I have designed a PCB for motor control. On this PCB there is a power part and a logic part.
The power part is composed of MOSFETs, MOSFET drivers, hall sensor for current feedback and some protections (resistances, diodes…). The logic part is based on a Teensy (a logic board with an ARM Cortex-M3), some Phoenix connectors, voltage dividers, etc. There are also switching regulators to power the logic.
This is a two-layer board with no internal layers. The tracks for the power part are 6 mm width, those for the logic are 1 mm width. Clearance between tracks is at least 0.2 mm. The board has been tested with a 35 um copper thickness and except for some interferences, present on the logic when the motor draws current, the board is working well. Up to now these interferences are software corrected (median filter).
I want then to make the board with a 70 um copper thickness, to be able to pass more current to the motor.
Questions and ideas:
What will happen to interference, if I change from a 35 um copper thickness to a 70 um one (for all the board, so power and logic will be changed to 70 um)?
I think they will increase because the sensitivity of a track to interference, depends on its section and length (wider and longer mean more subject to interference for me). True?
Do you think I need to increase my clearance? If yes, to which value?
I think it also depends on the MOSFET frequency commutation compared with track length (resonance…).
Any help will be greatly appreciated!