Abstract:
Motherboard 10M receives a voltage at post 14P from an off-board power source. Buried conductive layer 10B selectively distributes this electrical power to component sites 10S. Post bore 14 penetrates through local electrodes 12U and 12L into the motherboard for exposing post contact regions 14U and 14L and post contact region 14B in the buried layer. Connector post 14P is positioned within the post bore. Post bore conductor 14C within the post bore establishes electrical continuity from the connector post to the buried layer. The post bore conductor also establishes electrical continuity from the connector post to post contact regions 14U and 14L in the local electrodes. Auxiliary bore 16 proximate the post bore penetrates into the motherboard for exposing auxiliary contact regions 16U and 16L in the local electrodes, and auxiliary contact region 16B in the buried layer. Auxiliary bore conductor 16C within the auxiliary bore establishes electrical continuity along the auxiliary bore. Each auxiliary bore provides an upper circuit and lower auxiliary circuit in parallel relationship between the connector post and the buried layer for reducing the electrical resistance into the buried layer from the off-board power supply.
Abstract:
A circuit board is provided having a plurality of vias and uniformly spaced connector stubs arranged upon one or both outer surfaces of the control board. Sets of trace conductors are formed within the control board between the vias. The trace conductors are arranged in two planes within the control board, wherein trace conductors within one plane are laterally offset from trace conductors in the other plane. Laterally offset trace conductors allow close spacing of the trace conductor planes while maximizing the spacing between trace conductors and corresponding reference conductors also placed within the control board. Additionally, the trace conductors are serpentine-shaped when viewed from a perspective perpendicular to the planar surface of the control board. The serpentine shape, in conjunction with carefully controlled spacing between planes of trace conductors as well as between the trace conductor planes and reference conductors, provides high impedance trace conductors in a limited space area necessary to meet SCSI specifications.
Abstract:
A coupling connector relies on inductive and capacitive coupling over a length L.sub.c to "connect" signals from a first circuit card to a second circuit card. The coupling connector includes a flex circuit which in a connected state is compressed to provide a coupling length L.sub.c between the first and second circuit cards. A typical application is for coupling cards to a backplane having a plurality of parallel, signal carrying tracks. The near end of each coupling track is input to a receiver having an input impedance equal to the characteristic impedance of the coupling track. The far end of the coupling track is terminated by a resistor whose value equals the characteristic impedance of the coupling track.
Abstract:
A connector for connecting printed circuit boards includes a stepped member made of an insulating material and having a lower surface and at least two stepped upper surfaces communicated to the lower surface by a plurality of through holes. A plurality of conductive pins are respectively disposed within the through holes. This configuration allows a plurality of printed circuit board members to be affixed to the lower surface and each of the two upper surfaces so that the plurality of conductive pins allows electrical communication therebetween.
Abstract:
In a "Futurebus+" backplane, at each end of the backplane the signal lines are each electrically connected to a power bus on a face of the board or to a power plane encapsulated in the board via a discrete resistor mounted on the face of the board and separately formed with respect to the other resistors and the ground lines are each electrically connected to the power bus or power plane via a discrete capacitor mounted on the face of the board and separately formed with respect to the other capacitors. Preferably, at each end of the backplane the discrete resistors and capacitors are mounted on both faces of the board, the number on one face being approximately the same as the number on the other face. In the event that a resistor or capacitor should be faulty, only the signal or ground line to which the faulty resistor or capacitor is connected will be out of service until the faulty resistor or capacitor is replaced.
Abstract:
A bus system wherein the control signal traces on the system board are routed to eliminate noise caused by transmission line reflections. Each control signal trace is routed between the bus controller and the corresponding terminal of the first or last connector of the bus. One side of an isolation resistor whose value preferably matches the lowest impedance of a fully loaded bus is connected to the corresponding terminal of either the first or last connector in the bus connector row through a relatively short trace. The other side of the isolation resistor is connected to a trace which is routed directly to the corresponding terminal of the first of a series of system loads on the system board. The system load traces are then serially continued between each corresponding terminal of each system load until the corresponding terminal of every system load is connected. The serially routed traces are then terminated at the last system load with an RC series network forming an ac termination. This procedure is repeated for each bus control signal. Also, each of the control signals is coupled to ground through a Schottky diode having a forward bias of approximately one volt or less, in order to clamp the control signals to ground to prevent excessive undershoot.
Abstract:
An integral elastomeric card edge connector provides shorter signal paths through the contact with reduced interference. The card edge contact allows high density interconnection between several layers of multi-layer circuit card without routing signal paths to the card surface. Elastomeric contact tab supports provide positive contact pressure and the necessary wipe action to ensure electrical contact. The process for forming the integral contacts begins with a standard multi-layer card which is then beveled, etched to expose the contact tabs, filled with elastomeric material and processed to expose the tabs supported by elastomeric columns. The connector may be used in card on board technologies or for the connection of multi-chip organic substrates to boards or to other substrates.
Abstract:
A radial type of parallel system bus structure used bus wire-printed disks each having printed signal conductors of equal length extending radially from a common contact center. Each printed signal conductor comprises two twisted conductor lines, and each conductor line consists of many segments disposed alternately on opposite surfaces of the disk, the successive segments of each line being connected by plating in through-holes in the disk. The radial arrangement of signal conductors permits connection of selected CPU boards via equal length of signal path. Also, the use of twisted conductor lines improves the signal transmission characteristics of the bus in high-frequency ranges.
Abstract:
A cable assembly for an electrical signal transmission system comprises a plurality of elongated conductors, a conductive shield surrounding each conductor, and a dielectric layer between each shield and its respective conductor. The shielded conductors are embedded in a dielectric material and the dielectric material is wrapped in a double conductive shield. Adhesive layers are located between the double shield and the dielectric material and between the two shields making up the double shield. This cable assembly results in a signal transmission apparatus which has increased immunity to the effects of external electromagnetic fields, electrostatic charge, and mechanical vibration. It is particularly useful in transmitting low level signals produced by ionization detectors used in x-ray inspection apparatus.
Abstract:
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.