Heat sink and power module

Abstract

The utility model embodiment provides a kind of heat dissipation plate and the power module using the heat dissipation plate, the heat dissipation plate for example includes heat dissipation plate main body, the heat dissipation plate main body includes first surface, second surface opposite with the first surface, and the circumferential side between the first surface with the second surface is connected, the circumferential side is configured with first contact enhancement structure, the first contact enhancement structure extends along the circumferential direction of the heat dissipation plate main body. Through the optimization design of heat dissipation plate structure, the first contact enhancement structure such as groove along the circumferential direction is arranged on the surface of heat dissipation plate main body especially circumferential side, when it is applied to power module, the combination stability of heat dissipation plate and plastic package can be improved, the water vapor resistance of power module is improved, the delamination risk of plastic package is reduced, and then the device performance is improved.

Description

Technical Field

[0001] This utility model relates to the field of power electronic device technology, and in particular to a heat sink and a power module. Background Technology

[0002] The heat sink of traditional plastic-encapsulated power modules has the following defects: (1) The bonding between the plastic body and the surface of the heat sink (e.g., the front and peripheral sides) is poor, and delamination is easy to occur. This delamination phenomenon will be aggravated after reliability tests such as temperature shock test (TST); (2) The plastic body and the heat sink are not tightly bonded, especially in the area where the plastic body is thinner on the peripheral side. The power module has poor resistance to moisture and is more likely to cause device failure; (3) The heat sink and the substrate of the power module are not tightly bonded due to deformation or vibration, and the thermal resistance increases after long-term operation; (4) Existing improvement solutions mostly adopt the addition of surface coating, but there are problems such as high processing cost and poor compatibility.

[0003] Therefore, improving the bonding stability between the heat sink and the molding compound is a technical problem that urgently needs to be solved. Utility Model Content

[0004] In view of this, the present invention provides a heat sink and a power module. By optimizing the structure of the surface of the heat sink, especially the peripheral side, for example by setting a contact reinforcement structure extending in the circumferential direction, the bonding stability between the heat sink and the molding compound can be effectively improved.

[0005] Specifically, the present invention provides a heat sink, for example, including a heat sink body. The heat sink body includes a first surface, a second surface opposite to the first surface, and a peripheral side surface connected between the first surface and the second surface. The peripheral side surface is provided with a first contact reinforcement structure, which extends circumferentially along the heat sink body.

[0006] Furthermore, a power module provided in this embodiment of the present invention includes, for example, the heat sink, encapsulation body, substrate, and power device described in the foregoing embodiments; the substrate is fixedly connected to the first surface of the heat sink body of the heat sink, the power device is disposed on the surface of the substrate facing away from the heat sink, the encapsulation body encapsulates at least a portion of the substrate, the power device, and the first surface and peripheral side of the heat sink body of the heat sink, and at least a portion of the second surface of the heat sink body of the heat sink is exposed outside the encapsulation body.

[0007] In addition, another power module provided by this utility model embodiment includes, for example, a heat sink, a molding compound, a substrate, and a power device; the substrate is fixedly connected to the surface of the heat sink, the power device is disposed on the surface of the substrate facing away from the heat sink, the molding compound encapsulates the substrate, the power device, and a portion of the heat sink, and another portion of the heat sink is exposed outside the molding compound; wherein the surface of the heat sink that is combined with the molding compound is provided with a plurality of grooves, each groove having a depth of 0.1mm-0.3mm, a width of 0.1mm-0.3mm, and a spacing of 0.1mm-0.5mm between two adjacent grooves; wherein the heat sink includes a heat sink body, the heat sink body including a first surface, a second surface opposite to the first surface, and a peripheral side surface connected between the first surface and the second surface, and the surface of the heat sink that is combined with the molding compound includes at least a portion of the first surface and the peripheral side surface.

