PCB manufacturers with heavy copper

[rtarbell]

Does anyone know of a PCB manufacturer that offers heavy copper (i.e. 3 oz. or heavier) as an option for PCB boards? It seems that most only offer 1oz. copper (or lighter) these days.

[mwmkravchenko]

http://dkc3.digikey.com/PDF/C053/1463-1465.pdf

They have up to 4 oz

Mark

[pinkmouse]

Soldering to 4oz copper would be troublesome. Why do you need to go so high?

[peranders]

Unless you don't want the pcb's to be dirt cheap most manufactures can offer thicker copper. There are often conditions involved to get cheap boards, like thin copper, small boards, few holes etc.

[peranders]

Originally posted by pinkmouse
Soldering to 4oz copper would be troublesome. Why do you need to go so high?

Very right Use only as thick copper as you really need, not for -ish reasons.

0.1" wide trace 1 oz. copper can take 10-15 A and burns off at 25-30 A

[rtarbell]

Thanks for the replies! I'm looking for heavier copper because I want to solder my output transistors directly to the PCB board (i.e. no wires going from the PCB board to the transistors on heatsinks), but I often wonder if the copper itself is thick enough to take high current pulses.

What I've done in the past is soldered bare solid wire on top of the high current traces so that they combine for an effectively thicker trace, but sometimes this isn't always possible due to getting the wire in small spaces, so I was considering going to thicker copper.

[peranders]

1 oz. copper will do in most cases. Remember that 150 mil = 15-20 A.

[JensRasmussen]

Generally PA is right, but it all depends on how hot you like your traces.

I like to keep loses low, so I use 2,5 - 3 oz CU on my power PCBs

\Jens

[peranders]

Personally I would choose 95 um (70 + 25) for a power amp pcb.

Two reasons:

1 You don't have to worry about burning traces in case of fault.

2 Greater possibility to reduce unwanted voltage drops.

(For me it's the same price so it's only a matter of choice.)

The only thing you have to consider is the "solderability". You must make "heat relief" pads.

rtarbell, have you seen Jens' Leach pcb? Check his homepage.

[dmfraser]

I design power amps past 1KW and I use 2 oz copper on the boards. The widest trace I have room for is 0.175" wide, which I feel is not heavy enough at CSA/UL will no longer allow a trace to fail if the output devices are shorted.

To get my traces heavy enough, I just put a line in the solder mask layer so that those traces have no solder mask over them. When the board is wave soldered, it picks up solder along its entire length, effectively doubling to tripling the thickness. I've never had a trace failure since.

On a hand soldered board, just melt a layer of solder along the entire length of the trace where high current will flow.