3W principles:
In order to trace the quality of the signal cross-talk is not generated, we want to keep a signal line width of 3 times the distance between the signal trace and restricting the number of traces, the pitch refers to the distance from the center to the center of trace, as our English is the width width, so this rule we usually called 3W principles.
3W principle to ensure 70% of the lines will not interfere with each other.
To 80% requires 10 times the width