Metal clamp structure, power module, conversion circuit and vehicle

Abstract

The invention discloses a metal clamp structure, a power module, a conversion circuit and a vehicle. The metal clamp structure comprises a confluence metal belt; the confluence end part is electrically connected with the confluence metal belt and is positioned at a first position of the confluence metal belt; the at least two bonding belts are electrically connected with the second side wall of the confluence metal belt respectively; the plurality of heat dissipation bulges are positioned on the surface of the bonding belt; wherein the confluence end part is bonded with a substrate in the power module, and the bonding belt is bonded with at least one power chip in the power module; the first position is determined based on the current equalization of the current of the power chip bonded to the metal clip structure. According to the technical scheme provided by the invention, the service life of the power module is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a metal clip structure, a power module, a conversion circuit and a vehicle. BACKGROUND

[0002] HPD (Hybrid PACK Drive Module) packaged power modules and DCM (Dual-Cool Module) packaged power modules are widely used in the field of vehicles. The heat dissipation effect of the power chips in the existing HPD packaged power modules and DCM packaged power modules on the market is limited, and since the current sharing degree of the power chips is low, the power chip carrying a large current will overheat due to a significant increase in conduction loss, forming a local hot spot, and high-temperature aggregation is easy to cause the power chip to burn out, the plastic package body to crack, and the service life of the power module to be reduced. SUMMARY

[0003] The embodiments of the present application provide 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 an aspect of the present application, a metal clip structure is provided, which is applied to a power module, and the metal clip structure comprises:

[0005] a bus metal strip;

[0006] a bus end portion which is electrically connected to the bus metal strip and is located at a first position of the bus metal strip;

[0007] at least two bonding strips which are respectively electrically connected to second side walls of the bus metal strip;

[0008] a plurality of heat dissipation protrusions which are located on surfaces of the bonding strips;

[0009] The bus end portion is bonded to a substrate in the power module, the bonding strips are bonded to at least one power chip in the power module, and the first position is determined based on the current sharing degree of the power chip bonded to the metal clip structure.

[0010] Optionally, the current sharing degree is greater than or equal to 95%.

[0011] Optionally, the bus metal strip, the bus end portion and the bonding strips are integrally arranged to form an integrated metal clip.

[0012] The plurality of heat dissipation protrusions are welded on the surfaces of the bonding strips, or the plurality of heat dissipation protrusions are integrally arranged with the bonding strips.

[0013] Optionally, the bonding strips comprise first and second surfaces which are oppositely arranged.

[0014] The first surface comprises at least one bonding surface, and the second surface comprises at least one heat dissipation surface; the bonding surface is used for bonding with the power chip, and the plurality of heat dissipation protrusions are distributed on the at least one heat dissipation surface.

[0015] Optionally, the vertical projection of the bonding surface and the heat dissipation surface on the same plane at least partially overlaps.

[0016] Alternatively, the vertical projection of the bonding surface and the heat dissipation surface on the same plane does not overlap.

[0017] Optionally, at least part of the heat dissipation protrusions are in a cylindrical shape.

[0018] Alternatively, at least part of the heat dissipation protrusions are in a cuboid shape.

[0019] Optionally, the surface of the heat dissipation protrusion away from the heat dissipation surface is a wavy curved surface.

[0020] The surfaces of the plurality of heat dissipation protrusions in the heat dissipation protrusion unit away from the heat dissipation surface constitute a wavy surface.

[0021] Optionally, the bonding strip is wavy in the extension direction of the bonding strip; in the extension direction of the bonding strip, the bonding strip comprises a plurality of first metal segments and second metal segments arranged alternately, 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 plane where the first metal segment is located and the plane where the second metal segment is located are both parallel to the plane where the bus metal strip is located; 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 close to the substrate;

[0022] In the case that the vertical projection of the bonding surface and the heat dissipation surface on the same plane at least partially overlaps, the bonding surface and the heat dissipation surface are located on the surfaces on opposite sides of the same first metal segment; wherein the bonding surface is located on the side of the first metal segment close to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate; at least part of the first metal segment is bonded with the power chip.

[0023] In the case that the vertical projection of the bonding surface and the heat dissipation surface on the same plane does not overlap, the bonding surface is located on the side of the second metal segment close to the substrate; the heat dissipation surface is located on the side of the first metal segment away from the substrate.

