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Talking about 6 kinds of heat dissipation methods of electronic devices
In the rapid development of electronic devices, the total power density of electronic components is also increasing, but its size is getting smaller and smaller, and the heat flux density will continue to increase. In such high temperature environment, it will inevitably affect electronic The performance indicators of components, in this regard, must strengthen the thermal control of electronic components. How to solve the heat dissipation problem of electronic components is the focus at this stage. In this regard, the article mainly analyzes the heat dissipation method of electronic components.
The problem of efficient heat dissipation of electronic components is influenced by the principles of heat transfer and fluid mechanics. The heat dissipation of the electrical device is to control the operating temperature of the electronic device, thereby ensuring the temperature and safety of the working, and mainly involves different aspects of heat dissipation, materials and the like. The main heat dissipation methods at this stage are mainly natural, mandatory, liquid, refrigeration, grooming, and thermal isolation.
1. Natural heat dissipation or cooling method
Natural heat dissipation or cooling is in the natural state, does not accept the influence of any external auxiliary energy, and the temperature is controlled by the local heat-generating device in the way of heat dissipation in the surrounding environment. The main way is heat conduction, convection and radiation concentration. The main application is convection and natural convection. Among them, the natural heat dissipation and cooling methods are mainly applied to electronic components with low temperature control requirements, low-power devices and components with relatively low heat flux density. This approach can also be applied in sealed and densely assembled devices without the need to apply other cooling techniques. At some time, when the heat dissipation capability is relatively low, the characteristics of the electronic device itself are utilized, and the heat conduction or radiation influence of the adjacent heat sink is appropriately increased, and the natural convection is optimized by optimizing the structure, thereby enhancing the heat dissipation of the system. ability.
2. Forced cooling or cooling method
The forced cooling or cooling method is a way to accelerate the air flow around the electronic components by means of a fan or the like, and to remove heat. This method is simpler and more convenient, and the application effect is remarkable. This method can be applied to electronic components if the space is large such that air flows or some heat dissipation facilities are installed. In practice, the main way to enhance this convective heat transfer capability is as follows: To properly increase the total area of heat dissipation, a relatively large convective heat transfer coefficient is generated on the heat dissipating surface.
In practice, the way to increase the heat dissipation area of the surface of the heat sink is widely used. In the project, the surface area of the radiator is expanded by means of fins, thereby enhancing the heat transfer effect. The fin heat dissipation method can be divided into different forms, heat exchange devices applied to the surface of some heat-consuming electronic devices and air. Applying this mode can reduce the heat sink resistance and improve the heat dissipation. For some electrons with relatively large power, the turbulence method in aviation can be applied for processing. By adding a spoiler to the heat sink and introducing a spoiler in the surface flow field of the radiator, the heat exchange can be improved. effect.
Of course, the choice of the material of the radiator itself has a direct relationship with its heat dissipation performance. At present, the material of the radiator is mainly made of aluminum through die-casting and folding fins/stamped thin fins. Aluminum has high thermal conductivity (198W/ mK) and the advantage of not easily oxidizing. In addition, AIN ceramics with a conductivity of more than 200 W/mk, the heat sink made of this material has the advantages of high thermal conductivity, non-conductivity, and long-term exposure to air without oxidation. Materials have been used in packaging technology and traveling wave tubes for electronic components. In addition, the use of silicon materials to make heat sinks has also been widely used in micro-systems. Chemical processing methods can be used to obtain microchannels with ideal aspect ratios on silicon materials.
3. Liquid cooling method
The heat dissipation treatment of the liquid cooling method in the electronic component is a heat dissipation method based on the chip and the chip component. Liquid cooling can be divided into direct cooling and indirect cooling. Indirect liquid cooling is the application of the liquid coolant to the direct contact with the electronic components, through the intermediate media system, using liquid modules, thermal modules, spray liquid modules and liquid substrates and other auxiliary devices between the emitted thermal components Pass it. The direct liquid cooling method can also be called immersion cooling method, which is to directly contact the liquid with related electronic components, absorb heat by the coolant and take away heat, mainly in some heat loss volume density or high temperature environment. Applied device.
