High current PCB mounted busbar

[RowanSB]

I have a requirement similar to thread820-286770. I'm designing a PCB which drives 64 solenoids. Each can take up to 0.9A at 18V, and half of them can be on at once giving a peak current of 28.8A. I need a way of carrying this current which doesn't rely on the board tracks. I am imagining a laser cut or chemically etched copper busbar say 0.5 to 1mm thick, with "pins" formed every 20mm or so which could be soldered into holes on the PCB. I haven't been able to find anything off-the-shelf to do this. I've found one or two people who would make them for me, but in small quantities the price is excessive (about £16 per busbar for 12 off).

Does anyone know of anything that would do this job that's available off-the-shelf (and that's less labour intensive and neater than just soldering thick tinned copper wire to the power and ground tracks on the PCB)?

Or does anyone know of a cheap process or supplier for custom copper sheet products like this?

Or can you think of a better way of solving this problem?

Many thanks - Rowan

 

[itsmoked]

You can use solder-in studs. Then drop a drilled piece of copper on them and nut them down.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[RowanSB]

Thanks for this idea. Sounds like it would suit a larger busbar than I need though. Presumably you mean a stud that can be soldered into the baord, and that is threaded? Who makes these, and what's the smallest available?

I only need a busbar 1mm x 5mm (or it could be even smaller, possibly 0.5mm x 5mm), and the pins through the board only need to be 0.5 to 1mm in diameter. And it would be better if the busbar stood on edge on the board rather than lying flat, so it takes up less space. That's why I was thinking of a chemically etched or laser cut copper strip "with legs on". From my researches it sounds like laser cutting is not likely to be viable (copper seems to be notoriously difficult to cut via laser, and even those who have offered this have quoted prices much higher than chemically etched parts). So at the moment a custom, chemically etched part seems the best option. It's still very expensive in small quantities though.

I'm still surprised that I haven't found a more cost effective off-the-shelf busbar at a much lower cost. It seems like this is something that might often be needed on high power PCBs.

Rowan

 

[itsmoked]

Now I can't find the studs I've seen before..

Keep in mind that what you want to look for is "board stiffeners" not buss bar. Buss bar is almost always custom, whereas stiffeners are not.

You might also consider just using solid wire dropped in holes along the Big Trace. Bend them like large copper staples. They would just be wave soldered with everything else. You can get that almost anywhere as it's used as ground wire. (Local hardware stores, Home Despot, etc)

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mcgyvr]

http://www.cci-msc.com/Rigidbus/pdf/rigidbus.pdf

 

[StrykerTECH]

We have done that type of stuff. Generally we would get them water jet cut and then have them tin plated to prevent corrosion.

StrykerTECH Engineering Staff
Milwaukee, WI

http://www.stryker-tech.com/