dc trace thickness
For example, from **broken link removed** :
For top and bottom layers, 1oz (35um) copper thickness:
* 0.010" (0.254mm) - 0.8 Amps.
* 0.020" (0.508mm) - 1.2 Amps.
* 0.030" (0.762mm) - 1.8 Amps.
* 0.050" (1.270mm) - 2.7 Amps.
* 0.070" (1.778mm) - 3.4 Amps.
* 0.100" (2.540mm) - 4.2 Amps.
* 0.150" (3.810mm) - 5.8 Amps.
* 0.200" (5.080mm) - 7.0 Amps.
These values are for continuos current. For a variable signal, you can consider the rms value.
Also the copper thickness must be considered. Use the correct table.