Routing rules for PCB high-speed boards of four or more layers

1. 3 or more connections, try to let the lines pass through the points in order to facilitate testing, the line length is as short as possible.

2. Try not to put the wires between the pins, especially between and around the pins of the integrated circuit.

3. The lines between the different layers should not be parallel as much as possible to avoid the formation of actual capacitance.

4. The wiring is as straight as possible, or 45 degree fold line to avoid electromagnetic radiation.

5. The ground wire, power cord at least 10-15mil (for logic circuits).

6. Try to make the floor polyline connected together, increase the grounding area. Lines and lines are as neat as possible.

7. Pay attention to the uniform discharge of components for installation, plug-in and welding operations. The text is discharged in the current character layer, the position is reasonable, pay attention to the orientation, avoid being blocked, and easy to produce.

8. Component emissions more considering the structure, the chip components have positive and negative should be packaged and finally marked to avoid space conflicts.

9. The current printed board can be used for 4-5mil wiring, but usually for 6mil line width, 8mil line spacing, 12/20mil pad. Wiring should take into account the effects of sinking current, etc.

10. The function block components should be put together as much as possible, and the components near the LCD such as zebra strips cannot be too close.

11. The hole should be coated with green oil (set to a negative value).

12 It is best not to place the pad under the battery holder, empty, etc., PAD and VIL size is reasonable.

13. After the wiring is completed, carefully check whether each connection (including NETLABLE) is actually connected (available lighting method).

14. The oscillating circuit component is as close as possible to the IC, and the oscillating circuit is as far away as possible from the antenna and other susceptible areas. Place the ground pad under the crystal.

15. Consider many ways such as reinforcement and hollowing out components to avoid excessive radiation sources.