Circuit package for electronic systems

This invention relates to circuit packages, and more particularly, to circuit packages capable of reducing noise in electronic systems. A circuit package has been described for routing long traces between an electronic circuit, such as a phase locked loop, and external circuit components. The traces are routed through two substrates. In each substrate, the traces are routed primarily on a layer adjacent to and between a pair ground planes located close to the traces. Degassing apertures are located to the side of the long traces to avoid interfering with the shielding provided by the grounds planes. The circuit package uses two power plated through holes and two ground plated through holes to reduce the noise on the power supply lines. The circuit package also separates the signal carrying plated through holes from the power plated through holes, which reduces noise on the long traces. Noise is further reduced on the long traces by using the ground plated through holes to shield the signal carrying plated through holes from noise generated at the power plated through holes.