Data centers, filled with densely packed servers running resource-intensive processes, face significant heat-related challenges. Excessive heat can throttle server performance to prevent hardware damage, leading to efficiency losses, while persistent overheating accelerates wear and tear, increasing the risk of hardware failures and costly outages. These issues highlight the urgent need for advanced thermal management solutions to ensure optimal performance, reliability, and sustainability in high-performance data centers. In this article, let’s discover the advanced thermal interface materials (TIMs) that can transform thermal management in high-performance data centers.
The challenge with current solutions
As data centers scale to meet the increasing demands of modern computing, traditional thermal management solutions reveal significant shortcomings. Conventional heat dissipation methods, such as metal-to-metal interfaces struggle to handle the higher heat outputs of advanced hardware. These materials often fail to fill microscopic gaps completely, resulting in suboptimal thermal conductivity.
Legacy solutions like conventional phase-change films deteriorate after repeated insertions and removals, such as those required for pluggable optical modules (POMs). This degradation not only reduces thermal performance but also risks introducing volatile compounds into the data center environment, which can compromise sensitive electronic components.
Moreover, these traditional methods are often unable to handle the increased power densities of newer transceiver designs, which can exceed 20W or even 35W per module. With as many as 32 modules per line card, the cumulative thermal load becomes a critical challenge. These inefficiencies lead to overheating, increased energy consumption, and higher cooling costs, ultimately impacting data center performance and sustainability.
Because of these realities, a top switch manufacturer looked to a new, innovative solution for thermal control to reduce operating temperatures of its 20W transceiver application.
Why effective thermal interface materials matter in data centers
TIMs play a critical role by bridging microscopic air gaps between heat-generating components and their cooling solutions, such as heatsinks or heat spreaders. Without effective TIMs, these air gaps act as thermal barriers, reducing the efficiency of heat transfer and leading to several issues. TIMs ensure the following benefits:
- Avoiding performance degradation: Excessive heat can cause processors and other components to throttle their performance to prevent overheating, leading to reduced computational efficiency.
- Extending hardware lifespan: Effective heat dissipation reduces thermal stress, preventing wear and tear and significantly prolonging the lifespan of costly hardware.
- Enhancing energy efficiency & reducing operational costs: By optimizing heat transfer, TIMs enable cooling systems to operate more efficiently, reducing energy consumption. This not only lowers operational costs for large-scale data centers but also minimizes environmental impact, supporting sustainability goals.
Overview of Thermal Interface Materials’s application in data center
There are several types of TIMs commonly used in data centers, including:
1. Micro-Thermal Interface Coatings
MicroTIM is a durable, thermally conductive, thin film coating applied to networking line card heat sinks that come in contact with POMs. Ultra-thin and durable, micro-thermal interface coatings solutions provide efficient heat transfer between pluggable optical modules (POMs) and their riding heat sinks. Some materials reduce heat at a rate of 0.33 °C per watt, achieving up to 5°C reduction for a 15-watt module. They are ideal for high-speed switching and routing systems, such as 400 Gb designs.
2. Thermal Greases
Thermal grease, also known as thermal paste, is used to fill the gaps between CPUs/GPUs and their heat sinks. Its primary function is to ensure smooth heat transfer by eliminating air gaps, which are poor conductors of heat. Thermal grease remains stable over a wide temperature range (-40°C to +200°C), providing high thermal conductivity, electrical insulation, and resistance to environmental stress.
3. Thermal Gel
Thermal gels are highly viscous, thermally conductive materials made by mixing thermally conductive powders with silica gel. Produced in vacuum conditions, these materials contain no air, ensuring excellent heat transfer. Some one-part liquid gels offer process flexibility, low component stress, and thermal conductivities up to 6.0 W/m-K. Their dispensability makes them suitable for high-volume manufacturing, offering low volatility, gap stability, and reliability in challenging conditions.
4. Phase-Change Materials
Phase-change materials remain solid at room temperature but melt during operation, ensuring superior thermal contact. These materials are particularly effective for Layer 1/Layer 2 ASIC and FPGA devices, where high heat dissipation is critical for functionality. As a mess-free alternative to thermal grease, they are preferred in high-performance, high-reliability environments.
5. Thermal Pads
Pre-formed thermal pads are an easy-to-apply solution, ideal for mass production environments. With low modulus and high conductivity, these pads are suitable for integrated circuits (ICs) that do not require larger heat sink attachments. Their conformability ensures low-stress thermal performance while simplifying the application process.
6. Thermal conductive adhesives (TCA)
Thermally conductive adhesives (TCA) adhesives provide not only mechanical bonding but also thermal conductivity. TCAs exhibit a wide range of thermal conductivity values, generally ranging from 0.1 W/m·K to 60 W/m·K, which vary based on the type of filler material, its concentration, configuration, and the thermo-mechanical properties of the adhesive matrix.
Their primary uses include attaching SMDs (Surface Mount Devices) to PCBs (Printed Circuit Boards), bonding heatsinks to components such as PCBs, transformers, and coils. TCAs are also applied in thermal management tasks like dissipating heat from circuit boards or other electronic components, as well as potting and encapsulating parts in motors, batteries, lighting systems, and LED assemblies.
Common types of adhesives used for these applications are 1-part and 2-part silicones, 2-part epoxies, and polyurethanes, especially for potting purposes. In some cases, 1-part epoxy adhesives can be used, provided the components can tolerate the high temperatures required for curing.
Choosing the Right TIM Solution
Selecting the appropriate TIM for your data center depends on factors such as thermal conductivity requirements, application method, and compatibility with other materials. Key considerations include:
- Thermal conductivity: Measured in W/mK (watts per meter Kelvin), higher thermal conductivity values indicate better heat transfer capabilities.
- Application method: Ease of application and reworkability can impact maintenance schedules and overall efficiency. Pre-formed pads or dispensable gels may be preferred for their simplicity and adaptability.
- Durability: Materials should withstand operational stresses, including high temperatures and mechanical compression.
- Environmental compliance: Eco-friendly and RoHS-compliant materials contribute to sustainable operations.
The choice of the appropriate thermal interface materials depends on the specific requirements of the application and environmental conditions in the data center. Each type of material offers its own advantages and is suited to different demands during the manufacturing and usage processes. With many years of experience in the industrial material, Prostech is ready to assist customers in selecting the right thermal interface material and providing integrated solutions for production lines to optimize manufacturing efficiency. Contact us for free consultation.
