A vertical projection bus type three-level power module

Abstract

The application discloses a vertical projection and current collection type three-level power module, which comprises an insulating packaging structure and a heat-conducting insulating lining plate, a first power current collection conductive layer, a second power current collection conductive layer, a midpoint N current collection conductive layer and an NPC three-level bridge arm unit arranged in the insulating packaging structure. A power switch chip group is arranged between the two power current collection conductive layers, the drain electrode or the collector electrode, the source electrode or the emitter electrode of the chip is connected with the two power current collection conductive layers respectively, and the orthographic projection of the two power current collection conductive layers at least partially overlaps, so as to form a vertical projection and current conversion path. A neutral point clamping diode assembly is arranged between the first power current collection conductive layer and the midpoint N current collection conductive layer, the cathode side and the anode side of the neutral point clamping diode assembly are connected with the two layers respectively, so as to form a neutral point clamping path. The application can shorten the transmission path of main current conversion current and neutral point clamping current, reduce the parasitic inductance, and reduce the voltage peak and electromagnetic interference generated under a high-frequency switch working condition.

Description

Technical Field

[0001] This invention relates to the field of power semiconductor device technology, and in particular to a vertical projection bus type three-level power module. Background Technology

[0002] The three-level neutral point clamped (NPC) topology connects the AC nodes of the bridge arm to the neutral point of the DC bus through neutral point clamping diodes to achieve three-level power conversion. Due to its low voltage requirements and high output waveform quality, it is widely used in power conversion scenarios such as new energy power generation, motor drive and rail transit.

[0003] Existing NPC three-level power modules typically employ a planar bus structure, using wires, lead frames, or multilayer copper-clad conductors to achieve electrical connections between power switching devices, neutral point clamping diodes, and various bus conductors. Because the current paths from the AC node of the bridge arm to the neutral point clamping diode, and from the neutral point clamping diode to the DC bus neutral point, are relatively long, the parasitic inductance of the midpoint freewheeling circuit is large, making it prone to voltage spikes and electromagnetic interference under high-frequency switching conditions. Summary of the Invention

[0004] The purpose of this invention is to propose a vertical projection bus type three-level power module. By placing the power switch chip group between the first power bus conductive layer and the second power bus conductive layer to form a vertical projection commutation path, and placing the neutral point clamping diode assembly between the first power bus conductive layer and the midpoint N bus conductive layer to form a neutral point clamping path, the transmission paths of the main commutation current and the neutral point clamping current are shortened, the parasitic inductance of the commutation circuit and the neutral point clamping circuit is reduced, and the voltage spikes and electromagnetic interference generated under high-frequency switching conditions are reduced.

[0005] To achieve the above objectives, embodiments of the present invention provide a vertical projection bus type three-level power module, including an insulating package structure. The insulating package structure contains a thermally conductive insulating liner, a first power bus conductive layer, a second power bus conductive layer, a midpoint N bus conductive layer, and an NPC three-level bridge arm unit. Each NPC three-level bridge arm unit includes a power switch chipset and a neutral point clamping diode assembly. The first power bus conductive layer is disposed on the thermally conductive insulating substrate, and the power switch chip group is disposed between the first power bus conductive layer and the second power bus conductive layer; the drain or collector of each power switch chip in the power switch chip group is electrically connected to the first power bus conductive layer, and the source or emitter of each power switch chip is electrically connected to the second power bus conductive layer; the orthographic projections of the first power bus conductive layer and the second power bus conductive layer on the thermally conductive insulating substrate at least partially overlap to form a vertical projection commutation path passing through the first power bus conductive layer, the power switch chip group and the second power bus conductive layer; The neutral point clamping diode assembly is disposed on the side of the first power bus conductive layer away from the thermally conductive insulating liner, and is located between the first power bus conductive layer and the midpoint N bus conductive layer; the neutral point clamping diode assembly has a cathode-side electrode surface and an anode-side electrode surface disposed opposite to each other, the cathode-side electrode surface is electrically connected to the first power bus conductive layer, and the anode-side electrode surface is electrically connected to the midpoint N bus conductive layer, so as to form a neutral point clamping path passing through the first power bus conductive layer, the neutral point clamping diode assembly, and the midpoint N bus conductive layer.

[0006] In this embodiment, by stacking the first power bus conductive layer and the second power bus conductive layer in a vertical direction, and placing the neutral point clamping diode assembly between the first power bus conductive layer and the midpoint N bus conductive layer, the main commutation path and the neutral point clamping path are shortened, the circuit parasitic inductance is reduced, and voltage spikes and electromagnetic interference during high-frequency switching are reduced.

[0007] Furthermore, the power switch chipset includes a high-side power switch chipset and a low-side power switch chipset; The first power bus conductive layer includes a DC positive bus region, a first bridge arm AC bus region, and a first DC negative bus region that are electrically isolated from each other; the second power bus conductive layer includes a second bridge arm AC bus region and a second DC negative bus region that are electrically isolated from each other. The drain or collector of the high-side power switch chip group is electrically connected to the DC positive bus region, and the source or emitter of the high-side power switch chip group is electrically connected to the second bridge arm AC bus region. The DC positive bus region and the second bridge arm AC bus region at least partially overlap on the orthographic projection of the thermally conductive insulating substrate, so that the DC positive bus region, the high-side power switch chip group and the second bridge arm AC bus region are electrically connected in sequence to form a high-side commutation branch. The drain or collector of the low-side power switch chip group is electrically connected to the first bridge arm AC bus region, and the source or emitter of the low-side power switch chip group is electrically connected to the second DC negative bus region. The orthogonal projections of the first bridge arm AC bus region and the second DC negative bus region on the thermally conductive insulating substrate at least partially overlap, so that the first bridge arm AC bus region, the low-side power switch chip group and the second DC negative bus region are sequentially electrically connected to form a low-side commutation branch. The cathode side electrode of the neutral point clamping diode assembly is electrically connected to the first bridge arm AC bus region, and the anode side electrode of the neutral point clamping diode assembly is electrically connected to the midpoint N bus conductive layer, so that the first bridge arm AC bus region, the neutral point clamping diode assembly and the midpoint N bus conductive layer are sequentially electrically connected to form the neutral point clamping branch.

[0008] In this embodiment, the stability of three-level power conversion is improved by constructing a high-side commutation branch, a low-side commutation branch, and a neutral point clamping branch respectively.

[0009] Furthermore, the cathode-side electrode surface and the anode-side electrode surface of the neutral point clamping diode assembly are both parallel to the thermally conductive insulating liner and are located between the high-side power switch chip group and the low-side power switch chip group. The cathode-side electrode surface of the neutral point clamping diode assembly is integrally sintered on the side surface of the first bridge arm AC busbar region away from the thermally conductive insulating liner; the anode-side electrode surface of the neutral point clamping diode assembly is integrally sintered on the midpoint N busbar conductive layer.

[0010] In this embodiment, the cathode-side electrode surface and anode-side electrode surface of the neutral point clamping diode assembly are integrally sintered in the AC busbar region of the first bridge arm and the midpoint N busbar conductive layer, respectively, thereby increasing the conductive contact area and reducing the contact resistance and contact thermal resistance of the neutral point clamping branch.

[0011] Furthermore, the midpoint N bus conductive layer is insulated from the first power bus conductive layer and the second power bus conductive layer, and is electrically connected to the first bridge arm AC bus region in the first power bus conductive layer through the neutral point clamping diode assembly; The vertical projection bus type three-level power module also includes a midpoint power terminal, and the midpoint N bus conductive layer is electrically connected to the neutral point of the external DC bus through the midpoint power terminal.

[0012] In this embodiment, by isolating the midpoint N bus conductive layer from other power bus conductive layers and connecting it to the neutral point of the external DC bus via the midpoint power terminal, a reliable connection between the neutral point clamping branch and the neutral point of the external DC bus is achieved.

