A series topology power module

Abstract

A series topology power module is disclosed, relating to the field of power electronics technology. The power module is composed of power units connected in series, and voltage balancing is achieved through an active clamping control strategy. The disclosed power module improves the voltage and current ratings of the power module by densely connecting low-voltage power electronic chips in series and parallel. Its advantages include: the proposed high-density structural design based on power unit series connection significantly reduces the parasitic inductance of the module's main power circuit; the proposed power module and its structural design avoid the high cost and high loss disadvantages of using high-voltage power electronic devices to achieve high-voltage, high-current power conversion, and further improve the yield of manufacturing series topology power modules.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a series topology power module and its structural design that employs an active clamping voltage equalization control strategy. Background Technology

[0002] There are numerous medium- and high-voltage power conversion applications in industries such as industry, transportation, power grids, and national defense, creating a strong demand for high-voltage power electronic devices or power modules. Power conversion systems based on traditional silicon-based devices are increasingly constrained by voltage withstand capability and power loss. To achieve low-loss, high-voltage, high-power output, the research and development of novel wide-bandgap semiconductor power electronic devices has become a crucial trend. Silicon carbide (SiC) devices are a typical example of novel wide-bandgap semiconductor devices, characterized by fast switching speed and low loss, and have broad application prospects in power systems. Currently, 1.2kV and below voltage-rated SiC power electronic chips are fully commercialized on a large scale at a reasonable price. However, due to limitations in SiC materials and chip manufacturing technology, low-cost, reliable, high-voltage SiC devices remain a distant prospect. Therefore, using low-voltage, low-loss SiC devices to build high-voltage power conversion systems has become the best choice for reducing losses, lowering costs, and increasing system output power in medium- and high-voltage power conversion.

[0003] There are two possible solutions for building high-voltage power conversion systems using low-voltage components: the multilevel converter scheme and the power device series scheme. Multilevel converter schemes, represented by cascaded H-bridge multilevel converters (CHB) and modular multilevel converters (MMC), are characterized by modular structure, high efficiency, and high reliability, and have been applied in many medium-to-high power applications. However, multilevel converter schemes typically require the use of large-sized passive components. For example, CHB requires a large phase-shifting transformer, and in MMC, capacitors account for approximately 70% of the size of its sub-modules. These drawbacks hinder the use of multilevel converters in applications with strict weight and size requirements, such as electrified transportation and data centers.

[0004] Series connection of power electronic devices is another relatively direct way to apply low-voltage power devices to medium- and high-voltage applications. This method improves the voltage withstand rating and increases the output power of the power conversion system. Compared to multi-level technology, it offers advantages such as smaller system size, fewer passive components, and simpler circuit topology. However, due to differences in the electrical performance parameters of power electronic devices and external circuit conditions (e.g., junction capacitance, gate threshold voltage, gate drive signal delay, and instantaneous drive voltage applied to the gate), voltage imbalances in series-connected power electronic devices are highly likely, leading to low electrical reliability of the power conversion system. Therefore, achieving voltage balancing in series-connected devices is a key technology for further improving the voltage and current ratings of power conversion systems using low-voltage power electronic devices.

[0005] Voltage equalization control strategies and hardware optimization design of series topology power loops are the two main technical supports for achieving voltage balance of power devices in series. There are two types of voltage equalization control strategies: input gate-side voltage equalization control and output power-side voltage equalization control.

[0006] The disadvantages of the input gate-side voltage equalization control technology are: complex circuit design and control strategy, extremely high requirements for high-speed sensors and A / D conversion chips, and extreme sensitivity to changes in device temperature and load current. This technology necessitates the introduction of additional circuitry, increasing the complexity of the drive loop. Due to the involvement of high-speed control, the voltage equalization control circuit is costly and lacks practical usability.

[0007] Output power side voltage equalization control technologies include passive snubber circuits and active clamping circuits. Passive snubber circuits, relying on RC (Resistor-Capacitance) circuits, experience significant energy loss in the snubber resistor (R) during practical operation. The large size of passive components hinders integration, and the parallel connection of the snubber capacitor with the power circuit of the switching transistor results in a slower switching speed. However, active voltage clamping circuits, by introducing an auxiliary switching transistor in the clamping branch, feed the energy accumulated in the clamping capacitor back into the circuit instead of directly dissipating it as in RC solutions. This approach introduces less loss into the voltage equalization circuit. Furthermore, the active clamping circuit only clamps when the voltage across the power electronic device exceeds the voltage across the clamping capacitor, thus not reducing the switching speed of the main switching transistor or increasing its switching losses. Therefore, the voltage equalization control strategy based on active clamping circuits is a more ideal solution for addressing voltage equalization in series-connected devices.

[0008] Current research on active clamp control strategies primarily relies on discrete devices or conventional commercial power modules to build the hardware for series-connected power loops. This approach has several drawbacks, hindering the large-scale commercialization of power electronic series solutions employing active clamp control strategies. Discrete device-based series solutions suffer from low system power density and difficulty in high-current operation, failing to meet the high-power demands of medium- and high-voltage applications. While conventional commercial module-based solutions address the high-power requirements of medium- and high-voltage applications, the mismatch between the commercial module's power loop topology and the overall architecture of the power conversion system using active clamp control strategies leads to several limitations. These limitations include inconvenient voltage and current level expansion for the power conversion system, long internal power loop lines resulting in significant parasitic inductance, unreasonable main circuit topology of the power module, and low power density or slow dynamic response of the power module and its power conversion system.

[0009] Therefore, developing series topology power modules suitable for active clamp control strategies has become an essential path for the industrialization of active clamp technology in the field of high-voltage, high-power conversion. To extend the low-loss and low-cost advantages of low-voltage silicon carbide devices to high-voltage, high-power applications, and gradually replace multi-level or input-gate-side voltage equalization control technologies with numerous drawbacks, it is urgent to develop low-cost high-voltage, high-power modules based on series low-voltage power electronic chips and employing active clamp control strategies. Therefore, series topology power modules based on low-voltage electronic chips and employing active clamp voltage equalization control have enormous application prospects and economic value. Summary of the Invention

[0010] To address one or more of the technical problems of the prior art, this invention proposes a series topology power module and its structural design.

