Trace Width consideration for DirectFET

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User14744
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My application: I'm building a H-Bridge for Brushed DC motor, that can handle a peak of 70A for a couple of seconds.
I have found the AUIRF7736M2 in a DirectFET M4 package. The transistor can handle my requirement with ease, the continuous MSOA peaking at 102A.
The problem is with the package, the M4's total width is 6.25mm and in that space I have to squeeze the source trace, the gate trace and the edge of the drain pad.
I'm left with a trace of around 4mm for the source. On a 2oz/ft^2 board, if I let the trace heat up 60°C over ambient I might be able to pass 25A. Nowhere near the transistors ability to handle 100A DC.
On other packages, like D2PAK I'm able to solder wires on top of the trace so that it can handle more current, but with DirectFET I have an area covered by the transistor itself where I can not add any wires.
Am I missing something or this transistor was not designed to be put on a "normal" PCB? I really like how well tested and documented these transistors are and would not like to switch to something else.
Datasheet
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Daisy_T
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Here is an application note about the DirectFET technology Thermal Model and rating; and there are some pictures about the layout for your reference.
https://www.infineon.com/dgdl/an-1059.pdf?fileId=5546d462533600a401535591e1940fc6

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Daisy_T
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10 likes given 250 sign-ins 250 replies posted
Here is an application note about the DirectFET technology Thermal Model and rating; and there are some pictures about the layout for your reference.
https://www.infineon.com/dgdl/an-1059.pdf?fileId=5546d462533600a401535591e1940fc6
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