PCB manufacturers with heavy copper

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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.
 
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.
 
Thicker foil substitute

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.
 
peranders said:
Does it mean that you ever have burned off 176 mils 2 oz. traces? If yes, haven't you got any fuses?

Those trace widths are good for 30-40 A continuously.

Some aplifiers dont us B+/B- fuses. My SWR bass amp, in fact i dont think ANY SWR bass amps use B+/- fuses. when the outputs failed and shorted, it started the PCB on fire!

SWR felt that adding fuses would lesson the performance of there amp. so they omitted them!

I also have 2 DEAD and i mean DEAD, Crest VS450 amps here that the PCB's are charred to a crisp!

Personally i like heavy, thick traces, thanks DM for the tip! that is something i definitly will be incorporating.

I had been considering bonding a thin copper sheet to a bare PCB with some epoxy and using an engraving machine to route out a PCB. it would have to be a simple PCB like an output board or a PSU board.

We have an engraver at work for milling out labels and signs in dual layered colored plastic. it accepts a vector format like what you would output in Adobe Publisher.


ZC = Thinks too much.
 
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