As electronic device technology continues to advance, efficient thermal management becomes critical. Whether it’s an electric vehicle (EV), energy storage system (ESS) or consumer electronics, keeping components at the right temperature guarantees performance, reliability and long life. Thermal Pads play an important role in thermal interface materials (TIM). So what is a Thermal Pads? How does it work? Why is it so critical in your project?
Trumonytechs is a high-tech company originating from Shanghai Jiao Tong University, specialising in electric vehicles, energy storage systems and heat transfer technologies. We have provided diversified solutions for several industries, covering new energy (especially electric vehicles and energy storage systems), transport, consumer electronics and 5G communications. In this article, we will give you an in-depth analysis of the definition, functions, types, advantages, disadvantages and applications of thermally conductive pads, as well as combining Trumonytechs’ experience to help you select the most appropriate thermal management solution.
Table of Contents
Why Thermal Pads are Critical?
Heat is the invisible killer of electronic devices, from highly loaded CPUs to electric vehicle battery modules. Overheating can lead to performance degradation and even device damage. As devices become smaller and power requirements increase, heat dissipation becomes even more of an issue. Thermal pads, as a simple and efficient thermal management tool, can quickly transfer heat from the heat source to the heat sink to keep the system running stably. Trumonytechs has been widely applying thermal pads in EV Battery Thermal Management System (BTMS) and 5G infrastructure to help customers achieve better thermal control. Next, we’ll explore how thermal pads work in more detail.
What is a thermal pad?
A thermally conductive pad is usually made of silicone, paraffin or other flexible substrates with thermally conductive fillers (e.g., aluminium oxide, zinc oxide, boron nitride, or carbon fibre) to enhance thermal conductivity. It is typically placed between a heat-generating component (such as a CPU, GPU, or power transistor) and a heat sink to fill in the tiny air gaps – air is a poor conductor of heat – and significantly improve heat transfer efficiency.
Thermal pads work based on their softness. Even if the surface appears to be flat, there are irregularities at the microscopic level where air can get trapped and impede heat flow. A thermally conductive pad conforms to the surface under slight compression and fills these voids, thus reducing the thermal resistance (in °C/W). Its thermal conductivity (W/m-K) typically ranges from 1.0 to 45.0, depending on the material and design, and can meet the needs of applications ranging from general electronics to high-power EV.
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Role and Applicability of Thermally Conductive Pads
The role of thermal pads in heat dissipation cannot be underestimated. In computers running high-load applications, heat build-up can lead to system crashes. In electric vehicles, overheating of the battery can shorten battery life. Thermal pads help keep equipment cool by providing a stable path for heat transfer, and Trumonytech customer case studies show that the application of high-quality thermal pads in EV battery modules can effectively reduce temperatures and thus extend service life.
Thermal conductive pads are used in a wide range of scenarios, mainly including:
New energy: EV BTMS, energy storage system battery cooling.
Electronic products: smartphones, laptops, LED lighting.
Industrial field: automotive, telecom, power electronics.
5G communication: high-frequency equipment thermal management.
Compared with other TIMs, thermally conductive pads have unique advantages:
Thermal Conductive Paste: high thermal conductivity efficiency, but easy to leak, difficult to control, and may fail in long-term use.
Liquid metal: excellent thermal conductivity, but high cost and conductive, short circuit risk.
Analysis of the advantages and disadvantages of thermal pads
Advantages:
Efficient heat dissipation: wide range of thermal conductivity (e.g. N-B Supermax up to 15 W/m-K). It can quickly transfer heat from the heat source to the heat sink, keeping the equipment at a low temperature.
Easy to install: no need for precision equipment, can be easily cut to the required size. And it is more suitable for mass production than thermal paste.
Strong durability: It has good resistance to thermal cycling and has a service life of more than 5 years. Not easy to harden or attract dust, suitable for long-term application.
Electrical insulation: most of the thermal pads (e.g. silicone-based) have electrical isolation properties to avoid short circuits, especially suitable for voltage environments.
Vibration damping: Soft silicone-based pads cushion vibrations and protect delicate components, especially important in electric vehicles (EVs).
Cost-effectiveness: In large-scale applications, thermal pads are more cost-effective than thermal paste and do not need to be replaced as often.
Disadvantages:
Higher cost: High-performance models (e.g., carbon fibre or phase change mats) can be more expensive, increasing the initial investment.
