Thermal management refers to the tools and technologies used to maintain a system within its operating temperature range. With electronic devices, thermal management typically dissipates excess heat to prevent overheating. Most electronic systems generate heat, and sensitive internal components can become damaged if too much thermal energy accumulates inside the device. Similarly, electronics can become damaged due to excessive exposure to high temperatures in their external environments.
Engineers use thermal management solutions across a wide range of industries, including aerospace, automotive, batteries, and data centers. Temperature control can be a complex and critical aspect of any design. Engineers carefully consider each system’s unique features to optimize for performance, durability, and longevity in that application.
Some of the most popular tools for thermal management include cooling technologies such as heat sinks and fans. Some liquid-cooled systems use cryogenic fluids for rapid temperature reduction. In addition to cooling technologies, thermal engineers may use insulating materials to isolate or reduce the rate of heat transfer toward sensitive areas.
What is the difference between active and passive thermal management?
Engineers may design thermal management systems with active technologies, passive technologies, or both. Active devices, such as fans, pumps, and thermoelectric coolers, require an external power source to operate. Passive tools, on the other hand, do not require a power source. These include devices like heat sinks, heat spreaders, and heat pipes. Passive technologies enhance natural conduction, convection, or radiation taking place within the system.
Engineers use both active and passive technologies for the same purpose: to increase heat dissipation and maintain the system within its operating temperature range. Because passive tools don’t require an external energy source, they are often less expensive than active thermal management technologies.
Examples of passive cooling methods
Heat sinks are some of the most common passive cooling equipment. A heat sink consists of a thermally conductive metal such as copper or aluminum and attaches to the heat-generating component. Thermal energy transfers via conduction from the heat source through the metal. Then, the energy is dissipated via natural convection from the heat sink’s surface area into the surrounding atmosphere.
Heat spreaders are another example of popular passive cooling devices. Thermally conductive foils or metal plates help expand the distribution of concentrated heat over a wider area. Typically, heat spreaders operate as an intermediate material between the heat source and secondary heat exchangers.
Examples of active cooling technologies
Many active cooling devices use forced air to increase convective cooling. A blower or a fan increases the airflow in the vicinity of the heat-generating component. This technique increases convection and enables the high-temperature air to move away faster, significantly improving heat dissipation.
Thermoelectric coolers, also called solid-state heat pumps, are often used with semiconductors. Thermoelectric coolers are thin and compact and typically sit between a heat sink and a heat source. Voltage is applied to the unit, creating a temperature difference between the heat sink and the heat source. This increased temperature delta increases the rate of conduction.