[0008] The above embodiments of this utility model can have the following beneficial effects: By optimizing the structure of the surface of the heat sink, such as the surface that is combined with the molding compound, especially the peripheral side of the heat sink body, for example, by setting a first contact reinforcement structure extending circumferentially along the heat sink body, when it is applied to the power module, the first contact reinforcement structure can be used to achieve a fixed connection with the molding compound through the concave-convex fit, which is beneficial to improve the bonding stability between the heat sink and the molding compound, can improve the water vapor resistance of the power module, reduce the risk of molding compound delamination during operation, reliability testing and operation, thereby improving device performance. Attached Figure Description

[0009] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0010] Figure 1 This is a three-dimensional structural diagram of a heat sink provided for an embodiment of the present utility model.

[0011] Figure 2 for Figure 1 The diagram shows a top view of the heat sink.

[0012] Figure 3 for Figure 1 The diagram shows a bottom view of the heat sink.

[0013] Figure 4A and Figure 4B for Figure 1 The diagram shows the distribution of the first contact enhancement structures, namely continuous annular grooves and discontinuous annular grooves, on the circumferential side of the heat sink body.

[0014] Figure 5for Figure 1 An enlarged side view of the heat sink shown.

[0015] Figures 6A-6F The diagrams illustrate various cross-sections of the first contact enhancement structure in this embodiment of the invention, which is an annular groove.

[0016] Figure 7 This is a schematic diagram showing the dimensions of the first contact reinforcement structure according to an embodiment of the present invention.

[0017] Figures 8A-8E The diagrams illustrate various cross-sections of the first contact enhancement structure in this embodiment of the invention when it is an annular protrusion.

[0018] Figures 9A-9D These are schematic diagrams showing the various distributions of multiple second contact reinforcement structures in the second contact reinforcement structure group, which are embodiments of this utility model.

[0019] Figure 10 This is a schematic diagram of the structure of a power module according to an embodiment of the present utility model.

[0020] Figure 11 For along Figure 10 A sectional view along section XI-XI.

[0021] Figure 12 This is a schematic diagram showing the relative positions of a heat sink, a substrate, and power devices in a power module according to an embodiment of the present invention.

[0022] [Explanation of Key Figure Markings]

[0023] 11. Heat sink; 110. Heat sink body; 110T. First surface; 110B. Second surface; 110S. Peripheral side; 112. Heat dissipation protrusion; 113. Annular barrier; 1101. First contact reinforcement structure; 1103. Second contact reinforcement structure; 110C. Connection area; 110P. Peripheral area; H. Depth; W. Width; D. Spacing; B1. First direction; 13. Molded body; 15. Substrate; 17. Power device. Detailed Implementation

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0025] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] It should also be noted that the division of multiple embodiments in this utility model is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0028] See Figures 1 to 5 The present invention provides a heat sink 11, for example, including a heat sink body 110. The heat sink body 110 includes a first surface 110T, a second surface 110B opposite to the first surface 110T, and a peripheral side surface 110S connected between the first surface 110T and the second surface 110B. The peripheral side surface 110S is provided with a plurality of first contact reinforcement structures 1101. The plurality of first contact reinforcement structures 1101 are arranged at intervals along a first direction B1, and each first contact reinforcement structure 1101 extends along the circumference of the heat sink body 110. The first direction B1 is the direction from the first surface 110T to the second surface 110B.

[0029] As can be seen from the above, the present invention optimizes the structure of the surface of the heat sink 11, especially the peripheral side 110S of the heat sink body 110, by setting multiple first contact reinforcement structures 1101 extending circumferentially along the heat sink body 110. When applied to a power module, the multiple first contact reinforcement structures 1101 can be used to achieve a fixed connection with the molding compound through the concave-convex fit of the molding compound. This helps to improve the bonding stability between the heat sink 110 and the molding compound, improve the power module's resistance to moisture, reduce the risk of molding compound delamination during operation, reliability testing, and operation, thereby improving device performance.

