Heat sink and electric appliance

Abstract

The application provides a radiator and an electric equipment. The radiator comprises a substrate and a conducting plate. The substrate has a first connecting surface. The conducting plate and the substrate are made of different materials. The conducting plate is provided with a heat radiating member at one end. The end of the conducting plate, which is opposite to the heat radiating member, has a second connecting surface. The second connecting surface is suitable for being connected with the first connecting surface. One of the first connecting surface and the second connecting surface is provided with a recess structure, and the other is provided with a protrusion structure. The protrusion structure is suitable for being inserted into the recess structure. The radiator of the application has stable connection between the substrate and the conducting plate, and is not prone to loosening, so that the heat conduction performance between the substrate and the conducting plate can be ensured.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology, and in particular to a heat sink and electrical equipment. Background Technology

[0002] Existing electrical equipment is prone to generating heat during use due to the internal components. Overheating of these components can reduce their efficiency and cause them to be easily damaged. Therefore, heat sinks are needed to dissipate heat from these components.

[0003] In related technologies, composite heat sinks are used to dissipate heat from heat-generating elements. The composite heat sink is connected together by two substrates of different materials, which can not only effectively dissipate heat from heat-generating elements, but also reduce costs.

[0004] However, different materials have different properties, such as different degrees of thermal expansion, which leads to low bonding strength in composite heat sinks due to the different composite materials. Utility Model Content

[0005] This application provides a radiator and electrical equipment to solve the problem of low bonding strength in composite radiators.

[0006] On one hand, this application provides a heat sink, including a substrate and a conductive plate. The substrate has a first connecting surface. The conductive plate and the substrate are made of different materials. One end of the conductive plate is provided with a heat sink. The end of the conductive plate facing away from the heat sink has a second connecting surface. The second connecting surface is adapted to connect with the first connecting surface. One of the first connecting surface and the second connecting surface is provided with a recessed structure, and the other is provided with a protruding structure. The protruding structure is adapted to be inserted and engaged with the recessed structure.

[0007] The heat sink of this application, by providing a recessed structure and a raised structure between the substrate and the conductive plate, allows the raised structure to be inserted into the recessed structure when the substrate and the conductive plate are connected. In this case, the outer wall of the raised structure and the inner wall of the recessed structure can be connected. When the substrate and the conductive plate are made of different materials, the connection area between them can be increased, thereby increasing the bonding strength. This helps to eliminate the problem of insufficient bonding strength caused by connecting different materials, making the connection between the substrate and the conductive plate more stable and less prone to loosening, thus ensuring the thermal conductivity between the substrate and the conductive plate.

[0008] In one feasible embodiment, the first connecting surface is provided with a mating position, which is a recessed structure, and the second connecting surface is provided with a protruding mating portion, which is a raised structure, and the mating portion is adapted to connect to the mating position.

[0009] In one feasible approach, the bonding point is a through-hole penetrating the substrate, or the bonding point is a blind hole opened from the first bonding surface toward the second bonding surface.

[0010] In one feasible approach, the mating point is circular, conical, or dovetail-shaped, and the shape of the mating part matches the shape of the mating point, and the size of the mating part matches the size of the mating point.

[0011] In one feasible approach, multiple binding bits are set, and these multiple binding bits are arranged in a matrix manner.

[0012] Alternatively, the substrate can be divided into multiple regions, which are spaced apart, and each region has multiple bonding sites.

[0013] In one feasible approach, the conductive plate and the substrate are made of different materials.

[0014] In one feasible approach, the substrate is made of copper, the conductive plate is made of aluminum alloy, and the heat sink and the conductive plate are integrally formed.

[0015] In one feasible approach, the substrate and the conductive plate are joined together via a die-casting process.

[0016] In one feasible approach, the heat sink is a cylindrical structure;

[0017] And / or, the cross-section of the heat sink parallel to the conductive plate is square, circular or elliptical.

[0018] In one feasible embodiment, the heat sink extends from one end of the heat conduction plate away from the second connecting surface in a direction away from the second connecting surface, and a draft angle is provided between the peripheral wall of the heat sink and the extension direction of the heat sink, wherein the angle α of the draft angle satisfies: 2°≤a≤3°.

