Power module and power conversion equipment

Abstract

The utility model provides a power module and power conversion equipment. The power module comprises a packaging shell, a heat conduction plate located in the packaging shell and at least one substrate. The substrates are arranged on the surface of the heat conducting plate, and each substrate comprises a ceramic substrate and a metal layer covering the surface of the ceramic substrate. At least one containing groove is formed in the surface of the heat conduction plate and contains the welding layer. The welding layer welds the metal layer of the substrate and the heat conducting plate. One or more grooves are formed in the side wall of the containing groove. During reflow soldering, the solder is melted in the accommodating groove and can form a flat surface, so that a soldering layer with uniform thickness is formed after reflow soldering is completed. In the reflow soldering process, the groove can contain redundant welding flux, and therefore the welding flux is prevented from overflowing out of the containing groove in the reflow soldering process. And gas generated by volatile scaling powder and other components in the welding flux can be exhausted into the grooves in the periphery, so that the phenomenon that holes appear in the surface of the welding layer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronics, and particularly relates to a power module and a power conversion device. BACKGROUND

[0002] The power module is a functional module in which power electronic devices are combined according to certain functions and then molded or poured into a whole, and is widely used in servo motors, frequency converters, inverters and other devices. Considering the high heat dissipation and insulation requirements of the power module, the power module usually uses a metal-clad ceramic substrate with the advantages of high temperature resistance, corrosion resistance, high thermal conductivity, high mechanical strength, and difficulty in deterioration as a carrier of the electronic device, and the substrate is fixed on a heat-conducting plate through a reflow soldering process. The heat-conducting plate can be provided with multiple substrates, and the surface of the heat-conducting plate away from the substrates is used to be attached to a heat sink and exchange heat.

[0003] The reflow soldering process uses an external high-temperature heat source to heat the solder between the metal-clad ceramic substrate and the heat-conducting plate. Before reflow soldering, the heat-conducting plate is usually pre-bent to have a certain curvature to offset the deformation of the heat-conducting plate during reflow soldering, so as to ensure the flatness of the contact surface between the heat-conducting plate and the heat sink after reflow soldering, and achieve a better heat dissipation effect.

[0004] However, during reflow soldering, due to the unevenness of the connection interface between the curved surface of the heat-conducting plate and the flat surface of the metal-clad ceramic substrate, the thickness of the solder layer is uneven, and the solder is prone to overflow, so that one or more substrates have a height difference on the heat-conducting plate. On the one hand, the uneven thickness of the solder layer will cause the difference in chip thermal resistance, and on the other hand, the overflow of the solder will affect the insulation of the power module. CONTENT OF THE INVENTION

[0005] The present application provides a power module and a power conversion device to improve the uneven thickness of the solder layer and the overflow of the solder, thereby improving the reliability of the power module.

[0006] In a first aspect, this application provides a power module. The power module includes a package housing, a heat-conducting plate, and at least one substrate, wherein the heat-conducting plate and the aforementioned at least one substrate are located within the package housing. Specifically, the aforementioned at least one substrate is disposed on the surface of the heat-conducting plate, and each substrate includes a ceramic substrate and a metal layer, the metal layer being disposed on the surface of the ceramic substrate facing the heat-conducting plate. The package housing has an opening, and the surface of the heat-conducting plate facing away from the aforementioned at least one substrate is exposed to the opening, the heat-conducting plate being used for heat exchange with a heat sink. At least one receiving groove is disposed on the surface of the heat-conducting plate facing the aforementioned at least one substrate. The aforementioned at least one receiving groove is disposed one-to-one with the aforementioned at least one substrate. The aforementioned at least one receiving groove accommodates a solder layer. The solder layer solders the metal layer of the corresponding substrate and the heat-conducting plate. Each receiving groove has one or more grooves on its sidewall.

