I usually work with very small parts so I make an actual assembly layer with boxes close to courtyard size and put in the. If you are designing something for field service and especially for connectors that a user or test/production workers need to identify then make it as big and readable as possible.įor the assembly layer, I typically prefer TrueType Arial of varying sizes for text. If the design is not as small, say 0805 scale, then 1.5mm (60mil) height legend is easier on the eyes. I guess my preferred size for text on the overlay is 1mm high (40mil) and 6 mil line width using stroke SansSerif when using 0402 size parts. To me, down to 0.8 or maybe 0.7mm is readable but with eye-strain. If you get a PCB-Ruler from Digikey ( ), you will see it has examples of arial and stroke fonts down to 0.5mm high. In Altium Designer it is easier to use Find Similar Objects to pick these objects but in CS you can use the filter selections through PCB Filter to get at them. Then I can change them after that one by one for any that I want to be extra large and readable. TrueType) in the design, for example because multiple people did some of the footprints, then I select all the text on the overlay layers using PCB Filter and change them to be consistent method and size with the PCB Inspector. If I end up with mixed methods (stroke vs. The ink tends to sag and blur though in my experience.

True screenprinted may be cheaper for larger and high volume designs. I have had some boards with legend as small as 30mil height and it is readable under magnification. I usually specify that silkscreen legend should be liquid photo imaged or direct legend printed for very small type. I have found that whether it is legible or not will depend on how good the fabricator is. I haven't figured out how the TrueType font sizes are determined in CS or Altium. I usually pick the stroke type Sans Serif since it is simple and the line dimensions (height and width) are actually close to the specified values.

Altium designer pcb component font size