[0030] In some embodiments, see Figure 1 , Figure 4A , Figure 4B and Figure 5 Each of the first contact reinforcement structures 1101 is, for example, Figure 4A The continuous annular groove extending circumferentially along the heat sink body 110 shown is a closed annular structure; or, each of the first contact reinforcement structures 1101 is... Figure 4B The discontinuous annular grooves extending circumferentially along the heat sink body 110 shown are partially interrupted, for example, at the four corners of the heat sink body 110, thus forming an overall non-closed annular structure. Furthermore, it is understood that the discontinuous annular grooves are not limited to this type. Figure 4B The grooves are distributed on the four sides of the peripheral side 110S, as shown, but they can also be distributed on only two opposite sides or only on three sides. In this embodiment, by providing continuous or intermittent annular grooves on the peripheral side 110S of the heat sink body 110, when the heat sink 11 is applied to the power module, the molding compound material used to encapsulate the peripheral side 110S can extend into the annular grooves, making the annular grooves act as adhesive grooves. This facilitates the fixed connection between the heat sink 11 and the molding compound through a convex-concave fit, which can improve the bonding stability between the heat sink 11 and the molding compound, reduce the risk of molding compound delamination during operation, reliability testing, and work, and enhance the moisture resistance of the bonding area between the molding compound and the heat sink 11. Moreover, since the molding compound on the peripheral side 110S of the heat sink body 110 is relatively thin, moisture can easily enter the power module from the peripheral side 110S, causing device failure. Therefore, the annular grooves on the peripheral side 110S serve as adhesive grooves with significant effect.

[0031] In some embodiments, the cross-section of the annular groove perpendicular to the circumferential direction of the heat sink body 110 can adopt a variety of different shapes, for example... Figure 6A The regular trapezoid shown Figure 6B The inverted trapezoid shown Figure 6C The V-shape shown Figure 6D The rectangle shown Figure 6E The arc shape shown is, for example, a circular arc, or Figure 6F The bottom of the groove shown is formed with multiple spaced-apart protrusions or an inverted trapezoid with a single protrusion (each protrusion extends from the bottom of the groove in a direction away from the bottom). More specifically, when the cross-section is as shown... Figure 6A When the cross-section is a regular trapezoid as shown, the width of the annular groove opening is smaller than the width of the groove bottom; when the cross-section is as shown... Figure 6B When the inverted trapezoid shape is shown, the width of the annular groove opening is greater than the width of the groove bottom. It is worth mentioning that... Figures 6A-6F The cross-sectional shape shown is easy to process and can effectively increase the actual contact area between the molding compound and the heat sink 11. According to bonding theory, the bonding strength is positively correlated with the contact area, thereby improving the bonding stability between the molding compound and the heat sink 11; especially Figure 6A and Figure 6F The cross-sectional shape shown increases the geometric complexity of the surface of the heat sink 11, allowing the molding compound material to fill into these structures during curing, forming mechanical anchor points similar to "claws". After curing, the molding compound and the heat sink 11 are tightly bonded together through physical interlocking.

[0032] In some embodiments, see Figure 1 , Figure 5 and Figure 7 When each of the first contact reinforcement structures 1101 is an annular groove, the depth H of the annular groove is, for example, 0.1mm-0.3mm. If the depth H is too shallow, the adhesive bonding effect is poor; if the depth H is too deep, processing is difficult, and the encapsulating material may not reach the bottom of the groove, easily causing voids. The size of the annular groove needs to match the flowability of the encapsulating material to avoid unfilled areas or air bubbles. Furthermore, the width W of the annular groove in the first direction B1 is, for example, 0.1mm-0.3mm. If the annular groove is too narrow, it is difficult to process, and the tool is prone to breakage when using CNC milling. Moreover, the flow resistance of the encapsulating material in the narrow groove is large, making it difficult to completely fill and form voids. If the annular groove is too wide, the adhesive bonding effect is not obvious. In addition, the distance D between two adjacent annular grooves in the first direction B1 is, for example, 0.1mm-0.5mm. Theoretically, the more annular grooves there are, the better the adhesive bonding effect. However, if the distance D between adjacent annular grooves is less than 0.1mm, it is difficult to process, and the walls between the grooves are thin, making them prone to damage and deformation.

