Newbie level 4
- I've been taught that fiducial marks at the board level should not be exactly diagonally symmetrical, for by doing that one of them is rendered useless since if you know the coordinate of one, you'd know that of the other. Is that true?
- I've also been taught that the fiducial mark should have a paste mask layer for alignment purposes. But some say that by adding solder paste the contrast is lowered. Which one is correct?