What is the best way to create a board outline?

Rectangular boards are pretty straight forward.  Use the drawing tools of your given design tool and click twice and you have your shape.  Many PCB’s are not strictly rectangular though.  Usually there is something that is driving the board outline, such as an enclosure that it needs to be mounted in, and physical interface connectors and components on the board that have to be oriented a certain way.  So besides drawing the board outline by hand, what are some better ways to bring in a board outline shape?

 

PCB Enclosure
PCB Enclosure

 

PCB Outline (board envelope, baseline)

Most PCB design tools have ways to make creating a board outline easier.  It usually involves importing a file of a certain type, then defining a shape to be the board outline.

One way to create a board outline in PADS Professional, is to import a STEP model.  The process goes something like this:

  1. Import a STEP model that has a surface which will be used to define the board outline.
    • This is done in PADS Professional by going to 3D > Import Mechanical Model…
  2. Select the surface of the STEP model you want to use for the board outline.
    • This is done in PADS Professional by going to 3D > Create Board…
  3. Select an element of the defined surface to use as the board origin. Typically this is a corner of the board, or perhaps the center of a mounting hole.
    • Once the origin is defined, in PADS Professional a Map Hole Features dialog will appear.
  4. If the chosen surface has any holes in it, you will want to determine if you want them to be imported, and if so, how.
    • In PADS Professional, using the Map Hole Feature dialog, holes in a surface can be defined as a contour, a cavity, or a mounting hole.
  5. Lastly, it is useful to have the tool automatically create the Route Border.
    • In PADS Professional, this is done by activating the Route Border checkbox in the Map Hole Feature dialog, and entering the clearance desired between the board and route border.

There are other ways to bring in a board outline, as well as other data, into your PCB design.  If you want to check another way PADS Professional can quickly import a board outline, as well as other design data, check this out.

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This article first appeared on the Siemens Digital Industries Software blog at https://blogs.sw.siemens.com/pads/2019/06/12/what-is-the-best-way-to-create-a-board-outline/