[0019] On the other hand, this application provides an electrical device including the aforementioned radiator. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] Figure 1 An exploded view of a heat sink provided in an embodiment of this application;

[0022] Figure 2 A schematic diagram of the structure of a substrate provided in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of a conductive plate provided in an embodiment of this application;

[0024] Figure 4 A cross-sectional view of a heat sink provided in an embodiment of this application;

[0025] Figure 5for Figure 4 A schematic diagram of the local structure at point A.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10. Substrate; 11. First connecting surface; 12. Joint; 20. Conductive plate; 21. Second connecting surface; 22. Heat sink; 23. Joint.

[0028] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0029] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0030] This application provides a radiator and an electrical device using the radiator. The electrical device can be a vehicle, which can be a passenger car, bus, or truck. For example, the vehicle can be an electric vehicle (EV), a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, or any other electric vehicle. The radiator can dissipate heat from the engine water tank or turbocharger of a gasoline vehicle, or it can also serve as a cooling system for the power battery pack of an electric vehicle, dissipating heat from the power battery pack, or it can also dissipate heat from the motor controller.

[0031] To save costs while ensuring heat dissipation, related technologies often utilize composite substrates made of two different materials for heat sinks. One material needs to have good thermal conductivity, while the other needs to have some thermal conductivity while also being cost-effective or lightweight. In forming the composite substrate, it is usually necessary to manufacture components made of the two materials separately, with their end faces fitted together and then bonded or welded. Because the two materials have different properties, shear forces can easily occur between their joint surfaces, causing them to loosen, affecting the connection strength and thus the thermal conductivity.

[0032] Based on the above problems, the heat sink provided in this application is a composite material heat sink, which has a high bonding strength between the two materials, making it less likely for the two materials to loosen, thereby ensuring the heat dissipation effect.

[0033] See Figures 1 to 3 As shown, the heat sink of this application includes a substrate 10 and a conductive plate 20. The substrate 10 can be used to connect to a structure that needs heat dissipation, and the substrate 10 can also serve as a heat-conducting structure. The substrate 10 can be connected to the conductive plate 20. One end of the substrate 10 in the thickness direction has a first connecting surface 11, and the end face of the substrate 10 facing away from the first connecting surface 11 is used to connect to the structure that needs heat dissipation.

[0034] The conductive plate 20 and the substrate 10 of this application are made of different materials. One end face of the conductive plate 20 in the thickness direction has a plurality of heat dissipation elements 22. The end of the conductive plate 20 facing away from the heat dissipation elements 22 has a second connecting surface 21. The second connecting surface 21 is adapted to be attached to and connected with the first connecting surface 11. In this way, the conductive plate 20 and the substrate 10 can be connected together, and the heat on the substrate 10 can be transferred to the second connecting surface 21 through the first connecting surface 11, and then transferred to the conductive plate 20. Finally, the conductive plate 20 transfers the heat to the heat dissipation elements 22 for heat dissipation.

[0035] It should be noted that the first connecting surface 11 on the substrate 10 can be formed by a partial structure at one end of the substrate 10 in the thickness direction. This partial structure is a planar structure. The second connecting surface 21 on the conductive plate 20 can be formed by a partial structure at one end of the substrate 10 in the thickness direction. This partial structure is also a planar structure. This allows the first connecting surface 11 and the second connecting surface 21 to fit together so that the first connecting surface 11 and the second connecting surface 21 can be connected.

[0036] In this embodiment, both the substrate 10 and the conductive plate 20 are flat structures, and both end faces in the thickness direction are planar. Thus, an entire end face in the thickness direction of the substrate 10 can be used to form the first connecting surface 11, and an entire end face in the thickness direction of the conductive plate 20 can be used to form the second connecting surface 21.

[0037] One of the first connecting surface 11 and the second connecting surface 21 is provided with a recessed structure, and the other is provided with a protruding structure. When the first connecting surface 11 and the second connecting surface 21 are connected, the protruding structure is inserted into the recessed structure, and the outer wall of the protruding structure is connected to the inner wall of the recessed structure.