[0011] According to an embodiment of the present invention, a series topology power module is provided, characterized by: a base plate; a first solder layer located on the upper surface of the base plate; an insulating plate including a lower metal layer, an intermediate insulating layer, and an upper metal layer, wherein the lower metal layer is located on the upper surface of the first solder layer; a second solder layer located on the upper surface of the upper metal layer; and a power unit located on the upper surface of the second solder layer, which includes a first DBC structure, a second DBC structure, a third DBC structure, a fourth DBC structure, a fifth DBC structure, a third solder layer, a main switching transistor power electronic chip, and an auxiliary switching transistor. The system includes a power electronic control chip, a clamping capacitor, a main switch gate signal terminal, a main switch source signal terminal, an auxiliary switch gate signal terminal, an auxiliary switch source signal terminal, and a voltage sampling signal terminal. The first, second, third, fourth, and fifth DBC structures each include a lower copper foil, a middle ceramic layer, and an upper copper foil. The lower copper foil is located on the upper surface of the second solder layer and is used to connect to the upper metal layer of the insulating board. The third solder layer is located on the upper surface of the upper copper foil. The main switch power electronic control chip... Both the main power electronic chip and the auxiliary switching transistor are located on the upper surface of the third solder layer. The circuit topology of the power unit includes a first basic circuit unit and a second basic circuit unit connected in series. Each of the first and second basic circuit units includes a main switching transistor power electronic chip and an active clamping branch connected in parallel with it. The active clamping branch includes an auxiliary switching transistor power electronic chip and a clamping capacitor connected in series with it. The main branch of the power unit includes the main switching transistor power electronic chip of the first basic circuit and the main switching transistor power electronic chip of the second basic circuit connected in series with it. A series connection structure is located on the upper surface of the third solder layer to realize the series connection of the power units. Power electrodes include a "DC+" power electrode and a "DC-" power electrode. An auxiliary structure includes a plastic frame structure, a cover, and a potting compound. The potting compound fills the interior of the power module defined by the plastic frame structure. Multiple power units inside the power module are arranged in parallel and connected in series to realize the sequential series connection of the first basic circuit unit and the second basic circuit unit. The main power branch of the power module is formed by the series connection of the main branches of the power units.

[0012] According to another embodiment of the present invention, a series topology power module is provided, comprising: a power unit, which includes a first DBC structure, a second DBC structure, a third DBC structure, a fourth DBC structure, a fifth DBC structure, a third solder layer, a main switching transistor power electronic chip, an auxiliary switching transistor power electronic chip, a clamping capacitor, a main switching transistor gate signal terminal, a main switching transistor source signal terminal, an auxiliary switching transistor gate signal terminal, an auxiliary switching transistor source signal terminal, and a voltage sampling signal terminal. The first DBC structure, the second DBC structure, the third DBC structure, the fourth DBC structure, and the fifth DBC structure each include a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The lower copper foil is located on the upper surface of the second solder layer and is used to connect with the upper metal layer of the insulating board. The third solder layer is located on the upper surface of the upper copper foil. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip are both located on the third solder layer. On the upper surface, the circuit topology of the power unit includes a first basic circuit unit and a second basic circuit unit connected in series. Both the first and second basic circuit units include a main switching transistor power electronic chip and an active clamping branch connected in parallel with it. The active clamping branch includes an auxiliary switching transistor power electronic chip and a clamping capacitor connected in series with it. The main branch of the power unit includes the main switching transistor power electronic chip of the first basic circuit and the main switching transistor power electronic chip of the second basic circuit connected in series with it. A series connection structure is located on the upper surface of the third solder layer to realize the series connection of the power units. Power electrodes include a "DC+" power electrode and a "DC-" power electrode. Multiple power units within the power module are sequentially arranged in parallel and connected in series through the series connection structure to realize the sequential series connection of the first and second basic circuit units. The main power branch of the power module is formed by the series connection of the main branches of the power units.

[0013] Furthermore, the short axis centerlines of the multiple power units arranged in parallel in the power module are all parallel to the long axis centerline of the power module, and the series connection structures connecting the power units are all located on the same side of the long axis centerline of the power module.

[0014] Furthermore, in the first basic circuit unit of the power unit: the gate signal terminal and source signal terminal of the main switch are arranged on the second DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the third DBC structure. The connection line of these signal terminals in the first basic circuit unit after projection onto the horizontal plane is the horizontal line of the first signal terminal; in the second basic circuit unit: the gate signal terminal and source signal terminal of the main switch are arranged on the fourth DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the fifth DBC structure. The connection line of these signal terminals in the second basic circuit unit after projection onto the horizontal plane is the horizontal line of the first signal terminal; The connection line is the second signal terminal horizontal line. Both the first signal terminal horizontal line and the second signal terminal horizontal line are parallel to the short axis center line of the power unit and are located on the two outer side regions of the power unit respectively. The main switching power electronic chip, auxiliary switching power electronic chip, clamping capacitor and voltage sampling terminal of clamping capacitor in the first basic circuit unit and the second basic circuit unit are all arranged on the first DBC structure. The first DBC structure is located in the middle region of the power unit, and the source of the first basic circuit unit and the drain of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure.

[0015] Furthermore, the number of series connections of the power unit is N, and N is a natural number greater than or equal to 2. The main switching power electronic chip or the auxiliary switching power electronic chip in the power unit can also be connected in anti-parallel to a freewheeling diode chip. The anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain of the power electronic chip, and the anode of the freewheeling diode chip is connected to the source of the power electronic chip.

[0016] Further, in the first DBC structure, the source bar and gate bar of the gate-source path of the power electronic chip of the main switching tube and the source bar and gate bar of the gate-source path of the power electronic chip of the auxiliary switching tube in the first basic circuit unit are located in a short outer side region of the first DBC structure, and the source bar and gate bar of the gate-source path of the power electronic chip of the main switching tube and the source bar and gate bar of the gate-source path of the power electronic chip of the auxiliary switching tube in the second basic circuit unit are located in the other short outer side region of the first DBC structure; in the direction from the short outer side to the short axis center line of the first DBC structure of the power unit, the region immediately adjacent to the source bar and gate bar of the gate-source path of the power electronic chip of the main switching tube of the first basic circuit unit is the region for arranging the power electronic chip of the main switching tube of the first basic circuit unit, the region immediately adjacent to the source bar and gate bar of the gate-source path of the power electronic chip of the auxiliary switching tube of the first basic circuit unit is the region for arranging the power electronic chip of the auxiliary switching tube of the first basic circuit unit and said region is L-shaped; similarly, the region immediately adjacent to the source bar and gate bar of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit is the region for arranging the power electronic chip of the main switching tube of the second basic circuit unit, the region immediately adjacent to the source bar and gate bar of the gate-source path of the power electronic chip of the auxiliary switching tube of the second basic circuit unit is the region for arranging the power electronic chip of the auxiliary switching tube of the second basic circuit unit and said region is also L-shaped; the region for arranging the source of the power electronic chip of the main switching tube of the first basic circuit unit and the region for arranging the power electronic chip of the main switching tube of the second basic circuit unit integrally form a large 匚-shaped region and are located near the long side of the central region of the first DBC structure, wherein the upper horizontal side of the 匚-shape is nested between the layout region of the power electronic chip of the main switching tube of the first basic circuit unit and the layout region of the power electronic chip of the auxiliary switching tube of the first basic circuit unit, the lower horizontal side region of the 匚-shape is the layout region of the power electronic chip of the main switching tube of the second basic circuit unit, and said region is located between the layout region of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit and the source layout region of the second basic circuit unit; the region for arranging the source of the second basic circuit unit is integrally in an inverted ㄕ shape, the lower horizontal side of the inverted ㄕ shape is located between the lower horizontal side of the 匚 shape and the L-shaped region for arranging the power electronic chip of the auxiliary switching tube of the second basic circuit unit;

