Void Coverage

A copper plane will get stress against thermal expansion in manufacturing process, the hole is used to prevent this. To check the void coverage: get the hole area, expand the hole area by Hole Size Expanding value, and calculate the ratio of hole to copper area. If the result value is less than user defined ratio, it will be detected.

• Net Definition: Select net to check the hole area to copper plane. Usually, a Ground net will be defined. There are two ways to select the net: by Net Group or by Net Filter (naming rule of net).
• Layer Definition: Select the target layer.
• Option
  • Maximum Copper Dimension for Excluding: Enter the maximum copper dimension value to be excluded from checking, which will be excluded if calculated ratio is less than the entered value.
• Hole Size Expanding: Enter the value to be used to expand the hole size.

  
  
  Figure 1.

• Hole/Copper Ratio(%): Enter the ratio value. If the calculated ratio is less than the entered value, it is considered a fail.