[0038] By providing a recessed structure and a raised structure between the substrate 10 and the conductive plate 20, the raised structure can be inserted into the recessed structure when the substrate 10 and the conductive plate 20 are connected. In this case, the outer wall of the raised structure and the inner wall of the recessed structure can be connected. When the substrate 10 and the conductive plate 20 are made of different materials, the connection area between the substrate 10 and the conductive element can be increased, thereby increasing the bonding strength between the substrate 10 and the conductive plate 20. This helps to eliminate the problem of insufficient bonding strength caused by connecting different materials, making the connection between the substrate 10 and the conductive element more stable and less prone to loosening, thus ensuring the thermal conductivity between the substrate 10 and the conductive plate 20.

[0039] In some feasible embodiments, the first connecting surface 11 is provided with a mating position 12, which is a recessed structure, and the second connecting surface 21 is provided with a mating portion 23, which is a raised structure. The mating portion 23 is adapted to be connected to the mating position 12. When the substrate 10 and the conductive plate 20 are connected through the first connecting surface 11 and the second connecting surface 21, the mating portion 23 can be inserted into the mating position 12, and the mating portion 23 and the mating position 12 are connected.

[0040] In some embodiments, the bonding position 12 is a through hole penetrating the substrate 10, or the bonding position 12 is a blind hole opened from the first connecting surface 11 toward the second connecting surface 21, or the bonding position 12 can also be a groove structure penetrating the substrate 10, or the bonding position 12 can also be a groove structure opened from the first connecting surface 11 toward the second connecting surface 21 but not penetrating the substrate 10.

[0041] In other embodiments, the mating position 12 may also be formed by a structure disposed on the substrate 10, such as a surrounding plate connected to the first connecting surface 11, with a hole or groove structure formed between the surrounding plate and the first connecting surface 11. This application will describe the mating position 12 as a hole or groove structure formed on the substrate 10.

[0042] The shape of the mating part 12 is not limited. For example, the mating part 12 can be circular, conical, or dovetail-shaped. The mating part 23 in this application is used to connect with the mating part 12. The shape and size of the mating part 23 are the same as those of the mating part 12 so that when the mating part 23 is inserted into the mating part 12, the peripheral wall of the mating part 23 can fit against the inner wall of the mating part 12, thereby maximizing the connection area between the mating part 23 and the mating part 12.

[0043] By providing holes and grooves on the substrate 10 and connecting parts 23 on the conductive plate 20, the bonding strength between the substrate 10 and the conductive plate 20 can be increased. Furthermore, the holes, grooves, and connecting parts 23 are easier to process, making the substrate 10 and the conductive plate 20 easier to manufacture and ensuring processing efficiency.

[0044] It should be noted that the connecting portion 23 is a protruding structure on the second connecting surface 21. The connecting portion 23 can be formed on the second connecting surface 21 of the conductive plate 20 during the production of the conductive plate 20. The connecting portion 23 is inserted into the connecting position 12 while connecting the conductive plate 20 and the substrate 10. Alternatively, as in the embodiment of this application, the substrate 10 and the conductive plate 20 are connected by a die-casting process. Specifically, the solid substrate 10 can be placed in the die-casting mold first, and then the liquid metal can be poured into the mold. At this time, the connecting position 12 is filled with liquid metal. After solidification, a solid conductive plate 20 and a solid connecting portion 23 are formed. By using this die-casting process to combine the substrate 10 and the conductive plate 20, a joint portion 23 is formed on the conductive plate 20. The bonding process between the conductive plate 20 and the substrate 10 can be completed simultaneously by die-casting, reducing process steps, lowering process costs, and increasing production efficiency. Moreover, by combining the substrate 10 and the conductive plate 20 by die-casting, the bonding strength can be increased, making it less likely for the substrate 10 and the conductive plate 20 to loosen.