[0013] Furthermore, the first power bus conductive layer includes at least two mutually spaced and electrically isolated first bus branch regions, and the second power bus conductive layer includes at least two mutually spaced and electrically isolated second bus branch regions, with each first bus branch region corresponding to each second bus branch region. Each of the first bus branch regions includes a DC positive bus region, a first bridge arm AC bus region, and a first DC negative bus region; each of the second bus branch regions includes a second bridge arm AC bus region and a second DC negative bus region. The high-side power switch chip group includes at least two high-side power switch chip subgroups, and the low-side power switch chip group includes at least two low-side power switch chip subgroups. Each of the high-side power switch chip subgroups, each of the low-side power switch chip subgroups, each of the first bus branch regions, and each of the second bus branch regions are configured in a one-to-one correspondence. The NPC three-level bridge arm unit includes at least two neutral point clamping diode assemblies. Each neutral point clamping diode assembly is configured in one-to-one correspondence with each first bridge arm AC bus region and is electrically connected between the corresponding first bridge arm AC bus region and the midpoint N bus conductive layer. Each of the first bus branch regions, the corresponding second bus branch regions, the corresponding high-side power switch chip subgroup, the corresponding low-side power switch chip subgroup, and the corresponding neutral point clamping diode assembly together constitute an independent commutation branch.

[0014] In this embodiment, by setting up multiple electrically isolated independent converter branches, fault branch isolation is achieved, thereby improving the operational stability and fault tolerance of the power module.

[0015] Furthermore, the insulating encapsulation structure also includes a functional integration layer, which comprises multiple electrically isolated branch control units. Each branch control unit is electrically connected to the corresponding independent converter branch and is used to drive and control the corresponding independent converter branch and collect its operating status.

[0016] In this embodiment, by setting up branch control units that are electrically isolated from each other for each independent converter branch, independent drive control and operation status acquisition of each independent converter branch can be realized.

[0017] Furthermore, the functional integration layer also includes a driving unit and a fault logic discrimination unit; The drive unit is electrically connected to each of the branch control units and is used to generate drive signals for the power switch chip group in each of the independent converter branches according to the corresponding control signals. The fault logic discrimination unit is electrically connected to each of the branch control units and is used to determine the target independent converter branch that has failed based on the collected operating status data of each independent converter branch.

[0018] In this embodiment, the drive unit generates drive signals for each independent commutator branch in a unified manner, and the faulty branch is identified by the fault logic discrimination unit, thereby improving the accuracy of multi-branch drive control and fault location.

[0019] Furthermore, each of the aforementioned independent converter branches is provided with an independent power terminal group; The independent power terminal group includes a DC positive power terminal, an AC power terminal, and a DC negative power terminal; The DC positive power terminal is electrically connected to the DC positive busbar region in the corresponding independent converter branch, the AC power terminal is electrically connected to the first bridge arm AC busbar region and the second bridge arm AC busbar region in the corresponding independent converter branch, and the DC negative power terminal is electrically connected to the first DC negative busbar region and the second DC negative busbar region in the corresponding independent converter branch.

[0020] In this embodiment, independent power input and output of each independent converter branch are achieved by configuring independent power terminal groups for each independent converter branch.

[0021] Furthermore, each of the aforementioned independent converter branches is provided with an independent thermally conductive insulating liner; The independent thermally conductive insulating liner covers the area below the DC positive busbar region, the first bridge arm AC busbar region, and the first DC negative busbar region of the independent converter branch.

[0022] In this embodiment, by setting an independent thermally conductive insulating liner for each independent converter branch, the lateral thermal coupling between different converter branches is reduced, and the uniformity of heat dissipation of each branch is improved.

[0023] Furthermore, the drain or collector of the NPC three-level bridge arm unit is electrically connected to the first power bus conductive layer through an interconnect layer; or, the drain or collector of the NPC three-level bridge arm unit is electrically connected to the first power bus conductive layer through a conductive connector, and the drain or collector of the NPC three-level bridge arm unit is connected to the conductive connector through an interconnect layer. The source or emitter of the NPC three-level bridge arm unit is electrically connected to the second power bus conductive layer through an interconnect layer.

[0024] In this embodiment, the electrical connection between the power switch chip and the power bus conductive layer is achieved through an interconnect layer or conductive connector, thereby improving the reliability of the electrical connection.

[0025] Furthermore, the vertical projection bus power module also includes at least one heat dissipation device; The heat dissipation device is thermally connected to the surface of the thermally conductive insulating liner that is away from the first power busbar conductive layer; and / or, at least one of the heat dissipation devices is connected to the surface of the second power busbar conductive layer that is away from the first power busbar conductive layer through a thermally conductive medium.

[0026] In this embodiment, a heat dissipation device is provided on the side of the thermally conductive insulating liner to improve the heat dissipation capacity of the power module.

[0027] Furthermore, the insulating encapsulation structure is further provided with a first insulating layer, a second insulating layer, and a third insulating layer; The outer side of the thermally conductive insulating liner and the outer side of the first power bus conductive layer are surrounded by the first insulating layer. The third insulating layer is disposed on the surface of the second power bus conductive layer away from the first power bus conductive layer; The second insulating layer is disposed in the gap region between the first insulating layer and the third insulating layer.

[0028] In this embodiment, different areas inside the module are insulated by a first insulating layer, a second insulating layer, and a third insulating layer, thereby improving the insulation reliability between conductive structures and between conductive structures and the external environment. Attached Figure Description

[0029] Figure 1 This is a cross-sectional structural schematic diagram of a preferred embodiment of the vertical projection bus type three-level power module with a single-sided heat dissipation structure in this invention; Figure 2 This is a top view of the multi-branch isolation layout of the first power bus conductive layer in this invention; Figure 3 This is a top view of the multi-branch isolation layout of the second power bus conductive layer in this invention; Figure 4 This is a cross-sectional structural diagram of a preferred embodiment of the vertical projection bus type three-level power module with a double-sided heat dissipation structure in this invention.

[0030] The components include: 1. First power bus conductive layer; 101. DC positive bus region; 102. First bridge arm AC bus region; 103. First DC negative bus region; 2. Second power bus conductive layer; 201. Second bridge arm AC bus region; 202. Second DC negative bus region; 3. Thermally conductive insulating liner; 4. High-side power switch chipset; 5. Low-side power switch chipset; 6. Heat dissipation device; 7. DC positive power terminal; 8. AC power terminal; 9. DC negative power terminal; 10. Functional integration layer; 11. 11. First insulating layer; 12. Second insulating layer; 13. Third insulating layer; 14. Interconnect layer; 15. Connecting hole; 16. Thermally conductive medium; 18. Midpoint N-bus conductive layer; 19. Neutral point clamping diode assembly; 301. DC positive bus region; 302. First bridge arm AC bus region; 303. First DC negative bus region; 304. First bus branch region; 401. Second bridge arm AC bus region; 402. Second DC negative bus region; 403. Second bus branch region. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that the data involved in this invention (including but not limited to data used for analysis, data stored, data displayed, etc.) are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of related data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0033] In this embodiment of the invention, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplarily" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0034] In this invention description, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In this invention description, unless otherwise stated, "a plurality of" means two or more. In this invention description, the term "comprising" and its variations are open-ended, meaning "including but not limited to." The term "based on" means "at least partially based on." The term "according to" means "at least partially according to." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments."

[0035] In the description of this invention, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The technical solution of the present invention will be further described below with reference to specific embodiments: See Figure 1 This is a cross-sectional structural diagram of a preferred embodiment of the vertical projection bus type three-level power module with a single-sided heat dissipation structure in this invention. It includes a thermally conductive insulating liner 3, a first power bus conductive layer 1, a second power bus conductive layer 2, a midpoint N bus conductive layer 18, and an NPC three-level bridge arm unit disposed within an insulating encapsulation structure. The NPC three-level bridge arm unit includes a power switch chipset and a neutral point clamping diode assembly 19. Figure 1 The power switch chipset shown includes at least a high-side power switch chipset 4 and a low-side power switch chipset 5.

