Introduction
Thermal paste also known as thermal compound or thermal grease is a type of Thermal Interface Material (TIM). It is supplied in either liquid or grease form and is specifically designed to improve the heating conductions between two solid surfaces such as processors and heat sinks. It is also used for maintaining efficient heat flow between components and cooling solutions. Effective transfer of heat is considered one of the most important factors for reliability and performance in modern electronic devices. Without the thermal grease, even most advanced heat sinks or fans can fail to offer the best performance.
Thermal paste is most commonly used in appliances such as CPUs, GPUs, high-power electronic modules and LED lighting systems. All these appliances contain microscopic gaps and imperfections despite their flat surfaces. If the thermal grease is not applied properly, these gaps tend to trap air and damage the appliance as air is a bad conductor of heat.
How Thermal Paste Works
The metal plates and chips may look smooth from the naked eye however; it consists of tiny imperfections and air gaps. These gaps block the efficient transfer of heat by acting as an insulator. If applied correctly, thermal grease fills those spaces and eliminates the trapping of air. This results in many benefits such as reduction in thermal resistance, faster dissipation of heat, and stability in operating temperatures. Though thermal grease seems to be a simple material, it helps in running the high-electronic performances efficiently and reliably.
Important Tools for the Application of Thermal Paste
Below stated are some of the important tools and materials required in the application of thermal paste:
- Thermal Paste which can be available in different formulations such as:
- Other silicone-based pastes that can be used for general applications.
- High performance compounds that can be used for gaming PCUs, servers and other electronic devices.
- Metal-based pastes such as silver or liquid metal that can offer superior conductivity.
- Ceramic-based pastes that can cater electrically insulating needs.
- Cleaning materials such as isopropyl alcohol and lint-free clothes and wipes that can be used to remove old paste and clean the surface.
- Applicators such as plastic spatula or spreader that can be used to spread the paste evenly on the surface. Some pastes also come with syringe tips for more controlled applications.
- Target devices such as the processor and heat sinks must be ready to reassemble after the application of the thermal paste.
Surface Preparation for the Application of Thermal Paste
Preparing the surface is a critical step for applying thermal paste. Skipping this step can result in poor heat transfer and waste all the efforts. Below stated are the essential steps to prepare the surface properly:
- Dissemble the system: The first step is to dissemble the system completely. For this one needs to shut off the device, unplug it and discharge the electricity.
- Removal of Old Paste: The old paste should be removed properly from both the chip and the heat sink. Even the presence of small residues can reduce the effectiveness of newly applied thermal paste.
- Surety about the Surface: It is important to double check that the surface is clean, flat and dry and there is no dust, fibers or moisture on it.
Different Methods for the Application of Thermal Paste
Thermal paste can be applied in various methods. The correct method should be selected on the basis of device type, consistency of the paste and user’s experiences. The 3 main methods are stated below:
- Pea-Sized Dot Method: In this method, thermal paste is applied in a small pea-sized amount in the center of the chip. This paste spreads automatically and evenly due to pressure when the heat sink is mounted. The advantage of this method is that it is simple, quick and has low risk of over-application. However, its disadvantage is that it may fail to cover the larger chips.
- Line Method: In this method, a thin line of thermal paste is applied at the center of the processor. This method is mostly used for rectangular chips such as CPUs or battery modules. The advantage of this method is that it covers the whole length of the chips and is ideal for elongated designs. However, its disadvantage is that it requires careful alignment while application to prevent uneven spread of the paste.
- Spread Method: In this method a spatula or card is used to spread a thin and uniform layer of thermal paste over the entire chip. The advantage of this method is it guarantees full coverage and can be ideal for larger chips. However, its disadvantage is its time taking and may leave air bubbles if the paste is not applied properly.
Common Mistakes to Avoid While Applying Thermal Paste
Below stated are some of the common mistakes that should be avoided while the application of thermal pastes:
- Quantity of the Paste: One should avoid using more or less quantity than required as more quantity of paste can create a mess whereas less quantity can leave air gaps.
- Trapping of Air Bubbles: One should make sure that air bubbles are not trapped inside the chip as it can lead to hotspots and reduce the efficiency.
- Reusage of Old Paste: It is advisable to not reuse the paste as once it is dried out; it loses its effectiveness.
- Skipped Cleaning: It is important to clean the surface thoroughly after applying the thermal paste as dust, oil or residue attracted from this can reduce the proper heat transfer.
Take Away
This is the brief explanation about thermal paste, its working, important tools and different methods for its application. We hope this information will be effective for you. Please let us know through your valuable feedback and the suggestion in the drop box.