Several Efficient Heat Dissipation Methods for Electronic Products

The performance of electronic products is becoming more and more powerful, and with the continuous improvement of integration and assembly density, their working power consumption and heat generation have increased sharply. The material failures of electronic components caused by heat concentration account for the vast majority of the total failure rate. Thermal management technology is a key factor to be considered for electronic products. In this regard, it is necessary to strengthen the thermal control of electronic components. To help everyone have a deeper understanding, this article will summarize the relevant knowledge of the heat dissipation methods of electronic components.

The problem of efficient heat dissipation of electronic components is affected by the principles of heat transfer and fluid mechanics. The heat dissipation of electrical devices is to control the operating temperature of electronic equipment, thereby ensuring its working temperature and safety, which mainly involves different contents in various aspects such as heat dissipation and materials. At present, the main heat dissipation methods for electronic components include natural heat dissipation, forced heat dissipation, liquid heat dissipation, refrigeration, heat conduction, thermal isolation, etc.

Heat dissipation design

Heat dissipation technology mainly refers to the methods, approaches and techniques of external thermal design, involving various aspects such as heat dissipation or cooling methods related to heat transfer, and materials. According to the differences in heat conduction and heat convection means, heat sink products can be divided into two types: active and passive.

The meaning of “active” is that there is energy participation unrelated to the heat source for forced heat dissipation. For example, fans, water pumps in liquid cooling systems, and compressors in phase change refrigeration systems. The common characteristic of these heat dissipation methods is high efficiency, but they also require the assistance of other energy sources.

On the contrary, “passive” means relying only on the self-dissipation of the heat source or the heat sink to cool down. At present, the more widely applied heat dissipation technologies mainly include natural heat dissipation or cooling methods, forced heat dissipation or cooling methods, liquid cooling technology, active refrigeration heat dissipation methods, heat conduction heat dissipation or cooling methods, thermal isolation heat dissipation methods, etc.

Natural heat dissipation or cooling method

Natural cooling is a very commonly used heat dissipation method. Natural cooling is a cooling method that utilizes the high thermal conductivity of materials (mainly referring to profiles) to carry away heat and dissipate it into the air.

That is, in the absence of specific wind speed requirements, natural convection heat sinks such as copper-aluminum heat dissipation plates, extruded aluminum heat sinks, machined heat sinks or alloy heat dissipation castings are used to achieve the heat dissipation of products.

The natural heat dissipation and cooling method is mainly applied to electronic components with relatively low requirements for temperature control, low-power equipment and components in which the heat flux density of the heat generated by the devices is relatively low.

Forced heat dissipation

The forced heat dissipation or cooling method is a way to accelerate the air flow around electronic components through means such as fans and take away the heat.

Air cooling for heat dissipation is also a very common heat dissipation technology.

Its manufacturing is relatively simple, and it has the advantages of relatively low cost, simple installation, etc.

If there is a large space in electronic components to allow air flow or some heat dissipation facilities can be installed, this method can be applied. In practice, appropriately increasing the total heat dissipation area and generating a relatively large convective heat transfer coefficient on the heat dissipation surface are the main ways to enhance this convective heat transfer capacity.

Liquid cooling

Using the method of liquid cooling for heat dissipation treatment of electronic components is a heat dissipation method based on chips and chip components. Liquid cooling can mainly be divided into two methods: direct cooling and indirect cooling.

The indirect liquid cooling method means that the liquid coolant used does not come into direct contact with the electronic components. Instead, through an intermediate medium system, auxiliary devices such as liquid modules, heat conduction modules, liquid spraying modules, and liquid substrates are used to transfer heat between the heat-generating components.

The direct liquid cooling method, which can also be called the immersion cooling method, is to make the liquid come into direct contact with the relevant electronic components. The coolant is used to take away the heat. This method is mainly applied to some devices with a relatively high volume density of heat consumption or those used in high-temperature environments.

Active refrigeration for heat dissipation

The methods of heat dissipation or cooling through refrigeration mainly include two types: the phase change cooling of the refrigerant and Peltier refrigeration. Different methods are adopted in different environments, and they should be applied reasonably according to the actual situation.

01 Phase change cooling of the refrigerant

It is a method that absorbs a large amount of heat through the phase change effect of the refrigerant, and can cool electronic devices in some specific situations. In general, it mainly takes away the heat in the environment through the evaporation of the refrigerant, which mainly includes two types: pool boiling and flow boiling.

