Generating Gerber Fabrication Data in Altium NEXUS

The Gerber Setup dialog. Hover the mouse over the image to alternate between the Layers to plot and Advanced tabs.

Units

Use this region to choose the units used in the generated file:

• Inches – enable this option to use imperial units where all work is done in mils (1 mil = 1/1000 inch).
• Millimeters – enable this option to use metric units where all work is done in millimeters.

Decimal

Use the drop-down in this region to specify the numerical precision of the plot coordinates in the Gerber file.

Outputs: FileName.Extension

Use this region to choose the naming option for Gerber files to be generated:

• *.gbr – enable this option to generate layers with unique filenames but with the same single extension (.gbr).
• filename.* (gtl, gbl, gto,...) – enable this option to generate layers with the same filename but with different extensions (.gtl, .gbl, .gto,...).

Others

• Include unconnected mid-layer pads – enable this option to allow unconnected pads in the mid-layer on Gerber plots.
• Generate Reports – enable this option to generate the following files: .REP, .EXTREP, .apr, .APR_LIB, .DRR, and .LDP.
• Merge regions and pads inside Footprint – enable this option to merge regions and pads within a footprint during the generation of Gerber outputs.

Layers to Plot Tab

This tab allows you to configure which layers to plot in the Gerber output for the current PCB document.

• Layers List – a listing of layers in the current PCB available for output to Gerber. Layers are grouped by their types (Copper Layers, Silkscreen, Solder Mask, Paste Mask, Mechanical Layers, etc.). Each layer is presented in terms of the following:
  • File Name – the individual Gerber output file name. Naming is based on the project name, layer, and function, and uses an underscore character as a descriptive separator. Click on a layer name to type in a new name if required.
  • Layer Name – the layer name that applies to the output file as defined by the board’s layer stack.
  • Plot – enable this option to include a Gerber plot for that layer or layer group in the generated output. Disable to exclude the plot from being generated for that layer.

  • Mirror – enable this option for a layer or layer group if you want a mirrored Gerber file to be created.

    To access the Mirror column in the Gerber Setup dialog, the UI.Unification.GerberDialog.ShowMirrorColumn option must be enabled in the Advanced Settings dialog. The Advanced Settings dialog is accessed by clicking the Advanced button on the System – General page of the Preferences dialog. If any changes are made in the Advanced Settings dialog, the software must be restarted in order for the changes to take effect.
  Click the button at the far right of the Layer Name column header to access the Add Mechanical Layers dialog and select the mechanical layers that are added to all plot layers. Click the  button associated with a layer group to access the Add Mechanical Layers dialog and select the mechanical layers that are added to all plot layers in the selected layer group.

  When Gerber output is generated for a PCB panel (an embedded board array), the dialog includes a column for the panel as well as a column of layers for each board included in the panel. Use this new column to quickly verify that the various board layers are mapped to the correct panel layers.

  
  An example of the Gerber Setup dialog for a PCB document that contains a panel.

• Plot Layers – use the drop-down to access a menu of commands that allow the Plot field for all layers in the Layers to plot region to be enabled or disabled:
  • Select All – select to check all boxes in the Plot column (Gerber data will be created for all checked layers).
  • Deselect All – select to clear all checked boxes in the Plot column (no Gerber data will be created).
  • Select Used – select to check all boxes in the Plot column of the listed layers that are used in the design.
  • Edit Group – click to open the Add Mechanical Layers dialog in which you can select the mechanical layers that are added to all plot layers in the selected layer group. You can also click the  button associated with a layer group to access the Add Mechanical Layers dialog.
• Mirror Layers – use the drop-down to access a menu of commands that allow the Mirror field for all layers in the Layers to plot region to be enabled or disabled:
  • Select All – select to check all boxes in the Mirror column (Gerber data will be created for all checked layers).
  • Deselect All – select to clear all checked boxes in the Mirror column (no Gerber data will be created).
  • Select Used – select to check all boxes in the Mirror column of the listed layers that are used in the design.

Aperture Matching Tolerances

• Plus – use this box to define the positive tolerance for aperture matching.
• Minus – use this box to define the negative tolerance for aperture matching.

