Metallic clip structure, power module, conversion circuit and vehicle

Abstract

The application discloses a metal clip structure, a power module, a conversion circuit and a vehicle, wherein the metal clip structure comprises: a bus metal strip; a bus end portion which is electrically connected with the bus metal strip and is located at a first position of the bus metal strip; at least two bonding strips which are respectively electrically connected with second side walls of the bus metal strip; and a plurality of heat dissipation protrusions which are located on surfaces of the bonding strips; wherein the bus end portion is bonded with a substrate in the power module, and the bonding strips are bonded with at least one power chip in the power module; and the first position is determined based on current uniformity of the power chip bonded with the metal clip structure. The technical scheme provided by the application effectively improves the service life of the power module.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a metal clip structure, a power module, a conversion circuit, and a vehicle. Background Technology

[0002] HPD (Hybrid Pack Drive Module) and DCM (Dual-Cool Module) packaged power modules are widely used in the automotive field. However, the heat dissipation of the power chips in existing HPD and DCM packaged power modules on the market is limited. Furthermore, due to the low current distribution of the power chips, those carrying large currents will overheat significantly due to increased conduction losses, forming localized hot spots. This high-temperature accumulation can easily lead to chip burnout and cracking of the molding compound, reducing the lifespan of the power module. Summary of the Invention

[0003] This invention provides a metal clip structure, a power module, a conversion circuit, and a vehicle to improve the service life of the power module.

[0004] According to one aspect of this application, a metal clip structure is provided for use in a power module, the metal clip structure comprising: Busbar metal strip; The bus end is electrically connected to the bus metal strip and is located at a first position on the bus metal strip; At least two bonding bands are electrically connected to the second sidewall of the bus metal strip, respectively; Multiple heat dissipation protrusions are located on the surface of the bonding strip; The bus terminal is bonded to a substrate in the power module, and the bonding band is bonded to at least one power chip in the power module; the first position is determined based on the current uniformity of the power chip bonded to the metal clip structure.

[0005] Optionally, the flow uniformity is greater than or equal to 95%.

[0006] Optionally, the busbar metal strip, the busbar end, and the bonding strip are integrally formed to constitute an integrated metal clip; The plurality of heat dissipation protrusions are welded to the surface of the bonding strip, or the plurality of heat dissipation protrusions are integrally formed with the bonding strip.

[0007] Optionally, the bonding strip includes a first surface and a second surface disposed opposite to each other; The first surface includes at least one bonding surface, and the second surface includes at least one heat dissipation surface; the bonding surface is used to bond with the power chip, and the plurality of heat dissipation protrusions are distributed on the at least one heat dissipation surface.

[0008] Optionally, the bonding surface and the heat dissipation surface at least partially overlap in their vertical projections on the same plane; Alternatively, the vertical projections of the bonding surface and the heat dissipation surface onto the same plane do not overlap.

[0009] Optionally, at least a portion of the heat dissipation protrusions are cylindrical; Alternatively, at least some of the heat dissipation protrusions may be cuboid in shape.

[0010] Optionally, the surface of the heat dissipation protrusion away from the heat dissipation surface is a wavy curved surface; The surface of the multiple heat dissipation protrusions in the heat dissipation protrusion unit that is away from the heat dissipation surface forms a wavy surface.

[0011] Optionally, the bonding strip is wavy in its extension direction; in the extension direction of the bonding strip, the bonding strip includes a plurality of sequentially alternating first metal segments and second metal segments, and a third metal segment located between adjacent first metal segments and second metal segments for connecting the first metal segments and the second metal segments; wherein the planes containing the first metal segments and the planes containing the second metal segments are both parallel to the plane containing the busbar metal strip; the first metal segment is closer to the substrate in the power module than the second metal segment, and the bonding surface is located on the side of the first metal segment closer to the substrate; When the vertical projections of the bonding surface and the heat dissipation surface on the same plane at least partially overlap, the bonding surface and the heat dissipation surface are located on opposite sides of the same first metal segment; wherein, the bonding surface is located on the side of the first metal segment closer to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate; at least a portion of the first metal segment is bonded to the power chip; When the vertical projections of the bonding surface and the heat dissipation surface on the same plane do not overlap, the bonding surface is located on the side of the second metal segment closer to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate.

[0012] Optionally, the power module includes multiple upper-bridge power chips and multiple lower-bridge power chips; the surface metal layer of the substrate in the power module includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper-bridge chip contact layer, and a lower-bridge chip contact layer; the multiple upper-bridge chips are located on one side of the upper-bridge chip contact layer and are in contact with the upper-bridge chip contact layer; the multiple lower-bridge chips are located on one side of the lower-bridge chip contact layer and are in contact with the lower-bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper-bridge chip contact layer; When the metal clip structure is bonded to the plurality of upper bridge power chips, the metal clip structure is located on the side of the plurality of upper bridge power chips away from the substrate; the bus end is bonded to the AC signal transmission layer in the substrate, and the end of each bonding strip away from the bus metal strip is bonded to the lower bridge chip connection layer in the substrate; When the metal clip structure is bonded to the plurality of upper bridge power chips, the metal clip structure is located on the side of the plurality of lower bridge power chips away from the substrate; the bus end is bonded to the second DC signal transmission layer in the substrate.

