Re: What is the Difference B/W Hatch Cu and normal Cu in PC
AFAIK when you have a board that has lots of fine tracks on a layer, if you put solid ground plane in the un-used spaces, this can cause etching problems, also heat problems when going through processes.
For etching (home prototypes) , what can happen is that while etching if you have a fine track running near to lots of copper you can find the fine track etches away before the copper edge.
If say you have fine tracks & SMT on one side and then solid ground plane all over the other side and you put this board through a heating process, what can happen is the board will warp/bend because of an imbalance in the copper on each side.
Changing the ground plane to hatched can reduce/improve this problem.
A hatched ground plane will perform quite well for EMC (unless your into the Ghz ranges).
I have used hatched often (Esp on double sided SMT boards), but I always add little bits of copper around pads & vias or ensure that they are within the square of the hatches to ensure they have the maximum amount of copper attaching to them.
Roland.