A power module based on a series topology

Abstract

Disclosed is a power module based on a series topology structure, which relates to the field of power electronics technology. The disclosed power module integrates low-voltage withstand power electronic chips in a high density through the design of sequentially connecting a first power unit and a second power unit in series, so as to improve the voltage withstand and current rating of the power module. The beneficial effects are as follows: The design of the first DBC structure of the first power unit and the second DBC structure of the second power unit, which is symmetrical thereto, greatly reduces the parasitic inductance of the main power loop of the module. The design of arranging the signal terminals on the input side of the power module on the center line of the module reduces the parasitic inductance of the input side loop of the module, and at the same time improves the symmetry and compactness of the input side loop path, so as to achieve high-density integration of the drive circuit and the power module.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a series topology power module adopting an active clamping voltage sharing control technology and its structure design. Background Art

[0002] There are two possible solutions for building a high-voltage power conversion system using low-voltage devices, namely the multilevel converter scheme and the power device series scheme. Multilevel converter schemes represented by the cascaded H-bridge multilevel converter (CHB) and the modular multilevel converter (MMC) have the characteristics of modular structure, high efficiency and high reliability, and have been applied to many medium and high power conversion applications. However, multilevel converter schemes usually have to use large-sized passive components. For example, CHB needs to be equipped with a relatively large volume phase-shifting transformer, and capacitors in MMC account for about 70% of the size of its sub-modules. These disadvantages hinder the use of multilevel converters in some applications with strict requirements for weight and volume, such as electrified transportation and data centers.

[0003] The power device series scheme is another relatively direct way to apply low-voltage power devices to medium and high voltage application scenarios. The series scheme of power devices improves the withstand voltage level of the power conversion system and increases the output power of the power conversion system. Its advantages over the multilevel technology scheme are that the volume of the power conversion system after series connection is small, the number of passive components is small, and the circuit topology is simple. However, due to differences in the electrical performance parameters of power devices or external circuit conditions, such as: junction capacitance, gate threshold voltage, gate drive signal delay, instantaneous drive voltage applied to the gate, etc., the voltage of series-connected power devices is very likely to be unbalanced, resulting in the problem of low electrical reliability of the power conversion system. Therefore, achieving voltage balance of series devices has become the technical key for power conversion systems using low withstand voltage power devices to further improve voltage and current levels.

[0004] The voltage sharing control strategy and the hardware optimization design of the series topology power loop are the two main technical supports for achieving voltage balance of series power devices. There are two types of technical solutions for the voltage sharing control strategy, namely the input gate side voltage sharing control technical solution and the output power side voltage sharing control technical solution.

[0005] The disadvantages of the input-gate side voltage sharing control technical solution are as follows: the circuit design and control strategy are relatively complex, the requirements for high-speed sensors and A / D conversion chips are extremely high, and it is also extremely sensitive to device temperature and load current changes. This technical solution has to introduce additional circuits, increasing the complexity of the drive loop. Since it involves high-speed control, the cost of the voltage sharing control circuit is relatively high, lacking practical usability.

[0006] The output-power side voltage sharing control technical solution includes the Passive Snubber Circuit solution and the Active Clamp Circuits solution. In the Passive Snubber Circuit solution, due to the use of an RC circuit (Resistor-Capacitance circuit), a large amount of energy loss will occur on the buffer resistor (Resistor, R) during actual operation. The large volume of passive components is not conducive to integration. The buffer capacitor is connected in parallel with the power loop of the switching device, resulting in a slower switching speed of the switching device. However, in the Active Voltage Clamp Circuit solution, by introducing an auxiliary switching device in the clamping branch, the energy accumulated in the clamping capacitor is fed back to the circuit instead of being directly consumed as in the RC solution. The loss introduced by the voltage sharing circuit of this solution is small. In addition, the active clamp circuit will only play a clamping role when the voltage across the power electronic device exceeds the voltage across the clamping capacitor. This method will not reduce the switching speed of the main switching device itself and will not increase the switching loss of the main switch. Therefore, the voltage sharing control strategy based on the active clamp circuit is an ideal solution to solve the voltage sharing of series devices.