Leading/Trailing Zeroes

• Keep leading and trailing zeroes – if this option is enabled, all leading and trailing zeroes will appear in the generated Gerber file.
• Suppress leading zeroes – if this option is enabled, no leading zeroes will appear in the generated Gerber file.
• Suppress trailing zeroes – if this option is enabled, no trailing zeroes will appear in the generated Gerber file.

Plotter Type

• Unsorted (raster) – select to use raster machine (default).
• Sorted (vector) – select to use vector machine.

Others

• Optimize change location commands – when this option is enabled, X or Y location data is not included if it does not change from one object to the next.
• G54 on aperture change – check this option to rotate the aperture wheel of the plotter after each aperture change.
• Use software arcs – check this option to use software arcs.
• Use polygons for octagonal pads – check this option to use polygons for any octagonal pads.
• Generate DRC Rules export file (.RUL) – check this option to generate a DRC Rules Export file (.RUL). This file report details the design rules for the source PCB document from which the Gerber data is being generated.

Legacy Tab

The Legacy tab of the Gerber Setup dialog

Film Size

• X(horizontal) – enter a value for the film length.
• Y(vertical) – enter a value for the film width.
• Border size – enter a value for the border size of the film.

Position on Film

Use the following options to choose the position on the film:

• Reference to absolute origin
• Reference to relative origin
• Center on film

Batch Mode

• Separate file per layer – select this option if you want each layer to generate a separate Gerber file.
• Panelize layers – select this option if you want only one Gerber file to be generated in the format of panelization.

Apertures

• Embedded apertures (RS274X) – when this option is enabled, the apertures are embedded in the Gerber files according to the RS274X standard and all information for each layer is contained in a single file. Enabling this ensures that the current apertures list includes all the required apertures. If this option is disabled, the additional controls in this region become available.
• Maximum aperture size – input the maximum size of the apertures for the design.
• Generate relief shapes – check this option to create relief style apertures.
• Flash pad shapes – check this option to flash the pad shapes.
• Flash all fills – check this option to flash all fills.
• Apertures List – lists all the current aperture data.
• New – use the drop-down to access a menu of commands that allow adding a new aperture and save or load the aperture list to/from an aperture file:
  • Add Aperture – select to open the Edit Aperture dialog in which you can specify the properties of the new aperture.
  • Load – select to open a dialog with which you can select the location of the aperture file to load.
  • Save – select to save the current apertures in the apertures list.
• Edit – use the drop-down to access a menu of commands that allow editing of a selected aperture or the apertures list:
  • Edit Aperture – select to edit the properties of the selected aperture in the Edit Aperture dialog.
  • Rename Aperture – select to edit the properties of the selected aperture in the Edit Aperture dialog.
  • Clear All – select to clear all apertures from the apertures list.
  • Create List from PCB – select to create the apertures list from the current PCB design.
• – select to delete the selected aperture.

Notes about Apertures

Unless your PCB manufacturer does not support embedded apertures, it is highly recommended that you use the Embedded apertures (RS274X) option. Most modern photoplotters are raster plotters that can accept any size aperture. Generally, they also accept Gerber files with embedded apertures.

If your manufacturer does not use embedded apertures, a separate aperture file (*.apt) must be included with the Gerber files. If you use an existing aperture file rather than a generated one, the PCB Editor scans the primitives (tracks, pads, etc.) in the PCB document and matches these with aperture descriptions in the loaded *.apt file. If there is no exact match of aperture to primitive, the PCB Editor will automatically paint the primitive with a suitable smaller aperture. If there is no aperture suitable with which to paint, a *.MAT (match) file will be generated listing the missing apertures and Gerber file generation will be aborted.

The Gerber X2 Setup dialog. Hover the mouse over the image to alternate between the Layers to plot and Advanced tabs.

Units

Use this region to choose the units used in the generated file:

• Inches – enable this option to use imperial units where all work is done in mils (1 mil = 1/1000 inch).
• Millimeters – enable this option to use metric units where all work is done in millimeters.

