Best busbar materials?
nzoomed, Wed Nov 04 2015, 10:38PMWould you use copper or aluminium for the busbars on your IGBT's?
I know that copper is a better conductor than aluminium, but aluminium dissipates heat alot quicker.
Thanks for any advice.
Ive almost got the drawings finished in solidworks to get CNC cut.
Re: Best busbar materials?
Houdini0118, Wed Nov 04 2015, 10:54PM
I think copper dissipates heat faster as well. It is quite a bit more expensive. Typically for aluminum you want 6061 for bus bars as far as i know. Aluminum might come out cheaper for the same performance because you can use much thicker pieces for the same cost.
Houdini0118, Wed Nov 04 2015, 10:54PM
I think copper dissipates heat faster as well. It is quite a bit more expensive. Typically for aluminum you want 6061 for bus bars as far as i know. Aluminum might come out cheaper for the same performance because you can use much thicker pieces for the same cost.
Re: Best busbar materials?
nzoomed, Wed Nov 04 2015, 11:22PM
Im making a laminated bus. With copper i dont have to use as thicker material because of its better conductivity, so there is always a payoff. Each have their own advantages i guess.
Copper can also be soldered to as well.
nzoomed, Wed Nov 04 2015, 11:22PM
Im making a laminated bus. With copper i dont have to use as thicker material because of its better conductivity, so there is always a payoff. Each have their own advantages i guess.
Copper can also be soldered to as well.
Re: Best busbar materials?
..., Thu Nov 05 2015, 08:33AM
Aluminum quickly forms an insulating oxide layer, so it is not as easy as one might expect to get a reliable, low conductance, connection to it. Usually you can get away with just cranking down on the IGBT bolts since the aluminum is soft enough that it will deform and break the oxide layer, but people using aluminum bussbars in commercial applications go to ridiculous lengths to get reliable connections involving special star washers which penetrate the surface, special greases to prevent corrosion, etc.
Where as with copper you just bolt or solder it together (possibly clean it up with some sandpaper if the surface is highly corroded).
Also as mentioned, the resistivity of aluminum greatly depends on the alloy, pure aluminum is ~1.5x as resistive as pure copper, and 6061 is ~2.3 times as resistive as pure copper (by volume, the relative ratio of aluminum/copper is of course different if you go by weight)
..., Thu Nov 05 2015, 08:33AM
Aluminum quickly forms an insulating oxide layer, so it is not as easy as one might expect to get a reliable, low conductance, connection to it. Usually you can get away with just cranking down on the IGBT bolts since the aluminum is soft enough that it will deform and break the oxide layer, but people using aluminum bussbars in commercial applications go to ridiculous lengths to get reliable connections involving special star washers which penetrate the surface, special greases to prevent corrosion, etc.
Where as with copper you just bolt or solder it together (possibly clean it up with some sandpaper if the surface is highly corroded).
Also as mentioned, the resistivity of aluminum greatly depends on the alloy, pure aluminum is ~1.5x as resistive as pure copper, and 6061 is ~2.3 times as resistive as pure copper (by volume, the relative ratio of aluminum/copper is of course different if you go by weight)
Re: Best busbar materials?
nzoomed, Thu Nov 05 2015, 10:41AM
OK, that answers what i was suspecting.
I think i will go with copper.
nzoomed, Thu Nov 05 2015, 10:41AM
... wrote ...
Aluminum quickly forms an insulating oxide layer, so it is not as easy as one might expect to get a reliable, low conductance, connection to it. Usually you can get away with just cranking down on the IGBT bolts since the aluminum is soft enough that it will deform and break the oxide layer, but people using aluminum bussbars in commercial applications go to ridiculous lengths to get reliable connections involving special star washers which penetrate the surface, special greases to prevent corrosion, etc.
Where as with copper you just bolt or solder it together (possibly clean it up with some sandpaper if the surface is highly corroded).
Also as mentioned, the resistivity of aluminum greatly depends on the alloy, pure aluminum is ~1.5x as resistive as pure copper, and 6061 is ~2.3 times as resistive as pure copper (by volume, the relative ratio of aluminum/copper is of course different if you go by weight)
Aluminum quickly forms an insulating oxide layer, so it is not as easy as one might expect to get a reliable, low conductance, connection to it. Usually you can get away with just cranking down on the IGBT bolts since the aluminum is soft enough that it will deform and break the oxide layer, but people using aluminum bussbars in commercial applications go to ridiculous lengths to get reliable connections involving special star washers which penetrate the surface, special greases to prevent corrosion, etc.
Where as with copper you just bolt or solder it together (possibly clean it up with some sandpaper if the surface is highly corroded).
Also as mentioned, the resistivity of aluminum greatly depends on the alloy, pure aluminum is ~1.5x as resistive as pure copper, and 6061 is ~2.3 times as resistive as pure copper (by volume, the relative ratio of aluminum/copper is of course different if you go by weight)
OK, that answers what i was suspecting.
I think i will go with copper.
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