Wolfgang;
take a look at the attached (rough) sketch - is this what you are trying to
describe?  If so, the only way that I ever eliminated or reduced this
problem was to add a microetch step following the acid cleaner in the
electrolytic copper preclean line.

If you don't have a tank available, you can always add .25%-.5% v/v
hydrogen peroxide to the sulfuric dip tank.  The amount of peroxide that
you drag into the copper bath is so small that you won't harm the
brightener.  You really have to watch the dwell time...

Hope it helps;
Fred J.

>>> "Erat, Wolfgang" <[log in to unmask]> 02/27/98
01:36pm >>>
We have a customer which is very sensitive to separation between
plated
copper and outerlayer foil copper (doublesided product). This condition
is especially visible at high pad rotation after thermal shock. What can
be  done to minimize / avoid this issue ?

Wolfgang Erat / Viasystems Canada

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