[0037] A first power bus conductive layer 1 is disposed on a thermally conductive insulating substrate 3, and a power switch chip assembly is disposed between the first power bus conductive layer 1 and the second power bus conductive layer 2. Each power switch chip in the power switch chip assembly has a first power electrode and a second power electrode disposed opposite to each other. Specifically, when the power switch chip is a metal-oxide-semiconductor field-effect transistor chip, the first power electrode and the second power electrode are the drain and the source, respectively; when the power switch chip is an insulated-gate bipolar transistor chip, the first power electrode and the second power electrode are the collector and the emitter, respectively.

[0038] The drain or collector of each power switch chip is electrically connected to the first power bus conductive layer 1, and the source or emitter of each power switch chip is electrically connected to the second power bus conductive layer 2. Specifically, each power switch chip and its corresponding power bus conductive layer are electrically connected through an interconnect layer 14. The interconnect layer 14 is disposed between the power electrode of the power switch chip and the corresponding power bus conductive layer to form a conductive connection between them.

[0039] The first power bus conductive layer 1 is located on the side of the power switch chip assembly facing the thermally conductive insulating substrate 3, and the second power bus conductive layer 2 is located on the side of the power switch chip assembly away from the thermally conductive insulating substrate 3. The first power bus conductive layer 1, the power switch chip assembly, and the second power bus conductive layer 2 are arranged sequentially along the thickness direction of the thermally conductive insulating substrate 3, such that the orthographic projections of the first power bus conductive layer 1 and the second power bus conductive layer 2 on the thermally conductive insulating substrate 3 at least partially overlap. Therefore, power current can be transmitted sequentially through the first power bus conductive layer 1, the power switch chip assembly, and the second power bus conductive layer 2 to form a vertical projection commutation path.

[0040] It is understandable that the first power bus conductive layer 1 and the second power bus conductive layer 2 adopt a vertical projection overlapping layout, which can reduce the lateral connection distance between the two power bus conductive structures and reduce the loop area enclosed by the converter path.

[0041] A neutral point clamping diode assembly 19 is disposed on the side of the first power bus conductive layer 1 facing away from the thermally conductive insulating substrate 3, and is located between the first power bus conductive layer 1 and the midpoint N bus conductive layer 18. The neutral point clamping diode assembly 19 has a cathode-side electrode surface and an anode-side electrode surface disposed opposite to each other along the module stacking direction. The cathode-side electrode surface faces and is electrically connected to the first power bus conductive layer 1, and the anode-side electrode surface faces and is electrically connected to the midpoint N bus conductive layer 18. Based on this structure, the neutral point clamping current is transmitted sequentially through the first power bus conductive layer 1, the neutral point clamping diode assembly 19, and the midpoint N bus conductive layer 18 to form a neutral point clamping path.

[0042] Understandably, the neutral point clamping diode assembly 19 is directly disposed between the first power bus conductive layer 1 and the midpoint N bus conductive layer 18, which can reduce the distance that the neutral point clamping current is transmitted along the horizontal direction of the module.

[0043] The thermally conductive insulating liner 3 serves to support the first power bus conductive layer 1 and provides insulation and thermal conductivity between the first power bus conductive layer 1 and the external structure of the module. At least part of the heat generated during the operation of the power switch chipset and the neutral point clamping diode assembly 19 can be transferred outward through the first power bus conductive layer 1 and the thermally conductive insulating liner 3.

[0044] The insulating encapsulation structure is used to encapsulate the thermally conductive insulating liner 3, the first power bus conductive layer 1, the second power bus conductive layer 2, the midpoint N bus conductive layer 18, and the NPC three-level bridge arm unit into one unit, and to provide insulation protection for the conductive structures with different potentials inside the module.

[0045] It should be noted that the orthographic projections of the first power busbar conductive layer 1 and the second power busbar conductive layer 2 on the thermally conductive insulating liner 3 at least partially overlap. This means that when the first power busbar conductive layer 1 and the second power busbar conductive layer 2 are projected onto the plane of the thermally conductive insulating liner 3 along a direction perpendicular to the thermally conductive insulating liner 3, there is an overlap between the projection areas of the first power busbar conductive layer 1 and the second power busbar conductive layer 2.

[0046] It should be noted that the vertical projection commutation path is defined by the stacking position relationship between the first power bus conductive layer 1, the power switch chip group, and the second power bus conductive layer 2. It does not mean that the power current can only flow in a straight line strictly perpendicular to the thermally conductive insulating liner 3 within each conductive structure. The vertical projection commutation path is formed as long as the first power bus conductive layer 1 and the second power bus conductive layer 2 form at least partial projection overlap and a commutation electrical connection is formed through the power switch chip group located between them.

[0047] It should be noted that the neutral point clamping path and the vertical projection commutation path perform different current transmission functions. The vertical projection commutation path is used to transmit the main commutation current in the NPC three-level bridge arm unit, while the neutral point clamping path is used to connect the AC node of the bridge arm to the DC bus neutral point in the corresponding switching state to achieve neutral point clamping.

[0048] It should be noted that the power switch chipset in this embodiment includes at least one power switch chip. The specific number of chips, chip type, and number of chips connected in parallel are determined according to the rated voltage, rated current, and power level of the power module, and do not constitute a limitation on the scope of protection of this invention.

[0049] It is understandable that this embodiment, through the cooperation of the vertical projection commutation path and the neutral point clamping path, achieves NPC three-level power conversion while shortening the transmission path of the main commutation current and the neutral point clamping current, reducing the parasitic inductance of the corresponding circuit, and thus suppressing voltage spikes and electromagnetic interference under high-frequency switching conditions.

[0050] In another preferred embodiment, see Figure 1 The power switch chipset includes a high-side power switch chipset 4 and a low-side power switch chipset 5.

[0051] The first power bus conductive layer 1 includes a DC positive bus region 101, a first bridge arm AC bus region 102, and a first DC negative bus region 103, which are electrically isolated from each other. The second power bus conductive layer 2 includes a second bridge arm AC bus region 201 and a second DC negative bus region 202, which are electrically isolated from each other. The DC positive bus region 101, the first bridge arm AC bus region 102, and the first DC negative bus region 103 are respectively arranged according to the power circuit connection relationship of the NPC three-level bridge arm unit. The second bridge arm AC bus region 201 and the second DC negative bus region 202 are located on the side of the power switch chip group away from the thermally conductive insulating substrate 3.

[0052] The high-side power switch chip group 4 is disposed between the DC positive bus region 101 and the second bridge arm AC bus region 201. The drain or collector of each high-side power switch chip in the high-side power switch chip group 4 is electrically connected to the DC positive bus region 101, and the source or emitter of each high-side power switch chip is electrically connected to the second bridge arm AC bus region 201.

[0053] The orthographic projections of the DC positive busbar 101 and the second bridge arm AC busbar 201 on the thermally conductive insulating liner 3 at least partially overlap, thereby sequentially connecting the DC positive busbar 101, the high-side power switch chip group 4, and the second bridge arm AC busbar 201 to form a high-side commutation branch. The power current in the high-side commutation branch can be transmitted along the vertical projection path formed by the DC positive busbar 101, the high-side power switch chip group 4, and the second bridge arm AC busbar 201.

[0054] The low-side power switch chip group 5 is disposed between the first bridge arm AC bus region 102 and the second DC negative bus region 202. The drain or collector of each low-side power switch chip in the low-side power switch chip group 5 is electrically connected to the first bridge arm AC bus region 102, and the source or emitter of each low-side power switch chip is electrically connected to the second DC negative bus region 202.

[0055] The orthogonal projections of the first bridge arm AC combiner 102 and the second DC negative combiner 202 on the thermally conductive insulating liner 3 at least partially overlap, thereby sequentially connecting the first bridge arm AC combiner 102, the low-side power switch chip group 5, and the second DC negative combiner 202 to form a low-side commutation branch. The power current in the low-side commutation branch can be transmitted along the vertical projection path formed by the first bridge arm AC combiner 102, the low-side power switch chip group 5, and the second DC negative combiner 202.

