[SI-LIST] Re: Maximum Current Density for Copper Plane

Avtaar,
assuming uniform current density, 1 oz copper (34 um), and a temperature
rise of 15 deg C, you can run 10 amps per 1 cm width. The resistance of 1 oz
copper is 500 u ohms/sq. The 10 amps will cause a heat dissipation of 50 mW
for a 1 cm x 1 cm portion of the plane. The temperature rise will be roughly
15 deg C.

The limiting factor is the 'spreading resistance' from the via(s) to the
plane. Several vias are required. For this I use SPICE to calculate the
spreading resistance. SPICE can also be used to run a Thermal simulation
with the thermal resistance to air approximated as 5 deg C/ cm sq.

     Dave Cuthbert

On Wed, Aug 13, 2008 at 12:10 AM, Avtaar Singh <avtaarenator@xxxxxxxxx>wrote:

> Gurus:
> Can you kindly let me know the maximum current density that a copper plane
> can handle?
>
> Can anyone forward to me a detailed guideline on how to decide on amount of
> copper to use in a stackup, given the amount of current that needs to flow
> through the plane?
>
> Regards,
> Avtaar
>
>
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