How to enhance the design of the PCB ESD anti-static function

The PCB board designs, by layering, proper PCB layout and installation to achieve the anti-ESD design. In the design process, by predicting the vast majority of design changes can be limited to changes in components. By adjusting the PCB layout can be a good protection against ESD.
  From the human body, environment and even electronic equipment for the precision of static electricity inside the semiconductor chip can cause a variety of injuries, such as the internal components through a thin insulating layer; damaged MOSFET and CMOS components of the gate; CMOS devices in the trigger lock death; short reverse biased PN junction; short forward-biased PN junction; melting active components inside the welding wire or aluminum wire. In order to eliminate electrostatic discharge (ESD) of the interference and destruction of electronic equipment, need to take a variety of technical means for prevention.
  The PCB board designs, by layering, proper PCB layout and installation to achieve the anti-ESD design. In the design process, by predicting the vast majority of design changes can be limited to changes in components. By adjusting the PCB layout can be a good protection against ESD. Here are some common precautions.
  Possible, use multi-layer PCB, as opposed to double-sided PCB, the ground and power planes, and closely arranged signal line - ground spacing can reduce common-mode impedance and inductive coupling, so as to reach double-sided PCB, 1 / 10 to 1 / 100. As a signal to each layer are close to a power supply layer or ground layer. For both the top and bottom surface components, with very short cable, and many filled to the high density PCB, consider using the inner line.
  For double-sided PCB, the power to adopt and to tightly knit grid. Power line close to the ground, vertical and horizontal lines or fill in between the areas, to connect as many. Side of the grid size is less than equal to 60mm, if possible, the grid size should be less than 13mm.
  Ensure that each circuit as compact as possible.
  As far as possible all the connectors are on the side.
  If possible, the power cord from the card into the center, and stay away from affected areas directly affected by ESD.
  In the lead outside of the chassis connector (easy to hit directly by ESD) on the bottom of all PCB layers, width of the chassis to be placed or filled polygon to, and used at intervals of about 13mm distance from the hole to connect them together.
  Placed on the edge of the card mounting holes, mounting holes around the top with unimpeded flux and bottom pad connected to the chassis ground.
  PCB assembly, not at the top or bottom of any solder coating on the pad. Use screws with washers to achieve embedded PCB and metal chassis / shield or ground plane in close contact with the stent.
  In each layer of the chassis ground and circuit ground, to set the same "isolation zone"; if possible, to keep the interval distance of 0.64mm.
  Top and bottom of the card near the locations of the holes, at intervals of 100mm along the chassis ground to chassis ground and circuit ground with 1.27mm line width together. These connection points with the adjacent office, the chassis ground and circuit to be placed between the pad for mounting or mounting holes. The ground connection can be cut open with a blade to keep open, or bead / high-frequency capacitor jumper.
  If the board does not put the metal chassis or shielding device, the board of the chassis to the top and bottom line can not be coated solder, so that they can be used as ESD arc discharge electrode.
  The following ways to set up a ring around the circuit to:
      (1) Subject to the edge connector and chassis ground outside, put the ring in the outer four weeks to access.
      (2) ensure that all layers of the ring to the width of greater than 2.5mm.
      (3) at intervals of 13mm holes used to connect the ring.
      (4) ring with multi-layer circuit common connected together.
      (5) mounted on a metal chassis or shielding devices in the two-panel, the ring should be connected with the circuit public together. Double-sided circuit is not shielded ring should be connected to chassis ground, not coated with solder ring on the ground, so that the ring can act as ESD discharge to stick to the ring (all layers) on a place at least one location 0.5mm wide gap, to avoid forming a large loop. Signal wiring away from the ring to the distance not less than 0.5mm.