[0056] A neutral point clamping diode assembly 19 is disposed between the first bridge arm AC bus region 102 and the midpoint N bus conductive layer 18. The cathode side electrode surface of the neutral point clamping diode assembly 19 is electrically connected to the first bridge arm AC bus region 102, and the anode side electrode surface is electrically connected to the midpoint N bus conductive layer 18, thereby sequentially connecting the first bridge arm AC bus region 102, the neutral point clamping diode assembly 19, and the midpoint N bus conductive layer 18 to form a neutral point clamping branch.

[0057] The neutral point clamping branch is used to connect the AC node of the first bridge arm AC bus region 102 to the neutral point N bus conductive layer 18 in the corresponding switching state, so as to realize the neutral point clamping of the NPC three-level bridge arm unit.

[0058] Both the high-side power switch chipset 4 and the low-side power switch chipset 5 include at least one power switch chip. The number of power switch chips in the high-side power switch chipset 4 and the low-side power switch chipset 5 is determined based on the rated current and power rating of the vertical projection bus-type three-level power module. When the power switch chip is a metal-oxide-semiconductor field-effect transistor chip, it is electrically connected to the corresponding bus region through its drain and source, respectively; when the power switch chip is an insulated-gate bipolar transistor chip, it is electrically connected to the corresponding bus region through its collector and emitter, respectively.

[0059] The DC positive bus region 101 is used to connect to the positive terminal of the external DC bus, and the first DC negative bus region 103 and the second DC negative bus region 202 are used to form a power connection structure corresponding to the negative terminal of the external DC bus. The first bridge arm AC bus region 102 and the second bridge arm AC bus region 201 together correspond to the bridge arm AC node of the NPC three-level bridge arm unit.

[0060] The first bridge arm AC bus region 102 is located in the first power bus conductive layer 1, and the second bridge arm AC bus region 201 is located in the second power bus conductive layer 2. These two belong to different levels of bridge arm AC bus structures and together form the power bus path on the AC output side according to the connection relationship of the NPC three-level bridge arm units.

[0061] The first DC negative bus region 103 belongs to the conductive region in the first power bus conductive layer 1, and the second DC negative bus region 202 belongs to the conductive region in the second power bus conductive layer 2. The first DC negative bus region 103 is used to form the bottom bus structure on the DC negative side, and the second DC negative bus region 202 is used to connect to the source or emitter of the low-side power switch chip group 5.

[0062] It should be noted that the high-side commutator branch and the low-side commutator branch correspond to different main power commutation paths in the NPC three-level bridge arm unit.

[0063] It is understandable that by arranging the DC positive busbar 101 and the second bridge arm AC busbar 201 correspondingly along both sides of the power switch chip and making their orthogonal projections at least partially overlap, the connection path of the high-side commutator branch can be shortened; by arranging the first bridge arm AC busbar 102 and the second DC negative busbar 202 correspondingly along both sides of the low-side power switch chip group 5 and making their orthogonal projections at least partially overlap, the connection path of the low-side commutator branch can be shortened.

[0064] Understandably, both the high-side and low-side converter branches adopt a vertical projection bus structure, which can reduce the lateral extension distance of the main power converter path and the converter loop area, thereby reducing the parasitic inductance of the main power converter loop.

[0065] In yet another preferred embodiment, see Figure 1 The neutral point clamping diode assembly 19 is disposed between the high-side power switch chip group 4 and the low-side power switch chip group 5. The neutral point clamping diode assembly 19 has a cathode side electrode surface and an anode side electrode surface disposed opposite to each other. Both the cathode side electrode surface and the anode side electrode surface are disposed parallel to the thermally conductive insulating liner 3.

[0066] The cathode-side electrode of the neutral point clamping diode assembly 19 faces the first bridge arm AC bus region 102 and is integrally planar sintered on the side surface of the first bridge arm AC bus region 102 away from the thermally conductive insulating liner 3; the anode-side electrode of the neutral point clamping diode assembly 19 faces the midpoint N bus conductive layer 18 and is integrally planar sintered on the midpoint N bus conductive layer 18. Thus, the first bridge arm AC bus region 102, the neutral point clamping diode assembly 19, and the midpoint N bus conductive layer 18 are sequentially connected along the stacking direction of the module to form a neutral point clamping branch.

[0067] The neutral point clamping diode assembly 19 is located between the high-side power switch chip group 4 and the low-side power switch chip group 5. This means that the neutral point clamping diode assembly 19 is positioned on the plane of the thermally conductive insulating substrate 3 between the arrangement areas of the high-side power switch chip group 4 and the low-side power switch chip group 5. This arrangement brings the neutral point clamping diode assembly 19 close to the AC node of the first bridge arm AC combiner area 102, reducing the extension distance of the neutral point clamping branch along the surface of the thermally conductive insulating substrate 3.

[0068] In this design, both the cathode-side electrode surface and the anode-side electrode surface of the neutral point clamping diode assembly 19 are parallel to the thermally conductive insulating liner 3, so that the neutral point clamping diode assembly 19 is arranged in a planar stacked form between the first bridge arm AC bus region 102 and the midpoint N bus conductive layer 18. The neutral point clamping current enters the neutral point clamping diode assembly 19 from the first bridge arm AC bus region 102 via the cathode-side electrode surface, and is transmitted to the midpoint N bus conductive layer 18 via the anode-side electrode surface.

[0069] Specifically, the entire planar surface of the cathode-side electrode surface is sintered onto the first bridge arm AC busbar region 102. This means that the effective electrode area of ​​the cathode-side electrode surface forms a surface contact electrical connection with the first bridge arm AC busbar region 102 through a sintering connection method, rather than only being electrically connected to the first bridge arm AC busbar region 102 through a local connection point. Correspondingly, the entire planar surface of the anode-side electrode surface is sintered onto the midpoint N busbar conductive layer 18. This means that the effective electrode area of ​​the anode-side electrode surface forms a surface contact electrical connection with the midpoint N busbar conductive layer 18 through a sintering connection method.

[0070] It is understandable that the sintered connection area formed by the overall planar sintering simultaneously undertakes the functions of electrical and thermal conductivity. Specifically, the heat generated by the neutral point clamping diode assembly 19 can be transferred to the first bridge arm AC busbar region 102 via the cathode side electrode surface and to the midpoint N busbar conductive layer 18 via the anode side electrode surface, thereby forming heat transfer paths toward both sides of the neutral point clamping diode assembly 19.

[0071] It should be noted that the overall planar sintering referred to in this embodiment is different from local connection methods such as metal bonding wires, local solder joints, or metal through holes.

[0072] It should be noted that the cathode side electrode surface of the neutral point clamping diode assembly 19 is connected to the first bridge arm AC bus region 102, so that the neutral point clamping diode assembly 19 and the low-side power switch chip group 5 share the bridge arm AC node corresponding to the first bridge arm AC bus region 102; the anode side electrode surface of the neutral point clamping diode assembly 19 is connected to the midpoint N bus conductive layer 18, so that the bridge arm AC node can establish a clamping connection with the DC bus neutral point according to the working state of the NPC three-level topology.

[0073] In yet another preferred embodiment, see Figure 1 The midpoint N bus conductive layer 18 is insulated from the first power bus conductive layer 1 and the second power bus conductive layer 2, and is electrically connected to the first bridge arm AC bus region 102 in the first power bus conductive layer 1 through the neutral point clamping diode assembly 19.

[0074] Specifically, the neutral point clamping diode assembly 19 is disposed between the first bridge arm AC bus region 102 and the midpoint N bus conductive layer 18. The cathode side electrode surface of the neutral point clamping diode assembly 19 is electrically connected to the first bridge arm AC bus region 102, and the anode side electrode surface of the neutral point clamping diode assembly 19 is electrically connected to the midpoint N bus conductive layer 18, thereby forming a neutral point clamping branch in sequence from the first bridge arm AC bus region 102, the neutral point clamping diode assembly 19, and the midpoint N bus conductive layer 18.