[0007] In the power module of this application, the receiving groove of the heat-conducting plate can be used to hold the solder that forms the solder layer. The solder can specifically include solder paste or solder sheets. During reflow soldering, the solder is heated and melted in the receiving groove. Under the action of gravity and surface tension of the liquid, the solder in the receiving groove can form a relatively flat surface. Furthermore, a solder layer of uniform thickness is formed after reflow soldering, thereby improving the phenomenon of uneven solder layer thickness. The aforementioned one or more grooves can increase the holding space of the receiving groove. During reflow soldering, the grooves can hold excess solder, thereby preventing solder from overflowing from the receiving groove during reflow. Additionally, gases generated by volatile flux and other components in the solder can also be discharged into the surrounding grooves, thereby improving the phenomenon of voids in the solder layer.

[0008] In the aforementioned power module, a predetermined gap exists between the sidewall of the metal layer and the sidewall of the receiving tank. When the substrate is placed on the heat-conducting plate, the metal layer can cover the surface of the solder layer facing the substrate. A small gap remains between the metal layer and the receiving tank to allow volatile gases from the solder to escape.

[0009] Each of the aforementioned at least one substrate may include, but is not limited to, a direct-bonded copper (DBC) substrate, a direct-bonded aluminum (DBA) substrate, or an active metal brazing (AMB) substrate.

[0010] The aforementioned grooves not only accommodate excess solder that overflows during reflow soldering, but also allow small air bubbles escaping from the solder due to flux evaporation to dissipate into the surrounding grooves, thus preventing voids in the solder layer. Specifically, the number of grooves is not limited; for example, one or more grooves can be provided on the sidewall of the receiving groove, thereby making the surface of the sidewall uneven.

[0011] In one aspect, the sidewall can be provided with a plurality of grooves, and depths of at least two grooves of the plurality of grooves are different. By providing the plurality of grooves with different depths, the accommodation space of the accommodation groove can be further increased.

[0012] In order to facilitate the manufacturing, the plurality of grooves can be arranged in a stepped manner along a direction perpendicular to the heat conduction plate. In one aspect, depths of two adjacent grooves of the plurality of grooves are different, and the depth of the groove closer to the heat conduction plate is greater than the depth of the groove closer to the substrate. Alternatively, in another aspect, depths of two adjacent grooves of the plurality of grooves are different, and the depth of the groove closer to the heat conduction plate is less than the depth of the groove closer to the substrate.

[0013] In another aspect, the sidewall is provided with a plurality of grooves, and the plurality of grooves can be arranged in a zigzag manner along a direction perpendicular to the heat conduction plate. The zigzag space can accommodate excess solder and a small amount of bubbles escaping from the solder, thereby avoiding overflow of the solder and reducing the formation of voids in the solder layer.

[0014] In the accommodation groove, a surface of a bottom wall of the accommodation groove can be provided with a grid structure, and a height of the grid structure is less than or equal to a depth of the at least one accommodation groove. In this aspect, the bottom wall of the accommodation groove is provided with the grid structure, and the grid structure can make the solder uniformly cover the bottom wall to form a solder layer with uniform thickness.

[0015] The grid structure can include a plurality of first strip-shaped grids arranged in parallel, and each of the plurality of first strip-shaped grids is provided with a first gap. The plurality of first strip-shaped grids can divide the bottom wall of the accommodation groove into a plurality of rectangular regions arranged in parallel, and the rectangular regions are communicated through the first gaps. Excess solder or a small amount of bubbles in the reflow soldering can be discharged to the grooves around the grid structure along the communication path inside the grid structure, thereby preventing overflow or void structure of the solder layer.

[0016] The grid structure can further include a plurality of second strip-shaped grids arranged in parallel, and the plurality of second strip-shaped grids are perpendicular to the plurality of first strip-shaped grids. Each of the plurality of second strip-shaped grids is provided with a second gap. The plurality of first strip-shaped grids and the plurality of second strip-shaped grids can divide the bottom wall of the accommodation groove into a grid, and two adjacent regions in the grid can be communicated through the first gap or the second gap, so that excess solder or a small amount of bubbles can be discharged to the grooves around the grid.

[0017] In some other embodiments, the grid structure can include a plurality of circular grids, two adjacent circular grids in the plurality of circular grids are connected, and the plurality of circular grids are connected with the at least one groove. In this embodiment, the plurality of circular grids can divide the bottom wall of the accommodating groove into a plurality of circular regions arranged in an array, and the circular regions are connected through the third gaps of the circular grids.