[0007] However, in the current research on the active clamp control strategy, when building the hardware of the series topology power loop, it is basically carried out based on discrete devices or conventional commercial power modules, which also has many drawbacks, thus restricting to a certain extent the large-scale commercial use of the series scheme of power electronics using the active clamp control strategy. The series scheme based on discrete devices has the disadvantages of low system power density and difficulty in operating at high current, and cannot meet the high-power requirements of medium-voltage applications. Although the series scheme based on standardized commercial modules solves the high-power requirements of medium-voltage applications, the mismatch between the circuit topology of the power loop of the commercial module and the overall architecture of the power conversion system using the active clamp control strategy also makes the active clamp series scheme based on commercial modules have many limitations, such as inconvenient expansion of the voltage and current levels of the power conversion system, a relatively long internal power loop line in the power conversion system resulting in a large parasitic inductance, an unreasonable main circuit topology of the power module, a low power density of the power module and its power conversion system, or a slow dynamic response.

[0008] In view of this, developing a series topology power module suitable for the active clamping control strategy is of great significance for fully verifying the active clamping technology solution in the field of high-voltage and high-power conversion technology. Developing a series topology power module is also the only way for the active clamping technology solution to achieve industrialization in the field of high-voltage and high-power conversion technology.

[0009] In order to extend the low-loss and low-cost advantages of low-voltage withstand silicon carbide devices to the field of high-voltage and high-power applications and gradually replace technical solutions such as multilevel or input gate side voltage sharing control that have many disadvantages, it is urgent to develop a low-cost high-voltage and high-power module based on series-connected low-voltage withstand power electronic chips and adopting an active clamping control strategy. Therefore, a series topology power module based on low-voltage withstand electronic chips and adopting active clamping voltage sharing control has great application prospects and economic value. Summary of the Invention

[0010] To solve one or more of the above-mentioned technical problems of the prior art, the present invention proposes a power module and its structural design based on a power module with a series topology.

[0011] According to an embodiment of the present invention, a power module based on a series topology structure is provided, which includes: a bottom plate; a first solder layer located on the upper surface of the bottom plate; a first power unit, which includes a first DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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. Wherein the first DBC structure includes 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 first solder layer and is used to connect to the bottom plate. The circuit topology structure of the first power unit includes a first basic circuit unit and a second basic circuit unit connected in series therewith. Both the first basic circuit unit and the second basic circuit unit include a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the first power unit includes the main switch power electronic chip of the first basic circuit unit and the main switch power electronic chip of the second basic circuit unit connected in series therewith; a second power unit, which includes a second DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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. Wherein the DBC structure includes 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 first solder layer and is used to connect to the bottom plate. The circuit topology structure of the second power unit includes a third basic circuit unit and a fourth basic circuit unit connected in series therewith. Both the third basic circuit unit and the fourth basic circuit unit include a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the second power unit includes the main switch power electronic chip of the third basic circuit unit and the main switch power electronic chip of the fourth basic circuit unit connected in series therewith; a series connection structure located on the upper copper foils of the first DBC structure and the second DBC structure for realizing the series connection of the first power unit and the second power unit; power electrodes, including a "DC+" power electrode and a "DC-" power electrode; and inside the power module, the first power unit and the second power unit are arranged in parallel in sequence and connected together through the series connection structure. The "DC+" power electrode is located on the first basic circuit unit of the first power unit in the first of the parallel arrangement, and the "DC-" power electrode is located on the second basic circuit unit of the first power unit in the last of the parallel arrangement or the fourth basic circuit unit of the second power unit.In a module formed by sequentially connecting multiple said first power units and said second power units in series, said first basic circuit unit, second basic circuit unit, third basic circuit unit, and fourth basic circuit unit are also connected in series in sequence.

