Patent ID: 7390973

Claim:
A memory module, comprising: memory chips mounted on both sides of the module in a mirrored configuration; a printed circuit board (PCB) having same signal applying contact pads arranged on both sides in contact with same signal applying balls of the memory chips in the mirrored configuration, the PCB including a via at a location proximal to the same signal applying contact pad of one side of the PCB among the same signal applying contact pads arranged on both sides in the mirrored configuration, the via connecting an other side of the PCB to the one side of the PCB, and a contact junction connected to the same signal applying contact pad of the other side of the PCB, the contact junction being connected to the via of the other side of the PCB, and the via of the one side of the PCB being connected to the same signal applying contact pad of the one side of the PCB, the contact junction connected to a signal terminal from the other side of the PCB; and wherein the contact junction is positioned at a location such that a signal transmission time from the contact junction to the same signal applying contact pad of the one side of the PCB is equal to a signal transmission time from the contact junction to the same signal applying contact pad of the other side of the PCB.