EMZETT.Thermal pads
In short: Thermal pads are soft, heat-conducting silicone sheets that pass heat from a component (for example memory chips, voltage regulators, M.2 SSDs) to a heat sink. They bridge gaps where thermal paste would be too thin.
In more detail: Between two metal surfaces microscopic air gaps remain. Air conducts heat poorly. Pad or paste fills them with a better conductor. Pads are thick, clean and simple; paste conducts better and is thin.
In Depth
| Thermal paste | Thermal pad | |
|---|---|---|
| Form | viscous paste | solid, soft sheet |
| Thickness | wafer-thin (0.02 – 0.1 mm) | 0.5 – 3 mm and more |
| Thermal conductivity | 5 – 14 W/mK (liquid metal up to 70) | 3 – 17 W/mK |
| Use | between CPU/GPU die and cooler | Memory, VRM, SSD, case, where gaps are larger |
| Applying | Pea or line, spreads when mounting | Cut to size, lay on |
| Reusable | no, apply anew | usually yes, but deforms |
| Mess | can leak/smear | clean |
| Electrical | mostly insulating (liquid metal conducts!) | insulating |
When a pad?
- Graphics cards: Pads on memory and voltage regulators, paste on the GPU.
- M.2 SSD: Pad between chip and heat sink.
- Notebooks: Pads for chips of different heights.
- Power supplies, cases, LED strips.
Buying criteria:
- Choose the thickness exactly: Too thin → no contact, too thick → pushes the chip away or bends boards. Ideally 10 – 30 % compression.
- Thermal conductivity (W/mK): Higher is better but more expensive.
- Hardness (Shore): Soft pads compensate tolerances better.
Typical mistakes:
- Old, dried-out pad: Temperatures rise, replace after years.
- Stacking several pads on top of each other (worse conduction).
- Pad and paste doubled on the same component.
- Forgetting the protective films on the pad.
See also: Cooling and thermal paste, CPU structure: execution units and cache, NVMe