[0012] According to another embodiment of the present invention, a power module with a series topology is proposed, including: a first power unit, which includes a first DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 DBC structure includes a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The circuit topology of the first power unit includes a first basic circuit unit and a second basic circuit unit connected in series therewith. Each of the first basic circuit unit and the second basic circuit unit includes a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the first power unit includes the main switch power electronic chip of the first basic circuit unit and the main switch power electronic chip of the second basic circuit unit connected in series therewith; a second power unit, which includes a second DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 second DBC structure includes a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The circuit topology of the second power unit includes a third basic circuit unit and a fourth basic circuit unit connected in series therewith. Each of the third basic circuit unit and the fourth basic circuit unit includes a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the second power unit includes the main switch power electronic chip of the third basic circuit unit and the main switch power electronic chip of the fourth basic circuit unit connected in series therewith; a series connection structure, located on the upper copper foils of the first DBC structure and the second DBC structure, for realizing the series connection of the first power unit and the second power unit; power electrodes, including a "DC+" power electrode and a "DC-" power electrode; and inside the power module, the first power unit and the second power unit are arranged in parallel in sequence and connected together through the series connection structure. The "DC+" power electrode is located on the first basic circuit unit of the first power unit in the first position of the parallel arrangement, and the "DC-" power electrode is located on the second basic circuit unit of the first power unit in the last position of the parallel arrangement or the fourth basic circuit unit of the second power unit; in the module formed by sequentially connecting in series multiple of the first power units and the second power units, the first basic circuit unit, the second basic circuit unit, the third basic circuit unit, and the fourth basic circuit unit are also connected in series in sequence;

[0013] Further, in the power module, the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure, and the source electrode of the third basic circuit unit and the drain electrode of the fourth basic circuit unit are electrically interconnected through the upper copper foil of the second DBC structure; when the first power unit and the second power unit are connected in series in sequence, the short-axis centerlines of the first power unit and the second power unit are both parallel to the long-axis centerline of the power module. The drain electrode of the third basic circuit unit in the second power unit and the source electrode of the second basic circuit unit of the previous first power unit connected in series are electrically interconnected through a series connection structure, and the source electrode of the fourth basic circuit unit in the second power unit and the drain electrode of the first basic circuit unit of the next first power unit connected in series are also electrically interconnected through a series connection structure. After series connection, the sum of the numbers of the first power unit and the second power unit in the power module is N, and N is a natural number greater than or equal to 2. The withstand voltage of the power module is equal to 2N times the withstand voltage of the first power unit or the second power unit;

[0014] Further, in the first power unit, the first basic circuit unit and the second basic circuit unit are respectively located on both sides of the short-axis centerline of the first power unit. The gate signal terminal and the source signal terminal of the main switch tube and the gate signal terminal and the source signal terminal of the auxiliary switch tube in the first basic circuit unit are close to the short-axis centerline of the first power unit and are arranged on the same side of the short-axis centerline. The gate signal terminal and the source signal terminal of the main switch tube and the gate signal terminal and the source signal terminal of the auxiliary switch tube in the second basic circuit unit are also close to the short-axis centerline of the first power unit and are arranged on the other side of the short-axis centerline. The layout positions of the second basic circuit signal terminal and the first basic circuit signal terminal are symmetrically distributed with respect to the short-axis centerline of the first power unit; the clamping capacitors and the voltage sampling terminals of the clamping capacitors in the first basic circuit unit and the second basic unit are respectively arranged in the corresponding outer side area of the short side of the first power unit. The main switch tube power electronic chip and the auxiliary switch tube power electronic chip in the first basic circuit unit are arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal. The main switch tube power electronic chip and the auxiliary switch tube power electronic chip in the second basic circuit unit are also arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal, and the drain electrode of the second basic circuit unit is connected to the source electrode of the first basic circuit unit through the upper copper foil of the first DBC structure of the first power unit;

[0015] Further, in the second power unit, the third basic circuit unit and the fourth basic circuit unit are respectively located on both sides of the short-axis center line of the second power unit. In the third basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are all arranged close to the short-axis center line of the second power unit on the same side of the short-axis center line. In the fourth basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are also all arranged close to the short-axis center line of the second power unit and on the other side of the center line. The layout positions of the fourth basic circuit signal terminal and the third basic circuit signal terminal are symmetrically distributed with respect to the short-axis center line of the second power unit. The clamping capacitors and the voltage sampling terminals of the clamping capacitors in the third basic circuit unit and the fourth basic circuit unit are respectively arranged in the corresponding outer side regions of the short sides of the second power unit. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the third basic circuit unit are arranged in the middle region between the signal terminal and the layout regions of the capacitor and its sampling terminal. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the fourth basic circuit unit are also arranged in the middle region between the signal terminal and the layout regions of the capacitor and its sampling terminal. Moreover, the drain of the fourth basic circuit unit is connected to the source of the third basic circuit unit through the upper copper foil of the second DBC structure, and the drain of the third basic circuit unit is connected to the source of the second basic circuit unit of the first power unit through a series connection structure;

