User contributions
- 01:57, 1 June 2018 (diff | hist) . . (+21) . . 2000: xkcd Phone 2000 (→Explanation: PCBs are not made out of copper. Typically resin-bonded fiberglass (FR4) or phenolic paper (FR2). FR4 is definitely what a phone would use, though knowing the xkcd phone series, it might use FR2 just to be different.)