[0013] Optionally, the extension direction of the bus metal strip is perpendicular to the extension direction of the bonding strip; At least two bonding bands are arranged at intervals along the extension direction of the bus metal strip.

[0014] Optionally, different bonding bands can have the same number of bonded power chips; Alternatively, different bonding bands may have different numbers of bonded power chips; Alternatively, some bonded sections may have different numbers of bonded power chips, while others may have the same number of bonded power chips.

[0015] According to another aspect of this application, a power module is provided, including a substrate, a plurality of power chips and at least one metal clip structure as described in any embodiment of this application; In this configuration, multiple chips are arranged on the same side of the substrate; the side of the chip closest to the substrate is electrically connected to the first metal layer of the substrate; the metal clip structure is located on the side of the chip away from the substrate, and at least two of the multiple chips are bonded to the metal clip structure to be connected in parallel through the metal clip structure.

[0016] Optionally, the power module includes at least two upper-bridge power chips and at least two lower-bridge power chips; the power module includes an upper-bridge metal clip structure and a lower-bridge metal clip structure; The at least two upper-bridge power chips are connected in parallel through the upper-bridge metal clip structure; the at least two lower-bridge power chips are connected in parallel through the lower-bridge metal clip structure. Optionally, the surface metal layer of the substrate in the power module includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper bridge chip contact layer, and a lower bridge chip contact layer; The at least two upper bridge chips are located on one side of the upper bridge chip contact layer and are in contact with the upper bridge chip contact layer; the at least two lower bridge chips are located on one side of the lower bridge chip contact layer and are in contact with the lower bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper bridge chip contact layer; The upper bridge metal clip structure is located on the side of the at least two upper bridge chips away from the substrate; the bus end is bonded to the AC signal transmission layer in the substrate, and the end of each bonding band away from the bus metal band is bonded to the lower bridge chip connection layer in the substrate; The lower bridge metal clip structure is located on the side of the at least two lower bridge power chips away from the substrate; the bus end is bonded to the second DC signal transmission layer in the substrate.

[0017] According to another aspect of this application, a power conversion circuit is provided, including the power module described in any embodiment of this application, wherein the power conversion circuit is used for one or more of current conversion, voltage conversion, and power factor correction.

[0018] According to another aspect of this application, a vehicle is provided, including a load and a power conversion circuit as described in any embodiment of this application, the power conversion circuit being used to convert alternating current to direct current, convert alternating current to alternating current, convert direct current to direct current, or convert direct current to alternating current and then input the converted direct current to the load.

[0019] This application provides a metal clip structure, a power module, a conversion circuit, and a vehicle. The metal clip structure is applied to the power module and includes: a bus metal strip, including a first sidewall and a second sidewall disposed opposite to each other; a bus end electrically connected to the first sidewall of the bus metal strip; at least two bonding strips, each electrically connected to the second sidewall of the bus metal strip; and a plurality of heat dissipation protrusions located on the surface of the bonding strips. The bus end is bonded to a substrate in the power module, and the bonding strips are bonded to at least one power chip in the power module. The position of the bus end in the extension direction of the bus metal strip is determined based on the current equalization of the power chip bonded to the metal clip structure, and the current equalization of the power chip bonded to the metal clip structure is greater than or equal to 95%. The technical solution provided in this application provides a method to increase the heat conduction area of ​​the power chip and improve its heat dissipation by setting multiple heat dissipation protrusions on the surface of the bonding tape. These protrusions can be integrated with the bonding tape without glue or other thermally conductive media, resulting in stronger thermal conductivity. Furthermore, the protrusions can be located on the back of the power chip, closer to it, further enhancing thermal conductivity. Based on this, by controlling the position of the bus end in the extension direction of the bus metal strip within the metal clip structure, the loop length of the power chip in the power module is controlled, making the current flow values ​​of each parallel power chip similar. This improves the current sharing of the parallel power chips in the power module, prevents the formation of localized hot spots, and mitigates problems such as accelerated chip aging or even burnout, as well as cracking of the molding compound, thereby effectively extending the service life of the power module.

[0020] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a perspective view of a metal clip structure provided in this application; Figure 2 yes Figure 1 A top view of the bonding surface of the structure shown; Figure 3 yes Figure 1 A side view of the structure shown from one perspective; Figure 4 yes Figure 1 A side view of the structure shown from another perspective; Figure 5 This is a schematic diagram of the structure of a bonding band provided in this application; Figure 6 This is a schematic diagram of another bonding band structure provided in this application; Figure 7 This is a schematic diagram of a bonding band with cylindrical heat dissipation protrusions on its surface, as provided in this application. Figure 8 This is a schematic diagram of a bonding band with wavy heat dissipation protrusions on its surface, as provided in this application. Figure 9 This is a schematic diagram of the structure of an integrated metal clip provided in this application, which consists of a busbar metal strip, a busbar end, and the busbar metal strip being integrally formed. Figure 10 This is a schematic diagram of another integrated metal clip provided in this application, which consists of a busbar metal strip, a busbar end, and the busbar metal strip being integrally formed. Figure 11 This is a schematic diagram of another integrated metal clip provided in this application, which consists of a busbar metal strip, a busbar end, and the busbar metal strip being integrally formed. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application 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.

