For thermal zone I would submit:

fixing the T-50 definition

Thermal Zone of a PTH
An cylindrical region centered about a plated through hole.  This zone is
defined in order to facilitate reduced laminate system requirement(s) near
the pth.  This practice has been deemed necessary due to vast differences in
heat transfer to, and temperature extremes of, the laminate system near a
pth during assembly process(s).  The radius of the thermal zone cylinder is
defined as the radius of the largest internal land observed on the hole plus
0.08mm.

This definition affectively:
1) raises the risk of non-conformance due to laminate voids on samples which
are mis-registered
2) keeps the requirement exactly the same(minus the internal/external land
issue) for perfectly registered samples
3) removes all ambiguity

However, I think more importantly it would be an appropriate model of the
"thermal area", while still keeping the cylindrical shape.
It may seem simple but, I think it would be VERY cumbersome, and therefore
not worth the effort to define a piece-wise linear (zig-zag).

--------------------------

For panel acceptance I like to keep in mind the following:

We can't "test until we find a good one", nor can we test until we find a
bad one.
The bottom line is: we must define EXACTLY what the sample is, and what
product it is intended to represent.  It many cases it seems trivial but our
sampling relies on statistics not integrity.

For example: Say a manufacturer produces a 10 layer board, 4up.  If the
specification allows for the use any non-standardized coupon (e.g.
production board) it is possible that a microsection yields 6 inner layer
posts to evaluate, rather than the standardized 48.  If post separation is
found on some panels and not others, the manufacturer has every right to
sort and increase yield.  The manufacturers' integrity should not be in
question, but rather the quality of the specification.

I appreciate and agree with the attempt to make a robust sampling plan in
the 6010 series.  But the most important things are missing, or ambiguous.
The problem is not finding the verbiage to fix it, but rather, (potentially)
huge policy decisions.

Chris Mahanna
Quality Manager
Robisan Laboratory Inc.
6502 E. 21st Street
Indianapolis, Indiana 46219
317.353.6249 phone
317.917.2379 fax