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 is applied to the power module, and the metal clamp structure comprises a confluence metal belt; the confluence end part is positioned on one side of the confluence metal belt and is electrically connected with the confluence metal belt; the at least two bonding belts are positioned on one side of the confluence metal belt and are electrically connected with the confluence metal belt respectively; 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; and the connection position of the confluence end part on the confluence metal belt is determined according to the current sharing degree of the current flowing through the power chips bonded on the at least two bonding belts. According to the technical scheme provided by the invention, the current sharing degree of the power chips connected in parallel in the power module is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor technology, and particularly relate 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 current sharing degree of the parallel power chips in the existing HPD packaged power modules and DCM packaged power modules on the market is low. The power chip with a large current load will overheat due to a significant increase in conduction loss, form a local hot spot, accelerate chip aging, and shorten the service life of the power module. Therefore, how to improve the current sharing degree of the parallel power chips in the power module has become a technical problem to be solved in the field. SUMMARY

[0003] Embodiments of the present application provide a metal clip structure, a power module, a conversion circuit and a vehicle to improve the current sharing degree of the parallel power chips in 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 current-carrying metal strip;

[0006] a current-carrying end portion located on one side of the current-carrying metal strip and electrically connected with the current-carrying metal strip;

[0007] at least two bonding strips located on one side of the current-carrying metal strip and respectively electrically connected with the current-carrying metal strip;

[0008] wherein the current-carrying end portion is bonded with a substrate in the power module, and the at least two bonding strips are respectively bonded with at least one power chip in the power module; and the connection position of the current-carrying end portion on the current-carrying metal strip is determined according to the current sharing degree of the current flowing through the power chips bonded on the at least two bonding strips.

[0009] Optionally, the current sharing degree is greater than or equal to 95%.

[0010] Optionally, the power module comprises at least two upper bridge power chips and at least two lower bridge power chips; a surface metal layer of a 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; 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;

[0011] In the case that the metal clip structure is bonded with the at least two upper bridge power chips, the metal clip structure is located on a side of the at least two upper bridge power chips away from the substrate; the bus end portion is bonded with the AC signal transmission layer in the substrate, and each of the bonding strips is bonded with the lower bridge chip connection layer in the substrate away from the bus metal strip;

[0012] In the case that the metal clip structure is bonded with the at least two lower bridge power chips, the metal clip structure is located on a side of the at least two lower bridge power chips away from the substrate; the bus end portion is bonded with the second DC signal transmission layer in the substrate.

[0013] Optionally, the bus metal strip, the bus end portion and the at least two bonding strips are integrally arranged.

[0014] Optionally, the extension direction of the bus metal strip and the extension direction of the bonding strips are perpendicular to each other.

[0015] The at least two bonding strips are arranged in a spaced manner along the extension direction of the bus metal strip.

[0016] Optionally, in the case that the number of the bonding strips is greater than or equal to 3, the number of the bus end portions is greater than or equal to 2.

[0017] Optionally, the bus metal strip is in a planar shape, and the bonding strips are in a wavy shape in the extension direction of the bonding strips.

[0018] The bonding strip comprises a plurality of first metal segments and second metal segments arranged alternately in sequence in the extension direction of the bonding strip, and a third metal segment for connecting the first metal segment and the second metal segment between adjacent first metal segments and second metal segments.

[0019] The first metal segment and the second metal segment are 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; at least part of the first metal segment is bonded with the power chip, or at least part of the second metal segment is bonded with the power chip.

[0020] According to another aspect of the present application, a power module is provided, comprising a substrate, a plurality of power chips and the metal clip structure according to any one of the embodiments of the present application.

[0021] The plurality of power chips are arranged on the same side of the substrate; the power chips are electrically connected to the substrate on the side close to the substrate; the metal clip structure is located on the side of the power chips away from the substrate, and at least two of the power chips are bonded with the metal clip structure to be connected in parallel through the metal clip structure.

[0022] Optionally, the plurality of power chips comprise 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.

[0023] 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.

[0024] Optionally, the surface metal layer of the substrate 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.

[0025] The at least two upper bridge chips are located on the 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 the 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.

