Fiducial Marks in PCBs – What they are?

https://www.electronics-lab.com/fiducial-marks-pcbs-noticed/

In the past, I’ve  always seen small circuits of copper with no silk screen or solder mask on top of it and as a PCB designer I have always the question in my mind: What is it for? — I’ve never needed them before! As I can find them in Arduino’s PCBs as well, I […]