[0033] In some embodiments, see Figure 1 and Figures 8A-8E Each of the first contact reinforcement structures 1101 is a continuous or discontinuous annular protrusion extending circumferentially along the heat sink body 110. The cross-section of the annular protrusion perpendicular to the circumferential direction can adopt a variety of different shapes, for example... Figure 8A The inverted trapezoid shown Figure 8B The regular trapezoid shown Figure 8C The triangle shown Figure 8D The rectangle shown, or Figure 8E The arc shape shown is like a circular arc. It is worth mentioning that... Figures 8A-8E The cross-sectional shape shown is easy to process and can effectively increase the contact area between the molding compound material and the heat sink 11, thereby improving the bonding stability between the molding compound and the heat sink 11.

[0034] In some embodiments, see Figure 1 and Figure 3 The first surface 110T includes a connection region 110C and a peripheral region 110P surrounding the connection region 110C. The peripheral region 110P is configured with a plurality of mutually spaced second contact reinforcement structure groups, and each second contact reinforcement structure group includes a plurality of second contact reinforcement structures 1103. The plurality of second contact reinforcement structure groups are arranged at least in a plurality of corner areas of the peripheral region 110P. For example, with Figure 3 As shown in the example, the peripheral region 110P is configured with eight second contact reinforcement structure groups. Each second contact reinforcement structure group includes four second contact reinforcement structures 1103. Four of the eight second contact reinforcement structure groups are arranged in the four corner areas of the peripheral region 110P, and the remaining four second contact reinforcement structure groups are arranged in the four non-corner areas of the peripheral region 110P. Each non-corner area is located between two adjacent corner areas. In this embodiment, by providing multiple second contact reinforcement structures 1103 on the first surface 110T of the heat sink body 110, the bonding stability between the molding compound and the first surface 110T of the heat sink body 110 can be improved. Furthermore, by arranging multiple second contact reinforcement structure groups at least in multiple corner areas of the peripheral region 110P, the bonding force of the molding compound on each corner area of ​​the first surface 110T of the heat sink body 110 can be improved, further enhancing the bonding stability.

[0035] Furthermore, such as Figure 3As shown, each of the second contact reinforcement structures 1103 is, for example, an elongated groove, and the depth of the elongated groove is, for example, 0.1mm-0.3mm. If the depth is too shallow, the adhesive bonding effect is poor; if the depth is too deep, processing is difficult, and the flow depth of the encapsulating material may not reach the bottom of the groove, easily causing voids. The size of the elongated groove needs to match the flowability of the encapsulating material to avoid unfilled areas or air bubbles. The width W of the elongated groove is, for example, 0.1mm-0.3mm. If the groove is too narrow, it is difficult to process, and the tool is prone to breakage when using CNC milling. Moreover, the flow resistance of the encapsulating material in the narrow groove is large, making it difficult to completely fill and form voids. If the groove is too wide, the adhesive bonding effect is not obvious. The distance D between two adjacent elongated grooves is, for example, 0.1mm-0.5mm. Theoretically, the more grooves there are, the better the adhesive bonding effect. However, if the distance D between adjacent elongated grooves is less than 0.1mm, it is difficult to process, and the walls between the grooves are thin, making them prone to damage and deformation. Additionally, it is worth mentioning that in other embodiments, each second contact reinforcement structure 1103 may have the same cross-sectional shape as the aforementioned annular groove, for example... Figures 6A-6F The cross-sectional shape shown; furthermore, each second contact reinforcement structure 1103 is not limited to an elongated groove, but can also be replaced by an elongated protrusion, and the cross-section of the elongated protrusion can adopt the same cross-sectional shape as the aforementioned annular protrusion, for example Figures 8A-8E The cross-sectional shape shown.