4. Cooling method for heat dissipation or cooling method
The cooling methods of heat dissipation or cooling methods mainly include phase change cooling of refrigerant and Pcltier refrigeration. The manners adopted in different environments are also different, and it is necessary to comprehensively apply the actual conditions. 1 Phase change cooling of refrigerant is a way to absorb a large amount of heat through the phase change of the refrigerant, which can cool the electronic device in some specific occasions. The general state is mainly to take away the heat in the environment through the evaporation of the refrigerant, which mainly includes two types of volume boiling and flow boiling. Under normal conditions, cryogenic technology also has important value and influence in the cooling of electronic components. In some computer systems with relatively high power, cryogenic technology can be applied, which not only can improve the cycle efficiency, but also the number of refrigeration and temperature range. The structure of the whole machine is relatively compact and the cycle efficiency is relatively high. Higher. 2 Pcltier Cooling Heats or cools some conventional electronic components through semiconductor cooling, which has the advantages of small size, easy installation, high quality and easy disassembly. This method is also called thermoelectric cooling. It is through the Pcltier effect of the semiconductor material itself. In the direct current, a galvanic couple is formed under the action of a series of different semiconductor materials. It can absorb heat and release heat at both ends of the galvanic couple. In this way, the effect of cooling can be achieved. This method is a kind of refrigeration technology and means that produces negative thermal resistance. Its stability is relatively high, but because of its relatively high cost and relatively low efficiency, it is relatively compact in some volumes and has low requirements for refrigeration. Application in the environment. Its heat dissipation temperature is ≤100 °C; cooling load is ≤300W.
5. Energy dissipation in heat dissipation or cooling
The heat transferred by the electronic device is transferred to another environment by a heat transfer element that transfers heat. In the process of electronic circuit integration, high-power electronic devices are gradually increasing, and the size of electronic devices is becoming smaller and smaller. In this regard, this requires the heat sink itself to have certain heat dissipation conditions, and the heat sink itself must have certain heat dissipation conditions. Because the heat pipe technology has certain thermal conductivity characteristics, has good isothermal characteristics, has variability of heat flow density in the application, has good constant temperature characteristics, can quickly adapt to the advantages of the environment, and is widely used in heat dissipation of electrical and electronic equipment. It can effectively meet the characteristics of flexibility, high efficiency and reliability of the heat sink. At this stage, it is widely used in the cooling of electrical equipment, electronic components and heat dissipation of semiconductor components. The heat pipe is a high-efficiency mode for heat conduction through a phase change heat transfer method, and is widely used in heat dissipation of electronic components. In practice, it is necessary to design different types of heat pipes, design the heat pipes separately, and analyze the influence of factors such as gravity and external forces. In the process of designing the heat pipe, it is necessary to analyze the materials, processes and cleanliness of the production, and strictly control the quality of the products and carry out temperature monitoring and treatment.
6. Thermal isolation heat dissipation method
Thermal isolation is the effect of heat dissipation and cooling of electronic components through thermal insulation. It is mainly divided into two types: vacuum insulation and non-vacuum insulation. The main application of temperature control of electronic components is non-vacuum type adiabatic treatment. Non-vacuum insulation is carried out by thermal insulation materials. This type of insulation is also a way of volume insulation, directly affected by the thickness factor of the thermal insulation material, and the physical parameters of the thermal conductivity of the material directly affect its thermal insulation effect. The thermal isolation method is mainly caused by the temperature influence of the local device. It is necessary to strengthen the control, organize the temperature rise effect of the high temperature device and related objects, thereby ensuring the reliability of the entire component and prolonging the service life of the device. In practice, because the temperature directly affects the heat transfer performance of the insulating material, under normal conditions, if the temperature rises, the insulating material is increased. At the same time, an increase in temperature also increases the internal radiation in the porous medium in the insulating material. When applying insulation measures, if the equipment running time is relatively long, the actual insulation effect will be worse. At the same time, if the temperature rises, the total thermal conductivity of the porous heat insulating material itself is continuously increased. In this regard, it is necessary to ensure the overall performance of the insulation material, thereby improving the application effect.
In the development of integrated circuits, the density and heat density of electronic components continue to increase, and the problem of heat dissipation has become increasingly prominent. In this regard, high-quality heat dissipation and cooling methods can guarantee the performance of electronic components. In practice, it is necessary to integrate the heating power of the specific electronic components, its own characteristics, the reasonable application of different heat dissipation and cooling methods and means, to integrate specific application occasions, to rationally select the application methods and means, and to highlight the electronic components. Performance indicators.