Different types of heat sinks have different thermal resistance under different cooling conditions, which can be used as reference and change when designing, that is you can refer to the chipset heatsink thermal resistance to calculate in practical applications, and may adopt a heat sink made by profiles with similar structure and shape (cross-sectional area, perimeter) to substitute.
The heat sink surface treatment can improve the efficiency of cooling and insulation performance
Currently, the electronic products mainly use the chip package devices, but there are still many perforated package for the high-power devices and power modules, which is mainly because it can be easily installed on the heat sink for cooling purposes. Thermal calculation of high-power devices and power modules aims to select the appropriate heat sink in certain conditions, to ensure the device or module security to reliably work. Small heat sink (or heat sink fin) is made from aluminum sheet metal via stamping process and surface treatment, while the large heat sink is formed by the aluminum alloy extrusion profiles, and then made by machining and surface treatment. The heat sink is a standard work piece in general, which can also provide profiles to be cut into certain length and made into non-standard heat sink according to the request of the user. The heat sink surface treatment includes the electrophoresis coating or black oxygen polarization processing, which aims to improve the efficiency of cooling and insulation performance. The heat sink manufacturers give the thermal resistance of different types of heat sinks or give related curves, which also give different thermal resistance under different thermal conditions.
The thermal calculation is to determine the appropriate cooling measures and heat sink by calculating under certain conditions
Any device has a certain loss at work; most of the loss will turn into heat. Low power devices have low loss, which need no heat sink. High-power devices have high loss, it they don't take cooling measures, the die temperature can reach or exceed the allowable junction temperature and then the device will be damaged. Therefore, it must be added with the cooling device. The most commonly used method is to install the power devices on the heatsink chipset scatter the heat into the surrounding space by the use of heat sink. Coupled with the cooling fan when necessary, enhance the cooling heat to a certain wind speed. The power device in some large equipment also uses a flow of cold water cooling plate, which has a better cooling effect. The thermal calculation is to determine the appropriate cooling measures and heat sink by calculating under certain conditions. Power devices are installed on the heat sink. Its primary heat flow direction is from the die to the bottom of the device, which scatters the heat into the surrounding space through the heat sink. If there is no cooling fan to cool at a certain wind speed, it is called natural cooling or natural convection. The installation of the heat sink should consider whether it is conducive to the cooling direction, open the cooling holes at the corresponding position on the chassis or chassis (cool air enters from the bottom and the hot air is shed from the top).
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