[0025] This application provides a metal clip structure for use in a power module. Figure 1 This is a perspective view of a metal clip structure provided in this application. Figure 2 yes Figure 1 A top view of the bonding surface of the structure shown. Figure 3 yes Figure 1 A side view of the structure shown from one perspective. Figure 4 yes Figure 1 Another side view of the structure shown, see reference. Figures 1-4 The metal clip structure includes: Busbar metal strip 10; The bus end 20 is electrically connected to the bus metal strip 10 and is located at a first position on the bus metal strip; At least two bonding bands 30 are electrically connected to the second sidewall of the bus metal band 10, respectively; Multiple heat dissipation protrusions 40 are located on the surface of the bonding strip 30; The bus end 20 is bonded to the substrate in the power module, and the bonding band 30 is bonded to at least one power chip in the power module; the first position is determined based on the current equalization of the power chip bonded to the metal clip structure.

[0026] Specifically, the metal clip structure is used in power modules. Power modules can be either HPD-packaged or DCM-packaged. HPD is an automotive-grade power module packaging technology designed for new energy vehicles, primarily compatible with silicon-based semiconductor devices and silicon carbide semiconductor devices, and widely used in electric vehicle main drive inverters, on-board charging systems, etc. DCM is an advanced power module packaging technology optimized for silicon carbide (SiC) devices, specifically developed for high-frequency, high-voltage, and high-power-density scenarios, especially suitable for the 800V high-voltage platform of new energy vehicles. A power module includes a substrate, multiple power chips, a molding compound, and a metal clip structure; the power chips are located on one side of the substrate; the metal clip structure is located on the side of the power chips furthest away, serving as an electrical connection, current sharing, and heat dissipation mechanism.

[0027] The metal clip structure includes a bus metal strip 10, a bus end 20 electrically connected to the bus metal strip 10, and at least two bonding strips 30 electrically connected to the bus metal strip 10. The bus end 20 and the bus metal strip 10 may be located on the same sidewall of the bus metal strip 10 or on different sidewalls. Figure 1 In the structure shown, the bus metal strip 10 is exemplary, including a first sidewall and a second sidewall disposed opposite to each other. The bus end 20 is electrically connected to the first sidewall of the bus metal strip 10, and at least two bonding strips 30 are electrically connected to the second sidewall of the bus metal strip 10 respectively.

[0028] The surface of the metal clip structure near the substrate and power chip includes multiple bonding surfaces S for contacting or soldering with the substrate and power chip to achieve electrical connection. Specifically, the bus end 20 is bonded to the substrate in the power module, and each bonding strip 30 is bonded to at least one power chip. The bonding surface for bonding with the substrate is the substrate bonding surface SB, and the bonding surface for bonding with the power chip is the chip bonding surface SX. Since the metal clip structure includes at least two bonding strips 30, it can achieve parallel connection of at least two power chips. The distance between the bus metal strip 10 and the substrate is greater than zero, and the bus metal strip 10 does not contact the substrate or the power chip.

[0029] In the power module, the power chip is electrically connected to the substrate on the side closest to the substrate, and on the side furthest from the substrate, it is electrically connected via a bonding strip 30, a bus metal strip 10, and a bus end 20. Changes in the position of the bus end 20 along the Y-direction of the bus metal strip 10 cause changes in the current path between each power chip and the bus end 20, thus controlling the length of the loop for each power chip within the power module. These changes in loop length lead to changes in loop resistance, resulting in variations in the current flowing through the power chip. Therefore, by adjusting the position of the bus end 20 along the Y-direction of the bus metal strip 10, the current magnitude on each power chip can be adjusted, thereby achieving current sharing. The position of the bus end 20 along the Y-direction of the bus metal strip 10 is determined based on the current sharing efficiency of the power chips bonded to the metal clip structure. The position of the bus end 20 in the extension direction Y of the bus metal strip 10 when the current equalization of the power chips in the power module meets a preset target value can be determined through simulation. Then, the position of the bus end 20 in the extension direction Y of the bus metal strip 10 is set according to the determined position. The first position of the bus metal strip 10 is the determined position. Current equalization refers to the uniformity of current distribution among multiple parallel power chips, determined based on the ratio of the maximum current deviation (the maximum value among the differences between the current of each power chip and the average current of multiple power chips) to the average current. The preset target value can be greater than or equal to 95%, meaning the first position is determined based on the current equalization of the power chips bonded to the metal clip structure, and the current equalization is greater than or equal to 95%.

[0030] The bonding strip 30 is bonded to the power chip. Multiple heat dissipation protrusions 40 are formed on the surface of the bonding strip 30, which can conduct heat from the power chip to the heat dissipation medium in contact with the heat dissipation protrusions 40, thereby increasing the heat dissipation area, improving the heat dissipation capacity of the power module, and preventing the plastic package from cracking. The heat dissipation protrusions 40 are distributed on the surface of the bonding strip 30 away from the substrate.

