Here are some wiring rules for components:
1. The distance from the wiring area to the PCB board edge cannot exceed 1mm, and the wiring is prohibited 1mm around installation hole
2. The power wire should be as wide as possible and not be less than 18mil; signal line width should not be less than 12mil; cpu input the output line should not be less than 10mil (or 8mil); line spacing is not less than 10mil;
3. The normal through-hole is not less than 30mil;
4, Dual in-line: pad 60mil, aperture 40mil;
1 / 4W resistance: 51 * 55mil (0805 surface); pad 62mil, aperture 42mil;
Promise capacitance: 51 * 55mil (0805 surface); pad 50mil, aperture 28mil;
5. The power and ground wire should be as radial as possible, and the signal line can not appear loop alignment.