摘要:
A printed circuit board includes an insulating board, a pair of differential vias, and a number of wiring layers. A pair of via holes extends through opposite surfaces of the insulating board. The differential vias correspond to the pair of via holes. Each differential via includes a metal plated barrel and two via capture pads. The plated barrel is plated on the inner surface of the respective via hole, and terminates at each of the two opposite surfaces of the insulating board. The via capture pads are formed on the opposite surfaces of the insulating board around the openings of the via hole, and are electrically connected to the plated barrel. The wiring layers are arranged in the insulating board, and each define a clearance hole surrounding all of the via capture pads.
摘要:
A printed circuit board (PCB) with compound via includes a substrate and a pair of through holes passing through the substrate. The substrate includes a signal layer which is the top layer of the substrate, a first reference layer adjacent to the signal layer, and a second reference layer not adjacent to the signal layer. A first and a second pair of pads are mounted on the signal layer. Each of the through holes extends through the first pair of pads such that the through hole and the first pair of pads jointly form a compound via. A first reserved opening is formed on the first reference layer and corresponds to the first and the second pair of pads and the compound via. A second reserved opening is formed on the second reference layer and surrounds the through hole thereon.
摘要:
A computer motherboard includes a printed circuit board which includes a central processing unit (CPU) socket and a group of memory slots. The group of memory slots includes an in-line type memory slot and a surface mounted device (SMD) type memory slot. The in-line type memory slot includes a number of plated through holes. The SMD type memory slot is set between the in-line type memory slot and the CPU socket. The through holes of the in-line type memory slot are connected to the CPU socket through traces, pads of the SMD type memory slot are connected to corresponding through holes of the in-line type memory slot having the same pin definition.
摘要:
A printed circuit board includes a high-speed differential signal control chip, first to eighth coupling capacitor pads, first to fourth connector pads, a first transmission line, a second transmission line, a third transmission line, a fourth transmission line, first to eighth transmission lines, two ninth transmission lines, first and second vias, and first to fourth sharing pads. The printed circuit board is operable to selectively support multiple connectors.
摘要:
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.
摘要:
An electronic device and method for inspecting electrical rules of circuit boards includes selecting at least two design files that record electrical rules of the circuit boards and searching the electrical rules in the selected design files using preset parameter keywords. Same electrical rules of the selected design files are acquired by comparing the electrical rules in the selected design files. The same electrical rules and corresponding parameter values are input to a comparison table, and the comparison table is output.
摘要:
A bearing includes a main body, a plurality of first magnetic members, a plurality of second magnetic members, and a plurality of friction members. The main body defines a pivot hole, and a plurality of first receiving portions and a plurality of second receiving portions around the pivot hole. Each of the second receiving portions defines a cutout. The first magnetic members are received in the first receiving portions. The second magnetic members together with the friction members are received in the second receiving portions, thus generating a repelling force between the first magnetic members and the second magnetic members to impel the friction members to partially extend out of the cutouts.
摘要:
An electronic device includes a wiring unit. The wiring unit creates one or more circuit diagrams for a design of a first circuit board, and setting electrical rules for components of the first circuit board in each of the one or more diagrams. Based on the one or more diagrams having the electrical rules, the wiring unit generates a wiring diagram for the design of the first circuit board by executing a wiring application. If a second circuit board desires to use a circuit diagram of the first circuit board, the wiring unit copies the circuit diagram having the electrical rules into the wiring application. Then, based on the copied circuit diagram having the electrical rules and particular circuit diagrams of the second circuit board, and the wiring unit creates a wiring diagram for the design of the second circuit board by executing the wiring application.
摘要:
A printed circuit board includes a first signal layer, a first reference layer, a second signal layer, and a third signal layer in that order and includes a first slanted via and a second slanted via. The first signal layer includes an parallel first transmission wire and a second transmission wire. The first and second transmission wires are coupled with each other and cooperatively constitute a first differential pair with an edge-coupled structure. The second signal layer includes a third transmission wire. The third signal layer includes a fourth transmission wire parallel to and coupled with the third transmission wire. The third and fourth transmission wires cooperatively constitute a second differential pair with a broadside-coupled structure. The first slanted via obliquely are interconnected between the first transmission wire and the third transmission wire. The second slanted via obliquely are interconnected between the second transmission wire and the fourth transmission wire.
摘要:
The REVERSING TRANSMISSION includes a shaft, a retainer, a spacing collar, a plurality of reversing members, two gears and two covers. The holder is sleeved on the shaft with spaced sliding notches formed thereon. The spacing collar is mounted on an outer surface of the retainer. The reversing members each includes two spaced swing plates with two reversed spiral teeth dented on two diagonal half surfaces of the two spaced swing plate. The reversing members slide into the sliding notches of the holder with two swing plates distributed at different side of the spacing collar. Each of the gears has a group of spiral teeth formed on the inner side for engaging with the group of spiral teeth of the reversing members, and cogs formed on the outer circumference surface. The covers are mounted on two opposite ends of the holder to keep the reversing member in position.