LitePlacer.com forums

I plan on purchasing a LitePlacer in the future and want to have my PCBs prepared for its use.

Where exactly should fiducial markings be placed. Is it enough to put them roughly at three corners of the PCB?

That is sufficient. Four is better at least in theory, as the transform is most accurate inside the area enclosed by the fiducials. I haven’t run any real comparison between three and four fids.

Again theoretically: the accuracy increases when the number of fiducials increases, and I have tested that. When fids are roughly in the corners, four fiducials on a clean board already give better accuracy from the calculations than the machine can deliver, so with four (and I suppose three inside the triangle defined by them) you are good, no real world benefits by adding more.