Try www.pcb4u.com (or better known as Accutrace)
I just received a ten layer with 4/4 width/spacing, 4mil vias with 14mil
pads, controlled dielectric, and gold plating for a design of mine. I have
had them do blind and buried vias in the past too and they do a heck of a
job. I have not seen them do 6mil mechanical drill though. 8 mil mechanical
is pushing it and below that they transition to laser drilled holes. Not
cheap though but with these specs cheap is a dirty word anyway...

Regards
Madhu Annapragada 

-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
Vasile Surducan
Sent: Friday, January 12, 2007 12:54 AM
To: Microcontroller discussion list - Public.
Subject: Re: [PIC] - Fabricating PCB boards
Hi Alan,
8/8 mil is quite unusefull for 0.65 mm pitch BGA package. My question
was a precise one, based on my last work. 4/4 mil, 5 mil stacked
microvia in least three layers (better four) and 6 mil mechanical
drilling (blind vias) is a must.
Do you now any US PCB board house doing currently such boards ?

thx,
Vasile

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