1.PCB non insulated casing wire and other wire distance of at least 2.2 mm. This applies to all objects connected to the chassis ground, including trajectory.
2 chassis wire length should not be more than five times its width.
Metal objects 3 the circuit without insulation and the operator can touch to the PCB area or ungrounded separated by at least 2 cm.
4 power line and ground wire or ranking on PCB and in the same layer, or placed adjacent to the two layer.
5 the ground plane and ground wire must be connected to the network. In an arbitrary direction, at least 6 cm every connection a vertical line and horizontal line. Especially the double PCB plate, that is to say, the first layer PCB board layout can be ground level, and the second layer can be vertical ground, must be at least every 6 centimeters place a hole has been connected to both (of course, less than 6 cm in the local connection is better than the ground grid, ground plane.
) 6 of all signal lines must be in the ground plane edges or less than 13 mm above the ground. Wire can be distributed in the same layer signal line, also can be in the next layer. If the signal line length of 30 cm or more, it must be placed on a ground beside it, placed above the signal line or the adjacent surface of the ground can be.
Across the bypass capacitor between the 7 power line and the ground wire, the distance between each other is not greater than 8 cm (so that each piece of integrated block may have multiple bypass capacitor is connected).
8 mutual connection more components rely on together.
All 9 components must be as close as possible to the I/O connector (Note: should meet third).
The 10 part will spare all of PCB filled with ground (attention should be paid to every 6 centimeters place continuously to produce ground network).
11 if possible, which will feed power line or signal line from the edge at the center of PCB board, and not from a corner out.
12 for the signal line is particularly sensitive and long (30 cm or longer), should be at regular intervals and ground.
Note: these design rules must be applied to all PCB in the system (such as main board and plug in the above board). For example, when the application of article second, a ground length including the motherboard and the daughter board and the length of all the earth.