Heat dissipation device for power device

Abstract

The invention discloses a heat dissipation device for a power device. The heat dissipation device comprises a heat dissipation assembly, a chip assembly and an injection molding shell, the heat dissipation assembly comprises a base, a groove, an inlet, an outlet, a flow channel, a heat dissipation substrate and a step area. The flow channels are in a V shape, the opening directions of the two flow channels are opposite, and the bending positions of the flow channels are arranged in a round corner mode, so that the flow channels are communicated with the inlet or the outlet at an inclined upward angle, liquid accumulation or layering caused by horizontal flowing is avoided, and the liquid can pass through the flow channels more smoothly. The heat dissipation substrate is provided with a plurality of stepped areas, the stepped areas are located on the end face, facing the heat dissipation substrate, of the groove, the distances between the stepped areas and the heat dissipation substrate are increased in a stepped mode in the direction from the inlet to the outlet, and the distances between the stepped areas and the heat dissipation substrate are gradually increased along with flowing of cooling liquid, so that more cooling liquid is gradually contained. And the problem of poor heat exchange effect caused by relatively high temperature when the cooling liquid flows to the outlet along with heat exchange is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and particularly relates to a heat dissipation device for power devices. Background Art

[0002] With the rapid development of power electronics technology, the demand for high-power IGBT modules in high-frequency and high-power density applications is increasing day by day. However, if the heat generated during the operation of the power module cannot be dissipated in time, it will cause the chip temperature to rise, performance degradation, and even failure. Therefore, efficient and uniform heat dissipation technology has become the key to ensuring the reliability of power modules.

[0003] Currently, the cooling methods of power modules mainly include air cooling, circulating water cooling, heat pipe cooling, spray cooling, jet cooling, and microchannel cooling technologies, etc. Among them, liquid cooling has become the mainstream cooling solution for high-power IGBT modules due to its advantages such as high heat dissipation efficiency and compact volume. However, in the prior art, since the flow path of the coolant from the inlet to the outlet is relatively long, the temperature of the coolant gradually rises during the heat absorption process, and the subsequent heat dissipation ability decreases, resulting in a difference in the chip temperature difference near the inlet and outlet. Moreover, the existing flow channels are mostly single-depth structures and cannot be effectively matched with the fin column layout, resulting in insufficient heat transfer efficiency of the coolant in the high-temperature area and excessive heat transfer efficiency in the low-temperature area, making the overall heat transfer efficiency unbalanced. Summary of the Invention

[0004] In view of this, the present invention provides a heat dissipation device for power devices to solve the above technical problems.

[0005] A heat dissipation device for power devices, the heat dissipation device for power devices dissipates heat through a coolant, and the heat dissipation device for power devices includes a heat dissipation component, a chip component disposed on the heat dissipation component, and an injection molding housing disposed on the chip component. The heat dissipation component includes a base, a groove opened in the base, an inlet disposed at the bottom of the base, an outlet disposed at the bottom of the base, two flow channels respectively communicating the groove with the inlet or the outlet, a heat dissipation substrate disposed on the base, and at least two stepped areas disposed in the groove. The flow channels are in a V shape and the opening directions of the two flow channels are opposite to each other, the bending part of the flow channels is provided with a fillet, and a plurality of heat dissipation columns are arranged in an array on the end surface of the heat dissipation substrate facing the groove. The stepped areas are located on the end surface of the groove facing the heat dissipation substrate, and the distances between the plurality of stepped areas and the heat dissipation substrate increase step by step in the direction from the inlet to the outlet. The arrangement direction of the plurality of stepped areas is parallel to the flow direction of the fluid, and the length of the heat dissipation columns is the same as the depth of the corresponding stepped areas.

[0006] Furthermore, the heat dissipation columns in each row are arranged at equal intervals, the heat dissipation columns in adjacent rows are arranged staggeredly, the heat dissipation columns in each column are arranged at equal intervals, and the heat dissipation columns in adjacent columns are arranged staggeredly.

[0007] Furthermore, the radian of one end of the heat dissipation column close to the inlet is greater than that of the end close to the outlet. The end of the heat dissipation column close to the inlet is a semi-circular end, and the end of the heat dissipation column close to the outlet is a semi-elliptical end. The cross-section of the heat dissipation column is in the shape of a water droplet.

[0008] Furthermore, the fillet radius R at the bend of the flow channel satisfies 0.5 mm < R < 5 mm.

