Abstract:
An electronic circuit is obtained that has reduced EMI levels. The circuit includes an integrated circuit, which is a source of noise, a bypass capacitor, and a circuit substrate on which they are mounted. An electronic circuit one electrode terminal of the bypass capacitor and one connecting electrode of the integrated circuit are connected through a first wire interconnect formed in the circuit substrate, and, additionally, another electrode terminal of the bypass capacitor and another connecting electrode of the integrated circuit are connected through a second wire interconnect, and the gap between the first wire interconnect and the second wire interconnect is made smaller than either the gap between the one connecting electrode and the other connecting electrode on the integrated circuit or the gap between the one electrode terminal and the other electrode terminal of the bypass capacitor.
Abstract:
A method is disclosed for fabricating a PCB so that is can easily be determined if a via in the PCB has not been counterbored to a desired depth. A PCB fabricated according to the method also is disclosed.
Abstract:
A spark gap for protecting electronic circuits from excessive electrical surges comprises a substrate containing an opening, a dielectric medium occupying the opening, and first and second electrodes. The first electrode is embedded in the substrate, on one side of the opening, and has a first conductive surface that extends through the substrate and is substantially exposed in the opening and to the dielectric medium. The second electrode is embedded in the substrate, on another side of the opening, and has a second conductive surface that extends through the substrate and is substantially exposed in the opening and to the dielectric medium. The first conductive surface is in opposing relation to the second conductive surface, and they are spaced apart by a predetermined distance to establish a gap width. An electrical arc is generated across the opening when a voltage potential difference between the conductive surfaces exceeds a threshold value.
Abstract:
A filter for filtering noise generated by a differential signal having a specific wavelength transmitted by a first transmission line and a second transmission line is disclosed. The filter includes a multi-layer substrate, a first microstrip line and a second microstrip line. The first and the second transmission lines and the first and the second microstrip lines are disposed at the multi-layer substrate. In addition, one end of the first microstrip line and one end of the second microstrip line are electrically connected to the first and the second transmission lines, respectively, by passing through the vias, and the other end is in a floating state. The impedances of the first and the second microstrip lines match the impedances of the first and the second transmission lines, respectively. Thus, the first and the second microstrip lines may filter the noise generated by the differential signal having the specific wavelength.
Abstract:
A printed circuit board includes a number of signal layers, a number of ground layers, a first transmission line, a second transmission line, a first via, and a second via. The first transmission is located on one of the number of signal layers. The second transmission line is located on another of the number of signal layers. The first and second vias pass through the printed circuit board. The first via is electrically coupled to the first and second transmission lines, and is isolated from the number of ground layers. The second via is electrically coupled to one or more of the number of ground layers, and is isolated from the other of the number of ground layers to increase an inductance, thus compensating capacitive nature of an open stub and improving signal integrity.
Abstract:
A circuit board comprises a center segment distributing power and low-speed signaling, and outer segments for high-speed signaling. The segments use dielectric materials with different dielectric constants, with the outer segments supporting higher-speed signal transmission.
Abstract:
A printed circuit board can support different connectors by selectively setting connection components on the printed circuit board without changing wiring of transmission lines or making new vias in the printed circuit board.
Abstract:
A printed circuit board includes a number of signal layers, a number of ground layers, a first transmission line, a second transmission line, a first via, and a second via. The first transmission is located on one of the number of signal layers. The second transmission line is located on another of the number of signal layers. The first and second vias pass through the printed circuit board. The first via is electrically coupled to the first and second transmission lines, and is isolated from the number of ground layers. The second via is electrically coupled to one or more of the number of ground layers, and is isolated from the other of the number of ground layers to increase an inductance, thus compensating capacitive nature of an open stub and improving signal integrity.
Abstract:
A multilayer substrate is provided with a conductor plane region in which a plurality of conductor planes are disposed; a clearance region disposed adjacent to the conductor plane region so that the plurality of conductor planes are excluded from the clearance region. A plurality of signal vias are disposed through the clearance region so that the plurality of signal vias are isolated from the plurality of conductor planes. A conductor post is connected to one of the plurality of conductor planes and disposed between two of the signal vias in the clearance region.
Abstract:
An interposer is made of nested drawn copper shells with insulation between them. The shells are etched using methods of ordinary printed wiring fabrication, but being three dimensional, straight runs from the die to the motherboard can be made optimally short and wide without passing through any vias. Some shells can extend upward for top connections, and vias and crossing landlines can be used as required in the areas away from the die.