Jim Marsico wrote:
Can anyone tell me the standard aspect ratio for blind vias?
  What is the minimum and maximum hole diameters?

I think that I can only answer from experience rather than any
design guidelines.
We manufacture sequentially bonded blind vias with hole diameters
of 0.3mm in 007" laminate, 0.35mm in 028" laminate, and 0.6mm in
070" laminate, as well as lots of others in between.
The aspect ratio on sequentially bonded (resin filled) blind vias
is not as important as the length of the hole. We are aware of issues
with long holes due to the resin expansion during SMD assembly, and
it can be predicted that the maximum hole depth should be 0.6mm (024")
to avoid this issue.
I am currently evaluating the reliability of different aspect
ratio blind vias, in different thicknesses and types of material
with different plating thicknesses, and hopefully will be able to
publish a paper in the new year.

As far as depth drilled blind vias (access blind via holes), the
hole size is determined by the technique used (mechanical/laser etc)
but the rule of thumb is to keep the aspect ratio to 1 or less.

Dougal Stewart
Exacta Circuits
Scotland

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