Bill,

	The best resource that you can use is a discussion with the one
circuit board vendor that you think will win the job.  I did this one
time (because that is how many boards I have done with these types of
via's on them) and I basically stacked the deck in their favor.  The
quote I got from them was $4K for 10 boards.  The next closest quote I
got for the same card was $13K and then the next one was $25K.

	Talk with your PCB company and ask them what they want to see.

	Joe J.

-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of
Brooks,Bill
Sent: Monday, December 03, 2007 6:21 PM
To: [log in to unmask]
Subject: [DC] Blind and buried vias... advice?

Is there someone out there that has a good reference for setting up
blind
via and/or buried via technology for your board designs?
Questions that come to mind are things like:
 
Stackup options:
What is the best stackup arrangement for an 8 layer board with blind
vias? 
Best for electrical performance and best for manufacturing of the board?
What options do you have and what are the tradeoffs of using them? 
 
Aspect ratio of the vias: 
What is the best aspect ratio to use? 
When does it get too tough to build? 
What makes it easier to build? 
 
Mistakes to avoid: 
What are the cost drivers?  How can you avoid them? 
What examples of things you have seen attempted that just should not
have
been done that way? 
How should they have been done? 
Via geometries, board stackups, etc... 
 
Process options, pro's and con's
 
Etc.., etc.. 
 
Please let me know if you have a source for this sort of data and what
your
advice is for someone who is just getting into it.
 
Best regards,
 
Bill
 
 
 
 

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