99% of all the hole callouts I see are for finished hole size for
through hole as well as press fit connectors. You have to consider
what surface finish you are using when planning the drill size. Most
plated holes for components and connectors have a tolerance of
+/-.003 and vias are +.003/-nominal. Most fabricators have a good
historic knowledge of what drill size to use to obtain the desired
results. I would much prefer that a designer leave this type of
parameter up to the fabricator. Typically you specify what you expect
to receive and tolerance those expectations. Leave the manufacturing
methods and tools up to the fabricator.



At 01:45 PM 01/17/2006, you wrote:
>Hi Ofer,
>The reason for this is that many of the Fab houses still live in the past,
>and do not understand what is required for high reliability in high-density
>PCBs. The involved Fab houses cetainly understand those needs.
>
>
>
>Werner
>
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