[0045] In some embodiments, multiple bonding positions 12 are provided, spaced apart on the substrate 10, and multiple bonding portions 23 are correspondingly provided on the conductive plate 20, ensuring that each bonding position 12 can be connected to a bonding portion 23. By having multiple bonding positions 12 cooperate with multiple bonding portions 23 respectively, it is beneficial to increase the connection area between the substrate 10 and the conductive plate 20, thereby increasing the bonding strength between them.

[0046] It should be noted that the arrangement of the joints 23 on the conductive plate 20 needs to be adapted to the arrangement of the joints 12 on the substrate 10 to ensure a one-to-one correspondence between the joints 23 and the joints 12. The joints 12 in this application can be arranged in different ways according to the actual situation. For example, when the connection area between the substrate 10 and the conductive plate 20 is large, it is necessary to increase the connection area between the substrate 10 and the conductive plate 20. In this case, multiple joints 12 can be arranged in a matrix on the substrate 10, so that the first connection surface 11 of the substrate 10 is covered with joints 12, and the conductive plate 20 is correspondingly provided with joints 23 and joints 12 for connection. This can ensure that there is a large connection area between the substrate 10 and the conductive plate 20.

[0047] Alternatively, the distribution of bonding positions 12 can be determined based on thermal conductivity. For example, the thermal conductivity of the substrate 10 is generally higher than that of the conductive plate 20. If the structure corresponding to a certain position on the substrate 10 has a high heat dissipation requirement, then bonding positions 12 can be avoided in that area of ​​the substrate 10, and bonding positions 12 can be placed in areas with lower heat dissipation requirements. In this way, multiple regions can be divided on the substrate 10 according to the heat dissipation requirements, with multiple regions spaced apart. Each region has multiple bonding positions 12, and the conductive plate 20 is provided with bonding portions 23 corresponding to the bonding positions 12 in each region of the substrate 10.

[0048] See Figures 1 to 3 As shown, in some feasible ways, the substrate 10 and the conductive plate 20 are made of different materials, and the heat transfer efficiency of the substrate 10 is higher than that of the conductive plate 20. In this way, the heat sink made of composite material can reduce costs compared to the heat sink made of only material with good heat transfer efficiency, and can guarantee heat transfer efficiency compared to the heat sink made of only material with low heat transfer efficiency.

[0049] The substrate 10 of this application is a copper metal part made of pure copper material, and the conductive plate 20 is an aluminum alloy part made of aluminum alloy material. The pure copper substrate 10 has good thermal conductivity. Although the thermal conductivity of the aluminum alloy conductive plate 20 is not as good as that of the substrate 10, the cost of the aluminum alloy conductive plate 20 is lower. Thus, the heat sink structure formed by the pure copper substrate 10 and the aluminum alloy conductive plate 20 ensures both good thermal conductivity and cost savings.

[0050] It should be noted that the substrate 10 and the conductive plate 20 in this application are joined together by a die-casting process. Before performing the die-casting process on the substrate 10 and the conductive plate 20, the substrate 10 and the conductive plate 20 need to be manufactured separately. The manufacturing process of the substrate 10 and the conductive plate 20 is roughly the same as that of the substrate 10 and the conductive plate 20 in the prior art composite material heat sink. Among them, when manufacturing the substrate 10, since the substrate 10 in this embodiment of the application is also provided with bonding positions 12, it is also necessary to use sandpaper to remove burrs from the surface of the substrate 10, use an ultrasonic cleaner to clean with deionized water, and use an alkaline cleaning extruder to remove oil from the surface of the substrate 10.

[0051] Before connecting the substrate 10 and the conductive plate 20, hydrogen chloride is needed to remove the oxide film on the copper surface and activate the surface of the substrate 10. During activation, the pure copper substrate 10 is immersed in a 30% hydrogen chloride solution for 30-60 seconds. After removal, it can be immediately placed in alcohol to wash away the acid. Ultrasonic cleaning can also be used to speed up the process. The activated pure copper substrate 10 is then stored in deionized water and dried with nitrogen to prevent oxidation.

