Thermal Pads - A Comprehensive Analysis of Thermal Interface Gaskets

During the manufacturing and assembly of electronic devices, thermal management remains a key concern for manufacturers. High temperatures can lead to device overheating, shortening device lifespan and reducing performance. While thermal grease is a common solution, it still has limitations such as difficult application and high waste. Therefore, thermal pads have become a more suitable option in many scenarios. So, what are thermal pads? What are their types? What are their advantages over thermal grease? This article provides a comprehensive explanation!

Definition of Thermal Pads

A thermal pad (also known as a thermal interface gasket) is a pre-formed square or rectangular solid material (usually based on silicone). It is typically attached to the bottom of a heat sink to transfer heat from heat-generating components (such as CPUs or other chips) to the heat sink. Because air has extremely poor thermal conductivity, air gaps between uneven surfaces hinder heat transfer. A thermal pad fills these gaps, eliminating air layers and improving heat dissipation efficiency.

1. Classification by Base Material: Silicone-Based Thermal Pads: Silicone is the most commonly used base material in thermal interface materials (TIMs) due to its superior thermal conductivity compared to traditional polymers. It also offers excellent compressibility and high-temperature resistance, ensuring long-term, stable heat dissipation. Non-Silicone-Based Thermal Pads: These prevent silicone oil from precipitating at room temperature and are commonly used in high-precision medical devices such as precision optical devices and LEDs. They contain no volatiles that contaminate optical windows or PCBs. Suitable for applications including ICs, CPUs, MOSFETs, LEDs, motherboards, power supplies, LCD TVs, laptops, and communications equipment.

2. Classification by Structure: Adhesive-Backed Thermal Pads: These come pre-coated with an adhesive layer on one or both sides and can be directly applied to component or heat sink surfaces without the need for additional fixings. Non-Adhesive-Backed Thermal Pads: These rely on the weight or pressure of other components within the system to maintain their position and are suitable for press-fit applications.

Advantages of Thermal Pads vs. Thermal Grease

Ease of use and interchangeability, pre-molded design and flexible sizes prevent over- or under-application and reduce material waste. Residual silicone grease cleaning during replacement simplifies maintenance. Its solid form makes it easy to cut and position, allowing it to be applied to heat-generating electronic components, improving thermal contact efficiency. Considering the trade-offs in applicable scenarios, thermal pads typically offer lower thermal conductivity than high-end thermal greases, so selection should be based on specific application requirements. Applications of Thermal Pads: Computers and Electronic Components: Used in CPUs, GPUs, RAM, and motherboards to prevent overheating and maintain performance. Consumer Electronics: Manage heat from processor chips and batteries in mobile phones, tablets, and handheld game consoles. Communications Equipment: Ensure stable operation in network equipment such as routers and modems. Industrial and Automotive Electronics: Provide temperature management and component protection in industrial control systems and in-vehicle electronics. Power Supplies: Control temperature in computer power supplies, chargers, and adapters to prevent overheating.

Thermal interface materials, acting as the "heat bridge" between electronic components, are crucial to device life and performance. With the rapid development of the electronics industry, materials like thermal pads have become essential components.

However, selecting the right thermal pad requires a comprehensive consideration of size, thickness, and material properties. The current market offers products of various specifications, such as 1mm, 2mm and other thickness options, to meet the needs of different scenarios.