[0017] Further, in the upper copper foil of the first DBC structure, the area where the low-voltage pin of the clamping capacitor of the second basic circuit unit is arranged, the area where the capacitor voltage sampling terminal for sampling the low-potential voltage of the clamping capacitor is arranged, and the area where the source electrode of the second basic circuit unit is arranged form a single first connected area, the single first connected area is the "ㄕ"-shaped area and is characterized by low-voltage potential in the circuit topology of the power unit; in the upper copper foil of the first DBC structure, the area where the power electronic chip of the main switching tube of the second basic circuit unit is arranged, the area where the low-potential voltage pin of the clamping capacitor of the first basic circuit unit is arranged, the area where the capacitor voltage sampling terminal for sampling the low-potential voltage of the clamping capacitor of the first basic circuit unit is arranged, and the area where the source electrode of the power electronic chip of the main switching tube of the first basic circuit unit is arranged form a single second connected area, the single second connected area is the "匚"-shaped area, and the "匚"-shaped area is used to implement the electrical connection of the main power loop between the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit; the inverted "ㄕ"-shaped area is arranged in the central area inside the "匚"-shaped area, two "L"-shaped areas are nested between the "ㄕ"-shaped area and the "匚"-shaped area, and the vertical side of the inverted "ㄕ"-shaped area is used to implement the series connection with the juxtaposed power units;

[0018] Further, in the power module, the start point and end point of the series-connected power units are a "DC+" power electrode and a "DC-" power electrode respectively, wherein the "DC+" power electrode is connected to the first basic circuit unit of the first juxtaposed power unit inside the power module, and the "DC-" power electrode is connected to the second basic circuit unit of the last juxtaposed power unit inside the power module; the projection of the main branch of the power unit on the horizontal plane of the power module is generally "S"-shaped, and the projection of the main power branch of the power module on the horizontal plane of the power module is a series connection of a plurality of "S"-shaped branches, and the plurality of series-connected "S"-shaped branches are symmetrically distributed on the central axis of the long axis of the power module.

[0019] Compared with existing technical solutions, the beneficial effects of the series topology power module and its structural design disclosed in this invention are as follows: The proposed design of connecting the first and second basic circuit units in series to form a power unit significantly reduces the length of the power module in the series direction while maintaining the same voltage withstand capability; The proposed design of placing the high-voltage main branch and the active clamping branch in the central region of the power unit while placing the low-voltage gate signal terminals and source signal terminals of the power electronic chip in the outer side region of the power unit separates the high electric field region and the low electric field region inside the power unit, thereby improving the electrical reliability of the power module; The proposed series technology of arranging the main power circuit of the power module into multiple "S"-shaped branches in series reduces the length of the power module, reduces the deformation caused by thermal stress during module manufacturing, and improves the reliability of module manufacturing. Moreover, because there are parallel and adjacent current paths with opposite current directions in the "S"-shaped branches, although the length of the main power circuit of the module increases, its parasitic inductance is reduced. Attached Figure Description

[0020] Figure 1 A schematic diagram 1000 of the overall architecture design of the power module according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic cross-sectional view of a power module according to an embodiment of the present invention, 2000.

[0022] Figure 3 A schematic diagram 3000 of the power unit in the power module according to an embodiment of the present invention;

[0023] Figure 4 This is a top view schematic diagram 4000 of the power unit structure in the power module according to an embodiment of the present invention;

[0024] Figure 5 A schematic diagram 5000 of the circuit topology of the power unit in the power module according to an embodiment of the present invention;

[0025] Figure 6 A schematic diagram 6000 of the circuit topology of the power module in the power module according to an embodiment of the present invention;

[0026] Figure 7 A schematic diagram 7000 of the structural design of a power module according to an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram 8000 of the design of the first DBC structure according to an embodiment of the present invention;

[0028] Figure 9This is a schematic diagram 9000 showing the projection of the internal structure of the power module on the horizontal plane of the module according to an embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram 9100 showing the overall features of the main power branch of the power module projected onto the horizontal plane of the module according to an embodiment of the present invention. Detailed Implementation

[0030] Specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. In the following description, numerous specific details are set forth to facilitate a thorough understanding of the invention. However, those skilled in the art will understand that these specific details are not essential for carrying out the invention. Furthermore, in some embodiments, well-known circuits, materials, or methods are not specifically described to avoid obscuring the invention.

[0031] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the accompanying drawings provided herein are for illustrative purposes, with the same reference numerals indicating the same elements. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] The power electronic chips used in the power module of this invention include, but are not limited to, metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), and junction field-effect transistors (JFETs) in terms of chip structure. The materials used in the chips are not limited to silicon (Si), but may also include various wide-bandgap semiconductor materials, such as silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), and diamond. In the circuit topology of the power module of this invention, to clearly illustrate the series and parallel connections of the components in the circuit diagram, the body diode or anti-parallel freewheeling diode in the switching power electronic chip is omitted.

[0033] Figure 1 The diagram 1000 shows the overall architecture design of the power module according to an embodiment of the present invention. The power module includes a base plate 10, an insulating plate 20, a "DC+" power electrode 1, a "DC-" power electrode 2, and multiple parallel power units, forming a series connection structure 70 that connects the power units in series.

[0034] Figure 2 The cross-sectional structural diagram 2000 of the power module according to an embodiment of the present invention shows, from bottom to top, a base plate 10, a first solder layer 11, an insulating plate structure 20, a second solder layer 12, a power unit DBC structure 30, a third solder layer 13, a main switching transistor power electronic chip 40, an auxiliary switching transistor power electronic chip 50, and a clamping capacitor 60. The power unit DBC structure 30 includes a lower copper foil 31, a middle ceramic layer 32, and an upper copper foil 33. The insulating plate structure 20 includes a lower metal layer 21, a middle insulating layer 22, and an upper metal layer 23. The thickness of the middle insulating layer 22 is "ΔT".

