Four Heat Dissipation Methods for Electronic Devices
With the rapid development of high-frequency, high-speed, and integrated circuit technology, the overall power density of electronic components has sharply increased, while their physical dimensions have become increasingly smaller. The resulting high-temperature environment inevitably affects the performance of electronic components, necessitating more effective thermal control methods. Addressing the heat dissipation issues of electronic components has become a key task.
Natural cooling refers to temperature control that occurs under natural conditions without relying on any external auxiliary energy. It involves the dissipation of heat from localized heating components to the surrounding environment through conduction, convection, and radiation. Among these, convection and natural convection are the primary methods used. Natural cooling is mainly suitable for applications with lower temperature control requirements, relatively low power density, and low-power devices and components. In sealed and high-density assemblies, natural cooling alone can often meet requirements without the need for additional cooling technologies. In certain cases, when heat dissipation demands are relatively low, the system's heat dissipation capability can be optimized by increasing the thermal conduction or radiation transfer with nearby heat sinks.
2. Air Cooling
Air cooling involves accelerating the airflow around electronic components using devices like fans to carry away heat. This method is simple, convenient, and effective. If there is sufficient space for air circulation or cooling devices can be installed, this approach can be employed. In practical engineering, increasing the heat transfer capability through convection is typically achieved by enlarging the heat dissipation surface area to enhance the convection heat transfer coefficient.
In practice, methods to increase the heat sink surface area are widely applied. Techniques such as using fins to extend the heat sink surface area enhance heat transfer effectiveness. Different forms of finned heat sinks are utilized in various applications to improve heat exchange. For higher power electronic components, techniques from aerodynamics, such as adding turbulence fins, can be employed to introduce turbulence in the flow field on the heat sink surface, thereby improving heat transfer.
Liquid cooling is a method of heat dissipation based on chips and chip components. It mainly divides into direct and indirect cooling methods.The indirect liquid cooling method indirectly contacts the liquid coolant with the electronic components through the liquid cold plate, and transfers heat between the heat source components by using auxiliary devices such as the liquid module, the heat conduction module, the injection liquid module and the liquid substrate.Direct liquid cooling, also known as immersion cooling, allows the liquid to directly contact relevant electronic components, absorbing and carrying away heat. This method is particularly suitable for devices in high heat density or high-temperature environments.
A typical heat pipe structure includes a pipe shell, a porous capillary core, and a working fluid. In a vacuum state, the working fluid absorbs heat from the heat source in the evaporation section and vaporizes. Driven by a small pressure difference, it rapidly flows to the condensation section, releasing latent heat to the cold source and condensing back into a liquid. Then, under the action of the capillary suction force of the wick, the condensed liquid returns from the condensation section to the evaporation section, again absorbing heat from the heat source. This cycle continuously transfers heat from the evaporation section to the condensation section. The main advantage of heat pipes is their ability to transfer a large amount of heat under small temperature differences, with a relative thermal conductivity hundreds of times that of copper, earning them the title "near-superconducting heat transfer devices." However, each heat pipe has a heat transfer limit. When the heat generated at the evaporation end exceeds a certain critical value, the working fluid within the heat pipe completely vaporizes, interrupting the cycle and leading to heat pipe failure. As micro heat pipe technology in China is not yet mature, this technology has not been widely applied in the cooling of power electronic devices.
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