read several of the net's e-mail on cleaning and scrubbing - whole lo t of it
going on.

pth - usually a good acid neutralization and proper rinse after pth and an
anti-tarnish
        within proper pH range - and no scrubbing is required - straight to
the yellow
        room

prior to soldermask - good chemical clean is all that is really required -
don't forget
                               proper rinsing

this pumice - scrubbing ( actual copper grinding ) sure puts in alot of
processes that
 don't do more than contaminate the shop or makes more work

a good LPI process does not leave behind any residue on the copper surface
and shouldn't cause solder skipping after HASL - just a decent chemical clean
is all that is needed - maybe should look into the developing stage of the
LPI

now thermal cure soldermask is another story - usually on low quality boards
- alot of spacing so can handle the bleed - if not - e-mail me - tell you
what i've seen alot of plants doing

regards

richard fudalewski

Atotech Canada Ltd

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