You must be aware that using abrasive brushing (Scotchbrite (R) or
slurry) is a major cause of solder dewetting. Micro-particles of
abrasive get implanted in the metal, which is even swaged over some of
them. I have PROVED this time and time again. I published this in a
paper 'New Aspects on the Solderability of Printed Circuits' in the
Technical Proceedings of Inter/Nepcon '69, in Brighton, as well as in my
book (pp. 76 ff). It is amazing that a problem that was identified 35
years ago is still largely ignored! :-(

Brian

Susan Mansilla wrote:
> Hi Mike and All
> I am familiar with the abrasive wheel cleaning processes. but those are done
> AFTER the tin/lead has been stripped.  The response I got indicated that the
> abrasive was used on the Tin/Lead deposit, which didn't follow my idea of a
> possible process flow.
> Some PCB fab shops continue to use a "Scotch Brite" style of
> abrasive wheel or brush as a final surface prep operation prior to
> soldermask application.
> Susan Mansilla
> Robisan Lab
>
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