Paste Computer Systems K5 Pro
Product Images
General Information
Manufacturer Specifications
Notes and Recommendations
Measurements
Material Testing and TIMA Protocol (on request)
Microscopy and Particles
Measurement Process
Thermal Resistances Rth
Thermal resistance Rth correlates linearly with layer thickness, unlike thermal conductivity, which follows a non-linear curve. Layer thicknesses below 1000 µm are typically relevant for memory, whereas VRM applications may range from 1500 µm to 3000 µm depending on the heatsink design.
I have compiled a bar chart comparing relevant layer thicknesses from 250 to 3000 µm for Rth.
Minimum Possible Layer Thickness
This is exactly why I wanted to find out how far one can go with a bit of pressure and how much a putty can still be compressed. Here, I use the usual 9N pro cm², which is more than sufficient and exceeds the pressure typically achieved by, for example, a GPU cooler.
Effective Thermal Conductivity and Cooling Simulation
If Rth is already available, one wouldn't actually need λeff, the effective thermal conductivity. We can also observe how the values change across the BLT, although one cannot expect a linear curve due to the included area and BLT.
I have again illustrated the relevant layer thicknesses from 250 to 3000 µm as a bar chart for λeff for comparison.
Memory Simulation (VRAM)
First, we take the two temperatures at the two contact surfaces between which the paste is located and examine the difference (Delta). These curves are no longer entirely linear, as the interface resistance also changes. We now calculate using only two absolute values for the temperature difference instead of a gradient as with TTim, where the sample temperature remains constant at 60 °C. Why do this? The behavior is similar to that of the memory of a graphics card, which must function without an IHS and where the Delta between the substrate and the water or cooler temperature or air is measured. This can be projected quite well, as I test the temperature difference at the two surfaces between which the paste is located.
Voltage Regulator Simulation (VRM)
Now, I compare the surface temperatures of the tested products. When normalizing the values for the TIMA5 heater, we already have sufficient thermal resistance in the copper reference block to simulate the package of a voltage regulator chip (VRM). Depending on the thermal resistance of the putty, the temperature will either increase or decrease, much like what occurs on the VRM of a graphics card or a motherboard.