[0024] Optionally, the power module comprises a plurality of upper bridge power chips and a plurality of lower bridge power chips; the surface metal layer of the substrate in the power module comprises a first direct current signal transmission layer, a second direct current signal transmission layer, an alternating current signal transmission layer, an upper bridge chip contact layer and a lower bridge chip contact layer; the plurality of upper bridge chips are located on one side of the upper bridge chip contact layer and in contact with the upper bridge chip contact layer; the plurality of lower bridge chips are located on one side of the lower bridge chip contact layer and in contact with the lower bridge chip contact layer; wherein the first direct current signal transmission layer is in communication with the upper bridge chip contact layer;

[0025] In the case where 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 portion is bonded to the alternating current signal transmission layer in the substrate, and each bonding strip is bonded to the lower bridge chip connection layer in the substrate away from the end portion of the bus metal strip;

[0026] In the case where 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 portion is bonded to the alternating current signal transmission layer in the substrate, and each bonding strip is bonded to the lower bridge chip connection layer in the substrate away from the end portion of the bus metal strip;

[0027] Optionally, the extension direction of the bus metal strip is perpendicular to the extension direction of the bonding strip;

[0028] At least two bonding strips are arranged at intervals along the extension direction of the bus metal strip.

[0029] Optionally, the number of power chips bonded by different bonding strips is the same;

[0030] Alternatively, the number of power chips bonded by different bonding strips is different;

[0031] Alternatively, the number of power chips bonded by some bonding strips is different, and the number of power chips bonded by some bonding strips is the same.

[0032] According to another aspect of the present application, a power module is provided, comprising a substrate, a plurality of power chips and at least one metal clip structure as described in any embodiment of the present application;

[0033] Wherein, the plurality of chips are arranged on the same side of the substrate; the chips are electrically connected to the first metal layer of the substrate on the side close to the substrate; the metal clip structure is located on the side of the chips away from the substrate, and at least two of the plurality of chips are bonded to the metal clip structure to be connected in parallel through the metal clip structure.

[0034] Optionally, the power module comprises at least two upper bridge power chips and at least two lower bridge power chips; the power module comprises an upper bridge metal clip structure and a lower bridge metal clip structure;

[0035] 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;

[0036] Optionally, the surface metal layer of the substrate in the power module comprises 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;

[0037] The at least two upper bridge chips are located on one side of the upper bridge chip contact layer and 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 in contact with the lower bridge chip contact layer; wherein the first DC signal transmission layer is in communication with the upper bridge chip contact layer;

[0038] 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 each bonding strip is bonded to the lower bridge chip connection layer in the substrate away from the end of the bus metal strip;

[0039] 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.

[0040] According to another aspect of the present application, a power conversion circuit is provided, comprising the power module according to any one of the embodiments of the present application, and the power conversion circuit is used for one or more of current conversion, voltage conversion and power factor correction.

[0041] According to another aspect of the present application, a vehicle is provided, comprising a load and a power conversion circuit according to any one of the embodiments of the present application, and the power conversion circuit is used for converting AC into DC, converting AC into AC, converting DC into DC or converting DC into AC and then inputting to the load.

[0042] The embodiment of the application provides a metal clip structure, a power module, a conversion circuit and a vehicle, wherein the metal clip structure is applied to the power module, and the metal clip structure comprises: a bus metal strip comprising oppositely arranged first and second side walls; a bus end portion electrically connected with the first side wall of the bus metal strip; at least two bonding strips electrically connected with the second side wall of the bus metal strip; and a plurality of heat dissipation protrusions on the surface of the bonding strip; wherein the bus end portion is bonded with a substrate in the power module, and the bonding strip is bonded with at least one power chip in the power module; the position of the bus end portion in the extension direction of the bus metal strip is determined based on the current uniformity of the power chip bonded with the metal clip structure, and the current uniformity of the power chip bonded with the metal clip structure is greater than or equal to 95%. The technical scheme provided by the embodiment of the application can increase the heat conduction area of the power chip by arranging a plurality of heat dissipation protrusions on the surface of the bonding strip, improve the heat dissipation effect of the power chip, and the heat dissipation protrusions can be integrally arranged with the bonding strip without glue or other heat-conducting medium, thereby having stronger heat conduction performance. In addition, the heat dissipation protrusions can be arranged on the back of the power chip, which is closer to the power chip, thereby having stronger heat conduction performance. On this basis, the position of the bus end portion in the extension direction of the bus metal strip in the metal clip structure is controlled, so as to control the length of the loop of the power chip in the power module, so that the current flow values of the parallel power chips are close, thereby improving the current uniformity of the parallel power chips in the power module, preventing the formation of local hot spots, improving the problems of chip accelerated aging and even burning, and cracking of the plastic package, thereby effectively improving the service life of the power module.