[0018] In the power module of the present application, the surface of the heat conduction plate on the side facing the at least one substrate can be provided with at least one raised frame, the at least one raised frame and the heat conduction plate can enclose the at least one accommodating groove, and the sidewall of the at least one raised frame located in the accommodating groove is provided with the one or more grooves. This embodiment realizes the structure of the accommodating groove by providing a raised frame on the surface of the heat conduction plate. In another embodiment, the structure of the accommodating groove can also be realized by grooving the surface of the heat conduction plate on the side facing the at least one substrate, and the present application does not limit the implementation of the accommodating groove.

[0019] In actual applications, the height of the raised frame can be set according to the thickness of the solder layer. Specifically, the height of each raised frame in the direction perpendicular to the heat conduction plate can be less than or equal to the height of the solder layer. For example, in some embodiments, the thickness of the solder layer can be in the range of 50 microns to 300 microns. Therefore, the height of each raised frame in the direction perpendicular to the heat conduction plate can be correspondingly set to be greater than or equal to 50 microns and less than or equal to 300 microns.

[0020] In a second aspect, the present application provides a power conversion device. The power conversion device includes a circuit board and the power module of the first aspect. The power module is located on one side of the circuit board and is electrically connected with the circuit board. In the power conversion device of the present application, the surface of the heat conduction plate of the power module is provided with an accommodating groove for accommodating the solder layer. During reflow soldering, the solder melts in the accommodating groove, and under the action of gravity and liquid surface tension, the solder in the accommodating groove forms a solder layer with a relatively flat surface. Therefore, after reflow soldering is completed, a solder layer with uniform thickness is formed, thereby improving the phenomenon of uneven thickness of the solder layer. In addition, the grooves of the sidewall of the accommodating groove can increase the accommodating space of the accommodating groove, and during reflow soldering, the grooves can accommodate excess solder, thereby preventing the solder from overflowing outside the accommodating groove during reflow. In addition, the gas generated by the easily volatile flux and other components in the solder can also be discharged to the surrounding grooves, thereby improving the phenomenon of voids in the solder layer. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A schematic diagram of a power conversion device provided by an embodiment of the present application;

[0022] Figure 2 A schematic diagram of a power module provided by an embodiment of the present application;

[0023] Figure 3 Another schematic view of the power module provided for embodiments of the present application;

[0024] Figure 4 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0025] Figure 5 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0026] Figure 6 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 5 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0027] Figure 7 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0028] Figure 8 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 7 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0029] Figure 9 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 7 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0030] Figure 10 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0031] Figure 11 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 10 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0032] Figure 12 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0033] Figure 13 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 12 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0034] Figure 14 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0035] Figure 15 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 14 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0036] Figure 16 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0037] Figure 17 Another schematic view of the heat conducting plate provided for embodiments of the present application; Figure 16 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0038] Figure 18 Another schematic view of the heat conducting plate provided for embodiments of the present application;

[0039] Figure 19 A projection schematic view of the first metal layer on the heat-conducting plate provided by the embodiment of the present application is shown in FIG. 1.

[0040] Figure 20 Another projection schematic view of the first metal layer on the heat-conducting plate provided by the embodiment of the present application is shown in FIG. 2.

[0041] Reference signs:

[0042] 10 - power conversion device 11 - circuit board 12 - power module

[0043] 13 - heat sink 121 - package shell 122 - heat-conducting plate

[0044] 123 - substrate 124 - protruding frame 125 - accommodating groove

[0045] 126 - soldering layer 127 - groove 128 - grid structure

[0046] 129 - notch 1281 - first strip grid 1282 - second strip grid

[0047] 1283 - circular grid 1231 - ceramic substrate 1232 - first metal layer

[0048] 1233 - second metal layer DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0050] It should be noted that the terms used in the following embodiments are only for the purpose of describing the particular embodiments and are not intended to be limiting of the present application. As used in the specification and the appended claims, the singular forms "a," "an" and "the" are intended to include both the singular and the plural forms, unless the context clearly indicates otherwise.