[0009] Furthermore, the inclination angles of the extending directions of both ends of the flow channel with respect to the horizontal direction are from 5° to 35°.

[0010] Furthermore, the chip assembly includes a plurality of ceramic copper-clad substrates, a plurality of IGBT chips disposed on the ceramic copper-clad substrates, a plurality of FRD chips disposed on the ceramic copper-clad substrates, an NTC resistor disposed on the ceramic copper-clad substrate, and a plurality of Pin pins disposed on the ceramic copper-clad substrates.

[0011] Furthermore, the ceramic copper-clad substrate has a structure with copper layers on both the upper and lower surfaces and an insulating layer in the middle. The insulating layer is ceramic, specifically including at least one of an AlO ceramic layer, an AlO-doped zirconia ceramic layer, an AlN ceramic layer, a GAN ceramic layer, and a SiN ceramic layer.

[0012] Furthermore, the number of the ceramic copper-clad substrates is the same as the number of the stepped areas and their positions correspond to each other.

[0013] Furthermore, the injection-molded housing surrounds the chip assembly, and silicone is filled between the injection-molded housing and the chip assembly.

[0014] Compared with the prior art, the flow channels of the heat dissipation device for power devices provided by the present invention are V-shaped, and the opening directions of the two flow channels are arranged towards each other. The inclination angles of the extending directions of both ends of the flow channels with respect to the horizontal direction are from 5° to 35°. Thus, the flow channels communicate with the groove and the inlet or the outlet at an upward-inclined angle. The inclination angle guides the fluid to flow upward, avoiding liquid accumulation or stratification caused by horizontal flow, so that the coolant can flow through the flow channels more smoothly during the flow process. The distances between the multiple stepped areas and the heat dissipation substrate increase step by step in the direction from the inlet towards the outlet. The arrangement direction of the multiple stepped areas is parallel to the flow direction of the fluid. As the coolant flows, the distance between the stepped area and the heat dissipation substrate gradually increases, so as to gradually accommodate more coolant. By changing the volume of the coolant that can be accommodated by the stepped areas with different heights and changing the heat exchange area by the heat dissipation columns with different lengths, the heat dissipation effects of different regions are ensured to be balanced, avoiding the problem that the temperature of the coolant is relatively high when it flows to the outlet during heat exchange, resulting in poor heat exchange effect. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of a heat dissipation device for power devices provided by the present invention.

[0016] Figure 2 It is Figure 1 an exploded structural diagram of the heat dissipation device for power devices.

[0017] Figure 3 It is Figure 1 a schematic structural diagram of the base of the heat dissipation device for power devices.

[0018] Figure 4 It is Figure 1 a schematic structural diagram of the heat dissipation substrate of the heat dissipation device for power devices.

[0019] Figure 5 It is Figure 1 a cross-sectional view of the heat dissipation device for power devices.

[0020] Figure 6 It is Figure 1 a thermal simulation experiment diagram of the heat dissipation device for power devices. Detailed Description of the Embodiments

[0021] The following further details the specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein does not limit the protection scope of the present invention.

[0022] As Figures 1 to 6As shown, it is a schematic structural diagram of a heat dissipation device for a power device provided by the present invention. The heat dissipation device for the power device includes a heat dissipation component 10, a chip component 20 disposed on the heat dissipation component 10, and an injection molded housing 30 disposed on the chip component 20. It can be envisioned that the heat dissipation device for the power device further includes some other functional modules, such as a connection component, an electrical connection component, and a mounting component, etc., which are well-known technologies to those skilled in the art and will not be elaborated herein.

[0023] The heat dissipation component 10 includes a base 11, a groove 12 formed in the base 11, an inlet 13 disposed at the bottom of the base 11, an outlet 14 disposed at the bottom of the base 11, two flow channels 15 respectively communicating the groove 12 with the inlet 13 or the outlet 14, a heat dissipation substrate 16 disposed on the base 11, and at least two stepped regions 17 disposed in the groove 12.

[0024] The base 11 is used to carry the above-mentioned various functional modules. Therefore, the base 11 is provided with various functional structures, such as screws, mounting holes, etc. to complete the installation and assembly of the above-mentioned functional modules, which can be set according to actual needs and will not be elaborated in detail herein.

[0025] The groove 12 is formed on the end surface of the base 11 facing the heat dissipation substrate 16 and is used to provide a space for the coolant to flow after the heat dissipation substrate 16 is disposed.

