How to Apply Thermal Paste and How It Works

PC building can be a daunting task, but it’s a satisfying one once you’ve finished. One of the essential steps in building your PC is ensuring that your processor is cooled correctly. The thermal paste helps to ensure that your processor doesn’t overheat, and it’s an integral part of the cooling process.

This material is a thermal interface material applied to the CPU’s surface. Its purpose is to improve the contact between the thermal head and the heat spreader on the CPU. By enhancing this contact, thermal paste ensures that more of the heat generated by the CPU is dissipated away from the processor.

The thermal paste is a substance applied to processors and other heat-generating components to improve heat transfer. It is composed of silicon dioxide, metal oxides, or other metallic elements. Thermal paste can help improve the thermal conductivity of surfaces by up to 3,000 times.

Thermal Paste Syringe
Thermal Paste Syringe (Image credit: intel)

When Do You Need to Apply Thermal Paste?

Thermal paste is unnecessary, but it is usually recommended for processors and other heat-generating components. If your processor doesn’t have a thermal pad or if the thermal pad is damaged, then you will need to apply thermal paste. Thermal paste is also necessary when installing a new cooler or heatsink.

You don’t need thermal paste if you use a stock cooler or your processor already has a thermal pad. Thermal pads are less effective than thermal paste, but they can still help to improve heat transfer.

How to Apply Thermal Paste - Step by Step

Before applying thermal paste, it is essential to remove the IHS from the CPU. After removing the IHS machine screws, be sure to put them to one side so they won’t get lost.

How to Apply Thermal Paste on CPU
How to Apply Thermal Paste on CPU (Image credit: intel)
  • 1: Use the thermal paste for small applications (single-core processors, smaller heat-spreaders). Consider thermal pads instead for larger applications like server blade heatsinks or top-of-the-range air coolers.

    Some thermal pastes can be applied with an applicator, and some require a safe working environment after application to prevent it from drying out in a short period. Make sure you read the instructions carefully, so you know how to apply your thermal paste properly.

  • 2: If you have a thermal pad in place of thermal paste, clean it off before applying thermal paste.

  • 3: Place a small amount of thermal paste onto the center of the IHS. Use just enough to cover about half of the entire surface area when it is finished.

  • 4: Use the thermal spreader to evenly distribute thermal paste across the entire surface area of the IHS (see image below). This will be easier if you put thermal paste on half of the surface area first, then place a thermal pad or thermal tape at one end and press it over the complete width of the thermal interface. When doing this step, make sure you don’t apply an excess amount on areas other than your heat-generating components. Also, make sure that you use enough thermal paste to cover all hot spots on your processor.

  • 5: Finally, put the IHS back in place on top of your CPU die. Evenly tighten each screw to secure it into its correct positions without applying any thermal paste on the inside of the screws. Ensure you clean off the excess thermal paste and replace all your metal IHS machine screws before installing your cooler and powering up your system.

The heat produced by a thermal paste application will dissipate heat more efficiently than with a thermal pad or thermal tape, but not as efficiently as if there were no thermal compound at all (a thermal pad).

Using too much thermal paste can create another problem: it creates too much pressure between different components and prevents efficient heat transfer to the heatsink. So, make sure that you use only enough thermal paste to cover half of the entire surface area when finished, then apply it evenly across that half of the surface area with a rubber material like a silicon thermal spreader. This will help avoid using too much thermal paste and ensure that your processor is getting the most out of the thermal compound.

Thermal paste is a substance applied to components to increase the efficiency of heat transfer between them. Thermal paste is usually a thick, white compound in a small tube or syringe. When applied to a CPU, it makes contact with the heat-generating microchips and spreads out over the surface, filling in any air gaps.

This prevents air from coming into contact with the hot chips and allows for more efficient heat transfer to the cooler. The thermal paste then dissipates this heat through the metal heatsink fins.

Terms You Need to Know About Thermal Paste

You need to know a few thermal paste-related terms to understand how thermal paste works.