[0035] Figure 3The schematic diagram 3000 of the power unit according to an embodiment of the present invention includes a second DBC structure 135 for placing the gate signal terminal 101 and the source signal terminal 102 of the main switch of the first basic circuit unit; a third DBC structure 136 for placing the gate signal terminal 104 and the source signal terminal 103 of the auxiliary switch; a fourth DBC structure 137 for placing the gate signal terminal 105 and the source signal terminal 106 of the main switch of the second basic circuit unit; a fifth DBC structure 138 for placing the gate signal terminal 107 and the source signal terminal 108 of the auxiliary switch; and a first DBC structure 100 for placing the main switch power electronic chip 40, the auxiliary switch power electronic chip 50, the clamping capacitor 60, the high-potential voltage sampling terminal 16 and the low-potential voltage sampling terminal 17 of the clamping capacitor of the first basic circuit unit, and the high-potential voltage sampling terminal 18 and the low-potential voltage sampling terminal 19 of the clamping capacitor of the second basic circuit unit.

[0036] Figure 4 The diagram 4000 shows the projection of the power unit on the horizontal plane of the module structure according to an embodiment of the present invention. The dashed boxes in the diagram represent the first basic circuit unit and the second basic circuit unit, respectively. The line connecting the main switch gate signal terminal 102, the main switch source signal terminal 101, the auxiliary switch gate signal terminal 104, and the auxiliary switch source signal terminal 103 of the first basic circuit unit after projection on the horizontal plane of the module is a first signal terminal horizontal line parallel to the center line of the minor axis of the power unit. The line connecting the main switch gate signal terminal 105, the main switch source signal terminal 106, the auxiliary switch gate signal terminal 107, and the auxiliary switch source signal terminal 108 of the second basic circuit unit after projection on the horizontal plane of the module is a second signal terminal horizontal line parallel to the center line of the minor axis of the power unit.

[0037] Figure 5The circuit topology diagram 4000 of the power unit in the power module according to an embodiment of the present invention is shown. The power unit is composed of a first basic circuit unit and a second basic circuit unit connected in series. The circuit topology of the first basic circuit unit and the second basic circuit unit is the same, both of which are composed of a main branch and an active clamping branch connected in parallel. The main branch is the path from the drain (D) to the source (S) of the main switch Q1. The active clamping branch is composed of an auxiliary switch Q2 and a clamping capacitor C1 connected in series. The drain (D) of the auxiliary switch Q2 is connected to the high-potential voltage pin of the clamping capacitor C1, the source (S) of the auxiliary switch Q2 is connected to the drain (D) of the main switch Q1, and the low-potential voltage pin of the clamping capacitor C1 is connected to the source (S) of the main switch. As shown in schematic diagram 5000, the drain (D) of the main switch Q1 is connected to the source (S) of the auxiliary switch Q2, and the source (S) of the main switch Q1 is connected to the low-potential voltage pin of the clamping capacitor C1. Therefore, the power unit is a parallel connection of the main branch and the active clamping branch in the circuit topology.

[0038] Figure 6 The circuit topology diagram 6000 of the power module according to an embodiment of the present invention is formed by connecting N power units in series. The number of parallel connections of the main switching power electronic chip Q1, the auxiliary switching power electronic chip Q2, or the clamping capacitor C1 of the power units can be greater than or equal to 1.

[0039] Figure 7 The schematic diagram 7000 of the structural design of the power module according to an embodiment of the present invention shows that the number of power units connected in series in the power module is 3, and its technical features include: a base plate 10, an insulating plate 20, a "DC+" power electrode 1, a "DC-" power electrode 2, and a series connection structure 70.

[0040] Figure 8It is a design schematic diagram 8000 of a first DBC structure of a power unit according to an embodiment of the present invention. In the diagram, the upper copper foil of the first DBC structure comprises: a gate strip 120 and a source strip 110 that layout the gate-source path of the power electronic chip of the main switching tube of the first basic circuit unit, a source strip 121 and a source strip 111 that layout the gate-source path of the power electronic chip of the auxiliary switching tube, a region 130 for arranging the power electronic chip of the main switching tube of the first basic circuit unit, and a region 131 for arranging the power electronic chip of the auxiliary switching tube of the first basic circuit unit; a gate strip 210 and a source strip 220 that layout the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit, a source strip 211 and a source strip 221 that layout the gate-source path of the power electronic chip of the auxiliary switching tube, a region 230 for arranging the power electronic chip of the main switching tube of the second basic circuit unit, a region 231 for arranging the power electronic chip of the auxiliary switching tube of the second basic circuit unit, and a region 250 for arranging the source electrode of the second basic circuit unit. The overall upper copper foil region 230 is in a "匚" shape, both the upper copper foil region 131 and the region 231 are in an "L" shape, and the overall upper copper foil region 250 is in an inverted "ㄕ" shape.

[0041] Figure 9 It is a projection schematic diagram 9000 of the internal structure of a power module on the horizontal plane of the module according to an embodiment of the present invention. In the schematic diagram 9000, three power units are arranged in series and side by side on the long-axis center line of the power module, all series connection structures 70 are arranged in the same side region of the long-axis center line of the power module, the "DC+" power electrode is located on the first power unit arranged in parallel, and the "DC-" power electrode is located on the last power unit arranged in parallel.

[0042] Figure 10 It is a schematic diagram 9100 showing the overall characteristics presented after the main power path of a power module is projected on the horizontal plane of the module according to an embodiment of the present invention. The main power branch is directed from "DC+" to "DC-", the overall main power branch is formed by connecting a plurality of "S"-shaped paths in series, and the head of the next "S"-shaped path is directly connected to the tail of the previous "S"-shaped path.