[0036] In some embodiments, see Figure 5 and Figures 9A-9D The plurality of second contact reinforcement structures 1103 in each of the second contact reinforcement structure groups can be a plurality of straight strip structures (e.g., ...) arranged in parallel and spaced apart from each other. Figure 9A (as shown), or multiple straight strip-shaped structures arranged radially (such as...) Figure 9B (as shown), or multiple straight strip structures distributed in a grid pattern (such as...) Figure 9C As shown, multiple horizontal straight strip structures intersect perpendicularly with multiple vertical straight strip structures to form a grid structure, or multiple curved structures spaced apart from each other (such as...). Figure 9D (As shown). Because shrinkage stress is generated when the molding compound material cures and temperature changes, Figures 9A-9D The distribution of the multiple second contact reinforcement structures 1103 shown can disperse stress to multiple local areas, avoiding interface cracking or delamination caused by stress concentration; especially Figure 9B and Figure 9D The distribution pattern shown can distribute stress in all directions to produce better protection.

[0037] In some embodiments, see Figure 5Any two adjacent first contact reinforcement structures 1101 among the plurality of first contact reinforcement structures 1101 are arranged parallel to each other to facilitate processing.

[0038] In some embodiments, see Figure 1 and Figure 2 The heat sink 11 further includes a plurality of heat dissipation protrusions 112 (e.g., a plurality of heat dissipation pillars) and an annular baffle 113. The plurality of heat dissipation protrusions 112 are provided along the first direction B1 on the second surface 110B and are spaced apart from each other. The annular baffle 113 is provided along the first direction B1 on the second surface 110B and is arranged around the plurality of heat dissipation protrusions 112. In this embodiment, the arrangement of the plurality of heat dissipation protrusions 112 is beneficial to increasing the heat dissipation area of ​​the heat sink 11, and the arrangement of the annular baffle 113 can prevent the molding material from overflowing onto each heat dissipation protrusion 112 during molding, so as to ensure heat dissipation efficiency and the cleanliness of the product appearance.

[0039] See Figure 10 , Figure 11 and Figure 12 The power module provided in this embodiment of the present invention includes, for example: Figure 1 The diagram shows a heat sink 11, a molding compound 13, a substrate 15, and a power device 17. The substrate 15 is fixedly connected to the first surface 110T of the heat sink body 110 of the heat sink 11. The power device 17 is disposed on the surface of the substrate 15 facing away from the heat sink 11. The molding compound 13 encapsulates the substrate 15, the power device 17, at least a portion of the first surface 110T of the heat sink body 110 of the heat sink 11, and the peripheral side surface 110S. At least a portion of the second surface 110B of the heat sink body 110 of the heat sink 11 is exposed outside the molding compound 13. The material of the molding compound 13 may be epoxy molding compound (EMC) or other suitable materials. More specifically, Figure 12 The diagram shows a substrate 15 and two power devices 17 as an illustrative example, with the connection area 110C between the substrate 15 and the first surface 110T of the heat sink body 110 of the heat sink 11 (see reference). Figure 3The fixed connection is, for example, welding. Each power device 17 is respectively disposed on the surface of the substrate 15 opposite to the heat sink 11, for example, by means of a connecting material (e.g., welding material or sintering material). The substrate 15 is, for example, a multilayer substrate, which includes, for example, an insulating base layer and metal layers disposed on opposite sides of the insulating base layer. The metal layers may be made of copper, copper alloy, aluminum, aluminum alloy, or other metals. The insulating base layer is, for example, a ceramic base layer made of alumina, aluminum nitride, or silicon nitride. Each power device 17 includes, for example, a controllable semiconductor switch such as a MOSFET, IGBT, JFET, or thyristor, or an uncontrollable semiconductor switch such as a diode. Furthermore, from Figure 10 It can be seen that the molding compound 13 encapsulates a portion of the first surface 110T of the heat sink body 110 of the heat sink 11, and all the second contact reinforcement structures 1103 disposed on the first surface 110T are covered by the molding compound 13. Of course, in other embodiments, the entire first surface 110T of the heat sink body 110 can also be encapsulated. Furthermore, from Figure 11 It is understood that the molding compound 13 encapsulates the entire peripheral side surface 110S of the heat sink body 110 of the heat sink 11, so that each of the first contact reinforcement structures 1101 provided on the peripheral side surface 110S is covered by the molding compound 13. In this way, the bonding stability between the molding compound 13 and the heat sink 11 is enhanced, and each of the first contact reinforcement structures 1101 and each of the second contact reinforcement structures 1103 is encapsulated within the molding compound 13, without affecting the appearance of the power module. Moreover, the first contact reinforcement structures 1101 and the second contact reinforcement structures 1103 are far away from the heat dissipation protrusion 112 (see reference). Figure 1 and Figure 2 The area where it is located will not have reduced heat dissipation performance.

