1. According to the position of FPC board, the most important "ground" is used as the reference to independently cover copper, while the digital and analog are separately used to cover copper. At the same time, the corresponding power supply connection is thickened to form multiple deformation structures with different shapes before copper is covered.
2. For single point connections in different places, the method is to connect with 0 ohm or magnetic bead or inductance.
3. The crystal oscillator is coated with copper near the crystal oscillator. The crystal oscillator in the circuit is a high-frequency emission source.
4. The problem of isolated island (dead zone), if it is very big, it will not cost much to define a hole and add it into it.
5. At the beginning of wiring, the ground should be treated as the same, and the ground should be handled well when routing, instead of eliminating the ground pin as the connection by adding holes after copper coating, which has a poor effect.
6. It is better not to have sharp angles on the board, because from the perspective of electromagnetism, this constitutes a transmitting antenna!For others there will always be a difference between big and small, I recommend using the edge of the arc.
7. In the middle layer of the multi-layer board, the wiring is empty, and do not cover with copper.Because it's hard to make this copper "well grounded."
8. The metal inside the equipment, such as metal radiator and metal reinforcement strip, must achieve "good grounding".
9. The radiating metal block of the three-terminal voltage stabilizer must be well grounded.The earthing isolation belt near the crystal oscillator must be well grounded.