[0016] Further, in the first DBC structure, the source bars and gate bars of the gate-source paths of the main switch power electronic chips in the first basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all close to the short-axis center line of the DBC structure and are arranged on the same side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips in the second basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also close to the short-axis center line of the DBC structure and are arranged on the other side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips in the second basic circuit unit and the source bars and gate bars of the gate-source paths of the main switch power electronic chips in the first basic circuit unit are symmetric with each other with respect to the plane perpendicular to the DBC structure plane where the short-axis center line is located. In the direction from the short-axis center line of the first DBC structure to the short outer side, the area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip in the first basic circuit unit is the area for arranging the main switch power electronic chip of the first basic circuit unit, and this area is in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip in the first basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the first basic circuit unit, and this area is also in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip in the second basic circuit unit is the area for arranging the main switch power electronic chip of the second basic circuit unit, and this area is integrally set in an "F" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip in the second basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the second basic circuit unit, and this area is also in an "L" shape. The "L" shaped area for arranging the auxiliary switch power electronic chip of the first basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chip of the second basic circuit unit are both located in the left-side area of the DBC structure of the first power unit. The area with an "F" shape for the drain of the second basic circuit unit is located in the right-side area of the DBC structure of the first power unit.

[0017] Further, in the first DBC structure, the regions in the upper copper foil of the first DBC structure for laying out the low-voltage pins of the clamping capacitors of the second basic circuit unit, the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors, and the regions for laying out the sources of the second basic circuit unit form a single connected region. This single connected region is overall in an "L" shape and is characterized by a low-voltage potential in the circuit topology of the first power unit; the regions in the upper copper foil of the first DBC structure for laying out the power electronic chips of the main switching transistors of the second basic circuit unit, the regions for laying out the low-potential voltage pins of the clamping capacitors of the first basic circuit unit, the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors of the first basic circuit unit, and the regions for laying out the sources of the power electronic chips of the main switching transistors of the first basic circuit unit form a single connected region. This single connected region is an "F" shaped region, which is also used as the main branch path realized through the upper copper foil of the first DBC structure between the source of the first basic circuit unit and the drain of the second basic circuit unit;

[0018] Further, in the second DBC structure, the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all arranged close to the short-axis center line of the second DBC structure on the same side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also arranged close to the short-axis center line of the second DBC structure and on the other side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit are respectively symmetric to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit with respect to the plane perpendicular to the plane of the second DBC structure where the short-axis center line is located; from the short-axis center line of the second DBC structure towards the short outer side, the area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip of the third basic circuit unit is the area for arranging the main switch power electronic chip of the third basic circuit unit and this area is in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip of the third basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the third basic circuit unit and this area is also in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip of the fourth basic circuit unit is the area for arranging the main switch power electronic chip of the fourth basic circuit unit and this area is in an overall "F" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip of the fourth basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the fourth basic circuit unit and this area is also in an "L" shape; the "L" shaped area for arranging the auxiliary switch power electronic chip of the fourth basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chip of the third basic circuit unit are both located in the left-side area of the second DBC structure; the area in the shape of an "F" for arranging the drain of the fourth basic circuit unit is located in the right-side area of the second DBC structure; the upper copper foil pattern of the second DBC structure is in a mirror symmetry relationship with the upper copper foil pattern of the first DBC structure, and the mirror plane is parallel to the short-axis center line of the first DBC structure and perpendicular to the plane where the first DBC structure is located;

[0019] Further, in the power module, the starting point and the ending point of the series connection of the first power unit and the second power unit are the "DC+" power electrode and the "DC-" power electrode respectively. The main power branch path of the power module from the "DC+" power electrode to the "DC-" power electrode is formed by the series connection of the main branch of the first power unit and the main branch of the second power unit. The projection of the main power branch path of the power module on the horizontal plane of the power module is integrally distributed in a "rectangular wave" shape along the long-axis center line of the power module. The path portion perpendicular to the long-axis center line in the "rectangular wave" shape path is located in the right-side region of the first power unit or the second power unit where it is located.