[0040] Please see again. Figure 1 , Figure 10 , Figure 11 and Figure 12 Another power module provided in this embodiment of the present invention includes, for example, a heat sink 11, a molding compound 13, a substrate 15, and a power device 17; the substrate 15 is fixedly connected to the surface of the heat sink 11, the power device 17 is disposed on the surface of the substrate 15 facing away from the heat sink 11, the molding compound 13 encapsulates the substrate 15, the power device 17, and a portion of the heat sink 11, and another portion of the heat sink 11 is exposed outside the molding compound 13. (See reference...) Figure 3 , Figure 5 and Figure 7The surface of the heat sink 11 that is coupled to the molding compound 13 is provided with multiple grooves. The depth H of each groove is 0.1mm-0.3mm, the width W of each groove is 0.1mm-0.3mm, and the distance D between two adjacent grooves is 0.1mm-0.5mm. (Refer to...) Figure 1 The heat sink 11 includes a heat sink body 110, which includes a first surface 110T, a second surface 110B opposite to the first surface 110T, and a peripheral side surface 110S connecting the first surface 110T and the second surface 110B. The surface of the heat sink 11 that is combined with the molding compound 13 includes at least a portion of the first surface 110T and the peripheral side surface 110S. For example, the groove may be provided on the first surface 110T as the aforementioned second contact reinforcement structure 1103, or provided on the peripheral side surface 110S as the aforementioned first contact reinforcement structure 1101.

[0041] In some embodiments, see Figure 1 and Figure 5 The peripheral side surface 110S is provided with a plurality of grooves, and the plurality of grooves provided on the peripheral side surface 110S are arranged at intervals along the first direction B1, and each groove is a continuous or discontinuous annular groove extending along the circumference of the heat sink body 110, wherein the first direction B1 is the direction from the first surface 110T to the second surface 110B.

[0042] In some embodiments, see Figure 1 and Figure 3 The first surface 110T includes a connection area 110C and a peripheral area 110P surrounding the connection area 110C. The peripheral area 110P is provided with a plurality of grooves. The plurality of grooves in the peripheral area 110P are arranged at least in a plurality of corner areas of the peripheral area 110P. The substrate 15 is fixed to the connection area 110C by welding.

[0043] In some embodiments, see Figure 1 and Figure 2 The heat sink 11 further includes a plurality of heat dissipation protrusions 112 and an annular baffle 113. The plurality of heat dissipation protrusions 112 extend from the second surface 110B in a direction away from the first surface 110T and are spaced apart from each other. The annular baffle 113 extends from the second surface 110B in the same direction away from the first surface 110T and surrounds the plurality of heat dissipation protrusions 112. The plurality of heat dissipation protrusions 112 and the annular baffle 113 are exposed outside the encapsulation body 13.

[0044] Finally, it is worth mentioning that the number of first contact reinforcement structures 1101 in this embodiment of the present invention is not limited to the multiple ones described in the foregoing embodiments. For example, when the thickness of the peripheral side surface 110S in the first direction B1 is relatively thin, it is also possible to consider providing only one first contact reinforcement structure 1101 extending circumferentially along the heat sink body 110 on the peripheral side surface 110S.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A heat sink, characterized in that, The device includes a heat sink body, which includes a first surface, a second surface opposite to the first surface, and a peripheral side surface connecting the first surface and the second surface. The peripheral side surface is provided with a first contact reinforcement structure, which extends circumferentially along the heat sink body.

2. The heat sink according to claim 1, characterized in that, The first contact enhancement structure is a continuous or discontinuous annular groove extending circumferentially along the body of the heat sink, or a continuous or discontinuous annular protrusion extending circumferentially along the body of the heat sink.

