The Thermal solution of power supply
First of all, let's understand the current user's awareness of power supply cooling: the majority of DIY users pay more attention to CPU, graphics card, motherboard and other accessories that can directly affect the performance of the whole machine. However, the power supply has not been given enough attention, and the quality of the power supply has not been paid much attention. I always feel that the wattage is almost enough. However, the role of the power supply is actually very important, and it is definitely as improtant as the CPU. The stable operation of the entire power supply depends entirely on the power supply. The consideration of power supply cooling is mainly due to the cooling needs of the entire chassis, they often pay more attention to quietness, low prices and so on.
The biggest problem of power supply---high temperature
A complete power supply consists of a casing, a fan, a circuit board (with various electronic components inserted on the board), and a power socket. The basic working principle of the power supply is to convert the high voltage alternating current into the different low voltage direct current required by the computer through high frequency switching technology. In the AC-DC conversion process, due to technical limitations and the electronic components themselves have a hindering effect on the current, a part of the energy must be turned into heat energy, which is dissipated in the air in the form of heat, giving people the feeling of high temperature. When the power supply works at high temperature, its performance will be reduced compared with that at normal temperature, which is reflected in the reduction of output power. This is because high temperature will affect the accuracy and stability of electronic components, as well as the resistance, capacitance, and inductance of various electronic components. Sometimes even damage to electronic parts can cause the power supply to not work properly or not.
How to solve the thermal problem of power supply?
People have realized the importance of power supply heat dissipation, but how to solve this thermal problem is the designers have to think about. Judging from the current power supply design, they are all air-cooled. The high-level heat pipe + air-cooled dual heat dissipation is more and more popular in the market. Air cooling include traditional exhaust type, big windmill type, front row and rear blow type, front row down suction type, down blow back suction type, direct blow type, etc.
So in addition to the different cooling methods of fans and heat sinks, what other factors affect the cooling of the power supply?
Other factors that affect the heat dissipation of the power supply are: power conversion efficiency, circuit board layout, heat sink material, etc.
1. Power conversion efficiency refers to the ratio of the input power to the output power of the power supply. If the conversion efficiency of a power supply is only 70%, the rest is sometimes 30% converted into heat. If it is increased to 80%, the heat will be reduced by 10%. The actual effect will cause the temperature to drop by 5-10 degrees. If the working environment of the power supply is increased by 10 degrees, the lifespan will be reduced by half. Therefore, improving the conversion efficiency of the power supply virtually prolongs the life of the power supply.
2. Circuit board layout. The circuit board is the carrier of all electronic parts. Electronic components are arranged on a circuit board in a certain order. If the circuit board layout design is unreasonable, there will be a dead space for heat dissipation. The conversion efficiency of a power supply is determined by the power capacity of the transformer, the parameters of the power tube and the heat dissipation conditions, and is determined by the lowest one. If both the transformer and the power tube have a large margin, then if the heat dissipation conditions are not good, the conversion efficiency of the power supply will be reduced.
3. The material of the heat sink. In fact, if you turn on the power, you will see a lot of different colors and different shapes of heat sinks. Different materials and different shapes of heat sinks will have different effects on the heat dissipation of the power supply.
The material of the heat sink is divided according to the conductivity: silver>copper>gold>aluminum>iron>aluminum alloy.
Generally speaking, ordinary air-cooled radiators naturally choose metal as the material of the radiator. For the selected material, it is hoped that it has both high specific heat and high thermal conductivity. It can be seen from the above that silver and copper are the best thermally conductive materials, followed by gold and aluminum. But gold and silver are too expensive, so at present, heat sinks are mainly made of aluminum and copper. In comparison, both copper and aluminum have their own advantages and disadvantages: copper has good thermal conductivity, but it is expensive, difficult to process, heavy, and copper radiators have a small heat capacity and are easy to oxidize. Pure aluminum is too soft to be used directly. Only aluminum alloys are used to provide sufficient hardness. The advantages of aluminum alloys are low price and light weight, but their thermal conductivity is much worse than copper. So in the radiator
The following materials have also appeared in the history of development:
Pure aluminum radiator
Pure aluminum radiator is the most common radiator in the early days. Its manufacturing process is simple and the cost is low. So far, pure aluminum radiator still occupies a considerable part of the market. In order to increase the heat dissipation area of its fins, the most commonly used processing method for pure aluminum radiators is aluminum extrusion technology, and the main indicators for evaluating a pure aluminum radiator are the thickness of the radiator base and the Pin-Fin ratio. Pin refers to the height of the fins of the heat sink, and Fin refers to the distance between two adjacent fins. The Pin-Fin ratio is the height of the Pin (excluding the thickness of the base) divided by the Fin. The larger the Pin-Fin ratio, the larger the effective heat dissipation area of the radiator, and the more advanced the aluminum extrusion technology.
Pure copper radiator
The thermal conductivity of copper is 1.69 times that of aluminum, so all other things being equal, a pure copper heat sink can remove heat from the heat source faster. However, the texture of copper is a problem. Many advertised "pure copper radiators" are not really 100% copper. In the list of copper, copper with a copper content of more than 99% is called acid-free copper, and the next grade of copper is Dan copper with a copper content of less than 85%. Most of the pure copper heat sinks on the market currently have a copper content between the two. The copper content of some inferior pure copper radiators is not even 85%. Although the cost is very low, its thermal conductivity is greatly reduced, which affects the heat dissipation. In addition, copper also has obvious shortcomings, such as high cost, difficult processing, and too much mass of the heat sink, which hinder the application of all-copper heat sinks. The hardness of red copper is not as good as that of aluminum alloy AL6063, and the performance of some mechanical processing (such as grooving) is not as good as that of aluminum; the melting point of copper is much higher than that of aluminum, which is not conducive to extrusion and other problems.
Copper-aluminum bonding technology
After considering the respective disadvantages of copper and aluminum materials, some high-end radiators in the market often use copper-aluminum combination manufacturing processes. These heat sinks usually use copper metal bases, while heat sink fins are made of aluminum alloy. Of course, In addition to the copper base, there are also methods such as the use of copper pillars for the heat sink, which is also the same principle. With high thermal conductivity, the copper bottom surface can quickly absorb the heat released by the CPU; the aluminum fins can be made into the most favorable shape for heat dissipation by means of complex processes, and provide a large heat storage space and release it quickly. A balance has been found in all aspects.
Sinda Thermal is a professional heat sink manufacturer, we can design and manufacture all types of heat sinks, our factory has been founded over 8 years, we are very experienced in heat sink design and manufacturing. Please contact us freely if you have any thermal requirements.
