To all TechNet members,

I am requesting assistance with the intent interpretation of the barrel vertical fill requirement with ground plane exception in section 4.1 of the IPC-A-610 revision B. 

History:
I have a board design with two 1.0 oz ground planes at layers 4 and 8 in a 12 layer board.  The engineer designed an ineffective thermal relief pad to connect a leaded component's ground through-hole to the ground plane.  Also the component involved can not be wave solder due to thermal restrictions of it's design.  To make the situation worse, the component's ground lead, which causing all the problems, is connected directly to the steal shielding measuring 2x2x1.  Our contract manufacture is not able to solder past the first ground plane which leaves a 30% vertical fill.  Our requirement is Class 2, 75% vertical fill except when there is a thermal plane.  We are in the process of redoing the design but I need assistance with defending the supplier.

Question:
Figure 4-2 shows the vertical fill stopping at the Metal Core/Thermal/Heatsink plane half way through the board.  The paragraph following states that the vertical fill has to be 50% when there is a thermal heat sink plane.  Our design uses the ground plains as thermal/heatsinks.  Is the intent of the picture and the text to state that it is allowable for the solder not to pass the thermal plane.  With my design, would it be acceptable to have a vertical fill of 30%.

Please reply with your opinions to my question,

Thank You,

Doug Smith
Supplier Quality Engineer.
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