Steve;

Since current carrying capacity is based on the cross-sectional area of
copper, you will have to calculate the cross-sectional area of the copper
plating, in the hole. Most holes require a minimum copper hole wall
thickness of 0.001 inch. Subtracting the finished hole area from the drilled
hole area would net the total copper area in the hole. You can then use this
information in Figure 3-4 of IPC-D-275, to calculate the current carrying
capacity.

At 02:36 PM 6/25/96 -0400, Steve Murphy wrote:
>Is there an IPC spec, or otherwise, that provides some guideline on the
>current capacity of vias on PCBs, based on hole size, wall thickness,
>etc?  Any thoughts are appreciated.
>
>Steve Murphy
>TRW Automotive 
>
>
Regards,

Gary Ferrari
Tech Circuits
(203)269-3311
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