Why can't I apply too much thermal grease?

There are many ways to dissipate heat, and the common one is natural heat dissipation, but it is very limited by environmental factors, so in general, a radiator is installed above the heat source, so that the heat can be effectively guided to the radiator, and the radiator is directly connected to the heat source. The heat dissipation effect of the contact is very poor, mainly because there are a lot of gaps between the radiator and the heat source, even if it is two smooth and flat surfaces, there are also many large and small pits. Air is a poor conductor of heat. , So the heat transfer efficiency will be greatly reduced, resulting in poor heat dissipation.

Thermal  grease is a popular thermal conductive material in the field of thermal conductive materials. It is a semi-fluid paste-like compound based on silicone resin. It has high thermal conductivity, low thermal resistance, and excellent lubricating performance. It can be used on rough surfaces. A very thin surface layer is formed on the surface layer, which is easy to rework. It is commonly used to fill the gap between the power consumption electronic component and the radiator to improve the thermal conductivity of the radiator. It is generally applicable to the current industrial process field.

The use of Thermal  grease is very simple. Stir thoroughly before use to prevent oil powder from separating due to long-term storage. Apply it evenly on the heat source. Do not apply too much, otherwise it will affect the thermal conductivity. Why Will this happen? Shouldn't the more you apply it, the better the heat?

The first thing to know is that Thermal  grease itself is a thermally conductive auxiliary material, which fills the gap between the heat source and the radiator, reduces the thermal resistance, and improves the heat transfer efficiency, so that the radiator and the heat source can be closely combined, and too much application will affect the heat. The efficiency of conduction, resulting in a decrease in heat dissipation.

Then, if the amount of Thermal  grease is too much, part of the silicone grease may overflow during the process of squeezing the heat sink and the heat source, causing pollution to surrounding parts, thereby affecting its reliability.

When using thermal grease, you only need to apply a thin layer on the surface of the heat source. It does not need to be too much or too little, so as to avoid the decrease of heat dissipation effect due to poor contact.