Soldering technique for high current IGBT

Thread Starter

mtabadi2524

Joined May 2, 2021
9
Dear Sir/Madam,

I am going to design a printed circuit board with four Insulated Gate Bipolar Transistors (IGBT) with following specification:

Type: IKW40N120T2
Maximum collector-emitter voltage: 1200V
Maximum DC collector current: 72A
Maximum DC Diode forward current: 72A
Dimension: Shown in the attached file

Please let me know the suitable technique to attach and solder such IGBT to PCB.
1.jpg
 

Thread Starter

mtabadi2524

Joined May 2, 2021
9
The usual way (with solder) and traces sized to handle the current. Allow room for a heat sink if power dissipation will be high enough for one to be required.
Dear Dennis,
How should I connect the collector and emitter legs to the tracks of PCB? Is there a common and reliable procedure?
 

SamR

Joined Mar 19, 2019
4,292
Depending on power, you will find some that have wider traces on the board. Sometimes with a thickened layer of solder in addition to the trace. Anything greater that that is bolted onto the chassis for grounding/heatsinking and wired using heavier gauge wiring.
 

UweX

Joined Sep 2, 2020
17
Another point to take care of is the distance between the potentials. 1200V or something close to it will not work reliable with the minimum distance the pcb-manufacturer can handle. So collector on top layer and the emitter on bottom layer may be a good idea. Usually you also have some options for copper thickness. Using maximum thickness can avoid using thicknessing the conductor with solder. But all that can be calculated with some online calculators.
 

MisterBill2

Joined Jan 23, 2018
12,399
READ the specification section very carefully because that current rating is ONLY for some very specific condition, which is probably much different from your application.
Also know that voltage drops at high current can not be ignored, and that at high currents everything has a voltage drop. And those "small" voltage drops do add up, often to unanticipated levels. I speak from bitter experience.

So the cross-section of the entire connected conductor needs to be able to carry the current without excess voltage drop or excess heating. Using the standard rules for connections will result in an inadequate solder connection because of the normal hole clearance. The legs of the device will need to be bent over against the copper trace prior to soldering, and standard wave soldering may not be adequate.

And the voltage drop is instant, while heating effects will take a few milliseconds.
So while a part can survive a one millisecond pulse of 72 amps, the safe steady state max current for the circuit is probably a whole lot less. I am guessing that the one who designed the circuit is not the one who designed the circuit board.
 
Last edited:

MaxHeadRoom

Joined Jul 18, 2013
25,469
As others have mentioned, on increasing the load trace, if it is found it is needed, I have also used copper solder wick in order to reinforce said traces.
 
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