Jan Merstrand asked:

>I'm just wondering about a no-clean flux made by InterFlux called
>interflux2005M.
>Sometimes we need to put some extra flux on certain kinds of components,
>and if there's not enough heat it won't burn away and leave a white
>powder left on the PCB. This is to my knowledge Adipic acid (spelling?).

>How does this affect the components and PCB if it's in one kind of a
>place where you can't brush it off?

Adipic acid has a unique property of being non-hygroscopic. Its residue is
less active as a result, and I believe the Interflux residue is safe. Call
them for more details.

>Of course we can use a waterwash or any similar kind of washer, but we
>don't wan't that extra step in the production. Many people here at
>Ericsson have diffrent theorys about if the flux do harm or not.
>Anybody have any experience in this matter?

Adipic acid is much more soluble in methanol or ethanol than water. Remove
it if you choose, but small residual amounts should not affect reliability.
Flux from this manufacturer (not sure about 2005M) was at one time fairly
popular in the US, and was used by some telecom manufacturers. They made
one of the first successful "no clean" fluxes.


regards,


Jerry Cupples
Interphase Corp.
Dallas, TX USA
http://www.iphase.com

we don't make flux!


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