hi,
1.single layer board routing will be done on one side.
2.double layer board routing will be done on both the side.(top layer, bottom layer)
3. four layer board-power,gnd,top,bottom.routing will be minimized with gnd & power tracks by pouring copper.
this is the usual method ,
copper pour can be filled for top,bottom.
try to use proper constraints for the gnd,power tracks.
u can use PCB tool kit to calculate the track width,distance etc.(for example dowload saturn a pcb tool kit)
or
u can go with 4 layer board.but the cast will be more when compare with 2 layer board
now decide what kind of layer u r going to choose.
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hi
which software ur using?