Hi David,
Yes, such studies, both experimental and analytical have been done.
In terms of barrel integrity, non-functional lands do not make much of a
contribution, except displacing some high-CTE resin with low-CTE Cu, which is not
very significant.
In terms of resin recession, having a lands at every layer helps, but resin
recession is not a critical reliability issue.
In terms of innerlayer separation, having lands at layers 1, 2, 3, n-2, n-1
and n is very helpful.
Thus, for run-of-the-mill PCBs the question of non-functional lands is not
important; for high-aspect ratio vias, the lands strengthen the PTV barrel
against the expanding resin trying to collapse the barrel.



Werner

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