I am an amateur PCB designer. Trying to design my first PCB. It's a two layer board with ESP8266 module. I have read lot about ground plane and copper pour at the bottom layer. I have tried to use all those knowledge while designing this PCB. Can someone please tell me if I made any BIG mistake here? Here is an image of the bottom layer..

enter image description here

  • \$\begingroup\$ I'd consider flipping the Hi-Link Module, put AC on the edge of the board, and DC pins closer to the middle. Also check if the creepage distance/gaps are large enough for your voltage and PCB finish (mask or no mask, etc). Also, maybe some more margin around the antenna, since apparently you can afford it.. \$\endgroup\$
    – Wesley Lee
    Apr 20, 2018 at 8:42
  • \$\begingroup\$ Hi @WesleyLee Ohh sorry, that was an old gerber, I have already flipped it :) Let me change it.. I can also remove some copper beneath the atenna, no problem.. Beside these do you see any other major issue? \$\endgroup\$ Apr 20, 2018 at 9:09
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    \$\begingroup\$ What is connected to the relays? Mains voltage requires a minimum trace distance and your ground layer would make the design totally unsafe. \$\endgroup\$
    – Oldfart
    Apr 20, 2018 at 9:20
  • \$\begingroup\$ OMG, I totoally forgot AC on the relays.. Let me remove the copper there.. Thank you for reminding me.. \$\endgroup\$ Apr 21, 2018 at 7:10

1 Answer 1


Just a side-note, which I guess you already are familiar with: Take care for stray islands of copper (these are copper that are floating, not connected to GND or on any other signal). These islands can cause the signal to bounce on them, increasing cross talk issues.

  • \$\begingroup\$ Why is this downvoted ? It is a valid hint, though maybe not that relevant for a low frequency project. But leaving isolated plane patches in place also has almost no benefits, so it is a bad practise that should be avoided generally. \$\endgroup\$
    – tobalt
    Mar 29, 2021 at 9:08
  • \$\begingroup\$ It was downvoted before the edit. Now, its better/fine \$\endgroup\$ Mar 29, 2021 at 10:23
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    \$\begingroup\$ @ChristianidisVasileios - Hi, Thanks for trying to help. However your edit to that answer is too much of a change to be an edit - one reviewer spotted that. Edits are meant for small clarifications, typos, grammar fixes, layout changes etc. - not significant additions of your own. To put it another way: An edit "must not put significantly different words into someone else's mouth", since the answer has their name on it. Therefore, please write your own answer, if you want to keep your words. This answer (very short as it is) will soon be reverted back to its original state. Thanks! \$\endgroup\$
    – SamGibson
    Mar 29, 2021 at 13:34

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