The following dimensions will be on the cold plate only, and not including the solderd-on heat pipes. The bottom side of the cold plate is recessed - maybe due to shielding - but anyhow, if you assume the corners are not radiused, this cavity is 1.25" by 1.8", or 31.5 mm by 100 mm. The depth of the cavity is 0.03655" or ~0.9284 mm. The external thickness of the cold plate is 0.11585" or 2.9426 mm, including paint.

Here by thy mini

Upon opening up the mini, I was greeted by the heatsink and, despite knowing that it was not performing up to snuff, it was obviously designed and went through a couple of iterations.

The heatsink has about 10 mm of room to be maneuvered out of it's mounting path thanks to the RAM slots. The chamfer is to aid with the removal and installation. Also, due to this low profile, there is a large chunk of metal milled out of the center to accommodate the heat pipes.

The stock TIM is applied evenly and fairly well, but reputedly it has a low conductivity. One thing that I did not were the complimentary RF gaskets around the CPU, both on the heatsink and the PCB. The unpainted copper on the heat pipes mate with conductive foam on the ground plane. 2 of the 4 screws that how the finned portion of the heat sink to the PCB have the same contacts. The heat sink's cold plate retention leaf springs mount against solid hunks of metal that allow for a wear surface and pre-load for the springs, which are also grounded. The large holes for the 2 T-10 screws that hold the PCB/motherboard/logic board against the Unibody chassis have inserts in them and are also on the ground plane.

This computer has more ground contact points than my 300 MHz oscilloscope. It does make a bit of sense with 2-3 GB/s solid state storage, 2.667 GHz memory inside an RF cage, and a 4.3 GHz CPU. Despite the frequencies, this whole thing is grounded and shielded as much as possible.

But I've digressed...

Heat and thermal cycling have left microscopic surface defects in the CPU die, pictured above. They are visible only due to the similarly microscopic beads of water from my warm breath. This rough patch indicates the closest surface of the die to the heat sink. This theory was confirmed when I re-pasted with PK-3 TIM and started running the thermal load again only to have 3 of my 6 cores 8-10 ˚C cooler than the others. Looking at the PK-3 paste on the cold plate and the die confirmed this.

I flipped the heat sink image so visual comparison would be easier.

Judging from the placement of the memory, the die's orientation can be inferred. It is confirmed from the aforementioned inter-core temperature deltas, thus if you overlaid the image in the previous link onto the die shot of the last image, you can identify the location of the specific, um, zones?, of from Intel's false-color imagery. This matters when lapping the heat sink's cold plate. More on this later.

Stock Heat Sink Cold Plate

The following dimensions will be on the cold plate only, and not including the solderd on heat pipes. The bottom side of the cold plate is recessed. Maybe due to shielding, but anyhow, if you assume the corners are not radiused, this cavity is 1.25" by 1.8", or 31.5 mm by 100 mm. The depth of the cavity is 0.03655" or ~0.9284 mm. The external thickness of the cold plate is 0.11585" or 2.9426 mm including paint.

Now, recall how I mentioned, and you can see in the first photos, that the heat pipes sit in a recessed section of the cold plate? I don't have a blade anvil attachment for my micrometer so I cannot measure the thickness of the aluminum and copper in that area. Around it, however, I measured 0.08" or 2.032 mm for the Al, and 0.08045" or 2.0434 mm for the Cu, which means that area is definitely a lot thinner. Remember this.