A kind of manufacturing method of heat sink with high heat flux density and heat sink

Abstract

The invention discloses a method for manufacturing a high-heating-flux radiating fin type radiator and the radiator thereof. The method is characterized in that radiating fins of the radiator are cut according to a needed length, and one ends, used as one end of a radiating substrate, of the radiating fins are aligned so as to be located in the same plane; the portion between every two radiating fins is filled with a spacing sheet so that gaps can be formed among the radiating fins; the radiating fins and the spacing sheets are connected together through braze welding so as to be fused into a whole, and then the radiator with the substrate formed by the radiating fins and the spacing sheets in a combined mode is manufactured.

Description

technical field [0001] The invention relates to a heat sink manufacturing method and products, in particular to a manufacturing method of a heat sink type heat sink for power semiconductor devices and the heat sink thereof, which are mainly used for high-power thyristors above 200A and high-power thyristors above 25A Thyristor and rectifier module, high power IGBT above 50A. Background technique [0002] High-power semiconductor devices will generate a lot of heat during operation. In order not to burn out the power device, it is now necessary to use a radiator to help it dissipate heat; among them, the heat sink is a commonly used radiator. The heat sink mainly carries the heat transfer and heat dissipation functions of the power device. [0003] The current heat sink type radiator is basically combined by two units, the heat sink and the base plate, the heat sink mainly plays the role of heat dissipation, and the base plate plays the function of heat transfer. Generally,...

AI Technical Summary

Problems solved by technology

The existing main method to increase the heat sink area is to use porous heat sinks or corrugated fins to increase the heat dissipation area. However, in addition to the defects of large flow resistance and large temperature difference between the power device heat sinks of the air inlets, there are also the following two defects: : First, as the height of the heat sink increases, the efficiency of the heat sink is low; second, the heat sink cannot be formed with an integral profile, and can only use the technology of inserts or teeth; but if in order to increase the heat dissipation area, the distance between the heat sinks is reduced, Difficulties in realizing the chip and tooth insert process will increase, resulting in unstable quality. Therefore, the minimum spacing between the heat sinks of the existing profiles and (insert) sheet radiators is more than 2.5mm, and the heat dissipation capacity is limited. When the power density is higher, Only radiators that use other methods

The disadvantages of low-temperature tin-lead soldering are: 1. Before soldering, the overall surface treatment of the radiator, such as nickel plating or copper plating, must be carried out. The welding and surface treatment lead to high costs.

2. Soldering is difficult to ensure that the plane of the heat pipe and the aluminum alloy substrate is fully filled, and there will be local gaps, and because the heat pipe is under the power device, the heat flux density is high, and the gap will cause a local temperature rise of the power device, resulting in device loss

The disadvantages of filling the gap between the heat pipe and the substrate with the cementing scheme are as follows: 1. The power device heat sink usually requires a life span of more than 20 years or more, while the life of the glue is usually about 5 to 10 years, and it is difficult to guarantee the life of the heat sink. life requirements

2. The thermal conductivity of the glue is low, usually lower than 1W·m-1·K-1. Filling with glue will increase the thermal resistance of the radiator and reduce the performance of the radiator

[0007] 3) The use of this type of heat pipe radiator does not improve the heat dissipation capacity of the radiator per unit volume, but only exports the heat of the power device, and the volume of the heat pipe radiator will increase, which will increase the volume of the power electronic device, resulting in an increase in cost

The disadvantages of low-temperature tin-lead soldering are: 1. Before welding, the overall surface treatment such as nickel plating or copper plating must be carried out on the radiator. The material cost of the copper plate itself is high, and the welding and surface treatment costs are also high, resulting in the cost of this process plan. high

The disadvantages of filling the gap between the copper plate and the substrate with the cementing scheme are as follows: 1. The power device heat sink usually requires a life span of more than 20 years or more, while the life of the glue is usually about 5 to 10 years, and it is difficult to guarantee the life of the heat sink. life requirements

2. The thermal conductivity of the glue is low, usually lower than 1W·m-1·K-1. Filling with glue will increase the thermal resistance of the radiator and reduce the performance of the radiator

[0011] 3) Part of the substrate is made of copper and part of it is made of aluminum alloy, which will cause long-term corrosion caused by different potential differences between copper and aluminum, and reduce the life and reliability of the radiator

[0012] 4) When multiple power devices are installed on the same radiator in the direction of the air inlet and air outlet, the temperature rise of the wind will reach above 20°C in the pit, because the temperature of the power device at the air outlet will rise higher than that of the power device at the air inlet due to the difference in wind temperature Higher than 15°C, but when the temperature difference of the power device is large, the life of the power device will be different, and the control characteristics of the power device will be affected

[0017] Although the above-mentioned patents all relate to heat sinks, they are still heat sinks composed of two units of the heat sink and the substrate. Therefore, there are still some problems mentioned above, so it is necessary to improve this. further improvement

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