The fit of the prototype enclosure is fairly snug. Not mobile phone-snug, there is still 0.5mm headroom here and there… Still, we have to keep track of the height of all components, especially under and close to buttons and the LCD display. You really need a workflow where you can check if any changes to the PCB interferes with physical hardware. We needed a way to export a 3D model of the PCB and open it in SpaceClaim.
I still use Eagle and I could not find a way to do this. So I made some changes to an old IDF export utility for Eagle originally written by Andy Neubacher. It is a few simple changes that fixes import problems. If you are using Cadsoft Eagle for PCB layout and want to export your board as a set of IDF 3.0 files, you can download the ULP here, or visit the Eagle ULP library.
IDF 3.0 is a simple format for describing the height and outline of components on your board. Don’t expect anything fancy, this is previous century technology. The newer IDF 4.0 format is much more advanced, but if all you need is to check that your enclosure fits the PCB, this may be OK.
- Create your board outline on layer 50.
- In your library, draw the component outlines on layer 57 (tCad) and use the line thickness to set component height.
- 1000 mic = 1 mm (e.g. if your grid is in mm, then a line thickness of 0.001 equals a component height of 1 mm).
More info can be found here.