Hello T'Netters,
An aspect ratio for holes or vias is the ratio
of the depth of the via to its pre-plated diameter.
For sure.
I need a definition of "low aspect" vias.
I need to know what document defines it and
any other useful information there may be about it.
One of our customers has presented us with
coupons of PTHs and blind vias which have less
than either the minimum average or absolute minimum
copper plating required per IPC-6012A.
However, the same spec allows for about half of the
copper coverage for "low aspect" blind vias.
This document simply defines low aspect blind vias
by "Low Aspect Ratio Blind Vias refer to blind vias
produced using a controlled depth mechanism (e.g.,
laser, mechanical, plasma, or photo defined).  All
performance characteristics for plated holes, as
defined in this document, shall be met."
What does that mean?
Is there a numerical cut-off value separating low-
aspect vias from others? Where is this value defined?
Anyone with an answer, please contact me directly
at [log in to unmask]
TIA
Mike Simms
Trace Laboratories - Central

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