Hi,
As we know, delay of gate in chip is different in different PVT, or in worst case and in best case.
But in PCB, trace delay vary much in different case?
For example, 5 inch length 's delay is 5*160 = 0.8ns accroding to 160ps/inch. 0.8ns is in which PVT case?
The trace on a PCB is a true transmission line - it has both significant inductance and capacitance per unit length. The delay will vary with trace width, trace thickness, trace shape, distance of the trace from its reference plane, and the dielectric constant of the board material and/or any coating over the trace.
There is no fixed trace delay on a PCB it varys widely according to the above parameters.