Increased edge processing, performance enhancements, and miniaturisation of embedded platforms have led to an increase in power consumption and heat generation, creating thermal hotspots. Thermal stress can significantly degrade the performance of embedded systems and even cause entire system failures. Long-term exposure to excessive heat also reduces the lifespan of electronic components.
Understanding thermal management techniques is crucial for maintaining a device in optimal operating condition. Advancements in the electronics industry have driven the need for innovative thermal management technologies to enhance system reliability and performance.
Proper thermal management is essential for maintaining performance, reliability, and longevity in these devices. Below we consider thermal accessories and their importance to a range of products.
When it comes to CPUs and Graphics Processing Units (GPUs), especially in high-performance computers and servers, significant heat can be generated due to intensive computational tasks. Heatsinks, thermal paste, and cooling fans are critical for dissipating heat and ensuring stable performance. In terms of GPUs cooling solutions like large heatsinks, fans, and sometimes liquid cooling are necessary to maintain optimal temperatures, prevent overheating, and sustaining high performance.
Power supplies convert AC to DC power, which involves significant energy loss as heat, consequently, active cooling with fans and passive cooling with heatsinks are essential to maintain the efficiency and longevity of power supplies.
High-speed memory modules (RAM, DRAM) can also generate heat, which if unchecked, can lead to data corruption or system instability. Heat spreaders and cooling fans are used to dissipate heat and maintain data integrity and speed.
Networking equipment often runs 24/7, leading to continuous heat generation, so heatsinks, fans, and sometimes environmental cooling (like air conditioning in server rooms) are necessary to ensure consistent performance and prevent failure.
When it comes to embedded designs they often have to operate in constrained environments where heat dissipation is difficult. Custom heatsinks, thermal pads, and specialised enclosures with cooling are used to manage heat in these compact systems, ensuring reliability in industrial and automotive applications.
Mobile devices are compact with limited space for cooling, yet they run high-performance processors and batteries that generate heat. Techniques like thermal throttling, graphite heat spreaders, and advanced materials are used to manage heat without increasing device size.
Batteries, especially in electric vehicles and high-capacity storage systems, generate heat during charging and discharging. Cooling systems, including liquid cooling, thermal management systems, and heat-resistant materials, are vital to prevent overheating, which can lead to reduced battery life or even hazardous situations.
When it comes to base stations, antennas, and other telecom equipment they all generate constant heat during operation, so heatsinks, fans, and climate-controlled enclosures are essential for maintaining equipment reliability and service availability.
Finally, we have HPC systems, used in scientific research, AI, and big data analysis. Liquid cooling, immersion cooling, and sophisticated air-cooling systems are all deemed critical to manage heat and ensure uninterrupted, high-speed operation.
Thermal accessories are indispensable across a wide range of electronic products and play a vital role in dissipating heat, preventing overheating, and ensuring devices perform reliably and efficiently. Without proper thermal management, electronic products can suffer from reduced performance, instability, and potentially catastrophic failure. The choice of thermal solutions depends on the specific requirements of the product, including its power consumption, size, and operational environment.
Heat dissipation techniques
Heat dissipation techniques are more crucial than ever, with systems becoming smaller and more powerful. Designers can use several methods to remove heat from components and PCBs, with common mechanisms including th following:
Heatsinks are large surfaced, thermally conductive metallic parts that act as passive heat exchangers, dissipating heat to the surrounding air via conduction. Adding cooling fans to heatsinks aids in the faster and more effective removal of heat. This combination is one of the most common and effective methods for cooling embedded systems, especially in environments with limited airflow.
Heat pipes are cooling devices used in high-temperature applications. A typical heat pipe consists of a fluid that absorbs heat, vaporizes, and travels along the pipe. At the condenser end, the vapor turns back into a liquid, and the cycle repeats. Heat pipes are highly efficient and can transfer heat over long distances, making them ideal for compact and high-density electronic devices.
Heat spreaders have a large flat surface that is usually pressed directly against another large flat surface. They allow heat transfer from a smaller component to a larger metal surface. Heat spreaders are intended for devices that must withstand extreme shocks and vibrations or are housed inside sealed containers. They provide a robust solution for managing heat in ruggedized and sealed embedded systems.
Thermoelectric coolers are ideal for systems where component temperature must be kept constant. High-power dissipation processors often use a combination of TECs, air cooling, and liquid cooling to extend beyond conventional air-cooling limits. TECs can cool components to temperatures below ambient, providing precise temperature control.
Thermal via arrays are incorporated over copper-filled areas and placed close to power sources. In this method, heat flows from components to the copper area and dissipates through the air from the vias. Thermal vias are often used in power management modules and components with thermal pads, enhancing the thermal conductivity of the PCB.
Liquids can transfer heat four times faster than air, enabling higher thermal performance in smaller solutions. A liquid cooling system includes a cold plate or cooled enclosure to interface with the heat source, a pump or compressor to circulate the liquid, and a heat exchanger to absorb and dissipate the heat safely. Liquid cooling is particularly effective for high-power applications and densely packed electronic assemblies.
Above: This heatsink with cooling fan helps dissipate heat from the component(s) it’s mounted on. (Image source: iWave)
Custom designs
iWave is a designer of heatsinks, fan sinks, and enclosures tailored to the specific thermal characteristics of their products, and they use thermal simulation software to help their mechanical engineers determine the most appropriate cooling methods and understand the associated thermal parameters, ultimately improving overall product reliability.
Using tools like Ansys Icepak, engineers can simulate heat flow patterns within a device to identify thermal hotspots and optimise the placement of cooling components. By understanding how heat moves through a system, iWave's engineers can design more effective thermal management solutions.
iWave also designs custom heatsinks to fit the unique needs of each project. The design process involves calculating theoretical heat dissipation values based on surface area and material properties. Engineers then test these designs using simulation software to ensure they provide adequate cooling under various operating conditions.
Active cooling methods, such as the integration of TECs and cooling fans, are also considered during the design phase. iWave can evaluate the benefits and limitations of each method, selecting the most efficient and cost-effective solution for each application.
iWave offers thermal solutions for all form factors, including OSM, SMARC, Qseven, and SODIMM and utilises aluminium alloy AL6063 due to its excellent material properties. Aluminium is a superb conductor, non-toxic, recyclable, and highly durable, making it ideal for transferring heat from components.
Through in-house thermal solutions, their product designers can reduce implementation costs by eliminating engineering delays, field failures, and product iterations. Reducing the amount of heat dissipated by the device improves efficiency and reliability, ensuring the longevity of the product.
Conclusion
The increasing complexity and power density of embedded systems necessitate advanced thermal management techniques, but by employing a variety of heat dissipation methods, designers can ensure optimal performance and reliability of their devices.
Author details: Rolf Horn is an Applications Engineer, DigiKey
