What is a Thermal Pad
Nowadays, thermal pads are important components in modern electronic devices. They serve as a high-performance gap-filling thermal materials, typically featuring strong adhesion, flexibility, excellent compressibility, and superior thermal conductivity. These pads are commonly applied within the space between electronic components and heat sinks or product enclosures to facilitate heat transfer.
The specific function of thermal pads lies in filling the air gap between electronic components and heat sinks/enclosures. Air, as a medium, typically impedes efficient heat transfer. By occupying this void, thermal pads create a pathway for heat, enabling effective device cooling. This helps maintain optimal operating temperatures for electronic components and extends their service life.
Benefits of Using Thermal Pads
Stable Performance- Thermal pad does not leak oil at high temperatures and maintains high cleanliness.
Easy to Install- Most thermal pads are easy to cut and install, typically requiring no special tools beyond a common pair of scissors.
Vibration Damping- Some thermal pads, such as silicone-based thermal pads, also provide cushioning and vibration damping functions to protect precision components.
Cost-Effective- Compared to other thermal interface materials like thermal grease, thermal pads may be slightly more cost-effective, making them suitable for budget-constrained or large-scale applications.
Repeatability Of Use- Thermal pad can be repeatedly installed, tested, or used and stay its good function.
Soft and Elastic-Their soft characteristics make them are capable of covering highly uneven surfaces.
Superior thermal conductivity, natural tackiness, high compressibility, and 0.3mm to 12.0mm thickness available.
They are reusable, offers excellent performance, outstanding thermal conductivity, and easy to work for PC cooling.
Made from silicone rubber, these pads are suitable for irregular surfaces. They are perfect for CPUs, power components, etc.
Available in composite and single layer types. They are naturally soft and tacky to provide efficient cooling.
Our silicone-free thermal pads are extremely soft to reduce PCB stress while reducing thermal resistance.
These are UL94 V-0 listed thermal pads offering good conformability and excellent electrical insulation properties.
You can use them as an alternative to thermal paste, protecting many electronic components against overheating.
These pads are widely used for filling air gaps in heat sinks and other cooling devices with enhanced thermal conductivity.
Used for managing heat and protecting electronic components. These are made from silicone polymer offering efficient air gap bridging.
What are the Thermal Pad Types?
Classification by Material
Silicone Thermal Pads–Silicone thermal pads are one of the most common thermal materials on the market. They have good elasticity and temperature tolerance, can adapt to various complex equipment structures, and maintain stable properties in the temperature range of -60°C to 200°C. Generally speaking, electronic products such as smartphones and laptops use silicone thermal pads more often.
Graphene Thermal Pad–As the material with the highest known thermal conductivity in nature, graphene thermal pads typically have thermal conductivity values ranging from 10 W/(m·K) to 100 W/(m·K), and can even exceed this maximum value, far surpassing traditional silicone thermal pads (typically 1-6 W/(m·K)) and phase change materials. Its lightweight and flexible characteristics not only do not burden electronic devices but also make it highly durable.
Carbon fiber thermal pads– Carbon fiber delivers exceptional thermal performance. Due to its high-temperature tolerance, In high-power electronic devices and other applications demanding efficient heat dissipation, carbon fiber thermal pads are often an excellent choice. Additionally, their lightweight nature makes them a preferred material in aerospace for aircraft thermal management, as they impose minimal additional weight burden.
Non-Silicone Thermal Pad–The design of the silicone-free thermal pad avoids contamination caused by silicone oil leakage and does not react with some silicone-sensitive plastics and coatings, ensuring stability and safety during use. Its thermal conductivity ranges from 1.0 to 6.0 W/m·K. If you are looking for a thermal pad for your business that needs to be used in equipment with restricted use of silicone resin, GALLOP INNOTEK can provide you with a reliable product that can be used for long-term use.
Classification by Nature
Soft Thermal Pad–Due to their soft properties, they can better fill different gaps, especially in applications with irregular surfaces, to achieve better thermal conductivity. At the same time, they can also protect more fragile components from breakage during use, such as ceramic capacitors and some chips.