[0043] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0045] Figure 1 is a perspective view of a metal clip structure provided by the application;

[0046] Figure 2 is Figure 1 is a top view of the bonding surface of the structure shown in the figure;

[0047] Figure 3 is Figure 1 is a side view of the structure from a certain perspective;

[0048] Figure 4 is Figure 1 is a side view of another perspective of the structure shown in FIG. 1;

[0049] Figure 5 is a structure diagram of a bonding tape provided by the present application;

[0050] Figure 6 is a structure diagram of another bonding tape provided by the present application;

[0051] Figure 7 is a structure diagram of a bonding tape provided by the present application, which has a cylindrical heat dissipation protrusion on the surface;

[0052] Figure 8 is a structure diagram of a bonding tape provided by the present application, which has a wavy heat dissipation protrusion on the surface;

[0053] Figure 9 is a structure diagram of an integrated metal clip provided by the present application, which is composed of a bus metal tape, a bus end portion and a bus metal tape integrated setting;

[0054] Figure 10 is a structure diagram of another integrated metal clip provided by the present application, which is composed of a bus metal tape, a bus end portion and a bus metal tape integrated setting;

[0055] Figure 11 is a structure diagram of another integrated metal clip provided by the present application, which is composed of a bus metal tape, a bus end portion and a bus metal tape integrated setting. DETAILED DESCRIPTION

[0056] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should belong to the scope of protection of the present application.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and in the above description of the drawings are intended to distinguish similar objects, and are not necessarily used to describe a particular sequential or chronological order. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to such process, method, product or device.

[0058] The embodiments of the present application provide a metal clip structure applied to a power module, Figure 1 is a perspective view of a metal clip structure provided by the present application, Figure 2 is Figure 1 is a top view of a bonding surface of the structure shown in Figure 3 is Figure 1 is a side view of the structure shown in one perspective, Figure 4 is Figure 1 is a side view of the structure shown in another perspective, with reference to Figures 1-4 The metal clip structure comprises:

[0059] a bus metal strip 10;

[0060] a bus end portion 20 electrically connected to the bus metal strip 10 and located at a first position of the bus metal strip;

[0061] at least two bonding strips 30, each electrically connected to a second side wall of the bus metal strip 10;

[0062] a plurality of heat dissipation protrusions 40 located on the surface of the bonding strip 30;

[0063] Wherein, the bus end portion 20 is bonded to a substrate in the power module, the bonding strip 30 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.

[0064] Specifically, the metal clip structure is applied to a power module. The power module can be an HPD packaged power module or a DCM packaged power module. HPD is a vehicle-grade power module packaging technology designed for new energy vehicles, mainly adapting silicon-based semiconductor devices and silicon carbide semiconductor devices, and is widely used in the main drive inverter of electric vehicles, vehicle-mounted charging systems, etc. DCM is an advanced power module packaging technology optimized for silicon carbide (SiC) devices, developed for high-frequency, high-voltage, and high-power density scenarios, especially suitable for 800V high-voltage platforms for new energy vehicles. The power module includes a substrate, a plurality of power chips, a plastic encapsulation layer, 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 away from the power chips, and plays the roles of electrical connection, current sharing, and heat dissipation.

[0065] The metal clip structure includes a bus metal strip 10, a bus end portion 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 portion 20 and the bus metal strip 10 can be located on the same side wall of the bus metal strip 10, or on different side walls. Figure 1 In the structure shown, the bus metal strip 10 is exemplarily shown to include oppositely arranged first and second side walls, the bus end portion 20 is electrically connected to the first side wall of the bus metal strip 10, and the at least two bonding strips 30 are respectively electrically connected to the second side wall of the bus metal strip 10.

[0066] The surface of the metal clip structure close to the side of the substrate and the power chips includes a plurality of bonding surfaces S for contacting or welding with the substrate and the power chips, thereby realizing the electrical connection. Among them, the bus end portion 20 is bonded with the substrate in the power module, each bonding strip 30 is bonded with at least one power chip, the bonding surface for bonding with the substrate is a substrate bonding surface SB, and the bonding surface for bonding with the power chip is a chip bonding surface SX. The metal clip structure includes at least two bonding strips 30, so that the metal clip structure can realize the parallel connection of at least two power chips, and 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 and the power chips.

