Printed circuit board design for high speed application

Abstract

A printed circuit board includes a substrate having a top surface and a bottom surface. A reference plane is embedded in the substrate and adjacent to the top surface. The printed circuit board also includes a first signal net and a second signal net being in close proximity to each other and disposed within a specific region on the top surface of the substrate. An outermost insulating layer is disposed on the top surface of the substrate to cover the substrate, the first signal net and the second signal net. The outmost insulating layer comprises an opening to expose a portion of the second signal net. A conductive layer is disposed in the opening and on the outermost insulating layer corresponding to the specific region in which the first signal net and the second signal net are arranged, such that the conductive layer overlaps with the first signal net.

What is claimed is: 
     
         1 . A printed circuit board, comprising:
 a substrate having a top surface and a bottom surface;   a reference plane embedded in the substrate and adjacent to the top surface;   a first signal net and a second signal net being in close proximity to each other and disposed within a specific region on the top surface of the substrate;   an outermost insulating layer disposed on the top surface of the substrate to cover the substrate, the first signal net and the second signal net, wherein the outmost insulating layer comprises an opening to expose a portion of the second signal net; and   a conductive layer disposed in the opening and on the outermost insulating layer corresponding to the specific region in which the first signal net and the second signal net are arranged, such that the conductive layer overlaps with the first signal net.   
     
     
         2 . The printed circuit board of  claim 1 , wherein the reference plane provides one of the ground potential and the power potential. 
     
     
         3 . The printed circuit board of  claim 1 , wherein the reference plane is electrically connected to the second signal net by a via hole formed in the substrate. 
     
     
         4 . The printed circuit board according to  claim 1  further comprising:
 an insulating cap layer covering the conductive layer within the specific region. 
 
     
     
         5 . The printed circuit board according to  claim 1  further comprising:
 a third signal net embedded in the substrate and between the reference plane and the first signal net.