[0043] An embodiment of the present invention proposes a series topology power module, as shown in schematic diagrams 1000 and 2000, characterized in that it includes: a base plate 10; a first solder layer 11 located on the upper surface of the base plate 10; an insulating plate structure 20, which includes a lower metal layer 21, an intermediate insulating layer 22, and an upper metal layer 23, wherein the lower metal layer 21 is located on the upper surface of the first solder layer; a second solder layer 12 located on the upper surface of the upper metal layer 23 of the insulating plate; and a power unit located on the upper surface of the second solder layer 12, the power unit being shown in schematic diagram 3000, which includes a first DBC structure 100. The structure comprises a second DBC structure 135, a third DBC structure 136, a fourth DBC structure 137, and a fifth DBC structure 138; a third solder layer 13; a main switching transistor power electronic chip 40; an auxiliary switching transistor power electronic chip 50; a clamping capacitor 60; a main switching transistor gate signal terminal; a main switching transistor source signal terminal; an auxiliary switching transistor gate signal terminal; an auxiliary switching transistor source signal terminal; and a voltage sampling signal terminal. The DBC structure includes a lower copper foil 31, a middle ceramic layer 32, and an upper copper foil 33. The lower copper foil 31 is located on the upper surface of the second solder layer 12 and is used to connect to the insulating plate. The third solder layer 13 is located on the upper surface of the copper foil 33 of the DBC structure. The circuit topology of the power unit is shown in schematic diagram 4000, including a first basic circuit unit and a second basic circuit unit connected in series. Both the first and second basic circuit units include a main switching transistor power electronic chip and an active clamping branch connected in parallel with it. The active clamping branch is formed by an auxiliary switching transistor power electronic chip and a clamping capacitor connected in series. The main branch of the power unit includes the main switching transistor power electronic chip of the first basic circuit unit and the main switching transistor power electronic chip of the second basic circuit unit connected in series with it. Structure 70, located on the upper copper foil 33 of the power unit DBC structure, is used to realize the series connection of the power units; power electrodes, including "DC+" power electrode 1 and "DC-" power electrode 2; auxiliary structure, which includes a plastic frame structure, a cover, and potting material, the potting material filling the interior of the power module defined by the plastic frame structure; and multiple power units inside the power module are arranged in parallel and connected in series through the series connection structure 70 to realize the sequential series connection of the first basic circuit unit and the second basic circuit unit, the main power branch of the power module is formed by the series connection of the main branches of the power units.

[0044] The power module as described in claim 1 is characterized in that the short axis centerlines of the plurality of parallel power units are all parallel to the long axis centerline of the power module, and the series structure 70 connecting the power units is located on the same side of the long axis centerline of the power module, as shown in schematic diagrams 7000 and 9000.

[0045] The power unit as described in claims 1 and 2, as shown in schematic diagram 4000, is characterized in that, in the first basic circuit unit, the gate signal terminal and source signal terminal of the main switch are arranged on the second DBC structure 135, and the gate signal terminal and source signal terminal of the auxiliary switch are also arranged on the third DBC structure 136, and the line connecting these signal terminals in the first basic circuit unit after projection onto the horizontal plane is the first signal terminal horizontal line; in the second basic circuit unit, the gate signal terminal and source signal terminal of the main switch are arranged on the fourth DBC structure 137, and the gate signal terminal and source signal terminal of the auxiliary switch are also arranged on the fifth DBC structure 138, and the signal terminals of these signal terminals in the second basic circuit unit... The line connected after projection on the horizontal plane is the second signal terminal horizontal line. Both the first signal terminal horizontal line and the second signal terminal horizontal line are parallel to the short axis center line of the power unit and are located on the two outer side regions of the first power unit respectively. The main switching power electronic chip, auxiliary switching power electronic chip, clamping capacitor and voltage sampling terminal of clamping capacitor in the first basic circuit unit and the second basic circuit unit are all arranged on the first DBC structure 100. The first DBC structure is located in the middle region of the power unit, and the source of the first basic circuit unit and the drain of the second basic circuit unit are electrically interconnected through the upper copper foil 230 of the first DBC structure, as shown in the schematic diagram 8000.

[0046] The power unit as described in claims 1 to 3, as shown in schematic diagram 5000, is characterized in that the number of parallel main switching power electronic chips 40 of the first basic circuit unit or the second basic circuit unit is greater than or equal to 2, the number of auxiliary switching power electronic chips 50 is greater than or equal to 1, the number of parallel clamping capacitors 60 is greater than or equal to 2 and the size of the clamping capacitors may be different, and the withstand voltage of the first basic circuit unit is equal to the withstand voltage of the second circuit unit.

[0047] As described in claims 1 to 4, the number of series connections of the power unit is N, and N is a natural number greater than or equal to 2. The main switching power electronic chip or the auxiliary switching power electronic chip in the power unit can also be connected in anti-parallel to a freewheeling diode chip. The so-called anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain of the switching power electronic chip, and the anode of the freewheeling diode chip is connected to the source of the switching power electronic chip.

[0048] The first DBC structure according to any one of claims 1 and 3, as shown in the schematic diagram 8000, characterized in that, the source strip 110 and the gate strip 120 on the gate-source path of the power electronic chip of the main switch tube of the first basic circuit unit, and the source strip 111 and the gate strip 121 on the gate-source path of the power electronic chip of the auxiliary switch tube are located in a short outer side region of the first DBC structure; the source strip 220 and the gate strip 210 on the gate-source path of the power electronic chip of the main switch tube of the second basic circuit unit, and the source strip 221 and the gate strip 211 on the gate-source path of the power electronic chip of the auxiliary switch tube are located in another short outer side region of the first DBC structure; in a direction from the short outer side toward the short-axis center line of the first DBC structure of the power unit, the region immediately adjacent to the source strip 110 and the gate strip 120 on the gate-source path of the power electronic chip of the main switch tube of the first basic circuit unit is the region 130 where the power electronic chip of the main switch tube of the first basic circuit unit is arranged, the region immediately adjacent to the source strip 111 and the gate strip 121 on the gate-source path of the power electronic chip of the auxiliary switch tube of the first basic circuit unit is the region 131 where the power electronic chip of the auxiliary switch tube of the first basic circuit unit is arranged, and said region is L-shaped; similarly, the region immediately adjacent to the source strip 220 and the gate strip 210 on the gate-source path of the power electronic chip of the main switch tube of the second basic circuit unit is the region 230 where the power electronic chip of the main switch tube of the second basic circuit unit is arranged, the region immediately adjacent to the source strip 221 and the gate strip 211 on the gate-source path of the power electronic chip of the auxiliary switch tube of the second basic circuit unit is the region 231 where the power electronic chip of the auxiliary switch tube of the second basic circuit unit is arranged, and said region is also L-shaped; the region where the source of the power electronic chip of the main switch tube of the first basic circuit unit is arranged and the region where the power electronic chip of the main switch tube of the second basic circuit unit is arranged together form a large C-shaped region 230, which is located near the long side of the central region of the first DBC structure, wherein the upper horizontal side of the C-shape is nested between the layout region 130 of the power electronic chip of the main switch tube of the first circuit unit and the layout region 131 of the power electronic chip of the auxiliary switch tube of the first circuit unit, the lower horizontal side region of the C-shape is the layout region of the power electronic chip of the main switch tube of the second basic circuit unit, and said region is located between the layout region 220 of the gate-source path of the power electronic chip of the main switch tube of the second basic circuit unit and the source layout region 250 of the second basic circuit unit; the region 250 where the source of the second basic circuit unit is arranged is generally in an inverted "ㄕ" shape, and the lower horizontal side of the inverted "ㄕ" shape is located between the lower horizontal side of the C-shaped 230 and the L-shaped region 231 where the auxiliary power electronic chip of the second basic circuit unit is arranged.