[0067] The power chip in the power module is electrically connected to the substrate on the side close to the substrate, and is electrically connected to the substrate through the bonding belt 30, the bus metal belt 10 and the bus end portion 20 on the side away from the substrate. The change of the position of the bus end portion 20 in the extension direction Y of the bus metal belt 10 causes the change of the current path between each power chip and the bus end portion 20, that is, the control of the length of the loop of the power chip in the power module. The change of the length of the loop of the power chip in the power module causes the change of the resistance of the loop, so that the current flowing through the power chip changes. Therefore, by adjusting the position of the bus end portion 20 in the extension direction Y of the bus metal belt 10, the size of the current on each power chip can be adjusted, thereby achieving current sharing. The position of the bus end portion 20 in the extension direction Y of the bus metal belt 10 is determined based on the current sharing degree of the power chip bonded with the metal clip structure. The current sharing degree of the power chip in the power module can be determined by simulation when the current sharing degree of the power chip in the power module meets a preset target value, and then the position of the bus end portion 20 in the extension direction Y of the bus metal belt 10 is set according to the determined position. The first position of the bus metal belt 10 is the determined position. The current sharing degree refers to the uniformity of the current distribution of the plurality of parallel power chips, and is determined based on the ratio of the maximum deviation of the current (the maximum value in the difference between the current of each power chip and the average value of the currents of the plurality of power chips) to the average value of the current. The preset target value can be greater than or equal to 95%, that is, the first position is determined based on the current sharing degree of the power chip bonded with the metal clip structure, and the current sharing degree is greater than or equal to 95%.

[0068] The bonding belt 30 is bonded with the power chip, and a plurality of heat dissipation protrusions 40 are arranged on the surface of the bonding belt 30. The heat of the power chip can be conducted to the heat dissipation medium contacted by the heat dissipation protrusions 40, thereby increasing the heat dissipation area and improving the heat dissipation capacity of the power module to prevent the plastic package from cracking. The heat dissipation protrusions 40 are distributed on the surface of the side of the bonding belt 30 away from the substrate.

[0069] The metal clip structure provided by the embodiments of the present application can increase the heat conduction area of the power chip and improve the heat dissipation effect of the power chip by arranging a plurality of heat dissipation protrusions 40 on the surface of the bonding belt 30. On this basis, the length of the loop of the power chip in the power module is controlled by controlling the position of the bus end portion 20 in the extension direction of the bus metal belt 10, so that the current passing value of each parallel power chip is close, thereby improving the current sharing degree of the parallel power chips in the power module, preventing the formation of local hot spots, improving the problem of chip accelerated aging or even burning, and preventing the plastic package from cracking, thereby effectively improving the service life of the power module.

[0070] On the basis of the above embodiments, optionally,Figure 5 is a schematic view of a partial structure of a bonding ribbon provided by the present application, referring to Figure 5 , and combining with Figures 1-4 , the bonding ribbon 30 comprises a first surface 31 and a second surface 32 arranged oppositely; wherein the first surface 31 comprises at least one bonding surface S, and the second surface 32 comprises at least one heat dissipation surface R; the bonding surface S is used for bonding with a power chip, and a plurality of heat dissipation protrusions 40 are distributed on the at least one heat dissipation surface R.

[0071] Specifically, the bonding ribbon 30 is thin and in a sheet shape. The bonding ribbon 30 comprises a first surface 31 and a second surface 32 arranged oppositely, the first surface 31 is a surface of the bonding ribbon 30 close to a substrate, and the second surface 32 is a surface of the bonding ribbon 30 away from the substrate. The first surface 31 comprises one or more bonding surfaces S, and the bonding surface S is used for bonding with a power chip or a substrate. In the case that the first surface 31 comprises a plurality of bonding surfaces S, at least part of the bonding surfaces S are bonded with the power chip. The second surface 32 of the bonding ribbon 30 comprises one or more heat dissipation surfaces R, and a plurality of heat dissipation protrusions 40 are arranged on the heat dissipation surface R. The plurality of heat dissipation protrusions 40 can be arranged in an array on the heat dissipation surface R, or the plurality of heat dissipation protrusions 40 are arranged in a column on the heat dissipation surface R. Wherein, a vertical projection of each bonding surface S on the same plane as a heat dissipation surface R at least partially overlaps, and each heat dissipation surface R at least partially overlapping with the vertical projection of the bonding surface S on the same plane has a heat dissipation protrusion 40; or the vertical projection of the bonding surface S on the same plane as the heat dissipation surface R does not overlap. On the basis of each of the above embodiments, optionally, the bus metal ribbon 10 is in a planar shape and parallel to the substrate; the bonding ribbon 30 is in a wave shape in the extension direction X of the bonding ribbon 30.