[0026] 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 part is bonded with the alternating current signal transmission layer in the substrate, and each of the bonding strips is bonded with the lower bridge chip connection layer in the substrate away from the bus metal strip;

[0027] 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 part is bonded with the second direct current signal transmission layer in the substrate.

[0028] Optionally, the power chip comprises a metal-oxide semiconductor field effect transistor power chip or an insulated gate bipolar transistor power chip.

[0029] Optionally, the metal-oxide-semiconductor field-effect transistor power chip comprises a silicon carbide metal-oxide-semiconductor field-effect transistor power chip or a gallium nitride metal-oxide-semiconductor field-effect transistor power chip.

[0030] The insulated gate bipolar transistor power chip comprises a silicon carbide insulated gate bipolar transistor power chip or a gallium nitride insulated gate bipolar transistor power chip.

[0031] Optionally, the substrate comprises a direct bonded copper ceramic substrate or an active metal brazed ceramic substrate.

[0032] According to another aspect of the present application, there is provided a power conversion circuit comprising the power module of any of the embodiments of the present application, the power conversion circuit being used for one or more of current conversion, voltage conversion, and power factor correction.

[0033] According to another aspect of the present application, there is provided a vehicle comprising a load and the power conversion circuit of any of the embodiments of the present application, the power conversion circuit being used for converting alternating current into direct current, converting alternating current into alternating current, converting direct current into direct current, or converting direct current into alternating current, and then inputting to the load.

[0034] The embodiments of the present application provide 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 to the first side wall of the bus metal strip; and at least two bonding strips electrically connected to the second side wall of the bus metal strip; wherein the bus end portion 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 portion in the extension direction of the bus metal strip is determined based on the current uniformity of the power chip bonded to the metal clip structure, and the current uniformity of the power chip bonded to the metal clip structure is greater than or equal to 95%. The technical solution provided by the embodiments of the present application controls the position of the bus end portion in the extension direction of the bus metal strip in the metal clip structure, thereby controlling the length of the loop of the power chip in the power module, and making the current flow values of the parallel power chips close to each other, so as to improve the current uniformity of the parallel power chips in the power module.

[0035] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0037] Figure 1 is a perspective view of a metal clamp structure provided by the present application;

[0038] Figure 2 is a perspective view of a metal clamp structure provided by the present application; Figure 1

[0039] Figure 3 is a side view of the structure shown in FIG. 8 from a certain perspective; Figure 1

[0040] Figure 4 is a side view of the structure shown in FIG. 8 from another perspective; Figure 1

[0041] Figure 5 is a perspective view of another metal clamp structure provided by the present application;

[0042] Figure 6 is a perspective view of another metal clamp structure provided by the present application; Figure 5

[0043] Figure 7 is a side view of the structure shown in FIG. 10 from a certain perspective; Figure 5

[0044] Figure 8 is a side view of the structure shown in FIG. 10 from another perspective; Figure 5

[0045] Figure 9 is a perspective view of another metal clamp structure provided by the present application;

[0046] Figure 10 is a perspective view of another metal clamp structure provided by the present application; Figure 9

[0047] Figure 11 is a perspective view of another metal clamp structure provided by the present application;

[0048] Figure 12 is a perspective view of another metal clamp structure provided by the present application; Figure 11

[0049] Figure 13 is a perspective view of another metal clamp structure provided by the present application;

[0050] Figure 14 is a perspective view of another metal clamp structure provided by the present application; Figure 13 ​​​​​​​​a top view of the bonding surface of the structure shown;

[0051] Figure 15 is a schematic diagram of a partial structure of a bonding ribbon provided by the present application. DETAILED DESCRIPTION

[0052] In order for those 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 accompanying drawings of 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 those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0053] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. 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 those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0054] 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 a top view of the bonding surface of the structure shown, Figure 3 is Figure 1 a side view of the structure shown from one perspective, Figure 4 is Figure 1 a side view of the structure shown from another perspective; with reference to Figures 1-4 , the metal clip structure comprises:

[0055] a bus metal ribbon 10;

[0056] a bus end portion 20 located on one side of the bus metal ribbon 10 and electrically connected with the bus metal ribbon 10;

[0057] at least two bonding ribbons 30 located on one side of the bus metal ribbon 10 and respectively electrically connected with the bus metal ribbon 10;

[0058] The busbar end portion 20 is bonded with a substrate in the power module, and the at least two bonding strips 30 are respectively bonded with at least one power chip in the power module; the connection position of the busbar end portion 20 on the busbar metal strip 10 is determined according to the current uniformity of the current flowing through the power chip bonded with the at least two bonding strips 30.

