I’m having trouble in finding a relay that supports 440v-6A supply (For a single phase motor), i don’t know what material to use as trace in pcb design for such voltage.(besides FR-4) Can you guys suggest me a good trace material and relay?
This is a switching voltage and current. What about coil parameters (coil voltage)?
Here you can choose your relay by filtering parameters you need:
Please check this article about High Voltage PCB design: https://resources.altium.com/pcb-design-blog/high-voltage-pcb-design-tips-materials-for-high-voltage-pcbs
But I would say that 440V is not a very high voltage so just a regular FR-4 (about 50kV dielectric breakdown according to wikipedia info) can be a good choice here.
Of course you should order a 35 micron copper foil (it should be available on any PCB mfg).
If you not so sure - you can choose BT-epoxy or Isola but I think that could be quite expensive.
General tips for routing: route high voltage conductors only on one of the PCB sides - do not place different potential conductors one above the other from the different board sides (top/bottom). If you route high voltage traces at top layer - keep bottom layer clear from any copper.
To calculate an appropriate conductor spacing you can use this freeware tool: http://www.saturnpcb.com/pcb_toolkit/
This is the tab you need:
unfortunately it can only calculate it for FR-4.
Conductor properties tab can help you to select an appropriate conductor width for your design:
To quickly estimate what a conductor width we are talking about (at 6A) you can use this graph:
this means that for 10°C temperature rise at 6A using 35 micron copper foil you need to have at least 4mm track width.
Please let me know if you have any questions.