[0072] In the extension direction X of the bonding ribbon 30, the bonding ribbon 30 comprises a plurality of first metal segments 301 and second metal segments 302 arranged alternately, 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 the second metal segments 302; wherein the plane where the first metal segment 301 is located and the plane where the second metal segment 302 is located are both parallel to the plane where the bus metal ribbon 10 is located; 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 close 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 part of the first metal segments 301 are bonded with the power chip

[0073] Specifically, the bonding strip 30 is arranged to include a plurality of first metal segments 301 and second metal segments 302 arranged alternately in sequence and a third metal segment 303 arranged between the first metal segment 301 and the second metal segment 302, and the plane where the first metal segment 301 is arranged is parallel to the plane where the second metal segment 302 is arranged, and the plane where the third metal segment 303 is arranged intersects the plane where the first metal segment 301 is arranged, so that the bonding strip 30 is a wave-shaped bonding strip. The difference in the coefficient of thermal expansion (CTE) between the bonding strip 30 and the chip and the substrate material will cause stress in the thermal cycle, and the wave-shaped bonding strip can absorb the stress through elastic deformation to avoid cracking of the solder joint; and the surface area of the bonding strip 30 can be increased to facilitate heat dissipation of the power chip. Moreover, the wave-shaped bonding strip 30 can partially offset the loop inductance in the high-frequency switching process by lengthening the current path.

[0074] Reference Figure 1 and Figure 5 In the case where the vertical projection of the bonding surface S (the chip bonding surface SX) and the heat dissipation surface R on the same plane at least partially overlaps, the bonding surface S (the 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 (the chip bonding surface SX) is located on the side of the first metal segment 301 close to the substrate; the heat dissipation surface R is located on the side of the first metal segment 301 away from the substrate; and at least part of the first metal segment 301 is bonded to the power chip. By locating the heat dissipation surface R and the bonding surface S (the chip bonding surface SX) on opposite sides of the first metal segment 301, respectively, the vertical projection of the heat dissipation surface R and the bonding surface S (the chip bonding surface SX) in the same plane completely overlaps, i.e. the heat dissipation protrusion is located on the front and back surfaces of the power chip, further improving the heat dissipation effect of 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 arranged.

[0075] In another embodiment of the present application, with reference to Figure 6 , the vertical projection of the bonding surface S and the heat dissipation surface R on the same plane does not overlap, at this time the bonding surface S (the chip bonding surface SX) is located on the side of the second metal segment 302 close to the substrate; the heat dissipation surface R is located on the side of the first metal segment 301 away from the substrate, which can facilitate the space between the two first metal segments 301 to accommodate the power chip, and is conducive to reducing the thickness of the power module.

[0076] On the basis of the above embodiments, optionally, at least part of the heat dissipation protrusions 40 are in the shape of a cylinder, or at least part of the heat dissipation protrusions 40 are in the shape of a cuboid. Figures 1-4 Exemplarily, all the heat dissipation protrusions 40 are in the shape of a cuboid, and a plurality of cuboid-shaped heat dissipation protrusions 40 are arranged in a row on the heat dissipation surface R; Figure 7is a structural schematic diagram of a bonding tape 30 with cylindrical heat dissipation protrusions 40 provided by the present application, referring to Figure 7 , all the heat dissipation protrusions 40 are cylindrical, and the plurality of cylindrical heat dissipation protrusions 40 are arranged in an array on the heat dissipation surface R to form a heat dissipation protrusion array 400.

[0077] Specifically, the cylindrical heat dissipation protrusions 40 can have a larger surface area to volume ratio, and can more efficiently transfer heat; the cylindrical heat dissipation protrusions 40 can reduce local hot spots, and heat is evenly spread along the radial direction to avoid heat accumulation at the corners of the cuboid. The cuboid heat dissipation protrusions 40 can be mass-produced by traditional stamping or etching processes, and the cost is lower than that of a cylinder.

[0078] Based on the above embodiments, optionally, at least part of the surface of the heat dissipation protrusion 40 away from the heat dissipation surface R is a curved surface. Taking the heat dissipation protrusion 40 as an example, Figure 8 is a structural schematic diagram of a bonding tape with wave-shaped heat dissipation protrusions provided by the present application, referring to Figure 8 , the surface of the heat dissipation protrusion 40 away from the heat dissipation surface R is a curved surface. Compared with a plane, 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.