[0059] Specifically, the metal clip structure is applied to the 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, vehicle-mounted charging system, etc. of electric vehicles. 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 role of electrical connection and current sharing.

[0060] The metal clip structure includes a busbar metal strip 10, a busbar end portion 20 electrically connected to the busbar metal strip 10, and at least two bonding strips 30 electrically connected to the busbar metal strip 10. The busbar end portion 20 and the busbar metal strip 10 can be located on the same side wall of the busbar metal strip 10, or on different side walls. Figures 1-4In the structure shown, the exemplary busbar metal strip 10 includes oppositely arranged first and second side walls, the busbar end portion 20 is electrically connected to the first side wall of the busbar metal strip 10, and the at least two bonding strips 30 are respectively electrically connected to the second side wall of the busbar metal strip 10. The surface of the metal clip structure close to the side of the substrate and the power chip is used to contact or weld with the substrate and the power chip, and includes a plurality of bonding surfaces. The busbar end portion 20 is bonded with the substrate in the power module, each bonding strip 30 is bonded with at least one power chip, and the metal clip structure includes at least two bonding strips 30, so that the metal clip structure can realize parallel connection of at least two power chips, the distance between the busbar metal strip 10 and the substrate is greater than zero, and the busbar metal strip 10 does not contact the substrate and the power chip. Among them, the busbar metal strip 10, the busbar end portion 20 and the at least two bonding strips 30 can be integrally arranged, so as to enhance the firmness between the busbar end portion 20 and the busbar metal strip 10 and between the bonding strip 30 and the busbar metal strip 10; in addition, the integrated metal clip structure is formed by stamping, etching or 3D printing, so that the processes such as welding, binding or screw fixing are omitted. 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 thermal conductivity, strong mechanical stability and low parasitic parameters, and becomes the preferred solution for power module interconnection, and is especially suitable for high-frequency, high-power density and high-reliability scenarios (such as electric vehicles and renewable energy sources).

[0061] 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 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 is realized. 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 of the bus metal belt 10, the size of the current flowing through each power chip can be adjusted. The connection position of the bus end portion 20 on the bus metal belt 10 is determined according to the current uniformity of the power chip bonded with the metal clip structure. The position of the bus end portion 20 in the extension direction of the bus metal belt 10 when the current uniformity of the power chip in the power module meets the preset target value can be determined by simulation, and then the connection position of the bus end portion 20 on the bus metal belt 10 is set according to the determined position. The current uniformity refers to the uniformity of the current distribution of the plurality of parallel power chips, which is determined based on the ratio of the maximum deviation of the current (the maximum value of 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 connection position of the bus end portion 20 on the bus metal belt 10 is determined based on the current uniformity of the power chip bonded with the metal clip structure, and the uniformity is greater than or equal to 95%.

[0062] The metal clip structure provided by the embodiments of the present application comprises: a bus metal belt 10 comprising a first side wall and a second side wall arranged oppositely; a bus end portion 20 electrically connected to the first side wall of the bus metal belt 10; and at least two bonding belts 30 respectively electrically connected to the second side wall of the bus metal belt 10. The bus end portion 20 is bonded with a substrate in a power module, and the bonding belt 30 is bonded with at least one power chip in the power module. The position of the bus end portion 20 in the extension direction of the bus metal belt 10 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 embodiments of the present application controls the position of the bus end portion 20 in the extension direction of the bus metal belt 10 in the metal clip structure, thereby controlling the length of the loop of the power chip in the power module, so that the current passing through each parallel power chip is close, thereby improving the current uniformity of the parallel power chips in the power module.

[0063] On the basis of the above embodiments, optionally, the power module comprises at least two upper bridge power chips and at least two 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 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; and the first direct current signal transmission layer is in communication with the upper bridge chip contact layer.

