Board Component Clearance

This DFE rule checks whether components are placed enough distance away from board edges.

Components that are sensitive to RF or EMI (Electromagnetic Interference), ESD (Electrostatic Discharge) or EOS (Electrostatic Overstress) problems must be placed enough distance apart from the board edges to distance themselves from those outside EMI, ESD or EOS sources.
  • Item: Enter the item name.
  • Component Group: Select a component group or groups.
  • Clearance: Assign a minimum allowable distance from board edges.
  • Component Measure-Base: Define component measure base. (COC, Silk, PAD, Silk+Pad)
  • Component Type: Select the component's type. (SMD or DIP)
  • Board Outline: The board outline consists of two lines. Select the outline reference. (Edge/Center)
    • Edge: Select the outer line. The outer line of the lines is considered as the outline.
    • Center: The middle of the two lines is regarded as the outline.

      Figure 1.

20-H Rule

Different sizes of ground and power are recommended to maintain stability from noise. The 20-H Rule recommends the following:
  • Extend the ground plane about 20 times of the layer spacing (H) between the power plane and ground plane from the edge or power plane.

Figure 2.