I'm new to PCBs greater than 2 layers as well as 230V incorporated onto a PCB so pleased bear with any ignorance:
I have a 4-layer board with the following setup.
1st layer = components / signals
2nd layer = ground
3rd layer = Power plane consisting of 5V, +12V and -12V
4th layer = signals
Board is basically a controller for a CCTV. 5V is powering a microcontroller, +/-12V is powering op amps which control signals for a camera. No high speed signals on board. Questions are:
Is it ok to have the 5V, +12V and -12V signals on one power plane?
I have 230V supplying the circuit, I plan to have the 230V traces all on the bottom layer and on one side of the board, I will be using 6mm spacing between traces, vias etc. Standard electrical safety standards for Europe, board is not for resale. Is this ok to be safe and avoid potential arcing?
I presently have 9 mil (default on software) as the thickness of each substrate between the 4 layers, is that thick enough to avoid 230V issues?