4mil GND trace到底有無效果？

mic29

u r proposed to refer to 3W rule.  
; I4 ]0 R6 u2 X0 B# i. @when clock trace is 5 mils, u will need 10 mils spacing.
4 k2 \' Q# _) F" B9 eof course GND trace will help, but PTH through holes with proper interval will do it better.

google it for detailed information, please!