Wayne and Jack,

I have heard similar concerns about VII vias and wrap plating / etc on this and other forums.

It reminds me of the same stigma about ENIG and other finishes back in the late 1990's where serious issues could result from improper processing. My approach today is the same as it was back then: deal with reputable fabricators with proven processes.

I can assure you that VII vias are reliable and are not to be considered either "leading edge" or problematic when properly specified and processed. Are they more difficult to process? Certainly, but a 12 layer PCB is also more difficult to process than a single sided design.

My suggestion is to talk to your fabricator and decide whether VII vias make sense for your application. The majority of designs where I've specified VII vias of late are high vibration, high temperature, and high current Class 2 products. In many cases the only alternative would have been a much more expensive and equally complicated blind and buried via configuration due to required copper weights. Current volumes range between 2K to 100K per year with several designs being in production around 10 years ... no via failure issues identified as of yet.

Hth,
Dave