[0049] The first DBC structure according to any one of claims 1, 3 and 6, as schematically shown in 8000, characterized in that, in the upper copper foil of the first DBC structure, the region for laying out the low-voltage pin of the clamp capacitor of the second basic circuit unit, the region for laying out the capacitor voltage sampling terminal for sampling the low-potential voltage of the clamp capacitor, and the region for laying out the source electrode of the second basic circuit unit form a single connected region, said single connected region is said "ㄕ"-shaped region 250 and is characterized by a low-voltage potential in the circuit topology of said power unit; in the upper copper foil of the first DBC structure, the region for laying out the power electronic chip of the main switch tube of the second basic circuit unit, the region for laying out the low-potential voltage pin of the clamp capacitor of the first basic circuit unit, the region for laying out the capacitor voltage sampling terminal for sampling the low-potential voltage of the clamp capacitor of the first basic circuit unit, and the region for laying out the source electrode of the power electronic chip of the main switch tube of the first basic circuit unit form a single connected region, said single connected region is said "匚"-shaped region 230, said "匚"-shaped region is used to realize the electrical connection of the main power circuit between the source electrode of said first basic circuit unit and the drain electrode of said second basic circuit unit; said inverted "ㄕ"-shaped region 250 is arranged in the central region inside said "匚"-shaped region, two said "L"-shaped regions 131 and 231 are nested between said "ㄕ"-shaped region 250 and said "匚"-shaped region 230, the vertical side of the inverted "ㄕ"-shape is used to realize series connection with said parallel power units.

[0050] The insulating plate according to claim 1, wherein the lower metal layer is used for welding with said bottom plate, said intermediate insulating layer is used for electrically isolating said power unit from the bottom plate, the thickness of said intermediate insulating layer depends on the breakdown field strength of the material of said insulating layer and the withstand voltage of said power module, the thickness thereof is not less than the quotient obtained by dividing the withstand voltage of said power module by the breakdown field strength of said insulating layer material, and the withstand voltage of said power module is 2N times the withstand voltage of said power unit, the large rectangular upper metal layer region in said upper metal layer is welded to the lower copper foil of the first DBC structure 100 of said power unit, and the small rectangular upper metal layer regions are respectively welded to the lower copper foils of said second DBC structure 135, third DBC structure 136, fourth DBC structure 137 and fifth DBC structure 138.

[0051] As described in claim 1, the power module, as shown in schematic diagrams 7000 and 9000, is characterized in that the starting point and ending point of the series power units are respectively a "DC+" power electrode 1 and a "DC-" power electrode 2, wherein the "DC+" power electrode 1 is connected to the first basic circuit unit of the first power unit parallel to the power module, and the "DC-" power electrode is connected to the second basic circuit unit of the last power unit parallel to the power module. The projection of the main branch of the power unit onto the horizontal plane of the power module is generally "S" shaped. The projection of the main power branch of the power module onto the horizontal plane of the module is a series connection of multiple "S" shaped branches. The series connection of the multiple "S" shaped branches is symmetrically distributed on the long axis centerline of the power module, as shown in schematic diagram 9100.

[0052] Another embodiment of the present invention proposes a series topology power module, comprising: a power unit including a first DBC structure, a second DBC structure, a third DBC structure, a fourth DBC structure, a fifth DBC structure, a third solder layer, a main switching transistor power electronic chip, an auxiliary switching transistor power electronic chip, a clamping capacitor, a main switching transistor gate signal terminal, a main switching transistor source signal terminal, an auxiliary switching transistor gate signal terminal, an auxiliary switching transistor source signal terminal, and a voltage sampling signal terminal. The first, second, third, fourth, and fifth DBC structures each include a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The lower copper foil is located on the upper surface of the second solder layer and is used to connect to the upper metal layer of the insulating board. The third solder layer is located on the upper surface of the upper copper foil. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip are both located on the upper surface of the third solder layer. The circuit topology of the power unit includes a first basic circuit unit and a second basic circuit unit connected in series. Both the first and second basic circuit units include a main switching power electronic chip and an active clamping branch connected in parallel. The active clamping branch includes an auxiliary switching power electronic chip and a clamping capacitor connected in series. The main branch of the power unit includes the main switching power electronic chip of the first basic circuit and the main switching power electronic chip of the second basic circuit connected in series. A series connection structure is located on the upper surface of the third solder layer to realize the series connection of the power units. Power electrodes include a "DC+" power electrode and a "DC-" power electrode. Multiple power units within the power module are sequentially arranged in parallel and connected in series through the series connection structure to realize the sequential series connection of the first and second basic circuit units. The main power branch of the power module is formed by the series connection of the main branches of the power units.

[0053] The short axis centerlines of the multiple power units arranged in parallel in the power module are all parallel to the long axis centerline of the power module, and the series connection structures connecting the power units are all located on the same side of the long axis centerline of the power module.

[0054] In the first basic circuit unit of the power unit: the gate signal terminal and source signal terminal of the main switch are arranged on the second DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the third DBC structure. The connection line of these signal terminals in the first basic circuit unit after projection on the horizontal plane is the horizontal line of the first signal terminal. In the second basic circuit unit: the gate signal terminal and source signal terminal of the main switch are arranged on the fourth DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the fifth DBC structure. The connection line of these signal terminals in the second basic circuit unit after projection on the horizontal plane is the horizontal line of the first signal terminal. The line is the second signal terminal horizontal line. Both the first signal terminal horizontal line and the second signal terminal horizontal line are parallel to the short axis center line of the power unit and are located on the two outer side regions of the power unit, respectively. The main switching power electronic chip, auxiliary switching power electronic chip, clamping capacitor and voltage sampling terminal of the clamping capacitor in the first basic circuit unit and the second basic circuit unit are all arranged on the first DBC structure. The first DBC structure is located in the middle region of the power unit, and the source of the first basic circuit unit and the drain of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure.

[0055] The number of series connections of the power unit is N, and N is a natural number greater than or equal to 2. The main switching power electronic chip or the auxiliary switching power electronic chip in the power unit can also be connected in anti-parallel to a freewheeling diode chip. The anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain of the power electronic chip, and the anode of the freewheeling diode chip is connected to the source of the power electronic chip.