[0079] Further, the surface of the heat dissipation protrusion 40 away from the heat dissipation surface R is a wave-shaped curved surface, and the surfaces of the plurality of heat dissipation protrusions 40 away from the heat dissipation surface R form a wave-shaped surface 411. The wave-shaped curved surface expands the plane into a continuous wave crest and trough through a three-dimensional undulating structure, so that the heat dissipation surface R is increased, and the heat exchange efficiency is significantly improved.

[0080] Based on the above embodiments, optionally, Figure 9 is a structural schematic diagram of an integrated metal clip composed of a busbar metal strip, a busbar end portion, and an integrated busbar metal strip provided by the present application, Figure 10 is a structural schematic diagram of another integrated metal clip composed of a busbar metal strip, a busbar end portion, and an integrated busbar metal strip provided by the present application, referring to Figure 9 and Figure 10 The busbar metal strip 10, the busbar end portion 20, and the at least two bonding tapes 30 can be integrally provided to form an integrated metal clip, thereby enhancing the firmness between the busbar end portion 20 and the busbar metal strip 10 and between the bonding tapes 30 and the busbar metal strip 10; in addition, the integrated metal clip is formed by stamping, etching, or 3D printing, and the welding, binding, or screw fixing processes are omitted.

[0081] On the basis of the above embodiments, optionally, a plurality of heat dissipation protrusions 40 can be welded on the surface of the bonding strip 30, or the plurality of heat dissipation protrusions 40 are integrally arranged with the bonding strip 30. Preferably, the bonding strip 30 is integrally arranged with the heat dissipation protrusions 40, so as to increase the firmness between the bonding strip 30 and the heat dissipation protrusions 40; and the heat dissipation protrusions can be integrally arranged with the bonding strip, without glue or other heat-conducting medium in the middle, having stronger heat-conducting performance. 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. The copper clip technology has the advantages of low resistance, high heat conduction, strong mechanical stability, and low parasitic parameters, and becomes the 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).

[0082] On the basis of the above embodiments, optionally, the power module includes a plurality of upper bridge power chips and a plurality of lower bridge power chips; the surface metal layer of the substrate in the power module includes a first direct current signal transmission layer, a second direct current signal transmission layer, an alternating current signal transmission layer, an upper bridge chip contact layer, and a lower bridge chip contact layer; the plurality of upper bridge chips are located on one side of the upper bridge chip contact layer and in contact with the upper bridge chip contact layer; the plurality of lower bridge chips are located on one side of the lower bridge chip contact layer and in contact with the lower bridge chip contact layer; wherein the first direct current signal transmission layer is in communication with the upper bridge chip contact layer.

[0083] Figure 10 The illustrated integrated metal clip is an integrated metal clip in the upper bridge metal clip structure. In the case where the metal clip structure is bonded with 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 portion 20 is bonded with the alternating current signal transmission layer in the substrate, and the end portion of each bonding strip 30 away from the bus metal strip is bonded with the lower bridge chip connection layer in the substrate.

[0084] Figure 9 The illustrated integrated metal clip is an integrated metal clip in the lower bridge metal clip structure (see Figures 1-4 ) In the case where the metal clip structure is bonded with the plurality of lower 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 portion 20 is bonded with the second direct current signal transmission layer in the substrate.

[0085] 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 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. 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 in communication with 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 transmission layer, and the lower bridge chip contact layer are disconnected. The first DC signal transmission layer is electrically connected to a DC+ terminal, the second DC signal transmission layer is electrically connected to a DC- terminal, and the AC signal transmission layer is electrically connected to an AC terminal. Further, the substrate can include a first side edge and a second side edge arranged opposite each other. The DC+ terminal and the DC- terminal can be electrically connected on the first side edge of the substrate, and the AC terminal can be located on the second side edge of the substrate.

[0086] The upper bridge chip in the power module is located on one side of the upper bridge chip contact layer and in contact with the upper bridge chip contact layer to achieve electrical connection. The lower bridge chip in the power module is located on one side of the lower bridge chip contact layer and in contact with 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 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 uniformity of the parallel upper bridge chips, and the lower bridge metal clip structure improves the current uniformity of the parallel lower bridge chips.

[0087] The upper bridge metal clip structure is located on the side of the 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, and each bonding strip 30 is bonded to the lower bridge chip connection layer in the substrate away from the tail end of the bus metal strip 10 (the end of the bonding strip 30 away from the bus metal strip 10). The area between the tail end of the bonding strip 30 and the bus metal strip 10 is bonded to one or more upper bridge chips. The lower metal clip structure is located on the side of the 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, and each bonding strip 30 is bonded to one or more lower bridge chips.

