Soldering will work fine as long as you have enough cross section to carry the current.
But my concern is that the leads you are attaching will be quite heavy.
Solder is never a mechanical connection! So many clever engineers have been fooled by this because it seems non-intuitive. After all, the joint seems to be pretty strong right after its made. AND, you can actually get away with using it as a quasi-mechanical connection for through holes. This is because one of the fillets on a through-hole will be in compression, which works pretty well. But eventually even this will fall apart in a few years, depending on stress level.
The problem is that solder is too close to its melting point at room temperature. So it is annealing continuously, but it takes long enough that the average person is bored waiting for it to happen.
PCB traces really aren't held onto the board very well either.
If you can't through-bolt or otherwise anchor to the aluminum base plate, then you need to have a very low stress, low mass ribbon jumping the current from a nearby mechanical lug to the solder joint on the PCB.
Wayne Thayer
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Creswick
Sent: Wednesday, January 09, 2013 5:41 PM
To: [log in to unmask]
Subject: Re: [TN] 200A Connections to PCB
Robert,
This may be a bit too far out to be of use, but have you considered reactive nanofoils? Very much like Thermite in foil form instead of powder.
Used to be made by NanoBond, but appear to have been absorbed into Indium - http://www.indium.com/nanofoil/
Appear to still be limited to relatively low temps, but you might enquire.
You could prep the 'connector' off-line, then sandwich it to the board and foil, and initiate the reaction. Not sure how the resultant joint would hold up to the mechanical stress of your structure, but thought I would throw it out there and let you decide if it had merit.
My spark for the day
Steve Creswick
Sr Associate - Balanced Enterprise Solutions http://www.linkedin.com/in/stevencreswick
616 834 1883
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Robert Kondner
Sent: Thursday, January 03, 2013 10:32 AM
To: [log in to unmask]
Subject: [TN] 200A Connections to PCB
Hi,
I was wondering if anyone had suggestions about making high current connections to a PCB.
I am working with a design for a 2KW DC to AC converter. Input current will reach about 200 amps. The PCB will be a heavy copper single sided Aluminum PCB much like that used for high power LED apps. Conductor temp rise is not an issue as the thermal conduction to the Al base is very high and the base is on a heat sing. The FETs will dump much more heat than the copper.
The problem is bringing wire terminations to the PCB. Any Ideas? The Al base is applied against a heat sink so using through board type studs or bolt is difficult. I am considering the use of a couple of Keystone screw terminals with their legs cut off. The bodies could then be SMT reflowed to the copper planes.
http://www.keyelco.com/products/specs/spec186.asp
Any other ideas out there?
Thanks,
Bob K.
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