Tom

What you are doing shows that your fluxes are working. The key words are
that you oxidised the surface. The fluxes are reacting chemically with
this oxidised surface to form a copper salt, according to the
composition of the flux activator. This is the green stuff you are seeing.

That having been said, the figures from the ionic contamination testing
are totally meaningless as an absolute value, as has been pointed out
many times on this forum. I suggest you do an archive search on this
matter, with contributions from Doug Pauls, myself et alia. It is just
as likely for the flux giving the higher figure to be safer than vice versa.

What surprises me most is "We been using a couple of ORL0 no-cleans and
to date the customers have had us cleaning them.". Frankly, this is not
clever. You are getting the disadvantages of both worlds and the
advantages of neither. If you clean, use a flux designed for cleaning.
If you don't clean, then use either a "no-clean" flux or an RMA flux.

And some "no-clean" fluxes do have halide activation.

Brian

Tom Gervascio wrote:
> Trying to get some feedback. We been using a couple of ORL0 no-cleans and
> to date the customers have had us cleaning them. A new customer wants us to
> go no-clean. Being on a short fuse, they didn't want to run a full blown
> S&IR and electromigration but a ROSE test with an acceptance value of 10
> micrograms/sq inch. Vendor A's no clean have me an Omegameter reading of 60
> micrograms/sq in after running thru a simulated wave solder process using
> foam flux application and Vendor B's no clean produce a value of 9.7
> micrograms/sq in. (using the identical process).
>
> This picqued my curosity so I took some copper clad laminate and cleaned
> it , oxidized it and applied both fluxes to the topside and heated the
> panel to 250 F. Both produced some green oxide (I assume cupric oxide since
> both fluxes should be halide free) with Vendor A producing a dense green
> layer almost immediately.
>
> Haven't run an electromigration test yet but this doesn't leave me with a
> real warm and fuzzy- at least with Vendor A's flux. Is it reasonable to
> expect copper corrosion with a flux that passes S&IR and electromigration
> testing.
>
> Commments?
>
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