Hello.
I need to panelize round PCBs, not that I have done a panel for rectangular PCB before, but the round ones have seemed more complex and I started with them. I have not found any detailed information on how to do it, and I have decided to try it myself. I do not know if there is a simpler and faster way to do it.
The idea is to use mouse-bites to create a panel, in this case 2x1, of round PCBs with a diameter of 70mm.
I want to do it myself and give the manufacturer the Gerber already panelized, because I also need the Stencil and that each time I send to manufacture, the panels are identical, to be able to use the same stencil, and also because I am going to assemble with my own Pick and Place Neoden4. So I prefer not to leave the panelized in the hands of the manufacturer.
These are the steps I have taken, if someone knows another better way to do it, I would appreciate it if you comment.
1.- I make a square of 70 mm on the side and another exterior of 72 mm. This will create the 2mm groove that will separate the PCB from the panel, secured with 4 tabs made with mouse bites.
2.- I create the cuts for the eyelashes, in the center of each side of the square. They have a width of 5mm
3.- Insert a 70mm diameter circle in the center. This is only for reference so that when I apply the MITER to round the corners of the square, I can check that the board is really round, in the end I will eliminate that circle.
4.- Now I apply a MITER to each of the four corners of the inner square, which will be the round 70mm diameter PCB. However much I try different values of the MITER, as you can see in the image, the arcs never fit perfectly into the circle of reference.
5.- If I select, to see, the properties of the line, we see that it has a curvature of 90 degrees
6.- If I change the curvature to 83 degrees, then the arc does fit perfectly to the reference circle, to be able to leave the PCB perfectly round.
7.- With the outer square, I do the same, apply the MITER and correct the angle of 90 degrees to 83 degrees, so that it is concentric with the internal circumference of 70mm. Although this does not necessarily have to be perfectly round, it does not cost anything to make the correction.
8.- Now I can delete the reference circle that I put at the beginning. I add the holes to make the mouse bites, five holes of 0.5mm diameter, separated 1mm from each other, and at a distance of 0.25mm from the edge of the plate. Following the instructions I found online.
9.- Finally, I create a rectangular panel, I copy and paste the PCB twice, I add fiducials and four 4.2mm holes in the corners that will serve to apply the stencil without having to align with the PCB using a methacrylate plate with four round 4mm bolts.