Canon looking to improve heat sinking for mirrorless cameras.

In this patent Canon discusses ways of improving heat sinking around the stacked electronics board behind the sensor and the sensor itself.

As you can imagine, the "processing" side of the sensor generated more heat than the "imaging" side of the sensor, because the processing side is doing all the real work :) 

They show what appears to be an EOS-M6 leading one to believe that this is a problem domain they are looking at for the much smaller cameras and methods to sink heat away from the sensor.  This would certainly be necessary for 4K and other imaging applications, not to mention to reduce high ISO noise, and amp noise.

This patent also in great and incredible detail shows the exploded mechanical layout of such a sensor mount.   The amount of detail really leads one to believe that this is soon to be a reality. 

From the patent application;

An element substrate by which the aforementioned image sensor is mounted in the object side which becomes the transverse-plane side, and an electronic component is mounted in a back side, 
An element holder positioned and fixed to the aforementioned image sensor, 
A base member to which the aforementioned element holder is fixed by screw member, 
It has a heat sink of the aforementioned element substrate which contacts a back face at least, and has a radiating member fixed to the aforementioned base member by the aforementioned screw member with the aforementioned element holder, 
An imaging device, wherein the aforementioned heat sink is arranged so that it may not project on a back side of optical axis direction from the aforementioned electronic component. 

Japan Application 2017-169176

Some more organic sensor patent applications Canon patents a 17-35 IS 4-5.6