Extreme copper p.c.b.s

These guys can make pcbs with selective 30oz. copper on FR4...very cool. I possibly could've used this last year on my 500A switch.

I couldn't find a direct link or any decent equivalent articles on the web...load the digital version here, then search on "extreme copper":

formatting link

See fig. 2, pg. M6.

--
Cheers, 
James Arthur
Reply to
dagmargoodboat
Loading thread data ...

Can they do 5/5 mil traces and spaces?

--
John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
 Click to see the full signature
Reply to
John Larkin

://dc.ee.ubm-us.com/i/112771

I wonder what sort of copper to insulator ratio's they can get in printed transformer windings? They might be able to do better than round enamelled copper wire for low resistance windings.

--
Bill Sloman, Sydney
Reply to
Bill Sloman

They say they can make 200oz (which is over 7mm/0.28" thick)! That's a fairly hefty bus bar, and might be challenging to solder.

No online pricing over a few oz.

This presentation has more information, including the limits on spacing etc..

formatting link

Starting with 1-oz and going to 20oz (28 mils) final they recommend

0.04" minimum width and spacing minimum 0.029".
Reply to
Spehro Pefhany

a bit hard to do both at the same time ;)

I think the guide I've seem the limit is already something like 6/6 for 2oz, 12/12 for 4oz

40oz would be something like ~100 I guess

-Lasse

Reply to
langwadt

formatting link

formatting link

Interesting stuff. The article does talk explicitily about plated windings for transformers, but the web-site doesn't seem to, though I'd imagine it to be an appreciable fraction of their business.

The point that extra-thick copper is a lot more resistant to thermal cycling came as a surprise - presumably it's thick enough to accommodate differential expansion by deformation, rather than cracking.

--
Bill Sloman, Sydney
Reply to
Bill Sloman

What's the cost comparison against just using your classic PCB-style bus-bar? ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
 Click to see the full signature
Reply to
Jim Thompson

Advanced (4pcb.com) is also offering it. They got a new factory up in MN that does it, I think. I've heard of UPE before, too (owned by Methode, who make buses the conventional way).

The aspect ratios are pretty much the same, so don't count on making a 20 mil copper layer with 5 mil gaps and 5 mil prepreg. You might be able to get a 20 mil core between 10-20 mil copper, with 10-20 mil design rules.

Vias are similarly inflated, AFAIK, which probably means smaller ones are filled (or nearly so; probably want to check with them first to make sure it doesn't, say, trap electrolyte and corrode later on).

Tim

--
Deep Friar: a very philosophical monk. 
Website: http://seventransistorlabs.com 
 Click to see the full signature
Reply to
Tim Williams

tp://dc.ee.ubm-us.com/i/112771

I'm not sure. I wonder about the skin effect losses in thick plated copper. As another factor, the rectangular cross-section gives a good fill factor, but not if the multilayer construction adds too much space between windings.

So, could be pretty interesting, but I'm not sure. Somehow I suspect it's too pricey for casual uses.

--
Cheers, 
James Arthur
Reply to
dagmargoodboat

Yes, depending on who "they" is, and what "do" means. :-)

Reply to
dagmargoodboat

I don't know. I looked hard last year for bus bars and couldn't find any suitable standard products--they seem to have faded away. Lots of companies make custom, laminated, multi-conductor buss bars to your spec, but I couldn't find a simple, thru-hole part with 0.xxx"-spaced terminals.

I had to pass 1kA peak. Total resistance budget was 2 milliohms, with

1 milliohm allocated for the switch. Rather than mess around I spec'd a 3mm copper bar part, 12.5x30mm, surface-mounted. That served as conductor and connector, as posted here in sed. Commanded "closed," the proto measured 450e-6 ohms, terminal-to-terminal.

Here's what it wound up looking like:

bolt / washer crimp _ /_ / wire / _|_\/_|_/ ring terminal ______ |__|--|__| /

------| |------- |--| ---. copper bus bar, soldered to FR-4 .'.'.'| | \ \ \ \|--| \ \| /

------|_____|------- |--| ---'______________________. FR-4 | @ @ @|--|@ @ @ @ @ @ @ @ @ @ @ @ @ @| / |__@_@_|--|_@_@_@_@_@_@_@_@_@_@_@_@_@_|_____/ /________ |x| |__|--|__| |x x x x x x x x x x x x x / /x x x x x| | | /| |--| | | x x x x x x x x x x x x / /x x x x x | |x|/ |_|--|_| |x_x_x_x_x_x_x_x_x_x_x_x_/ /x_x_x_x_x_x| / '--' \ / / split nut . washer . . ||

--
Cheers, 
James Arthur
Reply to
dagmargoodboat

That in turn depends on what the meaning of "is" is.

It might be more economical to bolt [1] a PC board to hunks of copper or aluminum, in only the areas where you need a lot of current.

[1] very, very carefully.
--
John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    
 Click to see the full signature
Reply to
John Larkin

That's right, not clamping the board. FR4 will cold flow over time, especially if it warms up. The contact pressure will fall, resistance will increase, and you can get thermal runaway.

Somebody makes a huge stamped metal tapped lug landing thing that solders to a PCB through a bunch of holes.

--
John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    
 Click to see the full signature
Reply to
John Larkin

e

-4

-4

       /

/ /________

/ /x x x x x|

/ /x x x x x |

/x_x_x_x_x_x|

               / /
           .
            .
               .

ially

and

to a

look at something like this:

formatting link

claims hundreds of amps and it is press fit not soldered

-Lasse

Reply to
langwadt

e

I was thinking copper sheet etched or laser cut to the shape of the traces needed, might even be possible to place and solder with a more or less standard smd process

-Lasse

Reply to
langwadt

especially

a

Yeah. There's also a stamped inverted U shape with a bunch of pins formed into the bottom, tapped on the flat top part. That solders.

The problem then becomes to get the current distribution right on the board, and not have some of the pins hog most of the current. That needs a finite-element-analysis program to do right, but you can cheat with a big sheet matrix of resistors in Spice.

--
John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
 Click to see the full signature
Reply to
John Larkin

Should work if you give it some compliance, eg. a Belleville washer.

Reply to
Spehro Pefhany

I like wavy washers; they don't chew up the board as much.

Even better, solder in a bunch of fastons or a multipin Molex connector, and run a number of relatively smaller gage wires. It's more flexible, easier to handle, and the separate wire resistances tend to equalize the pin currents.

formatting link

--
John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
 Click to see the full signature
Reply to
John Larkin

Ugh! What about soldering it? Would you use an acetylene torch? Even a 2 Oz board gives me a headache with a good soldering iron.

Jon

Reply to
Jon Elson

That's what ovens are for. It gets to be a pain with RoHS but do-able.

Reply to
krw

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.