[0031] The metal clip structure provided in this application embodiment increases the heat conduction area of ​​the power chip and improves the heat dissipation effect of the power chip by setting multiple heat dissipation protrusions 40 on the surface of the bonding strip 30. Furthermore, by controlling the position of the bus end 20 in the metal clip structure in the extension direction of the bus metal strip 10, the loop length of the power chip in the power module can be controlled, making the current carrying capacity of each parallel power chip similar. This improves the current sharing of the parallel power chips in the power module, prevents the formation of local hot spots, and improves the problems of accelerated chip aging or even burnout, as well as cracking of the plastic package, thereby effectively improving the service life of the power module.

[0032] Based on the above embodiments, optionally, Figure 5 This is a partial structural diagram of a bonding band provided in this application, for reference. Figure 5 and combined Figures 1-4 The bonding strip 30 includes a first surface 31 and a second surface 32 disposed opposite to each other; wherein the first surface 31 includes at least one bonding surface S, and the second surface 32 includes at least one heat dissipation surface R; the bonding surface S is used to bond with the power chip, and a plurality of heat dissipation protrusions 40 are distributed on at least one heat dissipation surface R.

[0033] Specifically, the bonding tape 30 is thin and sheet-like. The bonding tape 30 includes a first surface 31 and a second surface 32 disposed opposite to each other. The first surface 31 is the surface of the bonding tape 30 closer to the substrate, and the second surface 32 is the surface of the bonding tape 30 farther from the substrate. The first surface 31 includes one or more bonding surfaces S for bonding to a power chip or substrate. When the first surface 31 includes multiple bonding surfaces S, at least a portion of the bonding surfaces S are bonded to the power chip. The second surface 32 of the bonding tape 30 includes one or more heat dissipation surfaces R. Multiple heat dissipation protrusions 40 are provided on the heat dissipation surfaces R. The multiple heat dissipation protrusions 40 can be arranged in an array on the heat dissipation surface R, or arranged in a row on the heat dissipation surface R. Each bonding surface S at least partially overlaps with the vertical projection of a heat dissipation surface R on the same plane, and each heat dissipation surface R that at least partially overlaps with the vertical projection of the bonding surface S on the same plane has a heat dissipation protrusion 40; or, the vertical projections of the bonding surface S and the heat dissipation surface R on the same plane do not overlap. Based on the above embodiments, optionally, the bus metal strip 10 is planar and parallel to the substrate; the bonding strip 30 is wavy in the extension direction X of the bonding strip 30.

[0034] In the extending direction X of the bonding strip 30, the bonding strip 30 includes a plurality of sequentially alternating first metal segments 301 and second metal segments 302, and a third metal segment 303 located between adjacent first metal segments 301 and second metal segments 302 for connecting the first metal segments 301 and second metal segments 302; wherein, the plane containing the first metal segment 301 and the plane containing the second metal segment 302 are both parallel to the plane containing the bus metal strip 10; the first metal segment 301 is closer to the substrate in the power module than the second metal segment 302. The bonding surface S is located on the side of the first metal segment 301 closer to the substrate; the heat dissipation surface R is located on the side of the first metal segment 301 away from the substrate; at least a portion of the first metal segment 301 is bonded to the power chip. Specifically, the bonding strip 30 is configured to include multiple sequentially alternating first metal segments 301 and second metal segments 302, and a third metal segment 303 disposed between the first metal segments 301 and the second metal segments 302. The plane containing the first metal segment 301 is parallel to the plane containing the second metal segment 302, and the plane containing the third metal segment 303 intersects the plane containing the first metal segment 301, making the bonding strip 30 a wavy bonding strip. The difference in the coefficient of thermal expansion (CTE) between the bonding strip 30 and the chip and substrate materials can cause stress during thermal cycling. The wavy bonding strip can absorb stress through elastic deformation, preventing solder joint cracking; it can also increase the surface area of ​​the bonding strip 30, which is beneficial for heat dissipation of the power chip. Moreover, the wavy bonding strip 30 can partially offset the loop inductance during high-frequency switching by extending the current path.

[0035] refer to Figure 1 and Figure 5 When the bonding surface S (chip bonding surface SX) on the bonding strip 30 and the heat dissipation surface R have at least partial overlap in their vertical projections on the same plane, the bonding surface S (chip bonding surface SX) and the heat dissipation surface R are located on opposite sides of the same first metal segment 301; wherein the bonding surface S (chip bonding surface SX) is located on the side of the first metal segment 301 closer to the substrate; the heat dissipation surface R is located on the side of the first metal segment 301 farther from the substrate; at least a portion of the first metal segment 301 is bonded to the power chip. By placing the heat dissipation surface R and the bonding surface S (chip bonding surface SX) on opposite sides of the first metal segment 301, their vertical projections on the same plane completely overlap, meaning the heat dissipation protrusions are located on the front and back sides of the power chip, further improving the heat dissipation effect on the power chip. It should be noted that the first metal segment 301, the second metal segment 302, and the third metal segment 303 are integrally formed.

