Pay attention to the specific wiring of PCB board design

Pay attention to the specific wiring of PCB board design
PCB layoutrules
1) Under normal circuits, all components shall be arranged on the same side of the circuit board Only when the top components are too dense, some devices have limited height and low heat, such as chip resistors, chip capacitors, chip integrated circuits, etc Place on the bottom layer
2) On the premise of ensuring electrical performance, components shall be placed on the grid and arranged in parallel or vertical to each other for neatness and beauty Generally, components are not allowed to overlap; The layout of components shall be compact and the components shall be placed on the whole layout Uniform distribution and uniform density
3) The small spacing between adjacent pad patterns of different components on the circuit board should be more than 1MM.
4) The distance from the edge of the circuit board is generally not less than 2MM × When 150MM, the mechanical strength that the circuit board can withstand shall be considered
PCB design setup skills

The PCB design requires different point settings at different stages In the layout phase, large grid points can be used for equipment layout For large equipment such as ICs and non positioning connectors, 50-100 mil grid points can be used for layout, while for passive small equipment such as resistors, capacitors and inductors, 25 mil grid points can be used for layout Large grid points facilitate equipment alignment and beautiful layout
PCB design layout skills
In the layout design of the PCB, the unit of the PCB shall be analyzed, and the layout design shall be based on the function The following principles should be followed:
1) Arrange the position of each functional circuit unit according to the circuit process
2) Take the components of each functional unit as the center The components shall be uniformly, integrally and compactly arranged on the PCB board, and the leads and connections between components shall be minimized and shortened
3) For circuits operating at high frequencies, the distribution parameters between components should be considered In general, the components should be arranged as parallel as possible, which is not only beautiful, but also easy to install and mass produce
When designing specific wiring, the following points should be noted: PCB board:
1) Keep the trace length as short as possible to minimize lead inductance.  In low-frequency circuits, avoid multipoint grounding because all circuit ground currents flow through a common ground impedance or ground plane
2) The common ground wire should be arranged at the edge of the printed circuit board as much as possible.  Copper foil shall be reserved as much as possible on the circuit board as the grounding wire, which can enhance the shielding capability
3) The double-layer board can use the ground plane.  The purpose of the ground plane is to provide a low impedance ground wire
4) In the multi layer printed circuit board, you can set the ground layer, which is designed as a grid The grid spacing of grounding wire should not be too large, because one of the main functions of grounding wire is to provide signal return path If the grid spacing is too large, a larger signal loop area will be formed Large loop areas may cause radiation and sensitivity problems In addition, the signal return actually uses a path with a small loop area, and other grounding wires do not work
5) The ground plane can make the radiation loop small on the PCB