Rectifier bridge, high-end style

Even though filled with copper or anything the connection area to inner layer is still limited by the hole diameter and copper thickness.

Example: hole diameter 2mm, copper thickness 35um
pi * 2mm * 0.035mm = 0.2mm2

I wouldn't use 0.2mm2 wire for 300 amps.

Another thing are those thermal reliefs with 10 mils tracks (estimated from the picture peranders posted). Those are not 300A stuff either.

You misunderstood me somewhat. It was 300 A in total and approx. 27 A / cm of the board. I had 44 pcs. 220 A mosfets in a H-bridge and I used no thermopads. The reason for so many fets was to reduce the power dissipation.

jdbakker, I agree with you in general. As I write, the prototype boards are yellow just because I was curious how it looked like. The group buy order will be red.

In the rectifier board you posted (and which we are talking about) you are using both inner layers for large currents as well as thermal pads with super thin traces. I wouldn't use that kind of board even for 1 amp current (see my arguments in the previous posts).

Those are the bottlenecks of your design, not the 1/2/4-layer question.

The thermopads have 4 x 20 mils in the crosses times 2 and only 15 mils long. Current per trace in the pads are in average 1.87 A (in a 20 mils trace with good cooling)

I told you my arguments (see the previous posts). That is all I can do.

I highly recommend to rethink your design. I believe your goal is to give your customers best possible products. My opinion is that the current version has some serious weaknesses. But it is of cource up to you what you decide to do about them.

audiox said:

I highly recommend to rethink your design.

Click to expand...

We are only concerned about the color of the PCB here. Because it's what matters.

PS. I find it refreshing to see such pure "hifi" angle on audio on this forum. Kind of puts things to perspective.

Kingston said:

We are only concerned about the color of the PCB here. Because it's what matters.

Click to expand...

;D ;D

Kingston said:

We are only concerned about the color of the PCB here. Because it's what matters.

Click to expand...

yes, yellow is reserved to GDIY51X projects 
but since the production run will be red all is fine  ;D

I think it works even better if you use one of those expensive gold plated mains connectors!  ;D

We only care what color the PCB is?  Is this Gearslutz now?  ;D

[silent:arts] said:

yes, yellow is reserved to GDIY51X projects 
but since the production run will be red all is fine

Click to expand...

Ahh.. you liar.
There is yellow and _yellow_.
For painting my boards, I use only virgin's blonde hairs.
And I can assure you, I have a live, crisp and pure sound with these boards.

audiox said:

In the rectifier board you posted (and which we are talking about) you are using both inner layers for large currents as well as thermal pads with super thin traces. I wouldn't use that kind of board even for 1 amp current (see my arguments in the previous posts).

Click to expand...

Could you explain how you see at 1.87 A in 20 mils traces which are 0.5 mm long? What theories are you referring to?

How does your board look like for 1 ampere currents?

BTW: I have made red boards for the group buy.