[0056] In the first DBC structure, the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube, and the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube in the first basic circuit unit are located in one short outer edge region of the first DBC structure; the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube, and the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube in the second basic circuit unit are located in the other short outer edge region of the first DBC structure; in the direction from the short outer edge to the short-axis centerline of the first DBC structure of the power unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the first basic circuit unit is the region for arranging the power electronic chip of the main switching tube of the first basic circuit unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube of the first basic circuit unit is the region for arranging the power electronic chip of the auxiliary switching tube of the first basic circuit unit and said region is L-shaped; similarly, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit is the region for arranging the power electronic chip of the main switching tube of the second basic circuit unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube of the second basic circuit unit is the region for arranging the power electronic chip of the auxiliary switching tube of the second basic circuit unit and said region is also L-shaped; the region for arranging the source of the power electronic chip of the main switching tube of the first basic circuit unit and the region for arranging the power electronic chip of the main switching tube of the second basic circuit unit integrally form a large U-shaped region and are located near the long side edge of the central region of the first DBC structure, wherein the upper transverse edge of the U-shape is nested between the arrangement region of the power electronic chip of the main switching tube of the first basic circuit unit and the arrangement region of the power electronic chip of the auxiliary switching tube of the first basic circuit unit, the lower transverse edge region of the U-shape is the arrangement region of the power electronic chip of the main switching tube of the second basic circuit unit, and said region is located between the arrangement region of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit and the source arrangement region of the second basic circuit unit; the region for arranging the source of the second basic circuit unit is integrally in an inverted ㄕ shape, and the lower transverse edge of the inverted ㄕ shape is located between the lower transverse edge of the U-shape and the L-shaped region for arranging the power electronic chip of the auxiliary tube of the second basic circuit unit;

[0057] The region for arranging the low-voltage pins of the clamp capacitors of the second basic circuit units, the region for arranging the capacitor voltage sampling terminals for sampling the low-potential voltage of the clamp capacitors and the region for arranging the source electrodes of the second basic circuit units in the upper copper foil of the first DBC structure are a single first connected region, the single first connected region is the "ㄕ"-shaped region and is characterized by a low-voltage potential in the circuit topology of the power unit; the region for arranging the power electronic chips of the main switching tubes of the second basic circuit units, the region for arranging the low-potential voltage pins of the clamp capacitors of the first basic circuit units, the region for arranging the capacitor voltage sampling terminals for sampling the low-potential voltage of the clamp capacitors of the first basic circuit units and the region for arranging the source electrodes of the power electronic chips of the main switching tubes of the first basic circuit units in the upper copper foil of the first DBC structure are a single second connected region, the single second connected region is the "匚"-shaped region, and the "匚"-shaped region is used to implement the electrical connection of the main power loop between the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit; the inverted "ㄕ"-shaped region is arranged in the central region inside the "匚"-shaped region, two said "L"-shaped regions are nested between the "ㄕ"-shaped region and the "匚"-shaped region, and the vertical side of the inverted "ㄕ"-shaped region is used to implement the series connection with the juxtaposed power units;

[0058] In said power module, the start point and the end point for series connecting the power units are a "DC+" power electrode and a "DC-" power electrode respectively, wherein the "DC+" power electrode is connected to the first basic circuit unit of the first juxtaposed power unit inside the power module, and the "DC-" power electrode is connected to the second basic circuit unit of the last juxtaposed power unit inside the power module; the projection of the main branch of the power unit on the horizontal plane of the power module is overall S-shaped, the projection of the main power branch of the power module on the horizontal plane of the power module is a series connection of a plurality of S-shaped branches, and the plurality of S-shaped branches connected in series are symmetrically distributed on the long-axis center line of the power module.

[0059] While the invention has been described with reference to several typical embodiments, it is to be understood that the terminology used is for the purpose of description and example, and not of limitation. Since the invention can be embodied in many forms without departing from the spirit or essential characteristics thereof, it is to be understood that the above embodiments are not limited to any of the foregoing details, but are to be construed broadly within the spirit and scope defined by the appended claims, and therefore all changes and modifications that fall within the scope of the claims or the equivalents thereof are intended to be embraced by the appended claims.

Claims

1. A series topology power module, characterized in that, include: Base plate; The first solder layer is located on the upper surface of the base plate; An insulating board includes a lower metal layer, an intermediate insulating layer, and an upper metal layer, wherein the lower metal layer is located on the upper surface of the first solder layer; The second solder layer is located on the upper surface of the upper metal layer; A power unit, located on the upper surface of the second solder layer, includes a first DBC structure, a second DBC structure, a third DBC structure, a fourth DBC structure, a fifth DBC structure, a third solder layer, a main switching transistor power electronic chip, an auxiliary switching transistor power electronic chip, a clamping capacitor, a main switching transistor gate signal terminal, a main switching transistor source signal terminal, an auxiliary switching transistor gate signal terminal, an auxiliary switching transistor source signal terminal, and a voltage sampling signal terminal. The first, second, third, fourth, and fifth DBC structures each include a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The lower copper foil is located on the upper surface of the second solder layer and is used to achieve […]. The upper metal layer of the insulating board is connected, the third solder layer is located on the upper surface of the upper copper foil, the main switching power electronic chip and the auxiliary switching power electronic chip are both located on the upper surface of the third solder layer, the circuit topology of the power unit includes a first basic circuit unit and a second basic circuit unit connected in series, the first basic circuit unit and the second basic circuit unit both include a main switching power electronic chip and an active clamping branch connected in parallel with it, the active clamping branch includes an auxiliary switching power electronic chip and a clamping capacitor connected in series with it, the main branch of the power unit includes the main switching power electronic chip of the first basic circuit and the main switching power electronic chip of the second basic circuit connected in series with it; A series connection structure is located on the upper surface of the third solder layer and is used to realize the series connection of the power units; Power electrodes, including "DC+" power electrodes and "DC-" power electrodes; The auxiliary structure includes a plastic frame structure, a cap, and a potting compound, the potting compound being filled inside the power module defined by the plastic frame structure; as well as The power module contains multiple power units arranged in parallel and connected in series to achieve the sequential connection of the first basic circuit unit and the second basic circuit unit. The main power branch of the power module is formed by connecting the main branches of the power units in series.

2. The series topology power module as described in claim 1, characterized in that, The short axis centerlines of the multiple power units arranged side by side are all parallel to the long axis centerline of the power module, and the series connection structures connecting the power units are all located on the same side of the long axis centerline of the power module.

