High frequency and wide band impedance matching via

Abstract

A high frequency and wide band impedance matching via is provided. As an application to multi-layer printed circuit boards, for example, the multi-layer circuit board has several signal transmission traces, several ground layers, signal transmission vias and ground vias. The signal transmission traces and the ground layers are sited on different circuit layers, and each signal transmission trace is opposite to one of the ground layers. The signal transmission vias are connected between the signal transmission traces. The ground vias are connected between the ground layers. The ground vias are opposite to the signal transmission vias, and the ground vias corresponding to the signal transmission vias are sited to stabilize the characteristic impedance of the transmission traces.

1 . A high frequency and wide band impedance matching via, comprising: 
 a first signal transmission trace;    a first ground layer opposite to the first signal transmission trace;    a second signal transmission trace;    a second ground layer opposite to the second signal transmission trace;    a signal via substantially perpendicular to the first and the second signal transmission traces for connecting the first signal transmission trace with the second signal transmission trace; and    at least one ground via opposite to the signal via and adjacent to the signal via for connecting the first ground layer with the second ground layer.    
   
   
       2 . The impedance matching via of  claim 1 , wherein a length of the signal via is preferably similar to a length of the ground via.  
   
   
       3 . The impedance matching via of  claim 1 , wherein a plurality of the ground vias are symmetrically sited around the signal via.  
   
   
       4 . The impedance matching via of  claim 1 , further comprising: 
 at least one conductor portion for connecting the ground vias.    
   
   
       5 . The impedance matching via of  claim 4 , wherein the conductor portion surrounds the signal via.  
   
   
       6 . The impedance matching via of  claim 4 , wherein the conductor portion is connected to the ground vias and around a side of the signal via.  
   
   
       7 . A high frequency and wide band impedance matching via applied to a substrate which has a first surface and a second surface opposite to each other, comprising: 
 a first signal transmission differential pair sited on the first surface of the substrate;    a second signal transmission differential pair sited on the second surface of the substrate;    a pair of signal vias sited in the substrate and substantially perpendicular to the first and the second signal transmission differential pairs for connecting the first signal transmission differential pair with the second signal transmission differential pair; and    a plurality of ground vias substantially perpendicular to the first and the second signal transmission differential pairs, symmetrically adjacent to the signal vias and connected to each other.    
   
   
       8 . The impedance matching via of  claim 7 , wherein a length of the signal via is preferably similar to a length of the ground via.  
   
   
       9 . The impedance matching via of  claim 7 , further comprise: 
 at least one plane conductor trace connected to the vertical signal vias to form an electrical connection.    
   
   
       10 . The impedance matching via of  claim 7 , further comprising: 
 at least one conductor portion for connecting the ground vias.    
   
   
       11 . The impedance matching via of  claim 10 , wherein the conductor portion is a hollow conductor portion.  
   
   
       12 . The impedance matching via of  claim 10 , wherein the conductor portion surrounds the signal via.  
   
   
       13 . The impedance matching via of  claim 10 , wherein the conductor portion is connected to the ground vias and around a side of the signal via.  
   
   
       14 . The impedance matching via of  claim 7 , further comprise: 
 a first ground layer opposite to the first signal transmission differential pair; and    a second ground layer opposite to the second signal transmission differential pair;    wherein the ground vias connect the first ground layer with the second ground layer.