Apparatus and system with increased signal trace routing options in printed wiring boards and integrated circuit packaging

Abstract

An apparatus and system comprising electrical interconnection devices (EIDs), such as printed wiring boards, semiconductor packages, and printed circuit boards, having novel via and signal trace positioning. The vias may be positioned off-center from the pattern of the surface pads. Via groups, or staircase vias, connect surface pads with vias extending into the electrical interconnection device. The via groups convert the pad geometry on the surface to a more open via pattern on one or more internal layers. The EID comprises a plurality of pads formed on a surface for providing electrical connections to another EID. A plurality of vias each extend from a corresponding pad to another layer of the printed wiring board. Each via is offset from a central location of its corresponding pad. A via group comprises a plurality of vias with a first via connecting a surface of the electrical interconnection device to a first inner layer electrically connects a pad on a surface of the electrical interconnection device to a second via. The second via extends from the first inner layer to a second layer of the electrical interconnection device. The centers of the first via and the second via are non-collinear. Another EID includes a uniformly spaced set of pads on the surface. Via groups, comprising a first set of vias and a second set of vias, extend from the uniformly spaced surface pads. Spacing among the second set of vias is non-uniform.