Decimal

Use the drop-down in this region to specify the numerical precision of the plot coordinates in the Gerber file.

Outputs: FileName.Extension

Use this region to choose the naming option for Gerber files to be generated:

• *.gbr – enable this option to generate layers with unique filenames but with the same single extension (.gbr).
• filename.* (gtl, gbl, gto,...) – enable this option to generate layers with the same filename but with different extensions (.gtl, .gbl, .gto,...).

Others

• Include unconnected mid-layer pads – enable this option to allow unconnected pads in the mid-layer on Gerber plots.
• Generate Reports – enable this option to generate the following files: .REP, .EXTREP, .apr, .APR_LIB, .DRR, and .LDP.
• Merge regions and pads inside Footprint – enable this option to merge regions and pads within a footprint during generation of Gerber outputs.

Layers to plot Tab

This tab allows you to configure which layers to plot in the Gerber X2 output for the current PCB document.

• Layers List – a listing of layers in the current PCB available for output to Gerber. Layers are grouped by their types (Board Outline, Copper Layers, Silkscreen, Solder Mask, Paste Mask, Mechanical Layers, Drills, etc.). Each layer is presented in terms of the following:
  • File Name – the individual Gerber output file name. Naming is based on the project name, layer, and function, and uses an underscore character as a descriptive separator. Click on a layer name to type in a new name if required.
  • Layer Name – the layer name that applies to the output file as defined by the board’s layer stack.
  • Plot – enable this option to include a Gerber plot for that layer or layer group in the generated output. Disable to exclude the plot from being generated for that layer.
  Click the button at the far right of the Layer Name column header to access the Add Mechanical Layers dialog and select the mechanical layers that are added to all plot layers. Click the  button associated with a layer group to access the Add Mechanical Layers dialog and select the mechanical layers that are added to all plot layers in the selected layer group.

  When Gerber X2 output is generated for a PCB panel (an embedded board array), the dialog includes a column for the panel as well as a column of layers for each board included in the panel. Use this new column to quickly verify that the various board layers are mapped to the correct panel layers.

  
  An example of the Gerber X2 Setup dialog for a PCB document that contains a panel.

• Plot Layers – use the drop-down to access a menu of commands that allow the Plot field for all layers in the Layers to Plot region to be enabled or disabled:
  • Select All – select to check all boxes in the Plot column (Gerber data will be created for all checked layers).
  • Deselect All – select to clear all checked boxes in the Plot column (no Gerber data will be created).
  • Select Used – select to check all boxes in the Plot column of the listed layers that are used in the design.
  • Edit Group – click to open the Add Mechanical Layers dialog in which you can select the mechanical layers that are added to all plot layers in the selected layer group. You can also click the  button associated with a layer group to access the Add Mechanical Layers dialog.

Advanced Tab

Aperture Tolerances

Use the options in this region to set the tolerance range used when matching apertures for each item in the plots.

• Plus – use to define the positive tolerance for aperture matching.
• Minus – use to define the negative tolerance for aperture matching.

Plotter Type

Use this region to specify the target photo-plotter type:

• Unsorted (raster) – select to use raster machine (default).
• Sorted (vector) – select to use vector machine.

Gerber X2 Specific

• File Subject – use this field to select the file type, which is included as a Part attribute in the Gerber X2 outputs. The drop-down list provides the following choices:
  • None
  • Autodetect – automatically assigns an attribute from the below list based on the type of board file. For example, a PCB document containing a single board design will be assigned the Single part attribute.
  • Single – a single PCB.
  • CustomerPanel – a board array or shipping panel.
  • ProductionPanel – a working panel or fabrication panel.
  • Coupon – a coupon (performance test board associated with a main board design).
  • Other – none of the above. In the file, a string appended to the attribute informally indicates the part.
• File Comment – enter a comment that will be included as an attribute in the generated outputs.

Others

• Optimize change location commands – when this option is enabled, X or Y location data is not included if it does not change from one object to the next.
• Generate DRC Rules export file (.RUL) – enable this option to generate a DRC Rules Export file. The report details the design rules defined for the source PCB document from which the Gerber data is being generated.