[0036] In another embodiment of the invention, reference is made to... Figure 6 The bonding surface S and the heat dissipation surface R do not overlap in their vertical projection on the same plane. At this time, the bonding surface S (chip bonding surface SX) is located on the side of the second metal segment 302 closer to the substrate; the heat dissipation surface R is located on the side of the first metal segment 301 away from the substrate. This allows the space between the two first metal segments 301 to accommodate the power chip, which helps to reduce the thickness of the power module.

[0037] Based on the above embodiments, optionally, at least a portion of the heat dissipation protrusion 40 is cylindrical, or at least a portion of the heat dissipation protrusion 40 is cuboid. Figures 1-4 The example shows that all the heat dissipation protrusions 40 are cuboid in shape, and multiple cuboid heat dissipation protrusions 40 are arranged in a row on the heat dissipation surface R. Figure 7This is a schematic diagram of a bonding band 30 with cylindrical heat dissipation protrusions 40 on its surface, as provided in this application. (Refer to...) Figure 7 The example shows that all the heat dissipation protrusions 40 are cylindrical, and multiple cylindrical heat dissipation protrusions 40 are arranged in an array on the heat dissipation surface R to form a heat dissipation protrusion array 400.

[0038] Specifically, the cylindrical heat dissipation protrusion 40 can have a larger surface area to volume ratio, enabling more efficient heat transfer; the cylindrical heat dissipation protrusion 40 can reduce local hot spots, allowing heat to diffuse evenly along the radial direction and avoiding heat accumulation at the corners of the cuboid. Furthermore, the cuboid heat dissipation protrusion 40 can be mass-produced using traditional stamping or etching processes, resulting in lower costs than the cylindrical protrusion.

[0039] Based on the above embodiments, optionally, at least a portion of the surface of the heat dissipation protrusion 40 on the side away from the heat dissipation surface R is curved. For example, if the heat dissipation protrusion 40 is cuboid in shape... Figure 8 This is a schematic diagram of a bonding band with wavy heat dissipation protrusions on its surface, as provided in this application. (Refer to...) Figure 8 The surface of the heat dissipation protrusion 40 away from the heat dissipation surface R is set as a curved surface. Compared with a flat surface, setting the surface of the heat dissipation protrusion 40 away from the heat dissipation surface R as a curved surface can further increase the surface area of ​​the heat dissipation protrusion 40 and improve the heat dissipation effect of the heat dissipation protrusion 40.

[0040] Furthermore, the surface of the heat dissipation protrusion 40 away from the heat dissipation surface R is a wavy curved surface. The surfaces of multiple heat dissipation protrusions 40 away from the heat dissipation surface R form a wavy surface 411. The wavy curved surface unfolds the plane into continuous peaks and valleys through a three-dimensional undulating structure, thereby increasing the heat dissipation surface area R and significantly improving the heat exchange efficiency.

[0041] Based on the above embodiments, optionally, Figure 9 This is a schematic diagram of an integrated metal clip provided in this application, which consists of a busbar metal strip, a busbar end, and the busbar metal strip being integrally formed. Figure 10 This is a schematic diagram of another integrated metal clip provided in this application, consisting of a busbar metal strip, a busbar end, and the busbar metal strip integrally formed. (Refer to...) Figure 9 and Figure 10 The busbar metal strip 10, the busbar end 20 and at least two bonding strips 30 can be integrally set to form an integral metal clip, thereby enhancing the firmness between the busbar end 20 and the busbar metal strip 10 and between the bonding strip 30 and the busbar metal strip 10; in addition, the integral metal clip is formed by stamping, etching or 3D printing, eliminating the need for welding, binding or screw fixing processes.

[0042] Based on the above embodiments, optionally, the multiple heat dissipation protrusions 40 can be welded to the surface of the bonding strip 30, or the multiple heat dissipation protrusions 40 can be integrally formed with the bonding strip 30. Preferably, the bonding strip 30 and the heat dissipation protrusions 40 are integrally formed, thereby increasing the firmness between the bonding strip 30 and the heat dissipation protrusions 40; moreover, the heat dissipation protrusions can be integrally formed with the bonding strip without glue or other thermally conductive media in between, thus possessing stronger thermal conductivity. The material of the metal clip structure includes, but is not limited to, copper, that is, the metal clip structure can be a copper clip structure. Copper clip technology, with its advantages of low resistance, high thermal conductivity, strong mechanical stability and low parasitic parameters, has become a preferred solution for power module interconnection, especially suitable for high-frequency, high-power-density and high-reliability scenarios (such as electric vehicles and renewable energy).

[0043] Based on the above embodiments, optionally, the power module includes multiple upper-bridge power chips and multiple lower-bridge power chips; the surface metal layer of the substrate in the power module includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper-bridge chip contact layer, and a lower-bridge chip contact layer; the multiple upper-bridge chips are located on one side of the upper-bridge chip contact layer and are in contact with the upper-bridge chip contact layer; the multiple lower-bridge chips are located on one side of the lower-bridge chip contact layer and are in contact with the lower-bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper-bridge chip contact layer.

