Hi,

        What I do is:

        1.      calculate the equivalent conductor width;
                This is the circumference of the via hole (Pi times
Dia).

        2.      use Fig 3-4, Conductor thickness and width, etc,  of
IPC-D-275 (or the newer equivalent) on the calculated width.

        Problem:        The conductor thickness (plating) in the via
hole may vary; I think.

Hope it helps...

Joe H.


> -----Original Message-----
> From: Robert T. Moncada [SMTP:[log in to unmask]]
> Sent: Friday, May 01, 1998 11:32 AM
> To:   [log in to unmask]
> Subject:      [TN] current carrying capacity of vias
>
>
>
>
> Technetters-
>
> Is there a formula for figuring current carrying capacity of
> vias?
>
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