Abstract:
A filter is provided with a planar transmission line and a combined via structure connected to (both) one ends of the planar transmission line. The planar transmission line and the combined via structure are disposed in a same multilayer board. The combined via structure comprises two working parts. The first working part comprises a segment of signal via and a plurality of segments of ground vias surrounding the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias, smooth conductive plate and corrugated conductive plate. The smooth conductive plate and the corrugated conductive plate are connected to the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias and corrugated conductive plate. The corrugated conductive plate is connected to the signal via.
Abstract:
A process for laser forming a blind via in at least one layer of a circuit substrate having a plurality of capture pads of varying geometry can include, for at least one blind via to be formed in at least one layer of a circuit substrate, evaluating a capture pad geometry value (such as area and/or volume) within a predetermined distance from a drilling location with respect to a blind via geometry value (such as area and/or volume) to be formed at the drilling location. The process can include setting at least one laser operating parameter based on the evaluation in order to obtain a desired capture pad appearance after blind via formation. The process can include imaging a capture pad area defined as an area within a predetermined distance from a blind via drilling location in at least one layer of a circuit substrate, quantifying at least one appearance value for the imaged capture pad area, and determining an acceptability of the imaged capture pad areas based on the quantified appearance value.
Abstract:
A high-speed router backplane, and method for its fabrication, are disclosed. The backplane uses differential signaling trace pairs on multiple high-speed signaling layers, the high-speed signaling layers separated by ground planes. Plated signaling thru-holes connect the trace pairs to the board surface for connection to external components. The signaling thru-holes pass through clearances in each ground plane. At selected ground planes, a conductive pad is patterned within each high-speed signaling thru-hole clearance, the pad slightly larger than the thru-hole diameter. The pads affect the impedance characteristics of the thru-holes, thus providing a better impedance match to the differential trace pairs, reducing signal reflections, and improving the ability to signal across the backplane at high speeds.
Abstract:
A stacked via structure for reducing vertical stiffness includes: a plurality of stacked vias, each via disposed on a disc-like structure. The disc-like structure includes a plated through hole landing supporting the plurality of stacked vias. The plated through hole landing includes a compliant center zone; and spring-like stiffness-reducing connectors for connecting the compliant center zone of the plated through hole landing.
Abstract:
A multilayer printed wiring board (100) which is excellent in reliability because of the short wiring distance of a conductor circuit, high freedom of conductor circuit design, and little possibility of cracks developing in an interlayer resin insulation layer in the vicinity of a via hole, and which comprises conductor circuits (105) and interlayer resin insulation layers (102) sequentially laminated on a substrate (101), conductor circuits sandwiching an interlayer resin insulation layer being connected via a via hole (107), characterized in that via holes in different hierarchies out of all the via holes are formed to be in a stack via structure, and at least one via hole (1072) out of the above via holes in different hierarchies has a land diameter different from those of other via holes (1071, 1073).
Abstract:
A printed circuit board (PCB) via (42), providing a conductor (56) extending vertically between microstrip or stripline conductors (44, 48) formed on separate layers of a PCB, includes a conductive pad (59) surrounding the conductor (56) and embedded within the PCB (40) between those PCB layers. The pad's shunt capacitance and the magnitudes of capacitances of other portions of the via (42) are sized relative to the conductor's inherent inductance to optimize frequency response characteristics of the via (42).