[0064] In the case where the metal clip structure is bonded with the at least two upper bridge power chips, the metal clip structure is located on the side of the at least two 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 each bonding strip 30 is bonded with the lower bridge chip connection layer in the substrate;

[0065] In the case where the metal clip structure is bonded with the at least two lower bridge power chips, the 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 with the second direct current signal transmission layer in the substrate.

[0066] Specifically, the substrate can be a Direct Bonded Copper (DBC) ceramic substrate or an Active Metal Brazing (AMB) ceramic substrate. The substrate comprises a ceramic substrate and a surface metal layer on the surface of the ceramic substrate, and the surface metal layer of the substrate 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 first direct current signal transmission layer, the second direct current signal transmission layer, the alternating current signal transmission layer, the upper bridge chip contact layer, and the lower bridge chip contact layer are located on the same side of the surface of the ceramic substrate. The first direct current signal transmission layer is in communication with the upper bridge chip contact layer, which can be understood as that the first direct current signal transmission layer and the upper bridge chip contact layer are the same continuous metal layer. Any two of the first direct current signal transmission layer, the second direct current signal transmission layer, the alternating current signal transmission layer, and the lower bridge chip contact layer are disconnected. The first direct current signal transmission layer is electrically connected with a DC+ direct current terminal, the second direct current signal transmission layer is electrically connected with a DC- direct current terminal, and the alternating current signal transmission layer is electrically connected with an AC alternating current terminal. Further, the substrate can comprise a first side edge and a second side edge arranged oppositely, the DC+ direct current terminal and the DC- direct current terminal can be electrically connected on the first side edge of the substrate, and the alternating current terminal is located on the second side edge of the substrate.

[0067] 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 the metal clip structure bonded with the upper bridge power chip and the metal clip structure bonded with the lower bridge power chip. Preferably, the power module includes the metal clip structure bonded with the upper bridge power chip, i.e. the upper bridge metal clip structure, Figures 5-8 The metal clip structure shown is the upper bridge metal clip structure, and includes the metal clip structure bonded with the lower bridge power chip, i.e. the lower bridge metal clip structure, Figures 1-8 The metal clip structure shown is the lower bridge metal clip structure. The upper bridge metal clip structure improves the current sharing degree of the parallel upper bridge chips, and the lower bridge metal clip structure improves the current sharing degree of the parallel lower bridge chips.

[0068] In the upper bridge metal clip structure, the bus end 20 is bonded with the alternating current signal transmission layer in the substrate, and each bonding strip 30 is bonded with 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), and the area between the tail end of the bonding strip 30 and the bus metal strip 10 is bonded with one or more upper bridge chips. In the lower bridge metal clip structure, the bus end 20 is bonded with the second direct current signal transmission layer in the substrate, and each bonding strip 30 is bonded with one or more lower bridge chips.

[0069] On the basis of the above embodiments, with reference to Figure 1 Optionally, in the same metal clip structure, the number of power chips bonded by different bonding strips 30 is the same; or the number of power chips bonded by different bonding strips 30 is different; or the number of power chips bonded by part of the bonding strips 30 is different, and the number of power chips bonded by part of the bonding strips 30 is the same, which can be set according to actual needs.

[0070] Illustratively, with reference to Figure 5In one embodiment of the present application, the upper bridge metal clip structure includes two bonding strips 30, which are a first bonding strip 31 and a second bonding strip 32, respectively. The first bonding strip 31 includes a chip bonding surface and a substrate bonding surface on the surface close to the substrate, and the first bonding strip 31 can be bonded with an upper bridge chip. The second bonding strip 32 includes two chip bonding surfaces and a substrate bonding surface on the surface close to the substrate, and the second bonding strip 32 can be bonded with two upper bridge chips. Therefore, the upper bridge metal clip structure includes six bonding surfaces, which are a first substrate bonding surface B1 located at the busbar end portion 20, a second substrate bonding surface B2 located at the tail end portion of the first bonding strip 31, a third substrate bonding surface B3 located at the tail end portion of the second bonding strip 32, a first chip soldering surface S1 located between the tail end portion of the first bonding strip 31 and the busbar metal strip 10, a second chip soldering surface S2 located between the tail end portion of the second bonding strip 32 and the busbar metal strip 10, and a third chip soldering surface S3. The first substrate bonding surface B1 is bonded with the alternating current signal transmission layer in the substrate, and the second substrate bonding surface B2 and the third substrate bonding surface B3 are bonded with the lower bridge chip contact layer in the substrate. The first chip soldering surface S1, the second chip soldering surface S2, and the third chip soldering surface S3 are respectively bonded with one side of an upper bridge chip away from the substrate, and each upper bridge chip is bonded with the upper bridge chip contact layer in the substrate on the side close to the substrate.