[0052] Before die casting, the conductive plate 20 of this application needs to be refined and heated to the casting temperature, followed by heat preservation treatment at a temperature of 700–750°C. A die casting mold is selected and filled with a protective gas such as argon. The treated substrate 10 is placed in a predetermined position on the mold. Under the protection of argon, the mold is preheated to 230–250°C. Then, molten aluminum alloy is injected into the mold, and die casting is performed under appropriate conditions. After holding the pressure for a predetermined time, a structure combining a pure copper substrate 10 and an aluminum alloy conductive plate 20 is formed. Through the die-cast substrate 10 and conductive plate 20, the first connecting surface 11 of the substrate 10 and the second connecting surface 21 of the conductive plate 20 are bonded together. The bonding strength between the first connecting surface 11 and the second connecting surface 21 can reach the metallurgical bonding strength, resulting in high bonding strength and reducing the likelihood of cracking and loosening.

[0053] In some embodiments, the heat sink 22 of this application is a columnar structure. The shape of the heat sink 22 is not limited. For example, the cross-section of the heat sink 22 can be square, circular, rhomboid or elliptical. The size of the heat sink 22 is not limited and needs to be set according to actual needs to ensure that the heat sink 22 has sufficient strength.

[0054] The heat sink 22 and the conductive plate 20 of this application are integrally formed. The conductive plate 20 can be formed on the conductive plate 20 by die casting when the conductive plate 20 and the substrate 10 are connected, or it can be formed on the conductive plate 20 when the conductive plate 20 and the substrate 10 are die cast. In this way, the heat sink 22 and the composite between the substrate 10 and the conductive plate 20 can be completed in one die casting, reducing process steps, increasing processing efficiency, and reducing processing costs.

[0055] See Figure 4 and Figure 5 As shown, it should be noted that when the heat sink 22 is die-cast, a demolding angle can be provided on the heat sink 22 to facilitate demolding after the heat sink 22 is formed. Specifically, the heat sink 22 of this application extends from the end of the conductive plate 20 away from the second connecting surface 21 in a direction away from the second connecting surface 21, that is, the heat sink 22 extends in a direction parallel to the thickness direction of the conductive component. Along the extension direction of the heat sink 22, the cross-sectional dimension of the heat sink 22 gradually decreases from the end near the conductive plate 20 to the end away from the conductive plate 20. Thus, along the extension direction of the heat sink 22, the peripheral wall of the heat sink 22 gradually tapers, so that there is an angle between the peripheral wall of the heat sink 22 and the extension direction of the heat sink 22. This angle is a draft angle suitable for demolding the heat sink 22. The draft angle angle α satisfies: 2°≤a≤3°. If the draft angle is too small, the demolding effect of the heat sink 22 is not very good. If the draft angle is too large, it will affect the surface area of ​​the heat sink 22, thereby affecting its heat dissipation effect. The draft angle of this application can be set to 2° or 3°.

[0056] This application provides multiple heat sinks 22, which can be arranged on the conductive plate 20 according to actual needs. For example, when dissipating heat from a heat-generating structure, the arrangement of some heat-generating structures is often irregular, or some components generate a lot of heat while others generate little. For locations with heat-generating structures, heat sinks 22 can be arranged in the corresponding area of ​​the conductive plate 20. For locations without corresponding heat-generating structures, heat sinks 22 do not need to be arranged on the conductive plate 20. Alternatively, for structures with high heat generation, more heat sinks 22 can be arranged in the corresponding area of ​​the conductive plate 20, while for structures with low heat generation or those that do not easily generate heat, fewer heat sinks 22 or no heat sinks 22 can be arranged in the corresponding position of the conductive plate 20.

[0057] In related technologies, the structure used for heat dissipation is finned, with the fins being relatively thin plates. Because of their thinness, these fins are only suitable for gas cooling, where gas flows over the surface of the fins to carry away heat. If a finned heat sink is used for heat dissipation via a liquid cooling medium, the liquid coolant flows between the fins, carrying away heat. However, the impact force of the flowing liquid coolant on the fins is significant, easily causing deformation and damage, thus affecting heat dissipation efficiency. Therefore, heat sinks using fins in related technologies cannot be used for highly integrated structures such as chips and high-power components that require liquid cooling.