[0075] The vertical projection bus type three-level power module also includes a midpoint power terminal N. The midpoint N bus conductive layer 18 is electrically connected to the midpoint power terminal N, which is used to connect to the neutral point of the external DC bus. Thus, the midpoint N bus conductive layer 18 is led out to the outside of the insulating package structure through the midpoint power terminal, so that the neutral point clamping branch can establish a power connection with the neutral point of the external DC bus.

[0076] The midpoint N-bus conductive layer 18 is a conductive structure used to transmit and collect neutral point clamping current. The neutral point clamping current can be transmitted between the first bridge arm AC bus region 102, the neutral point clamping diode assembly 19, the midpoint N-bus conductive layer 18, and the midpoint power terminal, enabling the bridge arm AC node corresponding to the first bridge arm AC bus region 102 to be connected to the neutral point of the external DC bus according to the operating state of the NPC three-level topology.

[0077] The fact that the midpoint N bus conductive layer 18 is insulated from the first power bus conductive layer 1 means that, except for the midpoint N bus conductive layer 18 forming a predetermined electrical connection with the first bridge arm AC bus region 102 through the neutral point clamping diode assembly 19, no other part of the midpoint N bus conductive layer 18 and the first power bus conductive layer 1 form a direct conductive connection.

[0078] The midpoint N bus conductive layer 18 and the second power bus conductive layer 2 are insulated from each other. This means that the midpoint N bus conductive layer 18 is separated from the second bridge arm AC bus region 201 and the second DC negative bus region 202 by insulation structures, so as to avoid unexpected conduction between the midpoint N bus conductive layer 18 and the second power bus conductive layer 2.

[0079] In yet another preferred embodiment, see Figure 2 and Figure 3 , Figure 2 This is a top view of the multi-branch isolation layout of the first power bus conductive layer 1. Figure 3This is a top view of the multi-branch isolation layout of the second power bus conductive layer 2. The first power bus conductive layer 1 includes at least two mutually spaced and electrically isolated first bus branch regions 304, and the second power bus conductive layer 2 includes at least two mutually spaced and electrically isolated second bus branch regions 403. Each first bus branch region 304 and each second bus branch region 403 are arranged in a one-to-one correspondence.

[0080] Each first bus branch region 304 includes a DC positive bus sub-region 301, a first bridge arm AC bus sub-region 302, and a first DC negative bus sub-region 303; each second bus branch region 403 includes a second bridge arm AC bus sub-region 401 and a second DC negative bus sub-region 402. The high-side power switch chip group 4 includes at least two high-side power switch chip sub-groups, and the low-side power switch chip group 5 includes at least two low-side power switch chip sub-groups. Each high-side power switch chip sub-group, each low-side power switch chip sub-group, each first bus branch region 304, and each second bus branch region 403 are configured in a one-to-one correspondence.

[0081] Each high-side power switch chip subgroup is electrically connected between the corresponding DC positive bus region 301 and the second bridge arm AC bus region 401; each low-side power switch chip subgroup is electrically connected between the corresponding first bridge arm AC bus region 302 and the second DC negative bus region 402.

[0082] The NPC three-level bridge arm unit includes at least two neutral point clamping diode assemblies 19. Each neutral point clamping diode assembly 19 is configured in a one-to-one correspondence with each first bridge arm AC bus sub-region 302 and is electrically connected between the corresponding first bridge arm AC bus sub-region 302 and the midpoint N bus conductive layer 18.

[0083] Thus, each first bus branch region 304, the corresponding second bus branch region 403, the corresponding high-side power switch chip subgroup, the corresponding low-side power switch chip subgroup, and the corresponding neutral point clamping diode assembly 19 together constitute an independent commutation branch.

[0084] in, Figure 2 and Figure 3 Three first bus branch areas 304 and three second bus branch areas 403 are illustrated, with each first bus branch area 304 and each second bus branch area 403 corresponding to one another in terms of location. The different first bus branch areas 304 are electrically isolated from each other, and the different second bus branch areas 403 are electrically isolated from each other, allowing each independent converter branch to form a relatively independent power transmission path. It should be noted that the specific number of independent converter branches is set according to the power rating and current carrying capacity requirements of the power module.

[0085] It should be noted that each neutral point clamping diode assembly 19 corresponds to a first bridge arm AC bus region 302, but each neutral point clamping diode assembly 19 is electrically connected to the midpoint N bus conductive layer 18. Therefore, each independent commutation branch has a corresponding neutral point clamping diode assembly 19 and shares the midpoint N bus conductive layer 18.

[0086] In yet another preferred embodiment, see Figure 1 The insulating encapsulation structure also includes a functional integration layer 10. The functional integration layer 10 includes multiple electrically isolated branch control units, each branch control unit being configured one-to-one with each independent converter branch and electrically connected to the corresponding independent converter branch.

[0087] Each branch control unit is used to transmit drive signals to the corresponding independent converter branch to control the power switch chip in the independent converter branch to turn on or off; at the same time, each branch control unit is also used to collect the operating status of the corresponding independent converter branch to obtain the operating status collection results of each independent converter branch.

[0088] The functional integration layer 10 includes a signal routing layer, a branch current sampling circuit, a chip temperature acquisition circuit, a bus voltage detection circuit, and a hardware fault isolation circuit. Specifically, the branch current sampling circuit collects the current status of the corresponding independent commutation branch, the chip temperature acquisition circuit collects the temperature status of the power switch chip in the corresponding independent commutation branch, and the bus voltage detection circuit detects the bus voltage status of the power module.

[0089] The gate and Kelvin terminals of the power switch chip are connected to the signal wiring layer through connection hole 15 to form a signal transmission channel between the power switch chip and the corresponding branch control unit. The signal wiring layer is used to transmit the drive signals of the power switch chip and the corresponding operating status acquisition signals.

[0090] When the branch current sampling circuit detects an overcurrent fault in the corresponding independent converter branch, or the chip temperature acquisition circuit detects an overtemperature fault in the corresponding independent converter branch, the hardware fault isolation circuit shuts off all drive signals for that independent converter branch, causing it to stop power output. The remaining independent converter branches that have not experienced a fault continue to operate and maintain derating output to achieve limp-out operation of the power module.

[0091] Each branch control unit includes at least a signal wiring section connected to the corresponding independent converter branch, a branch current sampling section, and a chip temperature acquisition section, so as to realize drive signal transmission, branch current acquisition, and power switch chip temperature acquisition, respectively.

[0092] The hardware fault isolation circuit is used to quickly shut down the faulty independent commutator branch when an overcurrent or overtemperature fault is detected. In some embodiments, the hardware fault isolation circuit shuts down all drive signals of the faulty branch within a microsecond time range to reduce the duration of the fault and the risk of fault propagation.

[0093] It should be noted that the branch control unit corresponds one-to-one with the independent converter branch. This means that each branch control unit is mainly used to drive and control the corresponding independent converter branch and collect its operating status, so as to distinguish the drive signals and operating status collection results of different independent converter branches.

[0094] In yet another preferred embodiment, the functional integration layer 10 further includes a driving unit and a fault logic discrimination unit.

[0095] The drive unit is electrically connected to each branch control unit to receive control signals corresponding to each independent converter branch and generate drive signals for the power switch chip group in each independent converter branch based on the corresponding control signals. Each drive signal is transmitted to the gate of the corresponding power switch chip through the corresponding branch control unit and signal wiring layer to control the corresponding power switch chip to turn on or off.

[0096] The fault logic discrimination unit is electrically connected to each branch control unit to receive the operating status acquisition results output by each branch control unit, and to determine the target independent converter branch where the fault has occurred based on the branch current status and chip temperature status corresponding to each independent converter branch.

[0097] In yet another preferred embodiment, see Figure 2 and Figure 3 Each independent converter branch is equipped with an independent power terminal group. Each independent power terminal group is electrically connected to the busbar area in the corresponding independent converter branch to form an independent power connection between each independent converter branch and the external power circuit of the module.

[0098] Each independent power terminal group includes a DC positive power terminal 7, an AC power terminal 8, and a DC negative power terminal 9.

[0099] The DC positive power terminal 7 is electrically connected to the DC positive busbar region 301 in the corresponding independent converter branch, and is used to lead the DC positive side of the independent converter branch to the outside of the insulating encapsulation structure.

