PCB high-speed board wiring experience more than 4 layers
1.3 or more connections, try to pass the lines through these points in order to facilitate testing, the line length is as short as possible.
2. Try not to place leads between pins, especially between and around the pins of an integrated circuit.
3. The lines between the different layers should not be as parallel as possible to avoid the formation of actual capacitance.
4.the wiring as straight as possible, or 45 degree fold line to avoid electromagnetic radiation.
5. ground wire, power cord at least 10-15mil (for logic circuits).
6. Try to connect the paved fold line to increase the ground contact area. Lines and lines are as neat as possible.
7. Note that the components of the installation, insertion and welding operations are evenly discharged. The text is ejected in the current character layer, the position is reasonable, attention is paid to the direction, avoiding being blocked, and being easy to generate.
8.component emission more consideration structure, 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 6mil line width, 8mil line spacing, 12 / 20mil pad. Wiring should take into account the effects of sinking currents, etc.
10. The function block components should be placed together as much as possible, and components near the LCD such as zebra should not be too close.
11. The green hole should be painted with green oil (set to a negative value).
12. It is best not to place mats, empty spaces, etc. under the battery holder. The size of PAD and VIL is reasonable.
13. After the wiring is complete, double check that each connection (including NETLABLE) is actually connected (available lighting methods).
14. The oscillating circuit components should be as close as possible to the IC. The oscillating circuit should be as far as possible from the antenna and other susceptible areas. Place the grounding pad under the crystal.
15. Consider many methods, such as reinforced and hollowed out components, to avoid excessive sources of radiation.