[0058] The heat sink 22 of this application has a columnar structure, and the heat sink 22 and the conductive plate 20 are integrally formed. Compared with the heat sink fins, the columnar heat sink 22 has higher strength. When applied to scenarios where heat is dissipated through liquid cooling media, it has stronger resistance to deformation and is not easily deformed under the impact of liquid cooling media. Therefore, the heat sink of this application has a wide range of applications. Moreover, the heat sink 22 of this application can also be adapted to the die-casting combination of the substrate 10 and the conductive plate 20, so that the integral forming of the columnar heat sink 22 and the conductive plate 20, as well as the combination between the substrate 10 and the conductive plate 20, can be completed in a single die-casting process.

[0059] Furthermore, the heat sink 22 of this application also has a draft angle. By setting the draft angle, the molding of the heat sink 22 is more suitable for die casting production. This allows the bonding between the substrate 10 and the conductive plate 20, as well as the integral molding of the heat sink 22 on the conductive plate 20, to be completed in one die casting process, reducing process steps, lowering production costs, and increasing production efficiency. Moreover, because the peripheral wall of the heat sink 22 has a draft angle, when the liquid cooling medium flows through the heat sink 22 and impacts the peripheral wall of the heat sink 22, part of the impact force of the liquid cooling medium will be dispersed, making the impact force on the surface of the heat sink 22 less than the actual impact force of the liquid cooling medium, which helps to reduce the impact force on the heat sink 22.

[0060] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0061] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A radiator, characterized in that, include: The substrate (10) has a first connecting surface (11); as well as A conductive plate (20) is provided with a heat sink (22) at one end. The end of the conductive plate (20) facing away from the heat sink (22) has a second connecting surface (21). The second connecting surface (21) is adapted to connect with the first connecting surface (11). One of the first connecting surface (11) and the second connecting surface (21) is provided with a recessed structure, and the other is provided with a protruding structure. The protruding structure is adapted to be inserted and engaged with the recessed structure.

2. The radiator according to claim 1, characterized in that, The first connecting surface (11) is provided with a connecting position (12), the connecting position (12) is the recessed structure, and the second connecting surface (21) is provided with a connecting part (23), the connecting part (23) is the protruding structure, and the connecting part (23) is adapted to be connected to the connecting position (12).

3. The radiator according to claim 2, characterized in that, The bonding position (12) is a through hole penetrating the substrate (10), or the bonding position (12) is a blind hole opened from the first connecting surface (11) toward the second connecting surface (21).

4. The radiator according to claim 3, characterized in that, The mating part (12) is circular, conical or dovetail shaped, the shape of the mating part (23) is the same as the shape of the mating part (12), and the size of the mating part (23) is the same as the size of the mating part (12).

5. The radiator according to any one of claims 2-4, characterized in that, The bonding positions (12) are provided in multiple ways, and the multiple bonding positions (12) are arranged in a matrix manner; Alternatively, the substrate (10) may be divided into multiple regions, which are spaced apart, and each region may have multiple bonding positions (12).

6. The radiator according to any one of claims 1-4, characterized in that, The conductive plate (20) and the substrate (10) are made of different materials.

7. The radiator according to claim 6, characterized in that, The substrate (10) is a copper metal part, the conductive plate (20) is an aluminum alloy part, and the heat dissipation part (22) and the conductive plate (20) are integrally formed.

8. The radiator according to any one of claims 1-4, characterized in that, The heat sink (22) is a columnar structure; And / or, the heat sink (22) has a square, circular or elliptical cross-section parallel to the conductive plate (20).

9. The radiator according to any one of claims 1-4, characterized in that, The heat sink (22) extends from one end of the conductive plate (20) away from the second connecting surface (21) in a direction away from the second connecting surface (21). A draft angle is provided between the peripheral wall of the heat sink (22) and the extension direction of the heat sink (22), and the angle a of the draft angle satisfies: 2°≤a≤3°.

10. An electrical appliance, characterized in that, Includes the heat sink as described in any one of claims 1-9.

Images