Abstract:
A method for achieving a desired value of electrical impedance between conductors of an electrical power distribution structure by electrically coupling multiple bypass capacitors and corresponding electrical resistance elements in series between the conductors. The resistance elements may be annular resistors, and may provide the designer a greater degree of control of the system ESR. The annular resistors may comprise a first terminal, an annular resistor, and a second terminal. The second terminal may be located within the confines of the annular resistor. The annular resistors may be printed onto a conductive plane (e.g. a power plane or a ground plane), or may be a discrete component.
Abstract:
A method for mounting a component on an assembly is provided, such as to prevent shorting between a voltage plane and a ground plane that may be caused when the component fails and generates temperature rises that result in insulation failure. The method includes removing a section of one or more of the group including a ground plane and a voltage plane in an area of the component, where the area of the section is selected to prevent damage to the component that can be caused by shorting between the ground plane and the voltage plane if insulation failure occurs.
Abstract:
Occurrence of EMI is reduced without a sharp increase of the manufacturing cost by suppressing a common mode current stably. There is provided a disclosed printed-circuit board being adapted such that a width of an outer edge section of a T-shaped pattern is widened so as to surround a recessed section with a frame-shaped additional electric conductor by electrically connecting the frame-shaped additional electric conductor with the T-shaped pattern making up a ground pattern so as to close the recessed section.
Abstract:
A chassis and associated telecommunication circuit card are disclosed. The chassis has heat dissipation and flame containment features while accommodating a high density of the circuitry cards. Embodiments include an inner housing with a double-layer middle floor dividing the chassis into top and bottom chambers. Each layer has partially aligned slots, and an air gap is provided between the two layers. Embodiments also include a double-layer mesh cover with an air gap existing between the two mesh layers. Projections and grooves are provided on the inner surfaces of the inner housing to receive circuit cards having a guide on one edge and a fin on another. The circuit card includes conductor structures such as multiple board layers with paired and segregated conductors. The circuit card also includes some components positioned to cooperate with the ventilation features of the chassis and includes some components chosen for low-power consumption or reduced flammability.
Abstract:
A chassis and associated telecommunication circuit card are disclosed. The chassis has heat dissipation and flame containment features while accommodating a high density of the circuitry cards. Embodiments include an inner housing with a double-layer middle floor dividing the chassis into top and bottom chambers. Each layer has partially aligned slots, and an air gap is provided between the two layers. Embodiments also include a double-layer mesh cover with an air gap existing between the two mesh layers. Projections and grooves are provided on the inner surfaces of the inner housing to receive circuit cards having a guide on one edge and a fin on another. The guide includes an opening that at least partially aligns with slots on the adjacent surface of the inner housing. The circuit card includes a finger extending from a faceplate that facilitates insertion and removal of the circuit card relative to the chassis.
Abstract:
A printed wiring board in which noise components at a high frequency side of a power supply voltage can be eliminated, and undesired radiation noisewhich is newly generated can be suppressed, such that noise can be greatly reduced overall. The printed wiring board includes a first signal layer, a GND layer, a power source layer and a second signal layer. A sub-power source layer is provided on a same layer as a main power source layer. The sub-power source layer is formed in a substantially oval shape at a predetermined position in a substantially oval opening in the main power source layer, such that it is not in direct contact with the main power source layer. Power supply voltage is supplied from the main power source layer through an L-type filter.
Abstract:
A semiconductor device package includes multiple build-up layers of metal sandwiching non-conductive layers. The metal layers include apertures, or degassing holes. A manual method and a computer-implemented method for designing the semiconductor device packages includes stepping polygons across a representation of a conductive layer. A signal routing layer that includes signal traces is then superimposed on the conductive layer. Signal traces overlap the polygons creating regions of intersection that can be enlarged. Regions of intersection are removed from the polygons and the remaining polygon area is designated as apertures in the conductive layer. A semiconductor device package and packaged integrated circuit includes apertures in a conductive layer such that the apertures generally form a radial pattern outward from a region on the package. Signal traces also traverse the package generally radially outward such that the traces and the apertures do not overlap. Impedance variations decrease due to the decreased variation in the number of degassing holes passed over or under by trace.
Abstract:
A multi-layer printed circuit board provides at least two sections thereon. One section has a grouping of high-impedance traces and another adjacent section, separated by a dividing line, has a mainly low-impedance signal traces. The high-impedance section has at least one of a ground and power plane separated from a grouping of central layers, containing the high-impedance traces, by at least one empty or “void” layer. The void layer is likewise filled by the ground and power planes in the within low-impedance section by stepping the ground/power plane inwardly toward the central layers while providing another low-impedance signal trace in the layer above and below the respective ground and power planes. In a preferred embodiment there are at least nine layers of circuit board material with high-impedance traces on a central grouping of at least three central board layers with three layers disposed respectively above and below the central board layers.
Abstract:
A circuit card for transmitting signals having one or more long and narrow holes in a ground/power supply plane under a pad, which is connected to a pattern, the hole extending in a direction substantially parallel with a direction of the pattern extending away from the pad. The holes are sized and positioned to substantially minimize a mismatch of impedance between the pad and the pattern so that reflection of transmission signals caused by impedance mismatch can be suppressed.
Abstract:
A low-EMI circuit which realizes a high mounting density by converting the potential fluctuation off a power supply layer with respect to a ground layer which occurs on switching an IC device etc., into Joule's heat in the substrate without using any parts as a countermeasure against the EMI. Its structure, a circuit board using it, and a method of manufacturing the circuit board are also disclosed. Parallel plate lines in which the Q-value of the stray capacitance between solid layers viewed from the power supply layer and ground layer is equivalently reduced and which are matchedly terminated by forming a structure in which a resistor (resistor layer) and another ground layer are provided in addition to the power supply layer and the ground layer on a multilayered circuit board. A closed shield structure is also disclosed. This invention can remarkably suppress unwanted radiation by absorbing the potential fluctuation (resonance) which occurs in a power supply loop by equivalently reducing the Q-value of the stray capacitance, absorbing the standing wave by the parallel plate lines matchedly terminated and, closing and shielding the parallel plate lines.