PCB board is based on the PCB circuit design, so PCB line layout becomes particularly important, the general layout of the PCB line needs to comply with the following principles:
1. According to the electrical performance of a reasonable partition, is generally divided into: digital circuit area (that is, afraid of interference, and interference), analog circuit area (afraid of interference), power drive area.
2. Complete the same function of the circuit, should be placed close to the place, and adjust the components to ensure that the connection is the most concise; at the same time, adjust the relative position between the functional blocks to make the connection between the functional blocks of the most concise;
3. For the quality of components should consider the installation location and installation intensity; heating elements should be placed separately with the temperature sensitive components, it is necessary to consider the thermal convection;
4. I/o driver as close as possible to the printing plate edge near the lead connector;
5. The clock generator (such as: crystal oscillator or clock oscillator) device should be as close as possible to use the clock.
6. In each integrated circuit between the power input pin and ground, the need to add a decoupling capacitor (usually with a good high frequency performance of the monolithic capacitor); circuit board space is more dense, but also in a few integrated circuits around the addition of a tantalum capacitor.
7. Relay coil to add discharge diode (1N4148 is ok);
8. Layout requirements should be balanced and orderly density, not top-heavy or a heavy head.
Strict adherence to the principles of PCB wiring is the basis for the design of the best PCB board.
Further Reading: Types of PCB Boards