As you probably know, so long as the trace on the PCB matches the file transfer rate, the signal is able to avoid interference. However, when the rate reaches 100Mhz or more, impedance control must be performed.

Impedance control actually refers to the practice of putting down printed circuit traces which have their impedance matched to the circuit devices they are connected to. That's to say, the trace width and the distance from the ground plane that are regulated so that the track is seen as a proper RF feedline with a specified characteristic impedance.

BTW, on the PCB, there are four main factors that affect impedance control: Dielectric constant, copper thickness, line width line spacing and reference plane.