📈 Traces

Traces #

The process of creating an .nc file for the isolation routing around your circuit’s traces and pads looks like this:

graph LR A[Open Bottom
Copper Gerber]-->|.gbr|B[Generate
Geometry] B-->|.gbr_iso|C[Generate
CNC Job] C-->|.gbr_iso_cnc|D[Export
G-code]

Open Gerber #

  1. Choose File | Open Gerber, then select the Gerber file for the bottom of your PCB
Notice that the PCB layout is displayed as if you are looking at the bottom of the board. Most EDA software packages display the PCB layout as if it were viewed from the top side of the board - even if you are examining traces on the bottom of the board. FlatCAM displays the PCB layout as described in the Gerber file, and since we exported the Gerber files with mirroring turned on, you should be seeing a view of the board from its bottom side at this point.

Generate Geometry #

  1. In the “Project” tab, double-click the .gbr list item
  2. Verify that the settings under “Isolation Routing” match what was entered in Configuring FlatCAM
  3. Click the “Generate Geometry” button

The red paths that are generated are the isolation routes that will be followed by the tools that we define in the next step.

Verify that there is at least one red path between all of the traces and pads on your board. If there are areas where the spacing was too tight for a path to be created, you will need to use a smaller end mill or bit. Sometimes these issues can be resolved by moving the traces in your EDA software.

Generate CNC Job #

  1. In the “Project” tab, double-click the .gbr_iso list item
  2. Verify that the settings under “Create CNC Job” match what was entered in Configuring FlatCAM, under “Geometry Options (for Isolation Routing)”
  3. Click the “Generate” button under the “Create CNC Job” section

The blue paths that are generated are the areas of copper that will be cut away by the tool we just specified. Yellow lines are “links”: movements where the tool is raised, and not cutting. Again, verify that everything looks correct.

Export G-code #

  1. In the “Project” tab, double-click the .gbr_iso_cnc list item
  2. Click the “Export G-Code” button
  3. Select a destination folder for the file and give it a name that includes the bit to be used for this job. For example, bottom_60deg_501.nc