PCB component routing plays a pivotal role in circuit design, directly influencing the performance, stability, and production costs of the circuit. A well-thought-out component layout can shorten trace lengths, minimize signal delays, reduce electromagnetic interference, and enhance the circuit's anti-interference capability. It can also optimize heat dissipation and alleviate overheating issues on the circuit board. While routing components, it's essential to consider not just the electrical performance but also the mechanical structure and manufacturing processes. Here are some common routing principles:

1. The spacing between different networks depends on factors like electrical insulation, manufacturing processes, and component size. Spacing settings must also take into account the manufacturer’s production capabilities. Electrical insulation is particularly crucial if there’s a significant potential difference between two components or networks. This becomes especially important when high-voltage and low-voltage circuits coexist on the same board—adequate safety clearances must be ensured.
2. The form of the circuit turn is another key consideration. To make the circuit board easier to produce and visually appealing, the cornering mode of the routing should be planned during the design phase. Choices include 45°, 90°, and arcs, with sharp corners generally avoided. The connection between the wire and the pad should be smooth to prevent sharp points. When a wire passes between two pads without connecting to them, it should maintain equal and maximum distance from both pads. Similarly, the spacing between wires should be even and maximized.
3. The trace width is determined by factors such as the current level flowing through the wire and interference resistance. Higher currents require wider traces. Power lines should generally be wider than signal lines. To stabilize the ground potential and minimize the effect of ground current fluctuations, the ground line should also be wider. Within the allowed board area and density, wider traces should be used to reduce circuit impedance and improve interference resistance. For power and ground lines, thickening them as much as possible when routing space permits is advisable, with a minimum width of 50 mils typically required.
4. Interference and electromagnetic shielding on printed circuit traces primarily involve interference between traces, interference from power lines, and crosstalk between signal lines. Proper arrangement and layout of the traces, along with appropriate grounding methods, can effectively reduce interference sources and enhance the electromagnetic compatibility (EMC) performance of the circuit board. For high-frequency or critical signal lines, such as clock signal lines, the trace should be as wide as possible. Shielding can also be achieved by enclosing the signal line with a ground line, forming a grounding shield layer that isolates it from surrounding signal lines.
5. For high-frequency or critical signal lines, such as clock signal lines, the trace should be as wide as possible. Additionally, shielding can be applied by enclosing the signal line with a ground line, creating a grounding shield layer that isolates it from surrounding signal lines.
6. A single via introduces about 10pF of parasitic capacitance, which can be detrimental in high-speed circuits. Excessive vias can also weaken the mechanical strength of the board. Thus, minimizing the number of vias during routing is ideal. Furthermore, when using through-hole vias, pads are often used instead. This is because, during manufacturing, some through-hole vias might not be fully drilled due to processing errors, whereas pads are guaranteed to be drilled through, ensuring a more reliable manufacturing process.

The above are general principles for PCB routing, but in practice, the routing of components remains a highly flexible process. These principles serve merely as design guidelines, with practical application being the ultimate test of their effectiveness.