Thermal Paste Syringe CPU
Thermal Paste Syringe CPU (Image credit: intel)
  • Central Processing Unit (CPU): The Central Processing Unit is the main component. It is responsible for executing all instructions and sending instructions to the other hardware in the computer. CPUs are usually cooled with a cooling apparatus designed just for this purpose, such as a CPU cooler. The thermal paste helps to ensure that the CPU operates at peak efficiency by improving heat transfer between the CPU and its cooler.
  • Integrated Heat Spreader (IHS): The Integrated Heat Spreader is a thermal interface that is factory-applied to some processors. It helps to improve thermal conductivity and contact between the thermal head and the heat spreader on the CPU. By enhancing this contact, thermal paste ensures that more of the heat generated by the CPU is dissipated away from the processor.
  • CPU Cooler: The apparatus used to cool the CPU. There are many different CPU coolers, from air coolers to liquid coolers. The cooler will have one or more base plates that contact the IHS on the CPU. Thermal paste is applied between these base-plates and the IHS to improve heat transfer.
  • Base-Plate: The bottom part of a CPU cooler that makes contact with the Integrated Heat Spreader on the CPU. Thermal paste is applied between this plate and the IHS to improve heat transfer.
  • Waterblock: A water block is designed to dissipate heat from a processor or other heat-generating component using water as the medium. Thermal paste is unnecessary when using a water block, but thermal paste can still be applied to improve heat transfer.
  • Thermal Paste: A thermal paste is a compound that consists of silicon dioxide, metal oxides, or other metallic elements that are added together in a specific ratio and then compressed into a paste or gel-like material with viscosity ranging from watery to peanut butter. It is usually packaged to be applied by hand without special tools and has a thermal conductivity of up to 3,000 times more than the thermal interface between the IHS and base plate.

Why Do You Need Thermal Paste?

Thermal Paste Imperfections
Thermal Paste Imperfections (Image credit: intel)

Thermal paste is unnecessary, but it is usually recommended for processors and other heat-generating components. If your processor doesn’t have a thermal pad or if the thermal pad is damaged, then you will need to apply thermal paste. Thermal paste is also necessary when installing a new cooler or heatsink.

You don’t need thermal paste if you use a stock cooler or your processor already has a thermal pad. Thermal pads are less effective than thermal paste, but they can still help to improve heat transfer.

Necessary Preparations for Thermal Paste Application

Before beginning the thermal paste application, removing the IHS from the CPU is essential. You should only do this if thermal paste is required for your situation or thermal pad damage has occurred.

Warning: It is easy to damage your CPU by removing the IHS! Before trying this at home, make sure you know how to do this without damaging your processor and that you have an anti-static strap for protection against static electricity. You can also take your system to a repair shop and ask them to apply the thermal paste and reattach the IHS (for a fee).

Thermal Paste CPU Wipe
Thermal Paste CPU Wipe (Image credit: intel)

You will need:

  • High-grade thermal paste (non-conductive)
  • Screwdriver (for unscrewing on the cooler’s base plate)
  • Ruler or measuring tape
  • Patience
Correct Amount of Thermal Paste
Correct Amount of Thermal Paste (Image credit: intel)

Situations to Avoid:

  • Applying thermal paste when not needed
  • Allowing thermal paste to come into contact with any other component except the CPU
  • Touching the thermal paste after it has been applied to the CPU
  • Using a thermal pad in place of thermal paste
  • Not applying thermal paste evenly

How Often Should You Replace Thermal Paste?

Thermal paste is one of those products that, once you have it, you hope you never have to use it again. It’s one of those things that, once you’ve applied it, you hope stays put for a long time. But thermal paste does eventually wear out and needs to be replaced. How often should you replace thermal paste?

There is no easy answer to this question because it depends on many factors: how often your system is used, what kind of thermal paste you are using, how much thermal paste is applied, and the thermal conductivity of the thermal paste. Generally, thermal pastes with a higher thermal conductivity rating will last longer than those with a lower rating.

Some thermal pastes advertise that they do not need to be replaced for the product’s life. While this may be true, it is advisable to check your thermal paste from time to time to see if it needs to be replaced. If you start to experience problems with your system running hot, it might signify that your thermal paste needs replacing.

Replacing thermal paste is not difficult, but it can be tricky if you don’t know what you’re doing. In most cases, it’s best to take your system to a professional if you are unsure. Replacing thermal paste can also void your warranty, so make sure you know what you’re getting into before taking the risk of doing it yourself.

Stay Cool Out There

As you can see, thermal paste is essential for keeping your system cool. When used correctly, the thermal paste can contribute to a cooler running system that will last longer. As long as you keep the above information in mind, you should have no problem applying thermal paste correctly.