[0051] To facilitate understanding of the power module and power conversion device provided in this application embodiment, their application scenarios are described below. The power module of this application is a semiconductor device that converts the voltage, current, and frequency of a power supply, and is a core device for power conversion. Power modules can be applied to power conversion devices in scenarios such as photovoltaic power generation equipment, electric vehicles, and energy storage equipment. Depending on the application field, power modules can be classified into automotive-grade power modules, industrial power modules, etc. In electric vehicles, power modules can be used for AC-DC conversion or DC conversion. For example, power modules can be applied to on-board chargers (OBCs) and motor control units (MCUs). In photovoltaic power generation equipment, power modules can be applied to power conversion devices. Power conversion devices can convert DC power generated by solar panels into AC power for output. In energy storage devices, power modules can be used to convert external AC power into DC power for storage in battery packs, or to convert DC power output from battery packs into AC power for output to AC loads.

[0052] Figure 1 This is a schematic diagram of a power conversion device provided in an embodiment of this application. Figure 1 As shown, the power conversion device 10 specifically includes a circuit board 11, a power module 12, and a heat sink 13. The power module 12 can be located on one side of the circuit board 11, and the power module 12 is electrically connected to the circuit board 11 via pins. The heat sink 13 is located on one side of the power module 12. Specifically, the power module 12 includes a package shell 121 and a heat-conducting plate 122 located within the package shell 121. The surface of the package shell 121 facing the heat sink 13 has an opening. One side of the heat-conducting plate 122 is exposed to this opening, and the heat-conducting plate 122 can be attached to the heat sink 13, which is used to dissipate heat from the power module 12 through the heat-conducting plate 122. At least one substrate 123 is disposed on the surface of the heat-conducting plate 122 facing away from the heat sink 13. The aforementioned at least one substrate 123 is a metal-clad ceramic substrate; specifically, the substrate 123 includes, but is not limited to, a direct copper-clad substrate, a direct aluminum-clad substrate, or an active metal brazing substrate. When a plurality of substrates 123 are provided on the surface of the heat-conducting plate 122, another metal layer may be provided on the surface of the aforementioned plurality of substrates 123 on the side opposite to the heat-conducting plate 122. The surface of the metal layer may be used to lay out metal traces, chips or other power devices.

[0053] In the existing power module, the heat-conducting plate and the substrate are welded by using the reflow soldering process. The heat-conducting plate is usually a metal substrate, which is easy to deform when heated in the reflow soldering process. Therefore, the heat-conducting plate is pre-bent before the reflow soldering to offset the deformation generated in the reflow soldering. However, the pre-bent surface of the heat-conducting plate forms a welding layer with uneven thickness when the heat-conducting plate and the substrate are welded, which causes thermal resistance difference and can cause height difference of multiple substrates on the heat-conducting plate, and on the other hand, the molten solder is easy to overflow between the substrate and the heat-conducting plate, affecting the insulation of the power module.

[0054] In view of this, the present application provides a power module and a power conversion device to improve the phenomenon of uneven welding layer thickness and solder overflow, thereby improving the reliability of the power module.

[0055] In this specification, the reference to "one embodiment" or "some embodiments" etc. means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Thus, the appearances of the phrases "in one embodiment", "in some embodiments", "in other embodiments", "in additional embodiments" etc. in various places in the specification are not necessarily all referring to the same embodiment, but can refer to one or more but not all embodiments, unless otherwise specifically stated. The terms "including", "containing", "having" and variations thereof mean "including but not limited to", unless otherwise specifically stated.

[0056] In this application, the terms "first", "second" and the like are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, unless otherwise stated, the meaning of "multiple" is two or more.

[0057] In addition, in this paper, the orientation terms such as "top", "bottom", "upper", "lower" and the like are defined with respect to the orientation of the structure shown in the drawing, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and they can change accordingly according to the change of the orientation of the structure.

