There are countless varieties of thermal pastes available on the market. You won’t notice much of a difference between all of those different types of thermal pastes until you are an expert. While some pastes advertise themselves as being metal-based, others are referred to as silicone, carbon, or non-metal. What exactly are these thermal pastes, and does it matter which one we use? If so, what pastes should you buy to transfer heat effectively?
Let’s understand the differences between these thermal pastes and find out which one is the best for you to buy among all of these different types of thermal pastes.
What are Thermal Pastes and why are they needed?
The same substance is known by the labels thermal paste, thermal grease, and thermal compounds. This material acts as a heat transfer between two surfaces because it is heat conductive. The surfaces of the CPU, coolers, and heat sinks all have minute gaps in them. These small gaps trap insulating air that prevents proper heat dissipation.
As it acts as a heat conductor, thermal paste flows into these tiny gaps, eliminating any air. The CPU operates smoothly and dissipates heat effectively in this manner. Thermal pastes are required to prevent the system from overheating and failing.
List Of Different Types Of Thermal Pastes
There are six main different types of thermal pastes, and each one differs in terms of density, price, electric conductivity, and thermal conductivity. It’s crucial to understand which one is important for your system. A system that generates a lot of heat cannot simply be treated with a thermal paste with a low heat conductivity value.
1. Metal-based Thermal Paste
It is among the oldest and most widely used varieties of thermal paste. Due to the exceptional heat conductivity of both silver and aluminum, it typically contains both of these materials. For appliances that quickly heat up, these are best suited. To help reduce temperature fluctuation, people occasionally combine these with ceramic thermal pastes.
Pros
- They contain metals that are naturally excellent heat conductors, therefore they are quite good at transferring heat.
Cons
- If these pastes leak, they could short-circuit because they include electrically conducting metals.
- They are capacitive as well as difficult to apply.
- To prevent short circuits caused by leaks, you need to tape the nearby components.
Note: Select thermal pastes made of metal if you want strong thermal conductivity. If this is your first time using thermal paste, you should not go for it.
2. Liquid Metal-based Thermal Paste
These are the liquid metals that are excellent heat conductors. Similar to metal thermal pastes, they fill up air gaps between surfaces to facilitate heat transfer. When it comes to what these products include, there is a significant difference. Gallium, a metal with a low melting point that is liquid at normal temperature, is typically present in the liquid metal thermal paste and helps in heat transfer.
Pros
- It transmits heat eight times more quickly than conventional thermal paste and ensures smooth, quick operation so it might be very helpful for you in keeping your appliances safe.
Cons
- Aluminum and gallium may react, thus you can’t use it with an aluminum heat sink.
- Because it is a liquid, it is challenging to apply as it can easily leak and cause a short circuit, therefore we advise using it only if you are an expert.
- Liquid metals are more expensive than other thermal interface materials, and because of their electrical conductivity, if they leak outside, they could seriously harm a system.
Note: The best choice is this if you need excellent heat conductivity or thermal interface material for systems that heat up very quickly. Please take note that you should only choose this option if you are certain that you can apply it evenly without it spilling.
3. Ceramic-based Thermal Pastes
The most popular pastes on the market right now are these thermal greases. These pastes, which are made of ceramic, are widely utilized and accessible. These are one of the different types of thermal pastes.
Pros
- It is inexpensive, easy to apply, and the best choice for quickly heated systems because it is not electrically conductive and therefore safe even if it spills.
Cons
- It is ineffective for highly heated systems because it won’t result in a considerable drop in system temperature.
Note: Use these if you are using thermal pastes for the first time.
4. Carbon-based Thermal Pastes
One of the different types of thermal pastes is carbon-based thermal pastes. Tiny carbon fibers are present in carbon-based thermal pastes and are identical to ceramic thermal paste in terms of conductivity. They have good density, making them easy to apply.
Pros
- They are the greatest choice for beginners because they have a longer lifespan and are not electrically conductive therefore does not cause short circuits if leaked.
Cons
- This heat transfer product is not very efficient.
Note: Use these if you are using thermal pastes for the first time.
5. Diamond Carbon-based Thermal Pastes
Do you know that compared to silver, diamonds are five times more effective in transferring heat? Because it incorporates diamond powder, this diamond carbon-based thermal paste will be a very effective heat transfer paste. Additionally, it won’t even leave a scratch on the surface.
Pros
- Diamond carbon-based pastes are excellent at transferring heat. It is neither capacitive nor electrically conductive.
- It has high stability and low viscosity, which can help fill any gaps that may arise. Since the diamond is in powder form, it won’t scratch the surface.
Cons
- When compared to other thermal pastes, diamond carbon thermal pastes are highly pricey.
Note: Select this option if you want extremely high heat conductivity and have money to spare.
6. Silicon-based Thermal Pastes
Another excellent thermal paste among different types of thermal pastes is silicon-based thermal pastes. These pastes contain silicone, as the term indicates. These are frequently used on thermal pads.
Pros
- Silicon-based thermal pastes are easy to apply and have a nice density that helps them spread evenly without leaking.
- They are good for heat transfer because they have a high thermal conductivity value.
- These pastes also provide a wide range of operating temperatures, which enables them to work with a variety of CPU systems and VGA cards. They also act as electrical insulators.
Cons
- Compared to other pastes, silicon-based pastes are more expensive
Note: They have the highest thermal conductivity and can be used on any system without risk because they don’t conduct electricity. Both beginners and experts can use them because it is easy to apply.
How to choose thermal paste?
Before selecting a thermal paste, there are a number of things to take into account that effectively transmit heat across surfaces without endangering the system.
Conductivity of Heat
The CPU temperature can be greatly reduced by a good thermal paste’s heat conductivity. If a thermal paste is non-metallic, any value between 6W/mK and 10W/mK will do; if it is metallic, the heat conductivity value should be 70W/mK. A substance conducts heat more effectively the higher its thermal conductivity value.
Conductivity of electricity
Electrical conductivity shouldn’t be present in thermal paste. Pastes that conduct electricity have the ability to short-circuit the system and harm it. The electrically conductive thermal paste will transmit electricity if it leaks to the surroundings and the system will be damaged by electricity.
Density
If the thermal paste is too thin then the surroundings will be exposed to it. If it is too dense then it might not spread adequately. You require a thermal paste whose density prevents leakage to the surroundings and even further from its surroundings.
What is the best type of thermal paste?
Three key considerations must be made in order to select the optimal thermal paste: heat conductivity, electrical conductivity, and density. The best paste is made from a substance with good heat conductivity, poor electrical conductivity, and a suitable density that is neither too thick nor too thin.
We suggest using silicon-based thermal pastes among all the different types of thermal pastes because they are versatile. They are electrically insulative, safe to use, generally compatible, and will spread uniformly. We also wrote an article on how to apply thermal paste. Read it thoroughly to know more.