Thermal interface materials such as thermal conductive gel deliver outstanding heat dissipation performance within the heating components of various equipment, including computers, automobiles, digital signage display, and electrical appliances, thereby enabling high-performance and stable operation. You may wonder how thermal conductive gel achieves this heat dissipation. This article can tell you more about the matter. Upon reading, you will gain a deeper understanding of thermal conductive gel and be better equipped to make informed choices.
What is Thermal Gel？
Thermal gel is a thixotropic thermal interface material characterised by high viscosity and fluidity. It offers a longer service life than thermal paste and a lower bond line thickness than thermal pads. It can be applied between the heat-generating components and heat sinks of various products and compressed to a very thin layer. This achieves excellent heat dissipation, thereby maintaining component operating temperatures within normal ranges and extending the service life of both components and equipment.
How does Thermal Gel Dissipate Heat?
Fill the Gap
Even components and heat sinks with highly polished surfaces have microscopic irregularities imperceptible to the naked eye. Without thermal interface materials such as thermal conductive gel, direct contact between components and heat sinks creates gaps filled with air—a medium of extremely low thermal conductivity—thereby compromising heat dissipation. Thermal conductive gel not only fills these voids to create a smoother interface but also replaces the high thermal resistance air within the gaps.
Reduce Contact Thermal Resistance
Uneven surfaces on heat sinks and components can influence thermal contact area, thereby reducing heat dissipation efficiency. Thermal gel has a degree of fluidity and exceptional conformability. So, compared to thermal pads, they can effectively fill such gaps and maximise contact between heat-generating components and heat sinks. Moreover, they achieve minimal thickness whilst filling voids, preventing air ingress whilst reducing contact thermal resistance to maximise heat transfer efficacy.
Provides High Thermal Conductivity
Thermal conductive gel typically has a thermal conductivity ranging from 3 to 8 W/(m·K), offering very high heat transfer efficiency compared to air. When heating components operate and generate heat, the thermal conductive gel rapidly absorbs thermal energy from the component surface, making it cool. Having absorbed the heat, the gel efficiently diffuses and transfers the thermal energy to the heat sink, thereby achieving effective heat dissipation.
Function of Thermal Gel
Enhance Equipment Operational Stability
High-performance equipment generates large heat during operation, while components typically have their own operating temperature ranges. When heat accumulates and exceeds these limits, the equipment activates thermal protection mechanisms that reduce performance, trigger shutdowns, or cause outright failure. Using thermal interface material makes your products maintain the best operating temperatures, thereby sustaining peak performance. This enhances reliability in devices such as computers. In medical equipment, this can enhance operational accuracy and stability, thereby further reducing errors and risks.
Extend the Service Life of Equipment
Operating equipment beyond its temperature range over extended periods accelerates ageing and may lead to sudden failure. This translates to higher maintenance and replacement costs, particularly for high-value equipment. Compared to repairs and replacements, using thermal conductive gel represents a highly cost-effective alternative. Moreover, unlike thermal paste, it is not prone to spillage or drying out during use. It can extend equipment lifespan, optimise energy efficiency, and reduce maintenance requirements.
Bonding and Fixing
Thermal conductive gel requires curing during application, yet its curing time is brief. Once cured, it offers adhesive properties and considerable mechanical strength. This confers greater reliability and durability compared to less viscous thermal pastes. Should you be seeking an appropriate thermal management solution for applications prone to vibration and impact, such as automotive systems, it represents an ideal choice.
Buffering and Protection
Unlike thermal conductive potting compounds, thermal conductive gel does not form an extremely hard solid upon curing. Instead, it retains elasticity and toughness. This enables it to better absorb stresses from vibration and impact, delivering superior durability. It also provides additional protection for components against damage. Furthermore, it can absorb some of the noise generated by components during operation, resulting in lower noise levels.
How to Enhance the Heat Dissipation Performance of Thermal Gel？
Selecting the Correct Thermal Gel
When selecting thermal conductive paste, you must first verify that its thermal conductivity sufficiently meets your heat dissipation requirements. Various thermal conductivities are available, such as 3W/(m·K), 5W/(m·K), and 8W/(m·K). Pastes with higher thermal conductivity can handle greater heat dissipation loads. Insufficient thermal conductivity will result in poor heat dissipation and a shortened service life. Additionally, thermal interface materials possess an optimal operating temperature range (typically between -50°C and 150°C), so your application temperature should be within this range. Should your product be susceptible to damage from silicone, silicone-free thermal gel materials offer a safer alternative.
Apply Thermal gel to the Right thickness
Thermal interface material is not pre-moulded by suppliers, nor does it require custom cutting to fit your components. Its application is flexible, requiring you to control the quantity, shape, and thickness of the application according to the size and form of your components. You should apply it as thinly as possible while making it completely covering the uneven surfaces. If applied too thinly, it fails to maximise contact area and minimise thermal resistance. Conversely, excessive thickness creates longer heat transfer paths, reducing cooling efficiency while offering unnecessary costs. For high-volume processing, automated dispensing equipment can achieve a more stable quality and higher application efficiency.
