Video card thermal pads replacement

To reduce the temperature of the GPU, as well as other elements of the video card, which become very hot during intensive use of the video card, a complex system of air and, in exceptional cases, liquid cooling is used.

A typical video card cooling system consists of several heat pipes that are tightly attached to the graphics adapter chip, evenly distributing heat over a large number of aluminum plates strung on them, which, in turn, when the temperature threshold specified by the manufacturer is exceeded, are forcibly blown by one or more coolers.

To avoid the need to manufacture a video card heatsink of a complex configuration and simplify the production of the cooling system as a whole, the hottest element of the video card - the graphics chip - has the closest contact between the crystal and the heatsink, while the rest of the hot elements have to be cooled according to the residual principle, resorting to various design tricks. But even close contact between the heated surface and the radiator is not enough for effective heat removal: between them there is always a small layer of air (poor heat transfer), which can be eliminated only by using a special filling composition with high thermal conductivity.

As a thermal interface on a video card, the following are used:

  • Thermal grease is a special paste-like composition with high thermal conductivity, used to fill gaps up to 0.2 mm thick.
  • Thermal pad (thermal rubber) - an elastic plate consisting of small particles of heat-conducting material (aluminum oxide, graphite, etc.), bonded with a silicone-based compound. Thermal pads are used where the distance between the surface of the radio component and the heat sink is from 0.2 mm to 5 mm or more.

Desktop video cards use thermal paste as a thermal interface on the graphics chip, while thermal pads are usually used on video memory chips, power converter transistors, and other elements subject to high heat.

The specialists of the service center have encountered the dishonesty of some video card manufacturers, who, despite testing the finished product, allowed cases of using thermal pads with a protective film not removed during assembly or foreign objects that got between the cooled microcircuit and the cooling system, leading to failure of components due to overheating . In addition, there are cases when, in order to reduce the cost, the manufacturer replaces the thermal pads on the video card with cheaper and lower-quality ones that lose their ability to conduct heat for a short period of time, and also completely refuse to install thermal pads in critical places, worsening thermal mode of operation of semiconductor elements and reducing their resource.

If you notice dark oily spots or “streams” on the surface of a new video card that has been in operation for only a few months after purchase, then most likely these traces were left by the liquid component of the thermal pad filler and it is recommended to urgently replace it!

Do not forget also that any thermal pads are disposable. In no case should you reuse the thermal pads on the video card when replacing them - dust or traces of your fingerprints that have fallen on the surface of the thermal interface lead to a catastrophic decrease in their thermal conductivity and can cause damage to the video card.

Liquid metal instead of thermal paste on a video card
Fig. 1: Liquid metal instead of thermal paste on a graphics card. A drop is clearly visible, squeezed out of the surface of the GPU chip and shorted the upper terminals of the capacitors.

Avoid using a thermal interface such as "liquid metal" to replace thermal paste on a graphics card. Due to its ability to easily conduct electricity, if excess is squeezed out of the surface of the GPU die, it can get on the pins of electronic components, lead to a short circuit and failure of the GPU.

Some users prefer to replace the thermal pads on the video card and thermal paste immediately after purchase in order to be 100% sure of the quality of the materials used for cooling and extend the life of the video card. It is worth noting that even if the highest quality materials were used and all heating components are provided with reliable cooling, even they can lose their properties over time, so it is recommended to replace thermal pads and thermal paste at least once a year.