Magnetic PCB holders
These are simple magnetic PCB holders, printed with a 3D-printer.
Their purpose is to keep a PCB in place during machine assembly, and especially when the PCB has components on both sides. These clips may also be used for manual assembly (and again, especially if there are components on the other side).
Our pick-&-place machine assumes PCBs to lie flat on its work surface. When the PCB has components on both sides, and you are doing the second phase, the PCB cannot simply lie flat, it must be raised in a frame. We made these clips to function as a general-purpose replacement for those frames.
In our case, we typically put only low-profile components on the bottom (high components are on the top side). So for us, it is sufficient to raise the PCB with 2mm. The STL files for the clips were generated for that "shoulder height". In case you need higher clips, you can adjust the OpenSCAD design file and generate new STL files.
The magnets are also enclosed in the holders. When slicing the STL files, you should therefore add a "Pause" command just before the layer that covers the magnet holes up (roughly at 1.4mm, for the STL files on this page). Then, when the 3D printer reaches that pause, you insert the magnets and resume printing.
When the PCB is large, or when it is a panel, it is not sufficient to just hold it by the edges; it should also be supported in the middle. The flat disks are for that purpose. Obviously, these should be positioned in a spot where there are no components on the bottom side.
We used 10mm by 1mm neodymium disk magnets. Larger (and thicker) magnets are stronger. You will have to adjust the OpenSCAD design file for these alternative magnets.
|Standard PCB holder (2mm shoulder height), STL file|
|PCB support (2mm), STL file|
|90° "corner" holder (2mm shoulder height), STL file|
|Design file for all PCB holders||OpenSCAD|