Where is the best location for Ground Plane (when there are two layers only)?

[card_claud]

Hi all !

Could anyone tell me where the best location for ground plane is, when I am using 2 layers only? (Bottom and Top).

Thanks

Added after 47 minutes:

I meant what is the best side to make the ground plane, Top or Bottom.

thanks

 

[Old Nick]

Re: Ground Plane

Both!

 

[zhl_gs1980]

Ground Plane

TOP IS bottom!

 

[taymoor2000]

Re: Ground Plane

both sides

 

[card_claud]

Re: Ground Plane

This board I doing now, has a Microcontroler, a Operational Amplifier and Optical Isolator.
Well, I have been doing the ground plane on top and I have never gotten problems, but now I wonder if I was doing right.

When you all said both, you meant that side doesn´t matter ? Can I mix the two sides, I mean ... in some area doing ground plane on top, in other on bottom ?

Thank you all very much!

 

[andre_luis]

Re: Ground Plane

Every free area must be filled with metalic plane connected to ground.
There are no constraints to perform at both sides, instead, it increase noise induced supressing cabability.

 

[rosu]

Re: Ground Plane

You can have ground planes on both sides, but if you have an analog ciurcuit and a digital one on the same board it will be advised to have 2 ground planes, one for the opamp circuit and one for the uC, connected in one point close to the power supply, after the main capacitor and I foud that placing capacitors after the common point it will reduce noise propagation between the 2 planes. Also you should make the power traks as wide as possible and you may want to separate them as well(for analog and digital).

 

[jayasuryan]

Re: Ground Plane

Preferably you can use both side as Ground Plane in two sided PCB....

 

[eswar_babu77]

Re: Ground Plane

If you have critical components placed on one side have the ground plane in immediate next layer. Also in case of high speed signals you have to consider layer choosen for routing of high speed signals, in which case u need to have a ground plane there also.

 

[eoasap]

Re: Ground Plane

Both. I'd also be sure to use guard traces around sensitive lines or high speed lines.

 

[prasad5551]

Ground Plane

hi,
i want to know about the microstrip and stripline aswell. split pwr plane pls

 

[dog1357]

Ground Plane

May I know whether I need to put a lot of via connected to ground so the ground plane from both sides will be connected?
If the ground via is put near 2.5Gbps signal line, will it improve the PCB performance?

Thanks very much!