Printed circuit board of probe card

A printed circuit board of a probe card, which is a substrate having a first side and a second side and comprises:

• a plurality of first contacts disposed on said first side of said substrate;
• a plurality of second contacts disposed on said first side of said substrate, wherein at least two of said first contacts are respectively corresponding to different ones of said second contacts and a signal trace or a signal cable is disposed between each of said second contacts and a corresponding one of said first contacts to electrically connect each other;
• a plurality of third contacts disposed on said second side of said substrate and respectively corresponding to different ones of said second contacts, wherein said first contacts and said third contacts are designed to have a fan-in layout;
• a plurality of second-side traces disposed on said second side of said substrate and each having a front end and a rear end, wherein said front end of each said second-side trace is electrically connected with one of said third contacts, and wherein said rear ends of said second-side traces are distributed in a predefined area which is located in a region encircled by a loop formed via connecting said front ends of said second-side traces;
• a plurality of plated through holes penetrating through said first side and said second side of said substrate to electrically connect each of said third contacts with a corresponding one of said second contacts;
• and
• at least one electric barrier disposed among at least two of said second-side traces.