Live Drill Drawing
Contents
A standard element in the package of data provided to the PCB fabricator is a drill drawing. The actual drill instructions are provided in a drill file, which presents the data in a format suitable for loading into an NC drill machine. To provide that same information in a human-friendly, visual format, designers will typically include a drill drawing.
The drill drawing is an outline of the board with each drill site marked by a small symbol. Next to the board image is a table, referred to as the drill table, that lists the symbols, the hole size assigned to that symbol, and well as other important hole properties, such as plated / non-plated, or the drill layer-pair that hole passes between.
Displaying the Live Drill Drawing
No longer do you need to generate output to see the drill drawing, it can be examined at any stage, directly in the PCB editor. This does require that the drill symbols are enabled for display, which happens automatically if a drill table has been placed, or if you have enabled the Always show Drill Symbols option in the Drill Symbols dialog (described below).
The drill drawing layer then becomes live - showing a drill symbol at each drill site. To view the drill drawing, make the Drill Drawing layer the active, or current layer, then switch the workspace display to single layer mode (Shift+S).
Designs that include Multiple Drill Pairs
If the design includes multiple drill pairs, for example it uses blind and/or buried vias, then you can display (and print) multiple drill drawings, one for each drill pair. In the PCB editor you can control the display of the drill drawing for each drill pair using the small triangle that appears automatically when the design includes multiple drill pairs.
Drill Drawing Layer Tab Menu
As well as the special drill pair menu just described, the Drill Drawing layer tab also has a right-click menu (as all layer tabs do). As well including the standard layer display control options, this menu is also used to access useful drill-specific commands, including:
- Configure Drill Pairs - it is the presence of drill pairs that determines if multiple drill drawings are required, select this menu command to configure these in the Drill Pair Manager.
- Configure Drill Symbols - this command opens the Drill Symbols dialog, where you define the grouping criteria used to assign symbols to holes.
Configuring the Drill Symbols
Dialog page: Drill Symbols
Drill symbols are assigned to hole sizes in the Drill Symbols dialog. The assignment of a symbols to hole sizes is performed automatically. Each symbol is mapped to a hole size based on the currently enabled grouping options, click the Grouping button to enable the grouping options you want used as criteria for determining uniqueness of hole size. Hole objects must share the same values in all visible grouping columns to be considered the same, if they are they will be assigned to use the same symbol.
For example, pads and vias with the same size hole will share a symbol, but if the Via/Pad option is enabled in the Grouping list (so that the Via/Pad column is displayed), then they will be listed separately and be assigned different symbols.
Improved Drill Table
Main article: Live Drill Table
When you place a Drill Table into the workspace (Place » Drill Table), it displays with the default columns, font, units and alignment defined in the PCB Editor - Defaults page of the Preferences dialog. If there are non-circular shapes present in the design (such as slots or punched (rectangular) holes), then the Hole Length column is automatically added during placement.
The display of columns is then configured via the right-click menu available in the grid region of the Drill Table dialog.
Defining a Drill Table when there are Multiple Drill Pairs
The Live Drill Table supports multi-layer boards that use layer-pair drilling. To support the designer in using the Live Drill Table during the design process the table includes the Layer pairs to preview option, set this to restrict the table to only show the drill holes for just the selected layer-pair.
The series of images below show the Drill Drawing layer as each layer-pair is selected, the drill table updates automatically to suit the chosen layer-pair.
Note that the Layer pairs to preview option is not used to control which layer-pair drilling is included in the Table during output generation, that is defined by the Drill Layers setting in the Layer Properties dialog in the output setup. That means that a single table can be placed on the design, the table will only include the appropriate layer-pair data during output generation for a drill drawing of that layer-pair.
Configuring the Display of Columns
In the Drill Symbols dialog, the columns are enabled/disabled by setting their state in the Grouping list. In the Drill Table dialog, the columns are initially defined by the default settings configured in the Preferences dialog. To add/remove columns from the Drill Table, right click in the grid region of the Drill Table dialog and select the required Add Column or Remove Column command. If a column is not used for grouping, but is displayed in the Drill Table, then it will display an * (asterix) whenever there are multiple possible values to display.
Printing the Drill Drawings
When you add a new Drill Drawing fabrication output, it is automatically configured to include a printout for each drill pair currently configured for the design.