trace width for 2A current

How thick is the copper? How thick is the board? How much temperature rise? How long?

The Cu is 0.0675 on top and 0.0350 on internal layers. Temp rise is not mentioned. but the system will operate in industrial area. 2A current is the max current. It is not constant.1.6-1.7A is the constant current. But sometimes 2A. board thickness is just 3.2782 .

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http://www.desmith.com/NMdS/Electronics/TraceWidth.html

There is no "Ideal". There is "good enough", or preferably, "Good enough plus some margin for error." More is approximately always better, since you don't care about capacitance.

How much room have you got? How wide can you make it?

If you can cram in a 3/8" (centimeter) wide trace, do so. If you have to narrow the ends down to make things fit, do that. If your PCB program can't manage that, use one that can. If you are tightly space constrained, the question becomes more along the lines of "what's the bare minimum I can get away with?" Then you can work up from that if you can make the space. Here a a couple of guesstimators for that:

tor/

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A skinny trace, 20 mils (0.02 inches) wide maybe, can handle 2 amps. But you should calculate the voltage drop and see if it's going to be a problem.

1 oz copper has a resistance of about 500 micro-ohms per square, and the number of squares is just the trace length/width ratio.

But you're lucky to get 1 oz copper even when you specify it, so overkill some.

John

Cool. The trace width should be NaN.

John