[0071] Reference Figure 9 The lower bridge metal clip structure includes two bonding strips 30, which are a third bonding strip 33 and a fourth bonding strip 34, respectively. The third bonding strip 33 includes a chip bonding surface on the surface close to the substrate, and the third bonding strip 33 can be bonded with a lower bridge chip. The fourth bonding strip 34 includes two chip bonding surfaces on the surface close to the substrate, and the fourth bonding strip 34 can be bonded with two upper bridge chips. Therefore, the lower bridge metal clip structure includes four bonding surfaces, which are a fourth substrate bonding surface B4 located at the busbar end portion 20, a fourth chip soldering surface S4 located at the third bonding strip 33, a fifth chip soldering surface S5 located at the fourth bonding strip 34, and a sixth chip soldering surface S6. The fourth substrate bonding surface B4 is bonded with the second direct current signal transmission layer in the substrate, and the fourth chip soldering surface S4, the fifth chip soldering surface S5, and the sixth chip soldering surface S6 are respectively bonded with one side of a lower bridge chip away from the substrate, and each upper bridge chip is bonded with the lower bridge chip contact layer in the substrate on the side close to the substrate.

[0072] The above embodiment exemplarily shows that the metal clip structure with two bonding strips 30 connects three power chips in parallel, which are odd-numbered power chips, and the number of power chips bonded on different bonding strips 30 is different.

[0073] Optionally, in another embodiment of the present application, the metal clip structure with two bonding strips 30 can also connect even-numbered power chips in parallel.

[0074] Exemplarily, Figure 10 is a perspective view of another metal clip structure provided by the present application, Figure 9 is Figure 11 is a top view of the bonding surface of the structure shown in Figure 12 is a perspective view of another metal clip structure provided by the present application, Figure 11 is Figures 9-12 is a top view of the bonding surface of the structure shown in Figure 9 , the metal clip structure can be connected in parallel with 2 power chips or 4 power chips. Among them, Figure 10 and Figure 11 The bonding surface on the metal clip structure includes a substrate bonding surface B located at the busbar end portion 20, and one chip bonding surface S located on each bonding strip 30, Figure 12 and Figure 13 The bonding surface on the metal clip structure includes a substrate bonding surface B located at the busbar end portion 20, and two chip bonding surfaces S located on each bonding strip 30.

[0075] On the basis of each of the above embodiments, Figure 14 is a perspective view of another metal clip structure provided by the present application, Figure 13 is Figure 13 is a top view of the bonding surface of the structure shown in Figure 14 and Figure 13 Optionally, 3 or more bonding strips 30 can be provided in the metal clip structure to connect in parallel with a larger number of power chips. Among them, Figure 14 and Figure 13 Exemplarily show that the metal clip structure includes 3 bonding strips 30, and the number of power chips bonded on different bonding strips 30 is the same.

[0076] Further, in the case where the number of bonding strips 30 is greater than or equal to 3, the number of busbar end portions 20 is greater than or equal to 2. Exemplarily shown in Figure 14 and Figures 1-14 Exemplarily show that the number of busbar end portions 20 is 2.

[0077] Specifically, if more power chips are connected in parallel, a single busbar end portion 20 may not be able to evenly control the loop distance, so it can be expanded to two or more busbar end portions 20 to adjust the loop length of each power chip, thereby meeting the requirement that the current flow values of each power chip are close in the case where the number of power chips connected in parallel is large.