[0044] Figure 10 The integrated metal clip shown is an integrated metal clip in the upper bridge metal clip structure. When the metal clip structure is bonded to multiple upper bridge power chips, the metal clip structure is located on the side of the multiple upper bridge power chips away from the substrate. The bus end 20 is bonded to the AC signal transmission layer in the substrate, and the end of each bonding strip 30 away from the bus metal strip is bonded to the lower bridge chip connection layer in the substrate.

[0045] Figure 9 The integrated metal clip shown is a lower bridge metal clip structure (see...). Figures 1-4 In the integrated metal clip in the substrate, when the metal clip structure is bonded to multiple lower-bridge power chips, the metal clip structure is located on the side of the multiple lower-bridge power chips away from the substrate; the bus end 20 is bonded to the second DC signal transmission layer in the substrate.

[0046] Specifically, the substrate can be a direct-bonded copper (DBC) ceramic substrate or an active metal brazing (AMB) ceramic substrate. The substrate includes a ceramic substrate and a surface metal layer on the surface of the ceramic substrate. The surface metal layer includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper bridge chip contact layer, and a lower bridge chip contact layer. The first DC signal transmission layer, the second DC signal transmission layer, the AC signal transmission layer, the upper bridge chip contact layer, and the lower bridge chip contact layer are located on the same side of the ceramic substrate. The first DC signal transmission layer is connected to the upper bridge chip contact layer, which can be understood as the first DC signal transmission layer and the upper bridge chip contact layer being the same continuous metal layer. Any two of the first DC signal transmission layer, the second DC signal transmission layer, the AC signal layer, and the lower bridge chip contact layer are disconnected. Specifically, the first DC signal transmission layer is electrically connected to the DC+ terminal, the second DC signal transmission layer is electrically connected to the DC- terminal, and the AC signal transmission layer is electrically connected to the AC terminal. Furthermore, the substrate may include a first side and a second side disposed opposite to each other, the DC+ terminal and the DC- terminal being electrically connected may be located on the first side of the substrate, and the AC terminal may be located on the second side of the substrate.

[0047] In the power module, the upper-bridge chip is located on one side of the upper-bridge chip contact layer and contacts the upper-bridge chip contact layer to achieve electrical connection. Similarly, the lower-bridge chip in the power module is located on one side of the lower-bridge chip contact layer and contacts the lower-bridge chip contact layer to achieve electrical connection. The power module includes at least one of a metal clip structure bonded to the upper-bridge power chip and a metal clip structure bonded to the lower-bridge power chip. Preferably, the power module includes both an upper-bridge metal clip structure bonded to the upper-bridge power chip and a lower-bridge metal clip structure bonded to the lower-bridge power chip. The upper-bridge metal clip structure improves the current sharing efficiency of the parallel-connected upper-bridge chips, and the lower-bridge metal clip structure improves the current sharing efficiency of the parallel-connected lower-bridge chips.

[0048] The upper bridge metal clip structure is located on the side of at least two upper bridge power chips away from the substrate. The bus end 20 of the upper bridge metal clip structure is bonded to the AC signal transmission layer in the substrate. The end of each bonding band 30 away from the bus metal band 10 (the end of the bonding band 30 away from the bus metal band 10) is bonded to the lower bridge chip connection layer in the substrate. The area between the end of the bonding band 30 and the bus metal band 10 is bonded to one or more upper bridge chips. The lower metal clip structure is located on the side of at least two lower bridge power chips away from the substrate. The bus end 20 of the lower bridge metal clip structure is bonded to the second DC signal transmission layer in the substrate. Each bonding band 30 is bonded to only one or more lower bridge chips.

[0049] The above embodiments exemplify a metal clip structure with two bonding bands 30 connecting three power chips in parallel, which is an odd number of power chips, and the number of power chips bonded on different bonding bands 30 is different. In another embodiment of this application, the metal clip structure with two bonding bands 30 can also connect an even number of power chips in parallel.

[0050] Figure 11 This is a schematic diagram of another integrated metal clip provided in this application, consisting of a busbar metal strip, a busbar end, and the busbar metal strip integrally formed. (Refer to...) Figure 11 Optionally, three or more bonding bands 30 can be incorporated into the metal clip structure to allow for the parallel connection of a greater number of power chips. Figure 10 An exemplary metal clip structure includes three bonding strips 30, with the same number of power chips bonded to each bonding strip 30. Furthermore, when the number of bonding strips 30 is greater than or equal to three, the number of bus terminals 20 is greater than or equal to one. Figure 11 The example shown has two bus terminals 20.

[0051] Based on the above embodiments, refer to Figures 9-11 Optionally, within the same metal clip structure, the number of power chips with different 30-bonded bonding bands is the same; or, the number of power chips with different 30-bonded bonding bands is different; or, some bonding bands have different numbers of power chips with 30-bonded bonding bands, while others have the same number of power chips with 30-bonded bonding bands, which can be set according to actual needs. Figure 9 and Figure 10 Examples show different bonding bands with varying numbers of 30-bonded power chips. Figure 11 Exemplary examples show different bonding bands with the same number of power chips with 30 bonds.

