博文

目前显示的是 十月, 2017的博文

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.

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 PrototypingPCBA 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

Product--Motor shield

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Juvtmall ( a company supply PCB PrototypingPCBA service and sell kinds of components, modules and so on) 

Motor shield is a platform for robotics and mechanical applications based on L298P. It can be used to drive double DC motor or a 4-wire stepper. When controlling double DC motor, there are Only 4 control pins are used, which makes more easily to control, and saves the control pins for controller. The Drive current can be up to 2A per motor output for the adding of the heat sink. Measure the driver current by the additional resistance, makes the system more smartly. 


10. The design of PCB (multiple layer board)--Basic requirement of designing multiple layer PCB VOL2

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The requirements of wire cloth and wiring Juvtmall ( a company supply PCB PrototypingPCBA service and sell kinds of components, modules and so on) 
In general, PCB multilayer board wiring is performed according to circuit function. In outer wiring, it is required to have a lot of wiring in the welding surface, and the components are less wiring, which is beneficial to the maintenance and platoon of printing plate. Thin, tight conductor and easily disturbed signal lines, usually arranged in the inner layer. The large area of copper foil should be evenly distributed in the outer layer, which will help to reduce the warping of the plate and make the plating more uniform on the surface. In order to prevent the short circuit between the surface and the printed wire and the mechanical processing, the distance of the conductive graph in the inner and outer layers should be greater than 50mil.


Wire direction and line width requirements

The PCB multilayer strake is to separate the power layer, the …