Cleansing before Application
Dust, moisture, and contaminants on component surfaces or heat sinks have extremely poor thermal conductivity. This not only prevents thermal paste from filling gaps adequately but also increases thermal resistance. Therefore, surfaces must be cleaned before applying thermal paste. Furthermore, only one thermal interface material should be used on a single component. Unless specified in the documentation, you’d better not apply additional layers, and if existing thermal interface material should be removed promptly.
Thermal Paste Lifespan
Thermal paste does not remain effective indefinitely, and both its storage life and service life are limited. It should be utilised within 12 months of the production date. Beyond this period, the thermal paste’s viscosity, heat dissipation performance, and other properties may deteriorate or even fail. This can lead to material wastage. It typically maintains a service life of approximately 2 to 8 years. If you use it in more extreme temperatures, its lifespan may be shorter. Once aged, the thermal paste’s performance diminishes markedly, necessitating prompt replacement with fresh material to sustain effective heat dissipation.
In Which Applications does Thermal Interface Material Work?
Electronic Devices and Computers
Thermal gel provides thermal conductivity and achieves lower contact thermal resistance, making it an ideal cooling solution for high-performance devices such as computers and gaming consoles. Moreover, it is lightweight enough and can be compressed to a very thin profile, allowing its use in space-constrained portable electronics like mobile phones, watches, and tablets. Primarily employed between heat-generating components such as GPUs, CPUs, and SoCs and their heat sinks, it effectively fills surface irregularities to maintain operating temperatures within acceptable ranges. It also stabilises performance when applied between RAM, SSDs, and heat sinks. Furthermore, thermal paste is electrically insulating, making it suitable for VRM cooling.
LED Lighting
During continuous operation, high-power LED lighting generates a lot of heat. Using thermal conductive gel enables efficient heat dissipation. This effectively prevents brightness reduction or even failure due to overheating, achieving reliable long-term operation and extending lifespan. Furthermore, the use of thermal conductive gel enhances the energy efficiency of LED lighting, thereby reducing the costs of long-term operation.
Automotive
Thermal conductive gel can be utilised in automotive applications such as battery management systems and intelligent driving systems. On the one hand, it facilitates heat dissipation for these components, ensuring safer and more stable vehicle operation while enhancing energy efficiency. Moreover, owing to the excellent elasticity of the cured thermal gel, it can cushion impacts and vibrations encountered during vehicle operation, thereby increasing component durability. Additionally, thermal gel can be applied to in-vehicle chargers and entertainment systems to achieve higher charging efficiency and smoother operation.
Medical
Should you be seeking an appropriate thermal management solution for temperature-sensitive medical equipment, thermal conductive gel is highly suitable. Firstly, its outstanding heat dissipation capabilities enhance the accuracy and operational stability of medical imaging equipment, life support and monitoring devices, diagnostic apparatus, and similar systems, thereby reducing errors and mitigating serious risks. Secondly, compared to thermal paste, it has minimal leakage, offering higher hygiene standards and lower maintenance requirements. Silicone-free thermal gel is also available here, permitting you to use it on expensive medical equipment sensitive to silicone.
Industrial Equipment
Industrial equipment, particularly automated machinery, can utilise thermal conductive gel to achieve more efficient heat dissipation for components such as CPUs and power supply systems, thereby ensuring reliable continuous operation. This reduces downtime and maintains high efficiency in automated production. Thermal conductive gel may also be used in industrial communication equipment to enhance signal accuracy and stability during highly complex operations.
FAQs
Which is Better: Thermal Gel or Thermal Paste?
Both thermal gel and thermal paste have fluidity and achieve high heat dissipation efficiency. Thermal gel requires curing during application, making its handling more complex than thermal paste. However, it offers a longer service life and greater resistance to vibration and impact. Thermal paste, conversely, necessitates more frequent maintenance.
Can Thermal Paste be Reused?
As thermal paste requires curing, its high viscosity makes it prone to damaging components during removal. Furthermore, its shape changes after use, so it is best not to reuse it.
What Types of Thermal Conductive Gel are Available?
There are single-component thermal conductive gels and two-component thermal conductive gels. Two-component thermal conductive gels require mixing before application and undergo a curing reaction after mixing. A silicone-free thermal conductive gel is also available for use in projects sensitive to silicone.
Is Thermal Paste Conductive?
Thermal paste is typically electrically insulating, posing no risk to existing circuitry systems and allowing safe use across various electronic devices.
What Alternatives are There to Thermal Conductive Gel?
Apart from thermal conductive gel, you may also use thermal paste, thermal putty, etc., though these offer lower adhesion. Should you require higher adhesion, certain thermal pads support the addition of an adhesive layer. Alternatively, you may opt for thermal conductive tape.
How to Extend the Service Life of Thermal Interface Material?
Firstly, select a thermal interface material with a thermal conductivity suitable for your heat dissipation load and use it within the specified operating temperature range. Secondly, apply the thermal interface material correctly according to the instructions and supplier guidance. Additionally, use it before the expiry date and do not reuse old thermal interface material.
Final Thoughts
Based on the operating principles, functions, and applications of thermal gel, you can better determine its suitability for your project. As an experienced supplier of thermal interface materials, GALLOP INNOTEK offers high-quality thermal gel and other thermal interface materials(thermal pads, thermal paste, etc.). Contact us for expert guidance.