[0052] Based on the above embodiments, optionally, refer to... Figure 2 In the same metal clip structure, the extension direction Y of the busbar metal strip 10 intersects the extension direction X of the bonding strip 30, and at least two bonding strips 30 are arranged at intervals along the extension direction Y of the busbar metal strip 10. The extension direction Y of the busbar metal strip 10 and the extension direction X of the bonding strip 30 can be perpendicular to each other.

[0053] This application also provides a power module, including a substrate, a plurality of power chips, and at least one metal clip structure as described in any embodiment of this application; wherein, the plurality of power chips are arranged on the same side of the substrate; the side of the power chips closest to the substrate is electrically connected to the substrate; the metal clip structure is located on the side of the power chips furthest from the substrate, and at least two power chips are bonded to the metal clip structure to be connected in parallel through the metal clip structure. It has the same technical effects, and will not be described again here.

[0054] Optionally, the multiple power chips include at least two upper-bridge chips and at least two lower-bridge chips; the power module also includes an upper-bridge metal clip structure and a lower-bridge metal clip structure; at least two upper-bridge chips are connected in parallel through the upper-bridge metal clip structure; at least two lower-bridge chips are connected in parallel through the lower-bridge metal clip structure. Furthermore, the surface metal layer of the substrate includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper bridge chip contact layer, and a lower bridge chip contact layer; at least two upper bridge chips are located on one side of the upper bridge chip contact layer and are in contact with the upper bridge chip contact layer; at least two lower bridge chips are located on one side of the lower bridge chip contact layer and are in contact with the lower bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper bridge chip contact layer. An upper bridge metal clip structure is located on the side of at least two upper bridge chips away from the substrate; the bus end 20 is bonded to the AC signal transmission layer in the substrate, and the end of each bonding strip 30 away from the bus metal strip is bonded to the lower bridge chip connection layer in the substrate; the lower bridge metal clip structure is located on the side of at least two lower bridge power chips away from the substrate; the bus end 20 is bonded to the second DC signal transmission layer in the substrate.

[0055] Optionally, the substrate includes a direct-bonded copper (DBC) ceramic substrate or an active metal brazing (AMB) ceramic substrate. The electrodes or pads of the power chip are fixed to one side of the substrate via sintering or soldering processes. The power chip is then connected to its pins using a clip-bonding packaging process, where a metal clip structure is soldered to the chip's leads to enable interconnection between multiple power chips.

[0056] Optionally, the power chip may include a metal-oxide-semiconductor field-effect transistor power chip (MOSFET power chip) or an insulated-gate bipolar transistor power chip (IGBT power chip).

[0057] Furthermore, metal-oxide-semiconductor field-effect transistor (MOSFET) power chips include silicon carbide (SiC) MOSFET power chips or gallium nitride (GaN) MOSFET power chips. Insulated-gate bipolar transistor (IGBT) power chips include silicon carbide (SiC) IGBT power chips or gallium nitride (GaN) IGBT power chips.

[0058] For example, the pads connected to the drain of the MOSFET power chip are fixed to one side of the substrate by sintering or welding, the pads connected to the source of the MOSFET power chip are welded to the bonding surface S of the metal clip structure, and then the power chip is encapsulated by a molding compound.

[0059] This application also provides a power conversion circuit, including the power module described in any embodiment of the present invention. The power conversion circuit is used for one or more of current conversion, voltage conversion, and power factor correction. It has the same technical effects and will not be described again here.

[0060] This application also provides a vehicle, including a load and the power conversion circuit described in any embodiment of this application. The power conversion circuit is used to convert AC power to DC power, convert AC power to AC power, convert DC power to DC power, or convert DC power to AC power and then input it to the load. It has the same technical effects and will not be described again here.

[0061] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A metal clip structure, characterized in that, The metal clip structure, applied to a power module, includes: Busbar metal strip; The bus end is electrically connected to the bus metal strip and is located at a first position on the bus metal strip; At least two bonding bands are electrically connected to the bus metal strip, respectively; Multiple heat dissipation protrusions are located on the surface of the bonding strip; The bus terminal is bonded to a substrate in the power module, and the bonding band is bonded to at least one power chip in the power module; the first position is determined based on the current uniformity of the power chip bonded to the metal clip structure.

2. The metal clip structure according to claim 1, characterized in that, The average flow rate is greater than or equal to 95%.

3. The metal clip structure according to claim 1, characterized in that, The busbar metal strip, the busbar end, and the bonding strip are integrally formed to constitute an integrated metal clip; The plurality of heat dissipation protrusions are welded to the surface of the bonding strip, or the plurality of heat dissipation protrusions are integrally formed with the bonding strip.

4. The metal clip structure according to claim 1, characterized in that, The bonding band includes a first surface and a second surface disposed opposite to each other; The first surface includes at least one bonding surface, and the second surface includes at least one heat dissipation surface; the bonding surface is used to bond with the power chip, and the plurality of heat dissipation protrusions are distributed on the at least one heat dissipation surface.

5. The metal clip structure according to claim 4, characterized in that, The bonding surface and the heat dissipation surface at least partially overlap in their vertical projections on the same plane; Alternatively, the vertical projections of the bonding surface and the heat dissipation surface onto the same plane do not overlap.

