Assuming a square trace, the resistance would be

Resistance, R = pL/A where
p = resistivity of copper = 6.787x10-4 ohms*mil (at 20 deg C)
L = length of trace (in mils)
A = cross sectional area (in mils)

If you want to assume the trace is trapezoidal in shape, then the cross sectional area is
A = [(w-h)*h] + (h*h)/2 where
w = the plotted trace width
h = height of trace

Regards,

John

-----Original Message-----
From: Kaye Knotts [mailto:[log in to unmask]]
Sent: Tuesday, April 10, 2001 9:59 AM
To: [log in to unmask]
Subject: [TN] PCB Trace Resistance Chart

A few years ago I used a chart that
showed the resistance of a pcb trace
of a specific length and cross-sectional area.
Now I cannot find this chart.
Does anybody know where I can find this
chart again or know of a way I can calculate
the resistance of a particular trace on a board?
Thanks,
Kaye

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