Werner, Eddie,
The finished hole diameter is important only in one instance - when it is used for accurately-matched TH component, such as press-fit component. It is not relevant in case of connecting via (provided it is well-designed for curent carrying and signal integrity aspects). 

Ofer Cohen
Seabridge
A Siemens Company

> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
> Sent: Friday, May 13, 2005 01:48
> To: [log in to unmask]
> Subject: Re: [TN] board fab
> 
> Hi Deac,
> Why is anybody still quoting finished hole diameters; for 
> vias we need the drilled hole diameters and the plating 
> thickness—the finished hole size is an anachronism left over 
> from through-hole technology.
> 
> Regards,
> Werner Engelmaier
> Engelmaier Associates, L.C.
> Electronic Packaging, Interconnection and Reliability Consulting
> 7 Jasmine Run
> Ormond Beach, FL 32174 USA
> Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
> E-mail: [log in to unmask], Website: www.engelmaier.com
> 
> 
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