Abstract: An apparatus and method that permits signal traces of different widths and the same impedance to be placed on the same layer of a printed circuit board (PCB). Alternatively, signal traces of different impedances but the same width may be placed on the same layer of the PCB. Ground and power planes are paired on adjacent layers of the PCB with a portion of the power plane relative to the ground plane removed. Signal traces of the same width and different impedances or vice-versa can be placed on the same layer because each signal trace is referenced to different planes.

Abstract: Designing a circuit apparatus involves determining locations and lengths of routing paths for signals, routing paths of a first length range being located in a first layer, and routing paths of a second length range being located in a second layer; determining propagation speeds for the signals to propagate through the routing paths within a propagation time range; and selecting dielectric materials for the layers in accordance with the determined propagation speeds for the routing paths.

Abstract: A socket is for use in an electronic system to hold a circuit board module that has spaced electrical pads proximate to two opposite edges thereof. The socket indudes a base and electrical conductors. The base has rectangularly arranged peripheral portions and is for receiving the circuit board module. The electrical conductors align with the electrical pads on the circuit board module. At least portions of the electrical conductors are disposed on respectively opposite ones of the peripheral portions to contact at least portions of corresponding ones of the aligned electrical pads on the circuit board module when the circuit board module is held in the socket.

Abstract: A first signal passes through a first layer of a circuit apparatus at a first propagation speed, and a second signal passes through a second layer of the circuit apparatus at a second propagation speed different from the first propagation speed.

Abstract: A multi-pin edge connector assembly for connecting a daughter board to a mother board, for example, comprises a plurality of vias with conductive surfaces that are formed in the daughter board adjacent a connection edge. A plurality of openings are also formed in the daughter board, with each opening extending from the connection edge to one of the vias. Electrically conductive pins are positioned in the openings, with each pin having a first end in electrical contact with one of the conductive surfaces and a second end that projects beyond the connection edge for electrically contacting conductive pads or surfaces on the mother board. A retainer is mounted to the daughter board for holding the pins in their respective openings.