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 ?
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.
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).
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.
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?