[0100] The AC power terminal 8 is electrically connected to the first arm AC busbar region 302 and the second arm AC busbar region 401 in the corresponding independent converter branch, respectively, so as to connect the two arm AC busbar regions in the same independent converter branch to the corresponding AC power terminal 8 and form the AC side power interface of the independent converter branch.

[0101] The DC negative power terminal 9 is electrically connected to the first DC negative bus region 303 and the second DC negative bus region 402 in the corresponding independent converter branch, so as to connect the two DC negative bus regions in the same independent converter branch to the corresponding DC negative power terminal 9 and form the DC negative side power interface of the independent converter branch.

[0102] in, Figure 2 The DC positive power terminal 7, AC power terminal 8 and DC negative power terminal 9 corresponding to each first bus branch area 304 are shown; Figure 3 The diagram shows the slotted area reserved for the DC positive power terminal 7 in the second power bus conductive layer 2, as well as the connection positions of each second bridge arm AC bus region 401 and the second DC negative bus region 402 with the corresponding power terminal.

[0103] Each independent power terminal group is configured to correspond one-to-one with each independent converter branch, so that each independent converter branch has an independent DC positive side, AC side and DC negative side power connection interface.

[0104] It should be noted that each independent power terminal group corresponds to an independent converter branch, and the power terminal groups of different independent converter branches are independent of each other within the module. When the independent converter branches need to be connected in parallel, the corresponding power terminals are connected through the bus structure outside the module. By setting an independent power terminal group for each independent converter branch, it is possible to avoid different independent converter branches directly sharing power terminals within the module, thereby maintaining the independence of the power transmission path of each independent converter branch.

[0105] In yet another preferred embodiment, see Figure 1 Each independent converter branch is equipped with an independent thermally conductive insulating liner 3. The independent thermally conductive insulating liner 3 are spaced apart from each other and respectively support the first busbar area 304 and related power devices in the corresponding independent converter branch.

[0106] An independent thermally conductive insulating liner 3 covers the DC positive terminal busbar region 301, the first bridge arm AC busbar region 302, and the first DC negative terminal busbar region 303 of the corresponding independent converter branch, and is used to form a thermally conductive insulating structure between the busbar regions and the heat dissipation device 6.

[0107] The DC positive busbar region 301, the first bridge arm AC busbar region 302, and the first DC negative busbar region 303 are located on the same side of the corresponding independent thermally conductive insulating liner 3, and are electrically insulated from the structure below by the independent thermally conductive insulating liner 3. Each independent thermally conductive insulating liner 3 corresponds to an independent converter branch, so that each independent converter branch has an independent insulation support area and a heat conduction path.

[0108] It should be noted that each independent thermally conductive insulating liner 3 is set independently of each other, corresponding to the electrical isolation relationship between each first bus branch area 304. This avoids the formation of unintended electrical connections between different independent converter branches through a common conductive substrate, which can reduce the electrical coupling and heat mutual influence between different independent converter branches, and provide a structural basis for the isolation of faulty branches and the continued operation of other fault-free branches.

[0109] In yet another preferred embodiment, see Figure 1 In the NPC three-level bridge arm unit, each power switch chip is electrically connected to the first power bus conductive layer 1 and the second power bus conductive layer 2 through the interconnect layer 14.

[0110] Specifically, the drain or collector of the power switch chip is electrically connected to the first power bus conductive layer 1 via interconnect layer 14; or, the drain or collector of the power switch chip is electrically connected to the first power bus conductive layer 1 via a conductive connector, and the drain or collector of the power switch chip is connected to the conductive connector via interconnect layer 14. The source or emitter of the power switch chip is electrically connected to the second power bus conductive layer 2 via interconnect layer 14. Thus, the two main power electrodes of the power switch chip are respectively connected to the first power bus conductive layer 1 and the second power bus conductive layer 2 to form a power transmission path through the power switch chip.

[0111] The interconnect layer 14 is used to form a conductive connection between the main power electrode of the power switch chip and the corresponding power bus conductive layer. The conductive connector is used to perform conductive switching between the power switch chip and the first power bus conductive layer 1.

[0112] In the connection method of setting conductive connectors, the drain or collector of the power switch chip is first connected to the conductive connector through the interconnect layer 14, and then the conductive connector is electrically connected to the first power bus conductive layer 1.

[0113] It should be noted that the source or emitter of the power switch chip is connected to the second power bus conductive layer 2 through the interconnect layer 14, which belongs to the main power connection structure; the gate and Kelvin of the power switch chip are connected to the functional integration layer 10 through the connection hole 15, which belongs to the control signal or acquisition signal connection structure, and the signals transmitted by the two are different.

[0114] In yet another preferred embodiment, see Figure 1 and Figure 4 , Figure 4 This is a cross-sectional view of a preferred embodiment of the vertical projection bus type three-level power module with a double-sided heat dissipation structure according to the present invention. The vertical projection bus type power module also includes at least one heat dissipation device 6.

[0115] The heat dissipation device 6 is thermally connected to the surface of the thermally conductive insulating liner 3 that is away from the first power busbar conductive layer 1; and / or, at least one heat dissipation device 6 is connected to the surface of the second power busbar conductive layer 2 that is away from the first power busbar conductive layer 1 through a thermally conductive medium 16.

[0116] Among them, see Figure 1 The heat dissipation device 6 is disposed on the side of the thermally conductive insulating liner 3 away from the first power busbar conductive layer 1, and is used to receive the heat transferred through the thermally conductive insulating liner 3 to form the lower heat dissipation path of the vertical projection busbar type power module.

[0117] Among them, see Figure 4 A heat dissipation device 6 is provided on the side of the second power bus conductive layer 2 away from the first power bus conductive layer 1. A heat-conducting medium 16 is disposed between the second power bus conductive layer 2 and the heat dissipation device 6 to transfer the heat on the side of the second power bus conductive layer 2 to the corresponding heat dissipation device 6, so as to form the upper heat dissipation path of the vertical projection bus type power module.

[0118] When both the lower heat dissipation device 6 and the upper heat dissipation device 6 are installed, the heat generated inside the power module is transferred to both sides of the module through the thermally conductive insulating liner 3 and the second power bus conductive layer 2, thereby forming a double-sided heat dissipation structure.

[0119] It should be noted that the heat-conducting medium 16 is disposed between the second power bus conductive layer 2 and the corresponding heat dissipation device 6, so as to keep the heat dissipation device 6 and the second power bus conductive layer 2 electrically isolated while transferring heat.

[0120] It should be noted that "and / or" indicates that the heat dissipation device 6 is configured in at least one of the following ways: the heat dissipation device 6 is thermally connected to the surface of the thermally conductive insulating liner 3 away from the first power busbar conductive layer 1; the heat dissipation device 6 is thermally connected to the surface of the second power busbar conductive layer 2 away from the first power busbar conductive layer 1 through the thermally conductive medium 16; or, both of the above configuration methods are used simultaneously.

[0121] It is understandable that by providing a heat dissipation device 6 on the side of the thermally conductive insulating liner 3 away from the first power bus conductive layer 1, the heat generated during the operation of the power switch chip and the neutral point clamping diode assembly 19 can be transferred outward through the thermally conductive insulating liner 3.

[0122] In yet another preferred embodiment, see Figure 1 The insulating encapsulation structure also includes a first insulating layer 11, a second insulating layer 12, and a third insulating layer 13.

[0123] The outer side of the thermally conductive insulating liner 3 and the outer side of the first power bus conductive layer 1 are surrounded by the first insulating layer 11 to provide insulation encapsulation for the outer areas of the thermally conductive insulating liner 3 and the first power bus conductive layer 1.

[0124] The third insulating layer 13 is disposed on the side surface of the second power bus conductive layer 2 away from the first power bus conductive layer 1, and is used to cover the outer area of ​​the second power bus conductive layer 2.

