For solutions to the problem of electrostatic discharge, according to the following rules to twelve (in order of preference)
Non-insulated casing on the ground 1.PCB and other traces of at least 2.2 mm apart. This applies to all objects connected to the chassis on the ground, including the rail line.
2. The length of the chassis ground should not exceed five times its width.
3. The operator of the circuit and uninsulated palpable PCB area or a grounded metal object separated by at least 2 cm or more.
4. The power line and ground and lined on either the same layer of the PCB, or on two adjacent layers.
5. The ground plane and the ground must be connected to the network. In either direction, vertical and horizontal earth ground connection at least every 6 cm. Especially the double-sided PCB board, that is, you can layout the PCB level ground to first floor and ground cloth can be perpendicular to the second layer, both must place a 6 cm hole has been connected to at least every ( of course, where less than 6 cm is better to connect the ground plane is better than the ground grid)
6. All signal lines must be less than the ground surface or edge 13 mm above the ground. Ground cloth either in the same layer as the signal line, but also on the cloth with the next layer. If the length of the signal line has reached 30 cm or more, it must be placed in a ground beside it, in the signal line side, or placed adjacent to the surface of the ground is also possible.
7. between the power line and the ground across the bypass capacitor, the distance between not more than 8 cm (so that each piece of the manifold may have a plurality of bypass capacitors are connected).
8. The connection between each other to rely on more elements together.
9. All elements must be as close to the I / O connector (note: should first satisfy the first three).
10. The PCB spare part all filled with ground (6 cm should be noted that every place continuously to produce a ground network).
11. If possible, it will feed the power line or signal line from the edge of the center of the PCB leads, rather than from the lead out of a corner.
12. A particularly sensitive and long signal lines (30 cm or longer), should be reversed to its ground at regular intervals.
Note: These design rules must be applied to all the PCB (such as plug-in board and top board) within the system. For example, when applying Article 2, the chassis ground and the length including the length of the motherboard and daughterboard all ground.