[0058] Figure 2 A schematic diagram of the power module provided by the embodiments of the present application, Figure 3 Another schematic diagram of the power module provided by the embodiments of the present application, Figure 4 A schematic diagram of the heat-conducting plate provided by the embodiments of the present application, wherein, Figure 2 and Figure 3 showing a side view of the power module in the xz plane, Figure 4A top view of the heat-conducting plate in the xy plane is shown, with the x, y and z directions being perpendicular to each other. As shown in Figure 2 , Figure 3 and Figure 4 The substrate 123 includes a ceramic substrate 1231, a first metal layer 1232 and a second metal layer 1233. The first metal layer 1232 and the second metal layer 1233 are respectively arranged on the two side surfaces of the ceramic substrate 1231. The first metal layer 1232 is arranged towards the heat-conducting plate 122, and the second metal layer 1233 is arranged on the side of the ceramic substrate 1231 away from the heat-conducting plate 122. The surface of the side of the heat-conducting plate 122 towards the substrate 123 is provided with at least one accommodating groove 125. The at least one accommodating groove 125 is arranged in one-to-one correspondence with the at least one substrate 123. The at least one accommodating groove 125 accommodates a solder layer 126. The solder layer 126 is arranged to solder the first metal layer 1232 and the heat-conducting plate 122. The sidewall of each accommodating groove 125 is provided with one or more grooves 127.

[0059] As shown in Figure 2 , in some embodiments, the accommodating groove 125 can be realized by directly grooving the surface of the heat-conducting plate 122, so that the accommodating groove 125 in this embodiment is a groove in the surface of the heat-conducting plate 122. In other embodiments, as shown in Figure 3 , the surface of the side of the heat-conducting plate 122 towards the substrate 123 is provided with at least one raised frame 124. The at least one raised frame 124 is arranged in one-to-one correspondence with the at least one substrate 123. Each raised frame 124 and the heat-conducting plate 122 enclose an accommodating groove 125.

[0060] The raised frame 124 and the heat-conducting plate 122 enclosing an accommodating groove 125 are taken as an example for description.

[0061] In the power module 12 of the present application, the raised frame 124 of the heat-conducting plate 122 can be used to accommodate the solder forming the solder layer 126, which can include solder paste or solder sheet. During reflow soldering, the solder is heated and melted in the accommodation groove 125, and under the action of gravity and liquid surface tension, the solder in the accommodation groove 125 can form a relatively flat surface. After reflow soldering is completed, a solder layer 126 with uniform thickness is formed, thereby improving the phenomenon of uneven thickness of the solder layer 126. In addition, the surface of the raised frame 124 on the side facing the accommodation groove 125 forms the side wall of the accommodation groove 125, and the surface of the heat-conducting plate 122 located in the accommodation groove 125 forms the bottom wall of the accommodation groove 125. The groove 127 of the raised frame 124 can increase the accommodation space of the accommodation groove 125, and during reflow soldering, the groove 127 can accommodate excess solder, thereby preventing the solder from overflowing outside the accommodation groove 125 during reflow. In addition, volatile flux and other components in the solder produce bubbles, most of which can be discharged from between the first metal layer 1232 and the raised frame 124, and a small part of which is discharged into the surrounding groove 127, thereby improving the phenomenon of voids in the solder layer 126.

[0062] Figure 5 Another schematic view of the heat-conducting plate provided for an embodiment of the present application, Figure 6 for Figure 5 a partial schematic view of the heat-conducting plate. As shown in Figure 5 and Figure 6 , the groove 127 can not only accommodate excess solder overflowing around during reflow soldering, but also a small part of the bubbles escaping from the solder due to the volatilization of the flux can be discharged into the surrounding groove 127 to avoid the formation of voids in the solder layer 126. Specifically, the number of grooves 127 of the raised frame 124 is not limited, for example, the side wall can be provided with one or more grooves 127, so that the surface of the side wall is uneven.

[0063] As shown in Figure 5 and Figure 6 , the side wall can be provided with a plurality of grooves 127, and the depths of at least two grooves 127 in the plurality of grooves 127 are not equal. By providing a plurality of grooves 127 with different depths, the accommodation space of the accommodation groove 125 can be further increased.

