Reducing noise coupling in high speed digital systems
View Patent ↗An apparatus having reduced noise coupling includes a core layer having an upper and lower surface, the upper and lower surface each including a copper sheet layer, a pre-preg layer having an upper surface and a lower surface, the upper surface of the pre-preg layer coupled to the lower surface of the core layer, a core insulating layer having an upper surface and a lower surface, the upper surface of the core insulating layer coupled to the lower surface of the pre-preg layer, a return current reference layer disposed on the lower surface of the core insulator layer and high-speed signal traces disposed on the upper surface of the core insulating layer, each of the high speed signal traces disposed on a pedestal defined by a section of the pre-preg layer and the core insulating layer, each pedestal being separated by an air gap disposed between adjacent pedestals.
1. A printed circuit board apparatus having reduced noise coupling, the apparatus comprising:
a core layer having an upper and lower surface, the upper and lower surface each including a copper sheet layer;
a pre-preg layer having an upper surface and a lower surface, the upper surface of the pre-preg layer coupled to the lower surface of the core layer, wherein the pre-preg layer is an insulation material including a mold-mat thickening agent and a combination of at least one of mat, fabric, non-woven material and roving with resin;
a core insulating layer having an upper surface and a lower surface, the upper surface of the core insulating layer coupled to the lower surface of the pre-preg layer;
a return current reference layer disposed on the lower surface of the core insulator layer; and
high-speed signal traces disposed on the upper surface of the core insulating layer, each of the high speed signal traces disposed on a pedestal defined by a section of the pre-preg layer and the core insulating layer, each pedestal being separated by an air gap disposed between adjacent pedestals.
2. The apparatus as claimed in claim 1 wherein the high speed signal traces are single layer nets, wherein each pedestal supports a single layer net.
3. The apparatus as claimed in claim 1 wherein the high speed signal traces are differential nets, wherein each pedestal supports a differential net pair.