The Back Drill Rules dialog is used to specify the nets required to be back drilled. You can also define a drill oversize and remaining stub length after back drilling.
The general rule matching mechanism is described here.
Shortcuts
Menu: Setup
Default Keys: T
Command: Technology
Locating this option
Available from: Setup menu > Technology option > Rules - High Speed - Back Drill page
Using the Back Drill Rules dialog
On selection, the Technology dialog opens, select Back Drill Rules. The existing Back Drill Rules for the Technology being used will be presented.
Navigation
The buttons to the right side of the dialog are used to navigate the grid, the general common buttons are detailed on the Technology Navigation page.
Using the editing pane
The appropriate Back Drill rule is found for each item by working down the list of rules until the first match is found. Hence, the order of the rules is important. A match is when the specified Attribute Name and Match Value match attributes of a net. So the net must have the given attribute, and it’s value must wildcard match the value.
The Vias rule is always enabled. This allows for the Back Drilling of vias.
The Component Pads rule defines whether or not component pads should be back drilled.
The Mounting Holes rule defines whether or not mounting holes should be back drilled.
Wildcard Wizard
The Wildcard Wizard is enabled
using the small icon next to the Match Value entry: 
Global Back Drill Rules
Drill Oversize
You must provide a drill oversize value, which is the difference in radius between the oversized drill size and the original drill size used. The oversize is in the current design units (Absolute Size), or as a percentage of the original drill size. The oversized drill will be added into the Drill Size Table.
Stub Length
This is the length of the remaining stub after Back Drilling has been performed. The distance is in the current design units. Ideally, the remaining stub will be less than 10 thou (0.250mm) in length.
Stub Length Calculation for Vias and Pads
When calculating Back drills for a via, the highest and lowest connected layers are found. For a top Back drill span, the Stop Layer of the span will be no layer lower than the highest connected layer.
For component pads the
This is calculated as:
(
Export and Import CSV
Use the Export CSV button to export the data in your PCB design into a CSV format file. Using the Export CSV option will provide you with a formatted template ready for you to edit in your own data.
Use the Import CSV button to import data back into the PCB design using a CSV format file.
The data in the file represents a spreadsheet of layers with the layer data headings along the top row.
Units
The Units button allows you to locally switch between Metric and Imperial units whilst in this dialog. Once the dialog is closed, the units revert back to the original design units. If switching to different units to the design units, the value typed will be converted when you next enter this page.
Related Topics
Technology Overview | Using Dialog Grids | Design Rule Check | Back Drilling | Back Drill Spans | Export CSV | Import CSV