[0026] The inlet 13 and the outlet 14 are disposed at the bottom of the base 11 to avoid the flow channels 15. The compact design reduces the volume of the heat dissipation base and facilitates integration into high-power density devices. The inlet 13 and the outlet 14 are respectively disposed on opposite sides of the bottom of the base 11.

[0027] The flow channel 15 is V-shaped and the opening directions of the two flow channels 15 are arranged in opposite directions. The bends of the flow channel 15 are rounded, and the radius of the rounded corner R is 0.5mm<R<5mm, which reduces fluid separation and vortex generation and improves the stability of the coolant flow. The extension direction of the two ends of the flow channel 15 is inclined at an angle of 5° to 35° to the horizontal direction, so that the flow channel 15 is connected to the groove 12 and the inlet 13 or the outlet 14 at an upward angle. The inclination angle guides the fluid to flow upward, avoiding liquid accumulation or stratification caused by horizontal flow, so that the coolant can pass through the flow channel more smoothly during the flow process. At the same time, the flattened design of the flow channel 15 increases the contact area between the coolant and the flow channel wall during the flow process, and increases the heat exchange area between the coolant and the flow channel wall. Since the flow channel 15 needs to be connected to the groove 12 and the inlet 13 or the outlet 14 at an inclined upward angle, arranging the inlet 13 and the outlet 14 at the bottom of the base 11 can avoid the bend of the flow channel 15 and ensure that the flow channel 15 has enough space for bending.

[0028] The heat dissipation substrate 16 is fixed to the base 11 by screws and covers the groove 12, thereby sealing the gap between the groove 12 and the heat dissipation substrate 16 to form a channel for the circulation of the coolant. The heat dissipation substrate 16 can be a nickel-plated aluminum plate or a nickel-plated copper plate.

[0029] A plurality of heat dissipation columns 18 are arranged in an array on the end surface of the heat dissipation substrate 16 facing the groove 12. The heat dissipation columns 18 in each row are arranged at equal intervals, and the heat dissipation columns 18 in two adjacent rows are arranged in a staggered manner. The heat dissipation columns 18 in each column are arranged at equal intervals, and the heat dissipation columns 18 in two adjacent columns are arranged in a staggered manner. Such a staggered arrangement can increase the density of the heat dissipation columns 18, take away more heat per unit area, and improve the heat dissipation capacity. At the same time, the linear flow path of the coolant is broken, forcing the fluid to flow around, prolonging the contact time, and improving the heat exchange efficiency. The curvature of the end of the heat dissipation column 18 close to the inlet 13 is greater than the curvature of the end of the heat dissipation column 18 close to the outlet 14. The end of the heat dissipation column 18 close to the inlet 13 is a semicircular end 181, and the end of the heat dissipation column 18 close to the outlet 14 is a semi-elliptical end 182, so that the cross-section of the heat dissipation column 18 is in the shape of a water drop.

[0030] When the water flow touches the semicircular end 181, the smooth shape of the semicircular end 181 can reduce the flow separation and turbulence generation when the coolant enters the heat dissipation column 18 area, and the tail of the semi-elliptical end 182 can lengthen the streamline, increase the residence time of the fluid on the surface of the heat dissipation column 18, and enhance convective heat exchange.

[0031] The step area 17 is located on the end surface of the groove 12 facing the heat dissipation substrate 16, and the distance between the multiple step areas 17 and the heat dissipation substrate 16 increases in a step-wise manner from the inlet 13 toward the outlet 14. The arrangement direction of the multiple step areas 17 is parallel to the flow direction of the fluid. When the coolant just enters the step area 17, the temperature of the coolant is still very low at this time, so the distance between the step area 17 near the inlet 13 and the heat dissipation substrate 16 is smaller. Due to the limitation of the distance between the step area 17 and the heat dissipation substrate 16, the length of the heat dissipation column 18 is shorter than that of the heat dissipation column 18 of the step area 17 at other heights, so that the heat exchange area is relatively small. At the same time, the space between the step area 17 and the heat dissipation substrate 16 can accommodate a smaller volume of coolant, so as to avoid excessive cooling causing the coolant to heat up too quickly, affecting the subsequent heat exchange. As the coolant continues to flow, the distance between the step area 17 and the heat dissipation substrate 16 gradually increases, thereby gradually accommodating a larger volume of coolant. At the same time, the length of the heat dissipation column 18 also gradually increases, so that the heat exchange area increases. A large amount of coolant flushes the surface of the heat dissipation column 18, quickly taking away the heat and ensuring the heat dissipation efficiency at the outlet. The volume of coolant that can be accommodated is changed by the step areas 17 of different heights, and the heat dissipation columns 18 of different lengths change the heat exchange area, ensuring that the heat dissipation effect of different areas is balanced, avoiding the problem of poor heat exchange effect caused by the relatively high temperature of the coolant when it flows to the outlet as the heat exchange proceeds. Please refer to the attached Figure 6 It can be seen from the figure that according to the test results, the temperature of the chip assembly 20 in different areas is average, and the heat dissipation effect meets the requirements.

