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Need to clean no-clean flux?

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#64726

Need to clean no-clean flux? | 30 July, 2011

Do we need to clean after hand soldering with no-clean flux solder wire?

I am just wondering. The flux is clearly visible. Will there be any long term negative effects on the modules?

Is there any IPC requirement on cleaning it?

BTW, I talk about normal resin based flux, not the water soluble type (which I think is not no-clean anyway)

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#64727

Need to clean no-clean flux? | 30 July, 2011

While you're waiting for others to reply, search the fine SMTnet Archives for similar discussions. For example, here's a link to to a similar posting: http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=15696&mc=6

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Reese

#64760

Need to clean no-clean flux? | 4 August, 2011

No need to clean unless the sticky residue is an issue for you. If you are working with RF, it could be an issue. You may have probe contact problems as well with ICT and FT fixtures. We use a low residue flux for our wave solder machines (Kester 977).

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#64879

Need to clean no-clean flux? | 22 August, 2011

we have never had a problem using no-clean flux as far as far as shorts and testing problems, using high pressure test probes helps overcome this. The problem we have had is if a unit comes back down the line a couple of years later we notice that the conformal coating we apply actually starts to peel off from the board because of the flux starting to loosen after it vibrates too much hence causing a potential to expose the components to the elements

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Reese

#64882

Need to clean no-clean flux? | 22 August, 2011

Yes, but even high force probes are not a cure-all. You still get flux build-up over time which can cause contact issues. The best way is to use a low residue flux in the wave to minimize what's left on the pcb post-wave.

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