[0088] The above embodiments exemplarily show the metal clip structure with two bonding strips 30 connecting three power chips in parallel, which are odd number of power chips, and the number of power chips bonded on different bonding strips 30 is different. In another embodiment of the present application, the metal clip structure with two bonding strips 30 can also connect even number of power chips in parallel.

[0089] Figure 11 is another structural schematic diagram of the integrated metal clip provided by the present application, which is composed of the bus metal strip, the bus end part and the integrated setting of the bus metal strip. Referring to Figure 11 Optionally, three or more bonding strips 30 can be arranged in the metal clip structure to connect more number of power chips in parallel. Among them, Figure 10 Exemplarily show the metal clip structure including three bonding strips 30, and the number of power chips bonded on different bonding strips 30 is the same. Further, in the case that the number of bonding strips 30 is greater than or equal to 3, Figure 11 Exemplarily show the number of bus end parts 20 is 2 in

[0090] On the basis of the above embodiments, referring to Figures 9-11 Optionally, in the same metal clip structure, the number of power chips bonded on different bonding strips 30 is the same; or the number of power chips bonded on different bonding strips 30 is different; or the number of power chips bonded on part of the bonding strips 30 is different, and the number of power chips bonded on part of the bonding strips 30 is the same, which can be set according to actual needs. Among them, Figure 9 and Figure 10 Exemplarily show the number of power chips bonded on different bonding strips 30 is different, Figure 11 Exemplarily show the number of power chips bonded on different bonding strips 30 is the same.

[0091] On the basis of the above embodiments, optionally, referring to Figure 2 In the same metal clip structure, the extension direction Y of the bus metal strip 10 intersects with the extension direction X of the bonding strip 30, and at least two bonding strips 30 are arranged along the extension direction Y of the bus metal strip 10. Among them, the extension direction Y of the bus metal strip 10 and the extension direction X of the bonding strip 30 can be perpendicular to each other.

[0092] The present application also provides a power module, which comprises a substrate, a plurality of power chips and at least one metal clip structure according to any embodiment of the present application; wherein the plurality of power chips are arranged on the same side of the substrate; the side of the power chip close to the substrate is electrically connected with the substrate; the metal clip structure is located on the side of the power chip away from the substrate, and at least two power chips are bonded with the metal clip structure to be connected in parallel through the metal clip structure. It has the same technical effect, which will not be repeated here.

[0093] Optionally, the plurality of power chips comprises at least two upper bridge chips and at least two lower bridge chips; the power module further comprises an upper bridge metal clip structure and a lower bridge metal clip structure; the at least two upper bridge chips are connected in parallel through the upper bridge metal clip structure; the at least two lower bridge chips are connected in parallel through the lower bridge metal clip structure.

[0094] Further, the surface metal layer of the substrate comprises 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 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 in contact with the lower bridge chip contact layer; wherein the first DC signal transmission layer is in communication with 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 portion 20 is bonded to the AC signal transmission layer in the substrate, and each bonding strip 30 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 portion 20 is bonded to the second DC signal transmission layer in the substrate.

[0095] Optionally, the substrate comprises a direct bonded copper (DBC) ceramic substrate or an active metal brazing (AMB) ceramic substrate. The electrodes or pads of the power chips are fixed to one side of the substrate through a sintering or welding process. The metal clip structure is welded to the pins of the power chips through a conditional bonding (Clip Bond) packaging process to realize the interconnection between the plurality of power chips.

[0096] Optionally, the power chips comprise metal-oxide-semiconductor field-effect transistor power chips (MOSFET power chips) or insulated gate bipolar transistor power chips (IGBT power chips).

[0097] Further, the metal-oxide-semiconductor field-effect transistor power chips comprise silicon carbide metal-oxide-semiconductor field-effect transistor power chips (SiC MOSFET power chips) or gallium nitride metal-oxide-semiconductor field-effect transistor power chips (GaN MOSFET power chips). The insulated gate bipolar transistor power chips comprise silicon carbide insulated gate bipolar transistor power chips (SiC IGBT power chips) or gallium nitride insulated gate bipolar transistor power chips (GaN IGBT power chips).

[0098] Optionally, the pad connected to the drain of the MOSFET power chip is fixed to one side of the substrate through a sintering or welding process, the pad connected to the source of the MOSFET power chip is welded to the bonding surface S of the metal clip structure, and then the power chips are encapsulated by a plastic encapsulation layer.