[0032] In this embodiment, three step areas 17 are provided, and the number thereof is related to the number of DBCs in the chip assembly 20, and the specific description will be described below in conjunction with the chip assembly 20. The length of the heat dissipation column 18 is the same as the depth of the step area 17 at the corresponding position, so that one end of the heat dissipation column 18 is closely attached to the step area 17, reducing the lateral flow and vortex generation of the fluid in the flow channel, thereby ensuring the heat exchange effect.

[0033] The chip assembly 20 includes multiple ceramic copper clad substrates 21, multiple IGBT chips 22 arranged on the ceramic copper clad substrates 21, multiple FRD chips 23 arranged on the ceramic copper clad substrates 21, an NTC resistor 24 arranged on the ceramic copper clad substrate 21, and multiple Pin needles 25 arranged on the ceramic copper clad substrate 21.

[0034] The ceramic copper-clad substrate 21 has a structure in which the upper and lower surfaces are copper layers and the middle is an insulating layer. The insulating layer is ceramic, specifically including at least one of an Al2O3 ceramic layer, an Al2O3-doped zirconia ceramic layer, an AlN ceramic layer, a GAN ceramic layer and a Si3N4 ceramic layer. The lower copper layer of the ceramic copper-clad substrate 21 facing the heat dissipation substrate 16 is welded to the heat dissipation substrate 16, and the upper copper layer facing away from the heat dissipation substrate 16 is used to set various electronic components such as IGBT chips 22, FRD chips 23, etc. The ceramic copper-clad substrate 21 is mainly used as a carrier for various electronic components in power electronic module technology, which should be a prior art and will not be repeated here. In this embodiment, three ceramic copper-clad substrates 21 are provided. The number of the ceramic copper-clad substrates 21 is the same as the number of the step areas 17 and their positions correspond to each other, thereby ensuring that the power devices on each ceramic copper-clad substrate 21 have a corresponding coolant path. Through the depth difference of the step area 17, more flow is accommodated on the side close to the outlet 14, affecting the heat exchange at the outlet 14.

[0035] The IGBT chip 22 is an insulated gate bipolar transistor, which is responsible for high-frequency switching and power control. The FRD chip 23 is a fast recovery diode, which is used for freewheeling and reverse voltage protection. The NTC resistor 24 is a negative temperature coefficient resistor, which is used to monitor the module temperature and feed back to the control system. The Pin 25 is connected to the external device as the signal end of the power module, and is used to transmit control signals and data.

[0036] The IGBT chip 22, the FRD chip 23, the NTC resistor 24, and the Pin needle 25 are fixed on the upper copper layer of the ceramic copper-clad substrate 21 by solder, such as soldering on the upper copper layer of the ceramic copper-clad substrate 21 by solder such as tin sheet or solder paste. The ceramic copper-clad substrate 21, the IGBT chip 22, the FRD chip 23, and the NTC resistor 24 are interconnected by bonding wires, thereby achieving internal connectivity of the chip assembly 20.

[0037] The injection molded housing 30 is used to carry the above-mentioned functional modules, so the housing 30 is provided with a variety of functional structures, such as screws, bolts, through holes, etc., to complete the installation and assembly of the above-mentioned functional modules, which can be provided according to actual needs and will not be described in detail here. The injection molded housing 30 is arranged around the chip assembly 20 and the space between the injection molded housing 30 and the chip assembly 20 is filled with silica gel to achieve electrical isolation.

