base plate

CKoeglsperger

Hello,

we're wondering about the shape of the baseplate for the module CAB450M12XM3.

It's more like convex by more than 0,25mm. If we mont it on a planar aluminium cooler it will be deformed to the planar shape of the aluminium cooler.

We had look to 5 pcs. of the CAB450M12XM3. Every CAB450M12XM3 showed the same.

What do you think about this? Is there any reason for this shape?

AustinC

Hello,

This is a feature common to most power modules with baseplates and is not unique to the XM3. The slight baseplate convexity guarantees a consistent connection between the baseplate and the cooler when the module is bolted down. The metal-to-metal connection between the module and the cooling system provides the lowest thermal resistance when compared to the thermal interface material, so the amount of contact area between the two metal surfaces is maximized with the convex baseplate. In contrast, if there were a slight concavity to the baseplate, then there would be a much larger gap under the module that must be filled with thermal interface material and the overall thermal resistance would be significantly increased.

Austin C