[0078] On the basis of each of the above embodiments, refer to Figure 15Optionally, in the same metal clip structure, the extension direction of the bus metal strip 10 intersects with the extension direction of the bonding strip 30, and at least two bonding strips 30 are arranged along the extension direction of the bus metal strip 10. The extension direction of the bus metal strip 10 and the extension direction of the bonding strip 30 can be perpendicular to each other.

[0079] On the basis of the above-mentioned embodiments, optionally, in the metal clip structure, the bus metal strip 10 is planar, and the bonding strip 30 is wavy in the extension direction of the bonding strip 30.

[0080] Figure 15 is a partial structure schematic diagram of the bonding strip 30 provided by the present application, referring to ​ In the extension direction of the bonding strip 30, the bonding strip 30 includes a plurality of first metal segments 301 and second metal segments 302 arranged alternately, and a third metal segment 303 arranged between adjacent first metal segments 301 and second metal segments 302 for connecting the first metal segments 301 and the second metal segments 302; the plane where the first metal segment 301 is located and the plane where the second metal segment 302 is located are parallel to the plane where the bus metal strip 10 is located; the first metal segment 301 is closer to the substrate in the power module than the second metal segment 302, and at least part of the first metal segment 301 is bonded with the power chip. That is, the bonding surface on the bonding strip 30 is located on the surface of the first metal segment 301 close to the substrate.

[0081] Specifically, in the power module, the shape design of the metal clip structure is a key factor to determine the performance of the module (such as heat dissipation, current distribution, parasitic inductance and mechanical reliability). By arranging the bonding strip 30 to include a plurality of first metal segments 301 and second metal segments 302 arranged alternately and a third metal segment 303 arranged between the first metal segment 301 and the second metal segment 302, and arranging the plane where the first metal segment 301 is located to be parallel to the plane where the second metal segment 302 is located, and the plane where the third metal segment 303 is located intersects with the plane where the first metal segment 301 is located, the bonding strip 30 can be a wavy bonding strip. The wavy bonding strip can absorb stress through elastic deformation to avoid cracking of the soldering point; it can also increase the surface area of the bonding strip 30, which is beneficial to heat dissipation of the power chip. Moreover, the wavy bonding strip can partially offset the loop inductance in the high-frequency switching process by lengthening the current path.

[0082] In other embodiments of the present application, the bonding surface on the bonding strip 30 can also be located on the surface of the second metal segment 301 close to the substrate, which can accommodate the power chip in the space between the two first metal segments 301, and is beneficial to reduce the thickness of the power module.

[0083] It should be noted that the first metal segment 301, the second metal segment 302 and the third metal segment 303 are integrally arranged. The thickness of the first metal segment 301 can be equal to the thickness of the second metal segment 302. Further, the thickness of the first metal segment 301, the thickness of the second metal segment 302 and the thickness of the third metal segment 303 are all equal.

[0084] On the basis of the above-mentioned embodiments, the bonding strip 30 is provided with a plurality of strip bonding needle fins on the side away from the power chip, the strip bonding needle fins are used for dissipating the heat generated by the power chip, and the heat dissipation capacity of the power module is improved.

[0085] The application further provides a power module, comprising a substrate, a plurality of power chips and at least one metal clip structure according to any of the embodiments of the 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. The same technical effects are achieved, and details are not repeated here.

[0086] 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.

[0087] Further, the surface metal layer of the substrate 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 at least two upper bridge chips are located on one side of the upper bridge chip contact layer and 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 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. 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 with the alternating current signal transmission layer in the substrate, and each bonding strip 30 is bonded with the lower bridge chip connection layer in the substrate away from the end portion of the bus metal strip; 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 with the second direct current signal transmission layer in the substrate.

[0088] Optionally, the substrate comprises a direct bonding 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 clip bond packaging process to realize the interconnection between the plurality of power chips.

[0089] Optionally, the power chip includes a metal-oxide-semiconductor field effect transistor power chip (MOSFET power chip) or an insulated gate bipolar transistor power chip (IGBT power chip).

[0090] Further, the metal-oxide-semiconductor field effect transistor power chip includes a silicon carbide metal-oxide-semiconductor field effect transistor power chip (SiC MOSFET power chip) or a gallium nitride metal-oxide-semiconductor field effect transistor power chip (GaN MOSFET power chip). The insulated gate bipolar transistor power chip includes a silicon carbide insulated gate bipolar transistor power chip (SiC IGBT power chip) or a gallium nitride insulated gate bipolar transistor power chip (GaN IGBT power chip).

