it defines the number of ounce copper on 1 sq. ft. area, such as 0.5,
1.0, 2.0, 3.0 oz, etc. Usually this parameter is used to specify the thickness
of the copper on each layer of the board. It is very easy to work out
the thickness of 1.0 oz copper on 1 sq. ft. board based on the copper
density (8.9 g/cm3), which is 34.29 µm and rounded up to 35 µm.
So we have the following list.