As a consistent method of heat dissipation through the phase change effect of the refrigerant, cryogenic technology also has important value and influence in the cooling of electronic components. Cryogenic technology can be applied in some computer systems with relatively high power. It can not only improve the cycle efficiency, but also has a wide range of refrigeration quantity and temperature range. The structure of the whole machine equipment is relatively compact, and the cycle efficiency is also relatively high.

02 Semiconductor refrigeration

When using semiconductor refrigeration to dissipate heat or cool some conventional electronic components, it has the advantages of a small device size, convenient installation, good quality, and easy disassembly. This method is also known as thermoelectric refrigeration. That is, through the Peltier effect of the semiconductor material itself, direct current passes through different semiconductor materials and forms an electric couple when connected in series. At this time, by absorbing heat at one end of the electric couple and releasing heat at the other end, the refrigeration effect can be achieved.

This is a kind of refrigeration technology and method that generates negative thermal resistance, and it has relatively high stability. However, due to its relatively high cost and low efficiency, it is only applied in some environments where the space is relatively compact and the refrigeration requirements are relatively low.

Heat conduction for heat dissipation

The heat emitted by electronic devices is transferred to another environment through heat transfer elements that transfer heat. In the process of integration of electronic circuits, the number of high-power electronic devices is gradually increasing, and the size of electronic devices is getting smaller and smaller. This requires that the heat dissipation device itself should have certain heat dissipation conditions.

The heat pipe technology itself has certain characteristics of thermal conductivity and good isothermality. In application, it has the advantages of variable heat flux density, good constant temperature characteristics, and the ability to quickly adapt to the environment. Therefore, it is widely used in the heat dissipation of electronic and electrical equipment, which can effectively meet the flexible, efficient and reliable characteristics of the heat dissipation device. At present, it is widely used in the cooling of electrical equipment, electronic components and the heat dissipation of semiconductor components.

The heat pipe is a highly efficient mode of heat conduction through the phase change heat transfer method, and it is widely used in the heat dissipation of electronic components. In practice, it is necessary to design the heat pipe independently according to the requirements of different types, and conduct a reasonable design by analyzing the influence of factors such as gravity and external force. During the design process of the heat pipe, it is necessary to analyze issues such as the manufacturing materials, processes, and cleanliness, and strictly control the product quality, and carry out temperature monitoring.

Thermal isolation heat dissipation method

Thermal isolation is to dissipate heat and cool electronic components through adiabatic technology. It is mainly divided into two forms: vacuum adiabatic and non-vacuum adiabatic. In the temperature control of electronic components, non-vacuum adiabatic treatment is mainly applied. And non-vacuum adiabatic treatment is carried out through adiabatic materials with a low thermal conductivity coefficient.

This adiabatic form is also a kind of volume adiabatic method, which is directly affected by the thickness of the adiabatic material, and the physical parameters of the thermal conductivity coefficient of the material also directly affect its adiabatic effect. The thermal isolation method mainly affects the temperature of local devices, strengthens control, and prevents the temperature rise effects caused by high-temperature devices and related objects, thereby ensuring the reliability of the entire component and extending the service life of the equipment.

In practice, since the temperature directly affects the heat transfer performance of the adiabatic material, generally, the higher the temperature, the more adiabatic material is required. At the same time, an increase in temperature will also increase the internal radiation in the porous medium of the adiabatic material. When applying adiabatic measures, if the equipment runs for a relatively long time, the actual adiabatic effect will be worse. Also, when the temperature rises, it will lead to an increase in the total thermal conductivity coefficient of the porous adiabatic material itself. In this regard, it is necessary to ensure the overall performance of the adiabatic material to improve the application effect.

Conclusion

In the development process of integrated circuits, the density of electronic components and the heat density have been continuously increasing, and the heat dissipation problem has gradually become more prominent. In this regard, high-quality heat dissipation and cooling methods can ensure the performance indicators of electronic components.

In practice, it is necessary to comprehensively consider the specific heat generation power and inherent characteristics of electronic components, and rationally apply different heat dissipation and cooling methods and means. It is also necessary to take into account the specific application scenarios and make a reasonable choice of the application methods and means, so as to highlight the performance indicators of electronic components.