[0091] Exemplarily, the pad connected with the MOSFET power chip drain is fixed to one side of the substrate through a sintering or welding process, the pad connected with the MOSFET power chip source is welded with the bonding surface of the metal clip structure, and then the power chip is encapsulated through the encapsulation layer.

[0092] The application also provides a power conversion circuit including the power module of any of the embodiments of the application, which is 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 herein.

[0093] The application also provides a vehicle including a load and the power conversion circuit of any of the embodiments of the application, which is used for converting alternating current into direct current, converting alternating current into alternating current, converting direct current into direct current, or converting direct current into alternating current and then inputting to the load. The same technical effects are achieved, and thus are not described herein.

[0094] Note 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 those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the protection scope of the application. Therefore, although the application has been described in more 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, located on one side of the bus metal strip and electrically connected to the bus metal strip; at least two bonding strips, located on one side of the bus metal strip and electrically connected to the bus metal strip respectively; The bus end is bonded to the substrate in the power module, and the at least two bonding strips are respectively bonded to at least one power chip in the power module; the connection position of the bus end on the bus metal strip is determined according to the current averaging of the current flowing through the power chips bonded to the at least two bonding strips.

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 power module includes at least two upper bridge power chips and at least two 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 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; When the metal clip structure is bonded to the at least two upper bridge power chips, the metal clip structure is located on a side of the at least two 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 at least two lower bridge power chips, the 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.

4. The metal clip structure according to claim 1, wherein: The bus metal strip, the bus end portion and the at least two bonding strips are integrally arranged.

5. 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; The at least two bonding ribbons are arranged at intervals along the extending direction of the bus metal ribbon.

6. The metal clip structure according to claim 1, characterized in that: When the number of the bonding ribbons is greater than or equal to 3, the number of the confluence ends is greater than or equal to 2.

7. The metal clip structure according to claim 1, wherein: The bus metal strip is planar, and the bonding strip is wavy in the extending direction of the bonding strip; The bonding ribbon includes a plurality of first metal segments and second metal segments alternately arranged in sequence in the extending direction of the bonding ribbon, 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; 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; at least part of the first metal segment is bonded to the power chip, or at least part of the second metal segment is bonded to the power chip.

8. 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 7; Among them, multiple power chips are arranged on the same side of the substrate; the side of the power chip close to the substrate is electrically connected to the substrate; the metal clip structure is located on the side of the power chip away from the substrate, and at least two of the power chips are bonded to the metal clip structure to be connected in parallel through the metal clip structure.

9. The power module according to claim 8, characterized in that: The plurality of power chips include at least two upper bridge chips and at least two lower bridge chips; the power module further includes an upper bridge metal clip structure and a lower bridge metal clip structure; The at least two upper bridge chips are connected in parallel via the upper bridge metal clip structure; and the at least two lower bridge chips are connected in parallel via the lower bridge metal clip structure.

10. The power module according to claim 9, characterized in that: 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 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.

11. The power module according to claim 8, characterized in that: The power chip includes a metal-oxide semiconductor field effect transistor power chip or an insulated gate bipolar transistor power chip.

12. The power module according to claim 11, characterized in that: The metal-oxide semiconductor field effect transistor power chip includes a silicon carbide metal-oxide semiconductor field effect transistor power chip or a gallium nitride metal-oxide semiconductor field effect transistor power chip; The insulated gate bipolar transistor power chip includes a silicon carbide insulated gate bipolar transistor power chip or a gallium nitride insulated gate bipolar transistor power chip.

13. The power module according to claim 8, characterized in that The substrate includes a direct-bonded copper ceramic substrate or an active metal brazed ceramic substrate.

14. A power conversion circuit, characterized in that: The power module comprises the power module according to any one of claims 8 to 13, wherein the power conversion circuit is used for one or more of current conversion, voltage conversion, and power factor correction.

15. A vehicle, characterized in that: It includes a load and the power conversion circuit as claimed in claim 14, 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.

Images