4

I have looked at some PCB designs and noticed that the bottom-layer silkscreens are mirrored, and the top ones aren't. Why is that?

ocrdu
  • 8,705
  • 21
  • 30
  • 42
Alexong123
  • 51
  • 4

1 Answers1

17

The default view from the software is generally “looking down” through the board, with some or all layers shown, so that the bottom silk screen layer will be shown as mirrored.

You can also flip the view to look upward through all layers of the board, in which case the bottom silk screen layer will be right-reading and the top will appear mirrored. You would typically prefer to use this view when manipulating the bottom markings directly (adding markings, adjusting designator positions etc) unless your brain works a bit strangely.

Spehro Pefhany
  • 376,485
  • 21
  • 320
  • 842
  • "unless your brain works a bit strangely" :-) – Michael Karas Jan 26 '23 at 03:24
  • @MichaelKaras ca. 1950 some Austrian scientists did experiments with optical goggles that flip vision top-bottom - after initial clumsiness the subject adjusted in a matter of days or weeks until things seemed normal again, and they were even able to drive a motorcycle. I wouldn't want to discount the possibility some full-time PCB designer has trained him or herself to 'see' a mirrored layer like it was right-reading. – Spehro Pefhany Jan 26 '23 at 04:01
  • @SpehroPefhany crucially though, the subject became dependant on the goggles, right? As in, they had to adjust again when taking them off? Still, I'm assuming it's quite possible to train for sometimes-mirrored reading. – Bart van Heukelom Feb 17 '23 at 07:10
  • @BartvanHeukelom The report said the subject had to re-adapt after taking them off, but it was quite fast. Reading mirrored should be possible. Reading upside-down is certainly a useful skill in some professions. – Spehro Pefhany Feb 17 '23 at 07:54