[0038] Compared with the prior art, the flow channel 15 of the heat dissipation device for power devices provided by the present invention is V-shaped and the opening directions of the two flow channels 15 are arranged in opposite directions. The extension direction of the two ends of the flow channel 15 is inclined at an angle of 5° to 35° to the horizontal direction, so that the flow channel 15 is connected with the groove 12 and the inlet 13 or the outlet 14 at an inclined upward angle. The inclination angle guides the fluid to flow upward, avoiding liquid accumulation or stratification caused by horizontal flow, so that the coolant can pass through the flow channel more smoothly during the flow process. The distance between the multiple stepped areas 17 and the heat dissipation substrate 16 increases in steps from the inlet 13 to the outlet 14. The arrangement direction of the multiple stepped areas 17 is parallel to the flow direction of the fluid. As the coolant flows, the distance between the stepped area 17 and the heat dissipation substrate 16 gradually increases, thereby gradually accommodating more coolant. The volume of the coolant that can be accommodated is changed by the stepped areas 17 of different heights, and the heat exchange area is changed by the heat dissipation columns 18 of different lengths, so as to ensure balanced heat dissipation effects in different areas and avoid the problem of poor heat exchange effects caused by relatively high temperature of the coolant when it flows to the outlet as the heat exchange proceeds.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent substitution or improvement within the spirit of the present invention is included in the scope of the claims of the present invention.

Claims

1. A heat dissipation device for a power device, wherein the heat dissipation device for a power device is performed by a coolant, and is characterized in that: The heat dissipation device for power devices includes a heat dissipation component, a chip component arranged on the heat dissipation component, and an injection molded shell arranged on the chip component. The heat dissipation component includes a base, a groove opened in the base, an inlet arranged at the bottom of the base, an outlet arranged at the bottom of the base, two flow channels respectively connecting the groove and the inlet or the outlet, a heat dissipation substrate arranged on the base, and at least two step areas arranged in the groove, the inlet and the outlet are respectively arranged on two opposite sides of the bottom of the base, the flow channel is V-shaped and the opening directions of the two flow channels are arranged facing each other, the bends of the flow channel are rounded, a plurality of heat dissipation columns are arranged in an array on the end surface of the heat dissipation substrate facing the groove, the step area is located on the end surface of the groove facing the heat dissipation substrate, the distance between the plurality of step areas and the heat dissipation substrate increases in a stepwise manner from the inlet toward the outlet, the arrangement direction of the plurality of step areas is parallel to the flow direction of the fluid, and the length of the heat dissipation column is the same as the depth of the step area at the corresponding position.

2. The heat dissipation device for power devices according to claim 1, characterized in that: The heat dissipation columns in each row are arranged at equal intervals, and the heat dissipation columns in two adjacent rows are arranged in a staggered manner. The heat dissipation columns in each column are arranged at equal intervals, and the heat dissipation columns in two adjacent columns are arranged in a staggered manner.

3. The heat dissipation device for power devices according to claim 1, characterized in that: The curvature of the heat dissipation column near the inlet is greater than the curvature of the heat dissipation column near the outlet. The end of the heat dissipation column near the inlet is a semicircular end, and the end of the heat dissipation column near the outlet is a semi-elliptical end. The cross-section of the heat dissipation column is drop-shaped.

4. The heat dissipation device for power devices according to claim 1, characterized in that: The fillet radius R of the bend of the flow channel is 0.5mm<R<5mm.

5. The heat dissipation device for power devices according to claim 1, characterized in that: The inclination angle between the extending direction at both ends of the flow channel and the horizontal direction is 5° to 35°.

6. The heat dissipation device for power devices according to claim 1, characterized in that: The chip assembly includes multiple ceramic copper-clad substrates, multiple IGBT chips arranged on the ceramic copper-clad substrates, multiple FRD chips arranged on the ceramic copper-clad substrates, an NTC resistor arranged on the ceramic copper-clad substrate, and multiple Pin needles arranged on the ceramic copper-clad substrate.

7. The heat dissipation device for power devices according to claim 6, characterized in that: The ceramic copper-clad substrate has a structure in which the upper and lower surfaces are copper layers and the middle is an insulating layer. The insulating layer is ceramic, specifically including at least one of an AlO ceramic layer, an AlO-doped zirconia ceramic layer, an AlN ceramic layer, a GAN ceramic layer and a SiN ceramic layer.

8. The heat dissipation device for power devices according to claim 6, characterized in that: The number of the ceramic copper clad substrates is the same as the number of the step areas and their positions correspond to each other.

9. The heat dissipation device for power devices according to claim 1, characterized in that: The injection molded shell is arranged around the chip component and the space between the injection molded shell and the chip component is filled with silica gel.

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