Non-reusable: Unlike thermal paste, thermal pads need to be replaced with new pads after disassembly.
Performance limitations: although more efficient in thermal conductivity, they are not as efficient as liquid metals and the thickness needs to be precisely chosen – too much thickness will reduce the effectiveness.
Lack of compressibility: Compared to thermal paste, thermal pads are slightly less capable of filling thin gaps and require a higher degree of surface flatness.
Thermal pad guide
Installation Methods and Tips
Clean the surface: Use alcohol to thoroughly wipe off old TIM, grease and stains to ensure the contact surface is clean.
Measurement Cutting: Cut the thermal pad accurately according to the size of the component (e.g. battery module, CPU or GPU). Leave 0.5mm margin to accommodate thermal expansion.
Fit and Install: Peel off one side of the protective film and gently press it against the heat source to ensure there are no air bubbles. Then remove the other side of the film, mount the heat sink and apply even pressure.
Optimise contact: Apply appropriate pressure (usually 10-20 PSI) to enhance the filling effect. Avoid distortion of the gasket due to excessive force.
For irregular surfaces, choose a softer silicone pad (e.g. Sur-Seal Sur-Cool series) for better ‘wettability’. In high temperature environments (e.g. EV battery packs), we recommend using gaskets with a wide temperature range (e.g. N-B Supermax from -60°C to 220°C).
Common mistakes in use and avoidance
- Avoid stacking multiple layers of thermally conductive pads, which will increase air gaps and reduce thermal conductivity efficiency.
- Don’t mix TIMs, such as pairing thermal pads with thermal paste, which may lead to uneven heat flow or even damage the device.
- Choose the right thickness, too thin or too thick will affect the heat conduction effect.
- Neglecting surface preparation will affect the lamination effect and reduce the heat dissipation performance.
Types and selection of thermal pads
There are many types of thermal pads, each with unique characteristics and applications. The following is a summary of the main types:
Silicone thermal pads (thermal conductivity: 1.0-15.0 W/m-K): soft, electrically insulating, suitable for general-purpose scenarios such as laptop computers, EV battery modules, and VGA cards. Non-corrosive, non-hardening for long-term use, easy to cut.
Graphite thermal pad (thermal conductivity: high, depending on design): ultra-thin, high thermal conductivity, suitable for 5G base station equipment and microcontrollers. Requires smooth surface, suitable for precision machining.
Carbon fibre thermal pads (thermal conductivity: 15.0-45.0 W/m-K): oriented carbon fibre, suitable for high power requirements, commonly used in EV BTMS and high load ESS, lightweight, in line with the trend of EV lightweight.
Silicone-free thermal pads (thermal conductivity: 1.0-6.0 W/m-K): avoid silicon contamination, non-corrosive, suitable for sensitive environments such as medical equipment, optical sensors and precision instruments.
Phase Change Thermal Conductive Pad (Thermal Conductivity: 1.8-8.0 W/m-K): Changes from solid to liquid between 45°C and 55°C, good wettability, very low thermal resistance, suitable for high heat scenarios such as CPUs, GPUs and MOSFETs.
Each type of thermal pad can provide targeted thermal management solutions depending on the thermal conductivity requirements, working environment and application scenarios.
How to choose the right thermal pad
Thermal conductivity: 1-6 W/m-K for low power devices, 15 W/m-K or more for high power (e.g. EV batteries).
Operating temperature: For extreme conditions (e.g. -60°C to 220°C), choose N-B Supermax type.
Thickness and Gap: Measure component gap and select matching thickness (e.g. 1.5mm or 2mm).
Environmental requirements: Choose silicone-free pads for sensitive scenarios, carbon fibre or phase change pads for high performance.
Other materials (e.g. acrylic, polyester, aluminium, fibreglass) can be used to meet specific needs, and Trumonytechs offers a bespoke service to help you match them precisely.
Optimising thermal management with Trumonytechs
Thermal pads are more than just a cooling tool, they are a strategic choice for improving the reliability and efficiency of your equipment. Their ease of use, efficiency and wide range of types make them the ideal solution for modern thermal management. Whether you are dealing with EV battery overheating or ESS long-term operation, thermal pads are there for you.
With 20 years of experience in the field of heat transfer, Trumonytechs offers innovative and cost-effective thermal pad solutions that help reduce BTMS costs and improve thermal management performance. Contact us today (#) for samples, technical support, or a custom solution to help make your project a success!