[0125] The second insulating layer 12 is disposed in the gap area between the first insulating layer 11 and the third insulating layer 13 to fill the area between the first insulating layer 11 and the third insulating layer 13 that is not occupied by the power device, the power bus conductive layer and the functional integration layer 10, and together with the first insulating layer 11 and the third insulating layer 13, forms an insulating encapsulation structure.

[0126] The first insulating layer 11 mainly surrounds the outer lateral edge of the thermally conductive insulating liner 3 and the first power busbar conductive layer 1, the second insulating layer 12 is located in the interlayer gap area inside the module, and the third insulating layer 13 is located on the upper side of the second power busbar conductive layer 2. The three layers together provide insulation and isolation for the internal conductive structure along the stacking direction of the module.

[0127] The functional integration layer 10, the second power bus conductive layer 2, and the connection hole 15 are disposed between the first insulating layer 11 and the third insulating layer 13, and the second insulating layer 12 fills the void area around the above structure.

[0128] It should be noted that the third insulating layer 13 is disposed on the surface of the second power bus conductive layer 2 away from the first power bus conductive layer 1, and it is not excluded that the connection hole 15, power terminal or other connection structure that needs to be led out passes through the third insulating layer 13.

[0129] It is understandable that by surrounding the thermally conductive insulating liner 3 and the first power bus conductive layer 1 with the first insulating layer 11, the risk of unintended conduction between the first power bus conductive layer 1 and the outside of the insulating encapsulation structure can be reduced.

[0130] In one specific embodiment, the vertical projection bus type three-level power module is a single-phase three-way parallel high-power double-sided heat-dissipated NPC three-level power module. This power module includes three electrically isolated independent commutation branches, each corresponding to the same phase AC output.

[0131] Each independent converter branch is equipped with an independent high thermal conductivity insulating liner 3. The thermally conductive insulating liners 3 are spaced apart from each other, and an insulating partition area is reserved between adjacent thermally conductive insulating liners 3. The side of each thermally conductive insulating liner 3 facing away from the first power busbar conductive layer 1 is thermally connected to the microchannel water-cooled base plate to transfer the heat generated by the corresponding independent converter branch to the bottom of the module.

[0132] Each thermally conductive insulating liner 3 has electrically isolated current-collecting regions on its surface. The first current-collecting branch region 304 corresponding to each thermally conductive insulating liner 3 includes a DC positive current-collecting sub-region 301, a first bridge arm AC current-collecting sub-region 302, and a first DC negative current-collecting sub-region 303.

[0133] Each first-arm AC bus region 302 is equipped with a corresponding neutral point clamping diode assembly 19. The cathode-side electrode surface of the neutral point clamping diode assembly 19 is integrally sintered onto the corresponding first-arm AC bus region 302, forming a surface contact conductive and thermally conductive connection between the cathode-side electrode surface and the first-arm AC bus region 302. The heat generated during the operation of the neutral point clamping diode assembly 19 can be transferred downwards to the microchannel water-cooled base plate through the first-arm AC bus region 302 and the thermally conductive insulating liner 3.

[0134] The second power bus conductive layer 2 is disposed on the source or emitter side of the power switch chip and is electrically connected to the source or emitter of each power switch chip through the interconnect layer 14. The functional integration layer 10 has a through slot corresponding to the heat dissipation position above the second power bus conductive layer 2. The aluminum nitride thermally conductive medium 16 passes through the corresponding through slot and is thermally connected to the second power bus conductive layer 2 and the heat dissipation device 6 located above the module, thereby forming an upper heat dissipation path from the power switch chip through the second power bus conductive layer 2 and the thermally conductive medium 16 to dissipate heat upwards.

[0135] The microchannel water-cooled base plate below the thermally conductive insulating liner 3 forms the lower heat dissipation path, and the thermally conductive medium 16 and the heat dissipation device 6 above the second power busbar conductive layer 2 form the upper heat dissipation path, thus forming a double-sided heat dissipation structure.

[0136] The midpoint N bus conductive layer 18 is disposed outside the through slot of the functional integration layer 10 and is separated from the thermally conductive medium 16 by an insulating film to avoid unintended conduction between the midpoint N bus conductive layer 18 and the upper heat dissipation structure.

[0137] In this embodiment, the midpoint N bus conductive layer 18 is a continuous integrated conductive structure that laterally connects three independent converter branches. The neutral point clamping diode assembly 19 in each independent converter branch is electrically connected to the same midpoint N bus conductive layer 18.

[0138] Specifically, the anode-side electrode surface of each neutral point clamping diode assembly 19 does not have openings for conductive connections to pass through, and is integrally sintered onto the lower surface of the midpoint N bus conductive layer 18. Thus, the neutral point clamping diode assemblies 19 in the three independent commutation branches are respectively connected to the common midpoint N bus conductive layer 18 through surface contact, so as to realize the collection of neutral point currents in each independent commutation branch.

[0139] The functional integration layer 10 contains branch control units corresponding to the three independent converter branches, and includes multi-channel independent sampling circuits and hardware fault isolation circuits. Each branch control unit collects the branch current status and power switch chip temperature status of its corresponding independent converter branch.

[0140] When any independent converter branch is detected to have an overcurrent fault or an overtemperature fault, the hardware fault isolation circuit quickly shuts off all drive signals of that independent converter branch, causing the faulty branch to stop power output; the remaining independent converter branches that have not experienced a fault continue to operate and maintain derating output.

[0141] The insulating encapsulation structure is formed by vacuum hot pressing multiple layers of solid insulating films. The first insulating layer 11, the second insulating layer 12, and the third insulating layer 13 are respectively disposed in the corresponding interlayer and peripheral regions to provide insulation isolation between the power bus conductor structure, the functional integration layer 10, and the midpoint N bus conductor layer 18 at different potentials. This embodiment does not use silicone gel potting; the interlayer insulation withstand voltage meets the preset requirements for high-voltage automotive applications.

[0142] In another specific embodiment, the vertical projection bus type three-level power module is a three-phase single-sided heat dissipation energy storage NPC three-level power module.

[0143] Compared to Embodiment 1, this embodiment eliminates the thermally conductive medium 16 and the upper heat dissipation device 6 disposed above the second power bus conductive layer 2, retaining only the heat dissipation structure disposed below the thermally conductive insulating liner 3. The heat generated during the operation of the power switch chip and the neutral point clamping diode assembly 19 is mainly transferred to the lower part of the module through the first power bus conductive layer 1 and the thermally conductive insulating liner 3.

[0144] The insulated encapsulation structure houses three independent NPC three-level bridge arm units, corresponding to the AC outputs of phases U, V, and W, respectively. Each corresponding NPC three-level bridge arm unit includes multiple electrically isolated independent commutator branches. Each independent commutator branch has a corresponding first bus branch area 304, a second bus branch area 403, a high-side power switch chip subgroup, a low-side power switch chip subgroup, and a neutral point clamping diode assembly 19. Each independent commutator branch in each phase has a corresponding branch control unit. Each branch control unit is used to drive and control the corresponding independent commutator branch and collect its operating status to identify the target independent commutator branch that has failed in each phase. When an independent commutator branch in any phase fails, the hardware fault isolation circuit shuts off all drive signals of the faulty branch, allowing that phase to maintain derating output through the remaining fault-free branches; the other two phases that have not failed maintain normal power output.

[0145] This embodiment is applicable to bidirectional converter equipment for energy storage, and the power switch chip adopts an insulated gate bipolar transistor chip or a silicon carbide power switch chip.

