Cost effective and efficient methods to maximize printed circuit board (PCB) utilization with minimized signal degradation are provided. The methods include electrically isolating a segmented via structure by controlling the formation of a conductive material within a plated via structure by utilizing different diameter drills within a via structure for trimming the conductive material at the via shoulder (i.e., the rim of a drilled two diameter hole boundary). The trimmed portion may be voided in the via structure for allowing electrically isolated plated through-hole (PTH) segments. One or more areas of trimmed rims within the via structure are used to form multiple stair like diameter holes to create one or more voids in the via structure. As a result, the formation of conductive material within the via structure may be limited to those areas necessary for the transmission of electrical signals.

The present invention aims to provide a backdrilling method and a backdrilling apparatus that can ensure the backdrilling depth accuracy. Using a multilayer printed wiring board in which a reference depth detection region is allocated where a reference depth detection layer is formed in the same layer with an internal wiring layer electrically connected to a stub, the thickness and the depth of the reference depth detection layer are measured in the reference depth detection region using a drill bit. The drill bit is moved relative to the multilayer printed wiring board to a backdrilling portion. The drilling is performed using the drill bit to the depth which is calculated using the ratio of the depth of the reference depth detection layer to the thickness of the multilayer printed wiring board in the reference depth detection region.

Methods and mechanisms for mitigating attenuation in a printed circuit board connection may include selecting the relative permittivities of resin layers proximate to the connection to control connection frequency resonances such that the attenuation of signals in the connection due to frequency resonance is mitigated.

A redundant part of a plated through hole that is formed in a printed wiring board is removed by a back drilling method; a penetration hole is filled entirely with a curable resin composition for hole filling; the curable resin composition is initially heated at a temperature less than 100 C. so that a curing rate of the curable resin composition may be 60% to 85%; and the curable resin composition is subsequently heated at a temperature 130 C. to 200 C. so that the curable resin composition may be cured completely, where the curable resin composition contains 1 part by mass to 200 parts by mass of a curing agent with respect to 100 parts by mass of liquid epoxy resin, and contains no solvent.

A high-speed router backplane is disclosed. The router backplane uses differential signal pairs on multiple signal layers, each sandwiched between a pair of digital ground layers. Thru-holes are used to connect the differential signal pairs to external components. To reduce routing complexity, at least some of the differential signal pairs route through a via pair, somewhere along their path, to a different signal layer. At least some of the thru-holes and vias are drilled to reduce an electrically conductive stub length portion of the hole. The drilled portion of a hole includes a transition from a first profile to a second profile to reduce radio frequency reflections from the end of the drilled hole.

Disclosed is a printed circuit board (PCB) having backdrill reliability anchors comprising nonfunctional pads to provide mechanical reinforcement for signal pads on backdrilled plated through hole (PTH) vias, as well as associated method and machine readable storage medium.

An electrical connector footprint on a printed circuit board (PCB) can include vias and antipads surrounding those vias. While conventional antipads surrounding vias are large in order to improve impedance of the PCB, the presence of the antipads can compromise the integrity of the ground plane and can permit cross talk to arise between differential pairs on different layers in the PCB. Antipads can be constructed and arranged so as to limit cross talk between layers in a PCB, while also maximizing impedance.

A printed circuit board includes metal layers, a metalized circuit via interconnecting a first one of the metal layers and a second one of the metal layers, and a back-drill hole drilled to remove metalization of the circuit via from a third metal layer adjacent to the second metal layer to a fourth metal layer at a first surface of the printed circuit board. The back-drill hole has a profile that includes a first undercut at a bottom of the first back-drill hole.

A method for controlled filling of a backdrill cavity in an unused portion of a via to a desired penetration depth of the backdrill cavity can begin with setting a starting gas pressure in the backdrill cavity to a back-filling fixture chamber pressure in a filling pressure chamber. The back-filling fixture chamber pressure is selected based on a desired penetration depth h of a non-conductive filling material within the backdrill cavity, given a fill application pressure to be applied to the backdrill cavity. Then, the non-conductive filling material is applied with the fill application pressure to the backdrill cavity until a final gas pressure in the backdrill cavity equals to the fill application pressure and the backdrill cavity has a final gas volume of /4d.sup.2(Hh), where H represents a backdrill depth and d represents a backdrill diameter of the backdrill cavity.

The disclosure relates to a machining station for machining platelike workpieces (1) by means of at least one tool (10, 13, 14). The machining station has a measuring device (16) for acquiring data relating to the position of bores, a drill (10, 13, 14) for generating bores in the workpiece (1), and a data processor (17) for processing data of the at least one measuring device (16) and/or for controlling the at least one drill (10, 13, 14). The data processor (17) is here suitable and set up for performing an adjustment between a desired drilling position and/or a desired bore depth and an actual position and/or actual depth as determined by the at least one measuring device (16) for a bore present in the workpiece (1), and adapting the drilling position and/or bore depth for generating bores by means of the at least one drill (10, 13, 14).