>Techneters:
>     I have recently experienced a hole wall pullaway issues on various
>     product. I completed a DOE using  various dep chemistries and various
>     plating chemistries. The results were inconclusive. Is anyone aware of
>     a root cause for hole wall pullaway unrelated to the Electroless
>     process.

Some possible causes:

Thin plating is a factor as is outgassing in the laminate. It is more
apparent on larger diameter holes as the barrel is more easily deformed.
Think of the plating as a copper tube. The thinner the plating the
weaker it is and more prone to deformation. The outgassing will apply
pressure to the barrel and larger diameters are more easily deformed
(eg a beer can). Make sure you have the right plating thickness and that
the laminate is fully cured to prevent outgassing. If the pullaway is
occurring after plating but before solder mask bake, you will find the
bake will make a difference to outgassing and reduce or eliminate the
problem.

If none of the above is relevant and the pullaway is apparent in micro
sections, but only evident on one side of the hole, then suspect the
grinding technique used.

Hope this helps
Regards
--
Paul Gould
Teknacron Circuits Ltd
[log in to unmask]
Isle of Wight,UK