Electrically Conductive Thermal Pad– This pad has both good thermal conductivity and electrical conductivity. The electrically conductive layer may be formed by blending in metal powders or other conducting materials within a non-conductive polymer matrix. This special thermal pad is needed when application need to be grounded for heat dissipation and electromagnetic shielding. It is important to note that this pad must never be used in ordinary circuits, as doing so could cause short circuits or even damage components.
Factors Affecting the Conductivity of Thermal Pads
Thermal conductivity of materials- Generally speaking, under constant conditions, the higher the thermal conductivity of a material, the better its heat transfer performance. Typically, thermal conductivity can be enhanced by increasing the filler content in silicone and incorporating other thermally conductive powders; correspondingly, this approach also incurs higher relative costs.
Material Thickness- Generally speaking, the thinner the material, the shorter the distance heat must travel, the faster heat is transferred, the lower the thermal resistance value, and the better the heat conduction effect.
Material Hardness- The hardness of the material determines how well the thermal pad adheres to the surface of the heat sink. A soft thermal pad with low hardness has low surface tension, allowing it to adhere more completely to the surface, greatly reducing the contact thermal resistance between the two.
Oil Seepage Rate of Materials-This applies specifically to silicone-based thermal pads. Softer thermal pads typically have a lower degree of curing, making them prone to silicone oil seepage when heated. This not only contaminates components but also increases the pad’s hardness, reducing its adhesion to the surface of heat dissipation components. Generally, the oil seepage rate of ordinary thermal pads is around 2.5% to 3.5%, while better products can be controlled between 2.0% and 2.5%.
Applications
Industrial Equipment—Thermal pads keep things running cool in various automotive and industrial machinery: such as motors, computers, transformers, power modules, and frequency conversion power sources.
Electronic Equipment Cooling – Thermal interface pads are installed between computer CPU etc and heat sink heat dissipation or fewer mobile phone tablet, between the IC and the heat sink interface to enhance the cooling of electronic equipment.
Automotive— Automotive industry is a big market for thermal pads which are used in heat dissipation process like motor controllers, inverters, and battery management system, so as to ensure the stability of some devices mounted in the automobiles.
LED Lighting—In LED lighting, TIMs are adopted as the TIM between an LED chip and a heatsink, thereby enhancing the effects of heat dissipation and leading to longer lives of lighting gear.
How to Use Thermal Pads?
First , the users need to clean the surface where the pad will be applied, including old thermal pads and any stains.
Then they should precisely measure its surface area and trim the thermal pad to the proper size.
Next it is the remove of the protective film from one side of the thermal pad and the users can place it on the surface and press gently.
Finally, after Removing the protective film from the other side, and ensure that they are fit very tightly, this process is down.
Thermal Pad Specification Selector
Turn the assembly gap, temperature and material restrictions into a practical thermal-pad RFQ starting point.
Planning/reference estimate: Material family and thickness are preliminary. Final selection requires stress-strain data, tested impedance, tolerance analysis and assembly validation.
When using thermal pads, you should avoid stacking them. This not only fails to enhance thermal conductivity but also creates additional air gaps between the pads, thereby reducing heat transfer efficiency.
Additionally, you should avoid using thermal pads and thermal paste simultaneously. Although both possess thermal conductivity properties, mixing them within the same system can impede heat transfer and may even damage components requiring cooling.
Thermal paste is a paste-like substance with excellent thermal conductivity, also classified as a thermal interface material. It is primarily applied at the contact interface between heat sinks and heat sources (such as chips or inductors). Its main functions include filling interface gaps, replacing air with its poor thermal conductivity, reducing thermal resistance, and enhancing heat transfer efficiency. The advantages of thermal paste lie in its superior thermal conductivity, its paste-like texture that perfectly conforms to various surfaces.
However, thermal pads may offer easier installation. Applying thermal paste often requires manual spreading, which can easily get on your hands. Furthermore, there is a risk of leakage into the environment during use. If thermal paste seeps into CPU pins or around the motherboard, it may cause short circuits or permanent damage to the CPU.
Thermal pads, on the other hand, offer straightforward installation. Users can easily trim them to the required size and apply them to components like the CPU, ensuring uniform thickness across all edges during adhesion. Their lifespan can exceed five years, and they are less prone to dust accumulation.
