When you build a circuit on breadboard, you take a wire from GND and put it in a row of bread board. Subsequently, whenever you need to ground a connection, you just connect it to that row. But how it is done on a PCB? PCB is not connected to any ground line and everything that needs to be grounded is grounded on the PCB itself. How to ground things on a PCB? Here is my understanding. Please correct me if I am wrong or add your own. Thanks
You can leave the copper on the bottom layer. You can then use this copper layer as your ground and connect any connection that needs to be grounded to this copper layer at the bottom. Right?
You can leave some copper on the top layer and use it in a similar manner to connect GND connections to it. Right?
What are the considerations, techniques, tips, etc for creating and dealing with grounding components?
You can simply run nice fat ground tracks around the board, on both sides if necessary. Alternatively, use copper pour on one or both sides of a double-sided board. For RF circuits, it’s a good idea to have one side as a ground plane, with all the tracks on the other side.
Another technique, which was popular when boards had lots of TTL or CMOS logic chips, is to use a gridded layout of power and ground tracks.
Paying a lot of attention to the ground and power connections is essential, always route them first.
leon_heller:
You can simply run nice fat ground tracks around the board, on both sides if necessary. Alternatively, use copper pour on one or both sides of a double-sided board. For RF circuits, it’s a good idea to have one side as a ground plane, with all the tracks on the other side.
Another technique, which was popular when boards had lots of TTL or CMOS logic chips, is to use a gridded layout of power and ground tracks.
Paying a lot of attention to the ground and power connections is essential, always route them first.
Leon
Thanks for response.
I understand what do you mean, when you say running ground track around the board. This is good when you connect the board to an outside power supply which has a gound line. But suppose you are using a coin battery. What to do in this case?
What about the size of the copper area used for grounding/ Is there any kind of rules or formulas to decide on the area/size of the copper pour? Thanks
Just connect the negative terminal of the cell to the ground tracks.
I normally use 50 mil wide tracks for ground and power.
Copper pour should cover as much of the board as possible. You might need some additional tracks and vias to make sure that you don’t have any unconnected ground pins. I always generate a net completion report to make sure that everything has been connected. If there are any split nets or unconnected pins I go back and adjust things until it is OK.
You can always post your layout here for comments, before you get your board made.
Since most of the time, I fabricate my own PCBs at home, I tend to use any unused board space (on both sides, if a 2 sided board) as copper pour, which is all connected to ground. This makes the etchant last much longer since there’s less copper to etch away than if running a simple set of ground tracks.
A nice fat ground like this is especially important with an IC with lots of signal lines to mitigate ground bounce problems (along with proper decoupling, of course).