3. The heat sink according to claim 2, characterized in that, The bottom of the annular groove has one or more spaced protrusions; and / or, The cross-section of the annular groove perpendicular to the circumference is a regular trapezoid, an inverted trapezoid, a V-shape, a rectangle, or an arc.

4. The heat sink according to claim 2, characterized in that, The depth of the annular groove is 0.1 mm - 0.3 mm, the width of the annular groove in the first direction is 0.1 mm - 0.3 mm, and the distance between two adjacent annular grooves in the first direction is 0.1 mm - 0.5 mm, wherein the first direction is the direction from the first surface to the second surface.

5. The heat sink according to claim 1, characterized in that, The first surface includes a connection area and a peripheral area surrounding the connection area. The peripheral area is configured with a plurality of mutually spaced second contact reinforcement structure groups, and each second contact reinforcement structure group includes a plurality of second contact reinforcement structures. The plurality of second contact reinforcement structure groups are arranged at least in a plurality of corner areas of the peripheral area.

6. The heat sink according to claim 5, characterized in that, Each of the second contact reinforcement structures is an elongated groove with a depth of 0.1 mm - 0.3 mm, a width of 0.1 mm - 0.3 mm, and a spacing of 0.1 mm - 0.5 mm between two adjacent elongated grooves. And / or, some of the plurality of second contact reinforcement structure groups are arranged in the plurality of corner areas of the peripheral region, and the remaining of the plurality of second contact reinforcement structure groups are arranged in the plurality of non-corner areas of the peripheral region, each of the non-corner areas being located between two adjacent corner areas.

7. The heat sink according to claim 5, characterized in that, The plurality of second contact reinforcement structures in each group of second contact reinforcement structures are a plurality of straight strip structures arranged in parallel and spaced apart from each other, or a plurality of straight strip structures arranged radially, or a plurality of straight strip structures arranged in a grid pattern, or a plurality of curved structures arranged in parallel and spaced apart from each other.

8. The heat sink according to claim 1, characterized in that, The number of the first contact reinforcement structures is multiple, and the multiple first contact reinforcement structures are arranged at intervals along a first direction, wherein the first direction is the direction from the first surface to the second surface, and any two adjacent first contact reinforcement structures in the multiple first contact reinforcement structures are arranged parallel to each other. And / or, the heat sink further includes a plurality of heat dissipation protrusions and an annular baffle, the plurality of heat dissipation protrusions being provided on the second surface along the first direction and spaced apart from each other, and the annular baffle being provided on the second surface along the first direction and surrounding the plurality of heat dissipation protrusions.

9. A power module, characterized in that, include: The heat sink, molding compound, substrate, and power device as described in any one of claims 1-8; The substrate is fixedly connected to the first surface of the heat sink body of the heat sink, the power device is disposed on the surface of the substrate opposite to the heat sink, the encapsulation encapsulates the substrate, the power device, and at least a portion of the first surface and the peripheral side of the heat sink body of the heat sink, and at least a portion of the second surface of the heat sink body of the heat sink is exposed outside the encapsulation.

10. A power module, characterized in that, include: Heat sink, molding compound, substrate, and power devices; The substrate is fixedly connected to the surface of the heat sink, the power device is disposed on the surface of the substrate facing away from the heat sink, the molding compound encapsulates the substrate, the power device and a portion of the heat sink, and another portion of the heat sink is exposed outside the molding compound. The heat sink has a plurality of grooves on the surface that is in contact with the encapsulation body. Each groove has a depth of 0.1 mm to 0.3 mm, a width of 0.1 mm to 0.3 mm, and a spacing of 0.1 mm to 0.5 mm between two adjacent grooves. The heat sink includes a heat sink body, which includes a first surface, a second surface opposite to the first surface, and a peripheral side surface connected between the first surface and the second surface. The surface of the heat sink that is combined with the encapsulation body includes at least a portion of the first surface and the peripheral side surface.

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