That's a very good question. I would like to know also how flat a plated
shut via can be if that's the correct term.

Is there an IPC specification addressing this?

The ~ 10 mil (.25mm) or greater finished hole vias in pad that I have
filled and plated-over are always very flat.

The ~ 4 mil (.1mm) finished hole micro vias in pad are mostly always flat.
Sometimes I see a small dimple in them that looks less than 1 mil deep.

Cheers

Donald Kyle


At 09:01 AM 10/25/2005, you wrote:
>Hi TN,
>
> From an assembly perspective, what is the maximum surface roughness
> tolerable for via in pad 0.5mm pitch BGA, particularly
>larger parts with pin counts >=80?
>
>Same topic, but from a fabrication viewpoint:- What is achievable using
>either 1 stage plated shut process or a 2 step process
>using filled/levelled microvia which is then plated over?
>
>Best Regards
>
>David Greig
>______________________________
>GigaDyne Ltd
>http://www.gigadyne.co.uk
><http://www.gigadyne.co.uk/>  <http://www.gigadyne.co.uk/>
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