[0064] Figure 7 Another schematic view of the heat-conducting plate provided for an embodiment of the present application, Figure 8 for Figure 7 a partial schematic view of the heat-conducting plate. As shown in Figure 7 and Figure 8 , in order to facilitate manufacturing, the plurality of grooves 127 described above can be arranged in a stepped manner on the surface of the side wall perpendicular to the heat-conducting plate 122. As shown in Figure 7 and Figure 8As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 9 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 7 Another partial view of the heat-conducting plate is shown in FIG. 2B. Figure 9 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127.

[0065] Figure 10 Another view of the heat-conducting plate is shown in FIG. 3. Figure 11 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 10 Another partial view of the heat-conducting plate is shown in FIG. 4. Figure 10 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 11 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127.

[0066] Figure 12 Another view of the heat-conducting plate is shown in FIG. 5. Figure 13 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 12 Another view of the heat-conducting plate is shown in FIG. 6. Figure 12 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 13 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127.

[0067] As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 12 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127. Figure 13 As shown, in one embodiment, the depth of the groove 127 close to the heat-conducting plate 122 is greater than the depth of the groove 127 close to the substrate 123 in the two adjacent grooves 127 of the plurality of grooves 127.

[0068] Figure 14 Another schematic view of the heat conduction plate provided in an embodiment of the present application, Figure 15 Figure 14 Another schematic view of the heat conduction plate. As shown in Figure 14 Figure 15 The grid structure 128 can further include a plurality of second strip-shaped grids 1282 arranged in parallel, and the second strip-shaped grids 1282 are perpendicular to the first strip-shaped grids 1281. Each of the second strip-shaped grids 1282 is provided with a notch 129. The first strip-shaped grids 1281 and the second strip-shaped grids 1282 can divide the bottom wall of the accommodating groove 125 into a grid, and two adjacent regions in the grid can be communicated through the notches 129 of the first strip-shaped grids 1281 and the notches 129 of the second strip-shaped grids 1282, so that the excess solder or small bubbles can be discharged along the grid to the grooves 127 around.

[0069] Figure 16 Another schematic view of the heat conduction plate provided in an embodiment of the present application, Figure 17 Figure 16 Another schematic view of the heat conduction plate. As shown in Figure 16 Figure 17 The grid structure 128 can include a plurality of circular grids 1283, and two adjacent circular grids 1283 in the plurality of circular grids 1283 are communicated. The plurality of circular grids 1283 can divide the bottom wall of the accommodating groove 125 into a plurality of circular regions arranged in an array, and the circular regions are communicated through the notches 129, and the circular regions close to the raised frame 124 are respectively communicated with the grooves 127. Therefore, in the reflow soldering, the excess solder or small bubbles can be discharged along the plurality of circular grids 1283 to the grooves 127 around, so as to prevent the solder from overflowing outward or the soldering layer 126 from being hollow.

[0070] In the power module 12 of the present application, a gap is provided between the sidewall of the first metal layer 1232 and the sidewall of the accommodating groove 125. When the substrate 123 is placed on the heat conduction plate 122, the first metal layer 1232 can cover the surface of the side of the soldering layer 126 facing the substrate 123. The small gap between the first metal layer 1232 and the accommodating groove 125 can provide a path for the volatile gas in the solder to be discharged. Figure 18 A partial schematic view of the power module provided in an embodiment of the present application, Figure 19 A projection schematic view of the first metal layer on the heat conduction plate provided in an embodiment of the present application. As shown in Figure 18 Figure 19 In an embodiment, the projection of the first metal layer 1232 on the heat conduction plate 122 has a contour (as shown in Figure 19 ​​​​​(As shown by the dashed line) The projection of the corresponding raised frame 124 onto the heat-conducting plate 122 (as shown by the dashed line) Figure 19 (As shown by the solid line in the middle). In this embodiment, the projection of the raised frame 124 on the heat-conducting plate 122 is annular, and the projection of the first metal layer 1232 on the heat-conducting plate 122 is rectangular, the outline of which lies within the annular projection. When the substrate 123 is placed on the heat-conducting plate 122, the first metal layer 1232 can cover the surface of the solder layer 126 facing the substrate 123, and a small gap is left between the first metal layer 1232 and the receiving groove 125 to allow volatile gases in the solder to escape. Figure 20 Another schematic projection of the first metal layer on the heat-conducting plate provided in an embodiment of this application. (See attached image.) Figure 20 As shown, in another embodiment, when the receiving groove 125 is a slot on the surface of the heat-conducting plate 122, the outline of the receiving groove 125 is rectangular, and the projection of the first metal layer 1232 onto the heat-conducting plate 122 is rectangular (e.g., Figure 20 As shown by the dashed line in the middle, the rectangular outline of the first metal layer 1232 is located within the rectangular outline of the receiving groove 125 (as shown by the dashed line in the middle). Figure 20 (As shown by the solid line in the middle)