[0099] The application also provides a power conversion circuit comprising the power module of any of the embodiments of the application, the power conversion circuit being used for one or more of current conversion, voltage conversion, and power factor correction. The same technical effects are achieved, and thus are not described here again.

[0100] The application also provides a vehicle comprising a load and the power conversion circuit of any of the embodiments of the application, the power conversion circuit being used for converting AC power into DC power, converting AC power into AC power, converting DC power into DC power, or converting DC power into AC power before inputting to the load. The same technical effects are achieved, and thus are not described here again.

[0101] It should be noted that the above only describes the preferred embodiments of the application and the technical principles applied. Those skilled in the art will understand that the application is not limited to the specific embodiments described herein, and that various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the scope of the application. Therefore, although the application has been described in detail through the above embodiments, the application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the application, and the scope of the application is determined by the scope of the appended claims.

Claims

1. A metal clip structure, characterized in that: Applied to a power module, the metal clip structure includes: Converging metal strips; a bus end portion, electrically connected to the bus metal strip and located at a first position of the bus metal strip; at least two bonding strips, each electrically connected to the bus metal strip; a plurality of heat dissipation protrusions located on a surface of the bonding tape; The bus end is bonded to the substrate in the power module, and the bonding tape is bonded to at least one power chip in the power module; the first position is determined based on the current sharing degree 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, wherein: The bus metal strip, the bus end portion and the bonding strip are integrally provided to form an integrated metal clip; The plurality of heat dissipation protrusions are welded on the surface of the bonding tape, or the plurality of heat dissipation protrusions are integrally provided with the bonding tape.

4. The metal clip structure according to claim 1, wherein: The bonding ribbon 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 multiple 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 vertical projections of the bonding surface and the heat dissipation surface on the same plane at least partially overlap; Alternatively, vertical projections of the bonding surface and the heat dissipation surface on the same plane do not overlap.

6. The metal clip structure according to claim 4, characterized in that: At least part of the heat dissipation protrusion is cylindrical; Alternatively, at least part of the heat dissipation protrusions are in a rectangular parallelepiped 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 surfaces of the plurality of heat dissipation protrusions in the heat dissipation protrusion unit away from the heat dissipation surface form a wavy surface.

8. The metal clip structure according to claim 4, characterized in that: The bonding ribbon is wavy in its extension direction; in the extension direction of the bonding ribbon, the bonding ribbon includes a plurality of first metal segments and second metal segments alternately arranged in sequence, 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 on which the first metal segments and the second metal segments are located are both parallel to the plane on which the bus metal ribbon is located; and the first metal segments are closer to the substrate in the power module than the second metal segments; 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 surfaces on opposite sides of the same first metal segment; wherein the bonding surface is located on a side of the first metal segment close to the substrate; the heat dissipation surface is located on a side of the first metal segment away from the substrate; and 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 a side of the second metal segment close to the substrate; and the heat dissipation surface is located on a side of the first metal segment away from the substrate.

9. The metal clip structure according to claim 1, wherein: The power module includes a plurality of upper bridge power chips and a plurality of 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 plurality of upper bridge chips are located on one side of the upper bridge chip contact layer and in contact with the upper bridge chip contact layer; the plurality of lower bridge chips are located on one side of the lower bridge chip contact layer and 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 a 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 multiple upper bridge power chips, the metal clip structure is located on a side of the multiple 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, wherein: The extending direction of the bus metal strip and the extending direction of the bonding strip are perpendicular to each other; At least two bonding ribbons are arranged at intervals along the extending direction of the bus metal ribbon.

11. The metal clip structure according to claim 1, wherein: Different bonding ribbons bond the same number of power chips; Alternatively, different bonding ribbons may bond different numbers of power chips; Alternatively, some bonding ribbons bond different numbers of power chips, and some bonding ribbons bond the same number of power chips.

12. A power module, characterized in that: comprising a substrate, a plurality of power chips and at least one metal clip structure according to any one of claims 1 to 11; Among them, multiple chips are arranged on the same side of the substrate; the side of the chip close 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, wherein: 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 via the upper bridge metal clip structure; and the at least two lower bridge power chips are connected in parallel via 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 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 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 a 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 strip 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 a 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: The power module comprises 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: It includes a load and the power conversion circuit as claimed in claim 15, wherein the power conversion circuit is used to convert AC power into DC power, convert AC power into AC power, convert DC power into DC power, or convert DC power into AC power and then input it into the load.

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