Hi

I am designing 4 layer PCB (Induction heating system).
I have 100 AMP current in a portion of my design. The application is Induction heating system for the soldering of metals. So, my supervisor suggested me to use copper area in 4 layers in high current path. I have a doubt. As I am using copper area in 4 layers in high current path. Is it not wrong to to use copper area in GND layer for current carrying. As the GND layer should be used for grounding purpose. of couse I am not assigning the copper area of ground layer to the net (GND).

Regards,
Vivek Alaparthi

 

Middle layers have lower current carrying capability than the outer layers because they are stuck in the middle of the board and have little cooling.
I don´t know if this is some kind of school assignement or something, but in normal situation I would never even try to pull 100A through a PCB unless absolutely necesary. You would need very thick copper and wide traces with many connection points to get a reliable link. Why don´t you simply put the high current stuff away from the board, use something like copper bus bars to make the resonant circuit and then connect the drivers to this? Or even have the drivers + resonant capacitors on a separate assembly, and the control circuit on its own pcb, but close to the drivers to drive them properly?

 

I run 100 Amps through copper traces all day long..
I use double sided 3 oz copper (4 oz after plating) PCB and a 1" wide trace on both the "exterior layers" (back to back). Expect around a 40-50 deg C rise over ambient.

Assuming dissipation in that area is only the trace dissipation its not a problem.. Now put some high dissipating components in that area and heat WILL be much more of a problem.

 

Hi mcgyvr,


Thanks for your reply.

I will use specifications you have given to me.

But can you please tell me what is copper plating????

And what is the need and use of plating for copper area or traces???



Regards,
Vivek Alaparthi

 

Hi mcgyvr,


Thanks for your reply.

I will use specifications you have given to me.

But can you please tell me what is copper plating????

And what is the need and use of plating for copper area or traces???



Regards,
Vivek Alaparthi

Well my boards are through hole so a plating process is used after holes are drilled to deposit copper into the barrels of the though holes.

PCB fabrication houses can also plate more copper onto a board vs starting with a heavy copper laminate.