[0071] In practical applications, solder pads or solder paste are located within the receiving groove 125. In some embodiments, the height (dimension along the z-direction) of the raised frame 124 can be set according to the thickness of the solder layer 126. For example, in some scenarios, the thickness of the solder layer 126 can range from 50 micrometers to 300 micrometers along the direction perpendicular to the heat-conducting plate 122. Therefore, the height of each raised frame 124 can be correspondingly set to be greater than or equal to 50 micrometers and less than or equal to 300 micrometers along the direction perpendicular to the heat-conducting plate 122.

[0072] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power module, characterized by The power module comprises a package shell, and a heat-conducting plate and at least one substrate located in the package shell, wherein: The at least one substrate is arranged on a surface of the heat-conducting plate, each of the at least one substrate comprises a ceramic substrate and a metal layer, and the metal layer is arranged on a surface of a side of the ceramic substrate facing the heat-conducting plate; the package shell is provided with an opening, a surface of a side of the heat-conducting plate away from the at least one substrate is exposed to the opening, and the heat-conducting plate is used for heat exchange with a heat sink; A surface of a side of the heat-conducting plate facing the at least one substrate is provided with at least one accommodating groove, the at least one accommodating groove is arranged in one-to-one correspondence with the at least one substrate; the at least one accommodating groove contains a solder layer; the solder layer is used for soldering the metal layer of the corresponding substrate and the heat-conducting plate; a side wall of the accommodating groove is provided with one or more grooves.

2. The power module of claim 1, wherein, A gap is arranged between a side wall of the metal layer and the side wall of the accommodating groove.

3. The power module of claim 1 or 2, wherein, The side wall is provided with a plurality of grooves, depths of at least two grooves of the plurality of grooves are not equal.

4. The power module of claim 3, wherein, The plurality of grooves are arranged in a stepped manner on a surface of the side wall in a direction perpendicular to the heat-conducting plate.

5. The power module of claim 1 or 2, wherein, The side wall is provided with a plurality of grooves, the plurality of grooves are arranged in a sawtooth manner on a surface of the side wall in a direction perpendicular to the heat-conducting plate.

6. The power module of claim 1 or 2, wherein, A surface of a bottom wall of the accommodating groove is provided with a grid structure, a height of the grid structure is less than or equal to a depth of the at least one accommodating groove.

7. The power module of claim 6, wherein, The grid structure comprises a plurality of first strip-shaped grids arranged in parallel, each of the plurality of first strip-shaped grids is provided with a first gap.

8. The power module of claim 7, wherein, The grid structure further comprises a plurality of second strip-shaped grids arranged in parallel, and the plurality of first strip-shaped grids are perpendicular to the plurality of second strip-shaped grids; each of the plurality of second strip-shaped grids is provided with a second gap.

9. The power module of claim 6, wherein, The grid structure comprises a plurality of circular grids, adjacent two of the plurality of circular grids are communicated, and the plurality of circular grids are communicated with the at least one groove.

10. The power module of claim 1 or 2, wherein, A surface of a side of the heat-conducting plate facing the at least one substrate is provided with at least one raised frame, the at least one raised frame and the heat-conducting plate enclose the at least one accommodating groove, and a side wall of the at least one raised frame located in the accommodating groove is provided with the one or more grooves.

11. The power module of claim 10, wherein, In a direction perpendicular to the heat-conducting plate, a height of each of the raised frames is less than or equal to a height of the solder layer.

12. A power conversion device, characterized by, The power module comprises a circuit board and the power module as claimed in any one of claims 1 to 11, the power module is located on one side of the circuit board and is electrically connected with the circuit board.

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