3. The series topology power module as described in claim 2, characterized in that, In the first basic circuit unit: the gate signal terminal and source signal terminal of the main switch are arranged on the second DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the third DBC structure. The connection line of these signal terminals in the first basic circuit unit after projection onto the horizontal plane is the first signal terminal horizontal line. In the second basic circuit unit: the gate signal terminal and source signal terminal of the main switch are arranged on the fourth DBC structure, and the gate signal terminal and source signal terminal of the auxiliary switch are arranged on the fifth DBC structure. The connection line of these signal terminals in the second basic circuit unit after projection onto the horizontal plane is the second signal terminal horizontal line. The horizontal lines of the first and second signal terminals are parallel to the short axis centerline of the power unit and are located on the two outer sides of the power unit, respectively. The main switching power electronic chip, auxiliary switching power electronic chip, clamping capacitor, and voltage sampling terminals of the clamping capacitor in the first and second basic circuit units are all arranged on the first DBC structure. The first DBC structure is located in the middle area of ​​the power unit, and the source of the first basic circuit unit and the drain of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure.

4. The series topology power module as described in claim 3, characterized in that, The number of parallel main switching power electronic chips in the first basic circuit unit or the second basic circuit unit is greater than or equal to 2, the number of auxiliary switching power electronic chips is greater than or equal to 1, the number of parallel clamping capacitors is greater than or equal to 2 and the sizes of the clamping capacitors are different, and the withstand voltage of the first basic circuit unit is equal to the withstand voltage of the second basic circuit unit.

5. The series topology power module as described in claim 4, characterized in that, The number of series connections in the power unit is N, and N is a natural number greater than or equal to 2. In the power unit, the main switching power electronic chip or the auxiliary switching power electronic chip is connected in anti-parallel with a freewheeling diode chip. The anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain of the main switching power electronic chip, and the anode of the freewheeling diode chip is connected to the source of the main switching power electronic chip.

6. The series topology power module as described in claim 3, characterized in that, The source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the first basic circuit unit, and the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube are located in a short outer side region of the first DBC structure; the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit, and the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube are located in the other short outer side region of the first DBC structure; in a direction from the short outer side toward the short axis center line of the first DBC structure of the power unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the first basic circuit unit is a region for arranging the power electronic chip of the main switching tube of the first basic circuit unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube of the first basic circuit unit is a region for arranging the power electronic chip of the auxiliary switching tube of the first basic circuit unit, and said region is L-shaped. Similarly, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit is a region for arranging the power electronic chip of the main switching tube of the second basic circuit unit, the region immediately adjacent to the source strip and gate strip of the gate-source path of the power electronic chip of the auxiliary switching tube of the second basic circuit unit is a region for arranging the power electronic chip of the auxiliary switching tube of the second basic circuit unit, and said region is also L-shaped; the region for arranging the source of the power electronic chip of the main switching tube of the first basic circuit unit and the region for arranging the power electronic chip of the main switching tube of the second basic circuit unit integrally form a large C-shaped region located near the long side of the central region of the first DBC structure, wherein the upper horizontal side of said C-shape is nested between the arrangement region of the power electronic chip of the main switching tube of the first basic circuit unit and the arrangement region of the power electronic chip of the auxiliary switching tube of the first basic circuit unit, the lower horizontal side region of said C-shape is the arrangement region of the power electronic chip of the main switching tube of the second basic circuit unit, and said region is located between the arrangement region of the gate-source path of the power electronic chip of the main switching tube of the second basic circuit unit and the source arrangement region of the second basic circuit unit; the region for arranging the source of the second basic circuit unit is integrally in an inverted "ㄕ" shape, and the lower horizontal side of the inverted "ㄕ" shape is located between the lower horizontal side of the C-shape and the L-shaped region for arranging the power electronic chip of the auxiliary tube of the second basic circuit unit.

7. The series topology power module as described in claim 3, characterized in that, A region where the low-voltage pins of the clamp capacitors of the second basic circuit unit are arranged, a region where the capacitor voltage sampling terminals for sampling the low-potential voltage of the clamp capacitors are arranged, and a region where the source electrode of the second basic circuit unit is arranged in the upper copper foil of the first DBC structure form a single first communication area, the single first communication area is a "ㄕ"-shaped area and is characterized by low-voltage potential in the circuit topology of the power unit; a region where the power electronic chip of the main switch tube of the second basic circuit unit is arranged, a region where the low-potential voltage pins of the clamp capacitor of the first basic circuit unit are arranged, a region where the capacitor voltage sampling terminals for sampling the low-potential voltage of the clamp capacitor of the first basic circuit unit are arranged, and a region where the source electrode of the power electronic chip of the main switch tube of the first basic circuit unit is arranged in the upper copper foil of the first DBC structure form a single second communication area, the single second communication area is a "匚"-shaped area, and the "匚"-shaped area is used to implement the electrical connection of the main power loop between the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit; the inverted "ㄕ"-shaped area is arranged in the central area inside the "匚"-shaped area, two "L"-shaped areas are nested between the "ㄕ"-shaped area and the "匚"-shaped area, and the vertical side of the inverted "ㄕ"-shaped area is used to implement the series connection with the juxtaposed power units.

8. The series topology power module as described in claim 1, characterized in that, The lower metal layer is used for welding with the base plate, the intermediate insulating layer is used for electrically isolating the power units from the base plate, the thickness of the intermediate insulating layer depends on the breakdown field strength of the material of the insulating layer and the voltage resistance of the power module, and the thickness is not less than the quotient obtained by dividing the voltage resistance of the power module by the breakdown field strength of the material of the insulating layer, wherein the voltage resistance of the power module is 2N times the voltage resistance of the power unit, the large rectangular upper metal layer area in the upper metal layer is welded with the lower copper foil of the first DBC structure of the power unit, and the small rectangular upper metal layers are respectively welded with the lower copper foils of the second DBC structure, the third DBC structure, the fourth DBC structure and the fifth DBC structure.

9. The series topology power module as described in claim 1, characterized in that, The starting point and the end point of the series-connected power units are "DC+" power electrode and "DC-" power electrode respectively, wherein the "DC+" power electrode is connected to the first basic circuit unit of the first juxtaposed power unit inside the power module, and the "DC-" power electrode is connected to the second basic circuit unit of the last juxtaposed power unit inside the power module, the projection of the main branch of the power unit on the horizontal plane of the power module is generally "S"-shaped, the projection of the main power branch of the power module on the horizontal plane of the power module is a series connection of a plurality of "S"-shaped branches, and the plurality of series-connected "S"-shaped branches are symmetrically distributed on the long-axis center line of the power module.

Images