

Are there post wash hand add steps (at supplier or in your own facility) where the wrong flux or too much flux is being used and not activated by soldering temps?

Does your supplier have the capability to perform a ROSE cleanliness test that you can compare your results to?

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