[0146] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided in this application, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0147] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vertical projection bus type three-level power module, characterized in that, The package includes an insulating encapsulation structure, within which are disposed a thermally conductive insulating liner, a first power bus conductive layer, a second power bus conductive layer, a midpoint N bus conductive layer, and an NPC three-level bridge arm unit; each of the NPC three-level bridge arm units includes a power switch chipset and a neutral point clamping diode assembly; The first power bus conductive layer is disposed on the thermally conductive insulating substrate, and the power switch chip group is disposed between the first power bus conductive layer and the second power bus conductive layer; the drain or collector of each power switch chip in the power switch chip group is electrically connected to the first power bus conductive layer, and the source or emitter of each power switch chip is electrically connected to the second power bus conductive layer; the orthographic projections of the first power bus conductive layer and the second power bus conductive layer on the thermally conductive insulating substrate at least partially overlap to form a vertical projection commutation path passing through the first power bus conductive layer, the power switch chip group and the second power bus conductive layer; The neutral point clamping diode assembly is disposed on the side of the first power bus conductive layer away from the thermally conductive insulating liner, and is located between the first power bus conductive layer and the midpoint N bus conductive layer; the neutral point clamping diode assembly has a cathode-side electrode surface and an anode-side electrode surface disposed opposite to each other, the cathode-side electrode surface is electrically connected to the first power bus conductive layer, and the anode-side electrode surface is electrically connected to the midpoint N bus conductive layer, so as to form a neutral point clamping path passing through the first power bus conductive layer, the neutral point clamping diode assembly, and the midpoint N bus conductive layer.

2. The vertical projection bus type three-level power module as described in claim 1, characterized in that, The power switch chipset includes a high-side power switch chipset and a low-side power switch chipset. The first power bus conductive layer includes a DC positive bus region, a first bridge arm AC bus region, and a first DC negative bus region that are electrically isolated from each other; the second power bus conductive layer includes a second bridge arm AC bus region and a second DC negative bus region that are electrically isolated from each other. The drain or collector of the high-side power switch chip group is electrically connected to the DC positive bus region, and the source or emitter of the high-side power switch chip group is electrically connected to the second bridge arm AC bus region. The DC positive bus region and the second bridge arm AC bus region at least partially overlap on the orthographic projection of the thermally conductive insulating substrate, so that the DC positive bus region, the high-side power switch chip group and the second bridge arm AC bus region are electrically connected in sequence to form a high-side commutation branch. The drain or collector of the low-side power switch chip group is electrically connected to the first bridge arm AC bus region, and the source or emitter of the low-side power switch chip group is electrically connected to the second DC negative bus region. The orthogonal projections of the first bridge arm AC bus region and the second DC negative bus region on the thermally conductive insulating substrate at least partially overlap, so that the first bridge arm AC bus region, the low-side power switch chip group and the second DC negative bus region are sequentially electrically connected to form a low-side commutation branch. The cathode side electrode of the neutral point clamping diode assembly is electrically connected to the first bridge arm AC bus region, and the anode side electrode of the neutral point clamping diode assembly is electrically connected to the midpoint N bus conductive layer, so that the first bridge arm AC bus region, the neutral point clamping diode assembly and the midpoint N bus conductive layer are sequentially electrically connected to form the neutral point clamping branch.

3. A vertical projection bus type three-level power module as described in claim 2, characterized in that, The cathode-side electrode surface and the anode-side electrode surface of the neutral point clamping diode assembly are both parallel to the thermally conductive insulating liner and are located between the high-side power switch chip group and the low-side power switch chip group. The cathode-side electrode surface of the neutral point clamping diode assembly is integrally sintered on the side surface of the first bridge arm AC busbar region away from the thermally conductive insulating liner; the anode-side electrode surface of the neutral point clamping diode assembly is integrally sintered on the midpoint N busbar conductive layer.

4. A vertical projection bus type three-level power module as described in claim 1, characterized in that, The midpoint N bus conductive layer is insulated from the first power bus conductive layer and the second power bus conductive layer, and is electrically connected to the first bridge arm AC bus region in the first power bus conductive layer through the neutral point clamping diode assembly; The vertical projection bus type three-level power module also includes a midpoint power terminal, and the midpoint N bus conductive layer is electrically connected to the neutral point of the external DC bus through the midpoint power terminal.

5. A vertical projection bus type three-level power module as described in claim 2, characterized in that, The first power bus conductive layer includes at least two mutually spaced and electrically isolated first bus branch regions, and the second power bus conductive layer includes at least two mutually spaced and electrically isolated second bus branch regions, with each first bus branch region corresponding to each second bus branch region. Each of the first bus branch regions includes a DC positive bus region, a first bridge arm AC bus region, and a first DC negative bus region; each of the second bus branch regions includes a second bridge arm AC bus region and a second DC negative bus region. The high-side power switch chip group includes at least two high-side power switch chip subgroups, and the low-side power switch chip group includes at least two low-side power switch chip subgroups. Each of the high-side power switch chip subgroups, each of the low-side power switch chip subgroups, each of the first bus branch regions, and each of the second bus branch regions are configured in a one-to-one correspondence. The NPC three-level bridge arm unit includes at least two neutral point clamping diode assemblies. Each neutral point clamping diode assembly is configured in one-to-one correspondence with each first bridge arm AC bus region and is electrically connected between the corresponding first bridge arm AC bus region and the midpoint N bus conductive layer. Each of the first bus branch regions, the corresponding second bus branch regions, the corresponding high-side power switch chip subgroup, the corresponding low-side power switch chip subgroup, and the corresponding neutral point clamping diode assembly together constitute an independent commutation branch.

6. A vertical projection bus type three-level power module as described in claim 5, characterized in that, The insulating encapsulation structure also includes a functional integration layer, which comprises multiple electrically isolated branch control units. Each branch control unit is electrically connected to the corresponding independent converter branch and is used to drive and control the corresponding independent converter branch and collect its operating status.

7. A vertical projection bus type three-level power module as described in claim 6, characterized in that, The functional integration layer also includes a driving unit and a fault logic discrimination unit; The drive unit is electrically connected to each of the branch control units and is used to generate drive signals for the power switch chip group in each of the independent converter branches according to the corresponding control signals. The fault logic discrimination unit is electrically connected to each of the branch control units and is used to determine the target independent converter branch that has failed based on the collected operating status data of each independent converter branch.

8. A vertical projection bus type three-level power module as described in claim 5, characterized in that, Each of the aforementioned independent converter branches is equipped with an independent power terminal group; The independent power terminal group includes a DC positive power terminal, an AC power terminal, and a DC negative power terminal; The DC positive power terminal is electrically connected to the DC positive busbar region in the corresponding independent converter branch, the AC power terminal is electrically connected to the first bridge arm AC busbar region and the second bridge arm AC busbar region in the corresponding independent converter branch, and the DC negative power terminal is electrically connected to the first DC negative busbar region and the second DC negative busbar region in the corresponding independent converter branch.

9. A vertical projection bus type three-level power module as described in claim 5, characterized in that, Each of the aforementioned independent converter branches is equipped with an independent thermally conductive insulating liner. The independent thermally conductive insulating liner covers the area below the DC positive busbar region, the first bridge arm AC busbar region, and the first DC negative busbar region of the independent converter branch.

10. A vertical projection bus type three-level power module as described in claim 1, characterized in that, The drain or collector of the NPC three-level bridge arm unit is electrically connected to the first power bus conductive layer through an interconnect layer; or, the drain or collector of the NPC three-level bridge arm unit is electrically connected to the first power bus conductive layer through a conductive connector, and the drain or collector of the NPC three-level bridge arm unit is connected to the conductive connector through an interconnect layer. The source or emitter of the NPC three-level bridge arm unit is electrically connected to the second power bus conductive layer through an interconnect layer.

11. A vertical projection bus type three-level power module as described in claim 1, characterized in that, The vertical projection bus power module also includes at least one heat dissipation device; The heat dissipation device is thermally connected to the surface of the thermally conductive insulating liner that is away from the first power busbar conductive layer; and / or, at least one of the heat dissipation devices is connected to the surface of the second power busbar conductive layer that is away from the first power busbar conductive layer through a thermally conductive medium.

12. A vertical projection bus type three-level power module as described in claim 1, characterized in that, The insulating encapsulation structure is further provided with a first insulating layer, a second insulating layer and a third insulating layer; The outer side of the thermally conductive insulating liner and the outer side of the first power bus conductive layer are surrounded by the first insulating layer. The third insulating layer is disposed on the surface of the second power bus conductive layer away from the first power bus conductive layer; The second insulating layer is disposed in the gap region between the first insulating layer and the third insulating layer.

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