Nine Tails Cat-- A Chinese traditional folk

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5. The design of PCB--design considerations and assembly rules

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. PCB design considerations   Juvtmall  ( a company supply  PCB Prototyping ,  PCBA service  and sell kinds of  components, modules  and so on)  (1) avoid setting important signal lines on the edge of PCB, such as clock and reset signal. (2) the distance between the ground wire of the enclosure and the signal line is at least 4mm; keep the length and width of the ground wire to be less than 5:1 to reduce the inductance effect. (3) lock the device and line that identified location with LOCK function, so that they will not be misused. (4) the width of the conductor should not be less than 0.2mm (8mil). In high-density and high-precision printed circuit, the width and spacing of the wires are generally preferable to 12mil. (5) Routing in the IC pin of DIP package, 10-10 and 12-12 principles can be applied, as between the two pins by 2 lines, diameter of bonding pad  can be set to 50 mil, width and spacing of line is 10 mil, when o...
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About PCB and PCBA

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PCB and PCBA A PCB (Printed Circuit Board) is a board that electrically connects electronic components using conductive traces, pads, and other features etched from copper foil laminated onto a non-conductive substrate. PCB’s can be  single sided  (one copper layer),  double sided  (two copper layers), or  multi-layer  (outer and inner layers). Conductors on different layers are connected with vias (plated-thru. holes). Multi-layer PCB’s allow for much higher component density and design complexity. PCBA (Printed Circuit Board Assembly) is the board obtained after all printing solder paste on the PCB and then mounting various components like resistors, ICs (Integrated Circuits), capacitors and any other components  like transformers depending on the application and desired characteristics of the board. A PCBA usually undergoes reflow furnace heating to establish a mechanical connection between the PCB and the components.
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11. The design of PCB (multiple layer board)--Basic requirement of designing multiple layer PCB VOL3

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Requirements of power layer, stratigraphic partition and flow-hole:     Juvtmall  ( a company supply  PCB Prototyping ,  PCBA service  and sell kinds of  components, modules  and so on)  For PCB multilayer, there is at least one power layer and one layer. Because of all the voltage on the PCB are in the same power level, so you have to partition the isolation of power supply layer, the size of the partition line generally USES 20 ~ 80 mil line width advisable, ultra-high voltage, the more coarse partition line. In order to increase the reliability of the welding hole and the power supply layer and the stratigraphic connection, it is necessary to design the shape of the flower hole to reduce the large area metal heat absorption in the welding process The aperture of the isolation pad is greater than that of borehole aperture +20mil Requirements for safe spacing The setting of safety spacing should meet th...
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