A bus bar of laminar construction useful for power distribution systems and the like is disclosed which features an improved contact pin arrangement for providing input, output, and ground connections to the bus bar, together with an improved method of fabricating the bus bar and installing the contact pins or posts. The bus bar comprises a plurality of metallic conductors in sheet form separated by insulator films in a laminated structure, alternate conductor sheets serving as ground planes with the power signal conductors interleaved between the ground conductors. The conductor sheet - insulator film sandwich is clamped between cover members of phenolic or glass epoxy and the whole is encapsulated in a semi-rigid epoxy which extends between and under the conductor sheets at one end thereof. Finally, a series of holes is drilled through the laminated structure thus formed and particularly through the conductor sheets and semi-rigid epoxy and metallic pins or posts are inserted under force into these holes to effect a mechanical and electrical connection of high quality with the separate signal conductors and ground conductors for external access to the elements of the bus bar. The post or pin is larger in cross-sectional area than the hole and at least one cross-sectional dimension of the pin through the center of the cross-section is larger than the diameter of the hole. A bead of an epoxy adhesive is placed over the hole prior to pin insertion. Insertion of the pin then carries only so much epoxy therewith as will go into the hole to provide additional adhesion of pin to bus bar as well as hermetic seal.

An integrated circuit board for mounting very high density chips of small size on its top surface including conductor planes for carrying very large values of .DELTA.I (transient current) is constructed with a plurality of essentially flat parallel power planes serving as conductive leads to the chip connectors (pins or solder balls). The land areas on the top surface of the board are connected to conductors below by integrated coaxial conductor extensions from the planes having a high degree of capacitive coupling to adjacent conductor planes.

Components having different heights are installed in a multilayer substrate using a metal core layer formed by bonding a plurality of metal layers. The metal core layer includes through-holes and a spot-faced portion. Passive components and an active component are disposed in the through-holes and the spot-faced portion, respectively. These components are connected to conductive patterns formed on wiring layers, with connecting vias therebetween. Contact faces of each component with the connecting vias are controlled so as to be disposed at the same level with the metal layers.

A metal voltage plate is drilled or punched first with alignment holes, placed upon a jig and drilled with contact clearance holes in preselected locations. A metal ground plate is also drilled or punched first with alignment holes, placed upon a jig and drilled with contact clearance holes in preselected locations. The clearance holes are preferably in the range of 80-90 mils in diameter and located in positions where contacts are to pass through a plate without making electrical connection therewith. Next, both the voltage and ground plates are coated, including the inner walls of the clearance holes, with a relatively thick layer of an insulative dielectric material, such as teflon, polyurethane, p.v.c., or the like. The coated voltage plate is then drilled or punched with an array of smaller connecting holes, on the order of 40 mils in diameter, through which contacts to be electrically connected with voltage will be pressed. Since the connecting holes are made after the plate has been coated with a dielectric, the insides of the connecting holes will comprise bare metal and, hence, make good electrical connection with a contact portion press fitted therein. The coated ground plate is similarly drilled or punched with an array of smaller connecting holes, also on the order of 40 mils in diameter, through which contacts to be electrically connected with ground potential will be pressed. Each connecting hole in the ground plate is in a different location, with respect to the alignment holes, than each connecting hole in the voltage plate. A pair of double-sided, glass-filled, epoxy resin printed circuit boards, with alignment holes corresponding to those in the metal plates, are placed one above and one below the pair of adjacent metal plates. The printed circuit boards include plated-through holes in each location where a contact is to be fitted and each corresponds to a connecting hole in either the ground or voltage plate or a clearance hole in either or both. When a contact is press fitted down through the axially aligned holes in the stacked layers, frictional engagement of the contacts with the plated walls of the holes in the top and the bottom printed circuit boards, as well as the connecting holes in the metal plates, mechanically joins the layers into a single unitary structure and electrically interconnects each point which is in interfering engagement with the contact.

A backplane power distribution system characterized by generally uniform current densities so as to be capable of handling very high levels of current. This is achieved with a stepped backplane construction. For example, in a system having, in order, a first conductive layer, a first dielectric layer, a second conductive layer, and a second dielectric layer, the second conductive and dielectric layers extend transversely beyond the first conductive and dielectric layers to present a substantial exposed area of the second conductive layer. Typically, a rectangular metal bus bar is bolted to the backplane to make contact with the exposed area, and power supply connections to the bus bar are made in any convenient manner.