The MacroFab platform requires a board outline gerber file to correctly manufacture your PCB. This board outline gerber file is used to determine the extents of your PCB, calculate the size of your PCB,  and remove excess features of your PCB that extend past this border. The PCB fab uses the board outline gerber file to route out your PCB and determine where slots and other cutouts should go.

Most EDA tools produce this gerber file but if you need additional help in creating this file try our EDA tool help area of the knowledge base. If you think the border file is correct and the MacroFab platform is not recognizing or rendering it correctly, try the outline troubleshooting guide, or contact support so we can take a look at it.

Check List for Valid Board Outlines

  • The line that defines the extend of the PCB must not contain gaps, it should be a continuous line or “watertight”
  • Thickness of the board outline is atleast 1 mil
  • Should not contain extra features outside of the pcbs extents

Board Outline In the PCB Viewer

In the MacroFab platform you can check your border file by using the PCB viewer. More information about how to use the viewer can be found in this knowledge base article. The board outline layer should be checked to ensure it looks correct and that any cutouts or slots where captured.

The MacroFab Platform: PCB interface showing the render of the Macro Watch

The MacroFab Platform: PCB interface showing the render of the Macro Watch

The MacroFab Platform: PCB interface showing the boarder layer for the Macro Watch

The MacroFab Platform: PCB interface showing the border layer for the Macro Watch

Determining the Edge of your PCB

When the edge of the PCB is milled out of the FR-4 material (what PCBs are made out of) the PCB fab uses a round bit similar to a CNC machine. This causes the inside corners of the border of the PCB to have a round edge to them. This is something to watch out for in enclosure designs. The smallest tool used for routing out boards is 1.0mm in diameter which means the smallest inside corner radius possible at MacroFab is 0.5mm. The tool cuts to the middle of the line regardless of the thickness of the line.

How the tool that cuts the boarder of your PCB routes. Green is the tool path. Grey is the board outline. Red is the copper layer.

How the tool that cuts the border of your PCB routes. Green is the tool path. Grey is the board outline. Red is the copper layer.

The tool that routes the edge of the board cuts up to the middle of the line. Due to the tool being round it leaves inside corners as rounded.

The tool that routes the edge of the board cuts up to the middle of the line. Due to the tool being round it leaves inside corners as rounded.

Cutouts, Slots, and Routes

Cutouts, slots, and internal routes in your PCB board should also be called out and included in the border file of your PCB. Cutouts and internal routes are drawn in a similar fashion as the board outline is. More information about cutouts, slots, and internal routes can be found on our blog here and in this knowledge base article.

Calculating PCB Size

PCB dimensions are calculated from the bounding area of your PCB which is determined by the smallest rectangle that encloses your design. The smallest billable area is 1 sq inch or 25.4mm² so any boards smaller then this will be rounded up.