6. The metal clip structure according to claim 4, characterized in that, At least a portion of the heat dissipation protrusions are cylindrical; Alternatively, at least some of the heat dissipation protrusions may be cuboid in shape.

7. The metal clip structure according to claim 4, characterized in that, The surface of the heat dissipation protrusion away from the heat dissipation surface is a wavy curved surface; The surface of the multiple heat dissipation protrusions in the heat dissipation protrusion unit that is away from the heat dissipation surface forms a wavy surface.

8. The metal clip structure according to claim 4, characterized in that, The bonding strip is wavy in its extension direction; in the extension direction of the bonding strip, the bonding strip includes a plurality of alternating first metal segments and second metal segments, and a third metal segment located between adjacent first metal segments and second metal segments for connecting the first metal segments and the second metal segments; wherein the planes containing the first metal segments and the planes containing the second metal segments are parallel to each other with the plane containing the busbar metal strip; the first metal segment is closer to the substrate in the power module than the second metal segment; When the vertical projections of the bonding surface and the heat dissipation surface on the same plane at least partially overlap, the bonding surface and the heat dissipation surface are located on opposite sides of the same first metal segment; wherein, the bonding surface is located on the side of the first metal segment closer to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate; at least a portion of the first metal segment is bonded to the power chip; When the vertical projections of the bonding surface and the heat dissipation surface on the same plane do not overlap, the bonding surface is located on the side of the second metal segment closer to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate.

9. The metal clip structure according to claim 1, characterized in that, The power module includes multiple upper-bridge power chips and multiple lower-bridge power chips; the surface metal layer of the substrate in the power module includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper-bridge chip contact layer, and a lower-bridge chip contact layer; the multiple upper-bridge chips are located on one side of the upper-bridge chip contact layer and are in contact with the upper-bridge chip contact layer; the multiple lower-bridge chips are located on one side of the lower-bridge chip contact layer and are in contact with the lower-bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper-bridge chip contact layer; When the metal clip structure is bonded to the plurality of upper bridge power chips, the metal clip structure is located on the side of the plurality of upper bridge power chips away from the substrate; the bus end is bonded to the AC signal transmission layer in the substrate, and the end of each bonding strip away from the bus metal strip is bonded to the lower bridge chip connection layer in the substrate; When the metal clip structure is bonded to the plurality of upper bridge power chips, the metal clip structure is located on the side of the plurality of lower bridge power chips away from the substrate; the bus end is bonded to the second DC signal transmission layer in the substrate.

10. The metal clip structure according to claim 1, characterized in that, The extension direction of the busbar metal strip is perpendicular to the extension direction of the bonding strip. At least two bonding bands are arranged at intervals along the extension direction of the bus metal strip.

11. The metal clip structure according to claim 1, characterized in that, The number of power chips bonded to different bonding bands is the same; Alternatively, different bonding bands may have different numbers of bonded power chips; Alternatively, some bonded sections may have different numbers of bonded power chips, while others may have the same number of bonded power chips.

12. A power module, characterized in that, It includes a substrate, multiple power chips, and at least one metal clip structure as described in any one of claims 1 to 11; In this configuration, multiple chips are arranged on the same side of the substrate; the side of the chip closest to the substrate is electrically connected to the first metal layer of the substrate; the metal clip structure is located on the side of the chip away from the substrate, and at least two of the multiple chips are bonded to the metal clip structure to be connected in parallel through the metal clip structure.

13. The power module according to claim 12, characterized in that, The power module includes at least two upper-bridge power chips and at least two lower-bridge power chips; the power module includes an upper-bridge metal clip structure and a lower-bridge metal clip structure. The at least two upper-bridge power chips are connected in parallel through the upper-bridge metal clip structure; the at least two lower-bridge power chips are connected in parallel through the lower-bridge metal clip structure.

14. The power module according to claim 13, characterized in that, The surface metal layer of the substrate in the power module includes a first DC signal transmission layer, a second DC signal transmission layer, an AC signal transmission layer, an upper bridge chip contact layer, and a lower bridge chip contact layer. The at least two upper bridge chips are located on one side of the upper bridge chip contact layer and are in contact with the upper bridge chip contact layer; the at least two lower bridge chips are located on one side of the lower bridge chip contact layer and are in contact with the lower bridge chip contact layer; wherein, the first DC signal transmission layer is connected to the upper bridge chip contact layer; The upper bridge metal clip structure is located on the side of the at least two upper bridge chips away from the substrate; the bus end is bonded to the AC signal transmission layer in the substrate, and the end of each bonding band away from the bus metal band is bonded to the lower bridge chip connection layer in the substrate; The lower bridge metal clip structure is located on the side of the at least two lower bridge power chips away from the substrate; the bus end is bonded to the second DC signal transmission layer in the substrate.

15. A power conversion circuit, characterized in that, Includes the power module according to any one of claims 12 to 14, wherein the power conversion circuit is used for one or more of current conversion, voltage conversion, and power factor correction.

16. A vehicle, characterized in that, The device includes a load and a power conversion circuit as described in claim 15, the power conversion circuit being used to convert AC power to DC power, convert AC power to AC power, convert DC power to DC power, or convert DC power to AC power and then input it to the load.

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