Abstract:
A module board has trace impedances that are matched at trace junctions. An input line that drives a signal to a junction has its impedance adjusted to match the equivalent impedance of branch traces output from the junction. Since input and output impedances match, reflections caused by the junction are minimized or eliminated. The input impedance can match by being within 20% of the equivalent impedance of the branch lines. The equivalent impedance of branches is the reciprocal of the sum of the individual branch lines' reciprocal impedance. Termination can be eliminated when such junctions are impedance-matched. Secondary junctions can also be impedance-matched, allowing for a variety of trace topologies. Such trace-impedance matching is especially useful for memory modules.
Abstract:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
Abstract:
An interconnect structure employs a closed-grid bus to link an integrated circuit tester channel to an array of input/output (I/O) pads on a semiconductor wafer so that the tester channel can concurrently communicate with all of the I/O pads. The interconnect structure includes a circuit board implementing an array of bus nodes, each corresponding to a separate one of the I/O pads. The circuit board includes at least two layers. Traces mounted on a first layer form a set of first daisy-chain buses, each linking all bus nodes of a separate row of the bus node array. Traces mounted on a second circuit board layer form a set of second daisy-chain buses, each linking all bus nodes of a separate column of the bus node array. Vias and other circuit board interconnect ends of the first and second daisy-chain buses so that they form the closed-grid bus. Each bus node is connected though a separate isolation resistor to a separate contact pad mounted on a surface of the circuit board. A set of spring contacts or probes link each contact pad to a separate one of the I/O pads on the wafer.
Abstract:
A memory module is capable of constituting short loop-through form memory bus systems in which the length of the entire channel can be reduced. As a result, the systems are suitable for a high-speed operation, and costs for fabricating systems such as a board and a module connector can be reduced. The memory module includes a plurality of tabs located in one side of the front and in one side on the rear of the memory module, for being interconnected by a connector on a system board, a plurality of vias for connecting two different signal layers of the memory module, and a plurality of data buses extended from the tabs on the front of the memory module to the tabs on the rear of the memory module through each of the vias. At least one memory device is connected to each of the data buses. Preferably, each of the data buses is formed to be perpendicular to one side of the memory module on which the tabs are formed.
Abstract:
A circuit module has a circuit board, multiple circuit units on the circuit board and at least one clock input on the circuit board for receiving an external clock signal. The circuit module has a first PLL unit on the circuit board for providing an internal clock signal based on the external clock signal to at least a first one of the circuit units. In addition, the circuit module has a second PLL unit on the circuit board for providing an internal clock signal based on the external clock signal to at least a second one of the circuit units.
Abstract:
An interconnect structure employs a closed-grid bus to link an integrated circuit tester channel to an array of input/output (I/O) pads on a semiconductor wafer so that the tester channel can concurrently communicate with all of the I/O pads. The interconnect structure includes a circuit board implementing an array of bus nodes, each corresponding to a separate one of the I/O pads. The circuit board includes at least two layers. Traces mounted on a first layer form a set of first daisy-chain buses, each linking all bus nodes of a separate row of the bus node array. Traces mounted on a second circuit board layer form a set of second daisy-chain buses, each linking all bus nodes of a separate column of the bus node array. Vias and other circuit board interconnect ends of the first and second daisy-chain buses so that they form the closed-grid bus. Each bus node is connected though a separate isolation resistor to a separate contact pad mounted on a surface of the circuit board. A set of spring contacts or probes link each contact pad to a separate one of the I/O pads on the wafer.
Abstract:
A method and apparatus for decreasing crosstalk between conductors, particularly differential pairs, that are routed in high-density patterns on printed circuit boards system. In one embodiment of the invention, a single-ended conductor is divided at a first point into two single-ended conductors of equal width, with the two single-ended conductors being routed around and alongside a differential pair of conductors. Equal and opposite noise is coupled onto each branch of the single-ended signal from each side of the differential pair. The two single-ended conductors are rejoined at a second point to form a combined single-ended conductor. Signals traveling along the two separate paths of the single-ended are combined at the second point and noise carried in the respective signals is cancelled. Noise coupled into the differential pair from the two single-ended paths is eliminated at the receiving end as common mode noise. In other embodiments of the present invention, the single-ended conductors and the differential pairs are oriented between two planes in stripline or dual stripline configurations. The method and apparatus of the present invention can be implemented in numerous media, such as vias and cables (including flex and ribbon).
Abstract:
A transmission line, a resonator, a filter, a duplexer, and a communication apparatus efficiently minimize power losses due to edge effects, thereby having superior loss-reduction characteristics. A continuous line and a plurality of thin lines each having a predetermined length and branching from both sides of the continuous line are formed on a dielectric substrate. With this structure, edges of the individual thin lines substantially do not exist, so that losses due to edge effects can be efficiently minimized.
Abstract:
A suspended transmission line with an embedded signal channeling device includes a support layer and a conductor supported by the support layer between first and second plates each having a ground plane. The conductor includes a combined signal line and a plurality of discrete signal lines extending from the combined signal line. The discrete signal lines each transmit a portion of a signal transmitted on the combined signal line. A propagation structure is disposed between the first and second plates to substantially contain an electromagnetic field generated by the propagating signal.
Abstract:
A flat panel display comprising a display panel, and a first and second printed circuit boards connected to the display panel. The first printed circuit board has a connector. The second printed circuit board comprises a core layer having a main body and a branch extending from the main body. The branch has a terminal portion. A plurality of electrically conductive leads are formed on the surface of the main body and extends to the terminal portion. The terminal portion of the branch including the conductive leads formed thereon is directly inserted into the connector of the first printed circuit board.