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Flux Classifications.


Flux Classifications. | 4 March, 2004

I am looking at two different type fluxes, Kester 951nc and AIM 264-5nc. The two seem to be comparable, but the Kester is listed as an ORL0 and the AIM as a ROL0. My product builds are all military and I have been dictated to use only ROl0 flux. I know that J-STD-004 list the OR as organic and the RO as Rosin. So, my question is, what long term affect would there be using the ORL0? Thanks for any input.

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Flux Classifications. | 9 March, 2004

Obviously, if your customer instructs you to use a certain flux type, using THAT flux type is probably a good idea.

Responding to your question: Chloride is one of the more detrimental materials found on printed circuit assemblies. Chlorides can come from a variety of sources, but is most often attributable to flux residues. Chlorides will generally initiate and propagate electrochemical failure mechanisms, such as metal migration and electrolytic corrosion, when combined with water vapor and an electrical potential.

The amount of chloride that can be tolerated on an assembly depends on the flux chemistry being used. Assemblies processed with high-solids rosin fluxes (RA, RMA) can tolerate higher levels of chloride due to the encapsulating nature of the rosin. Organic [water soluble] fluxes and no-clean fluxes are generally based on resins or very low levels of rosin, and so do not have this encapsulating protection, therefore, they require lower levels of flux on final assemblies.

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Flux Classifications. | 10 March, 2004

Take look also at IPC-HDBK-001, if not yet done, you can find helpful flux informations.

Rgards GLS

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