[0020] Compared with the prior art solutions, the beneficial effects of a power module based on a series topology structure and its structural design disclosed by the present invention are as follows: The structural design of the power unit in which two series-connected basic circuit units are symmetrically distributed on both sides of the short-axis center line of the power unit and the switching tube signal terminals are arranged close to the short-axis center line is beneficial to the high-density integration of the power module and the drive circuit; The design method of forming the second DBC structure by simply mirror-symmetry of the first DBC structure simplifies the structural design of the power module and at the same time improves the symmetry of the overall path of the main power branch of the power module; Since there are paths that are parallel to each other, close to each other but with opposite current flow directions in the main branches of the first power unit and the second power unit inside the basic circuit unit, the technical solution based on the sequential series connection of the first power unit and the second power unit is proposed, thereby reducing the parasitic inductance of the main power branch of the power module and thus improving the dynamic electrical performance of the power module; Since the overall path of the main power branch of the power module can be simplified into a "rectangular wave" shape, therefore, the proposed power module and its structural design can significantly reduce the length of the power module in the series direction, reduce the power difficulty of module manufacturing, and facilitate improving the manufacturing yield of high-voltage withstand series topology structure power modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural design diagram of the power module according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic cross-sectional structure diagram of the power module according to an embodiment of the present invention;

[0023] Figure 3 It is a schematic structural diagram of the first power unit in the power module according to an embodiment of the present invention;

[0024] Figure 4 It is a schematic structural diagram of the second power unit in the power module according to an embodiment of the present invention;

[0025] Figure 5Schematic diagram of the circuit topologies of the first / second power units in the power module according to an embodiment of the present invention;

[0026] Figure 6 Schematic diagram of the circuit topology of the power module according to an embodiment of the present invention;

[0027] Figure 7 Schematic diagram of the design of the first DBC structure according to an embodiment of the present invention;

[0028] Figure 8 Schematic diagram of the design of the second DBC structure according to an embodiment of the present invention;

[0029] Figure 9 Schematic diagram for comparing the symmetry relationship between the first DBC structure and the second DBC structure according to an embodiment of the present invention;

[0030] Figure 10 Schematic diagram of the projection of the internal structure of the power module on the module horizontal plane according to an embodiment of the present invention;

[0031] Figure 11 Schematic diagram of the overall path characteristics presented after the projection of the main power branch path of the power module on the module horizontal plane according to an embodiment of the present invention. Detailed implementation manners

[0032] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments described here are only for illustrative purposes and do not limit the present invention. In the following description, a large number of specific details are set forth for the purpose of providing a thorough understanding of the present invention. However, those of ordinary skill in the art will understand that these specific details are not necessary for implementing the present invention. In addition, in some embodiments, well-known circuits, materials, or methods are not specifically described to avoid obscuring the present invention.

[0033] Throughout the specification, the reference to "an embodiment", "embodiments", "an example" or "examples" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Thus, the phrases "in an embodiment", "in embodiments", "an example" or "examples" appearing throughout the specification do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Moreover, those of ordinary skill in the art should understand that the accompanying drawings provided herein are for illustrative purposes only, where the same reference numerals indicate the same elements. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] The power electronic chips used in the power module of the present invention include, but are not limited to, Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), Insulated Gate Bipolar Transistor (IGBT), and Junction Field-Effect Transistor (JFET) in terms of chip structure; and are not limited to silicon material (Silicon, Si) in terms of the materials used for the chips, and may also include various wide-bandgap semiconductor materials, such as Silicon Carbide (SiC), Gallium Nitride (GaN), Gallium Oxide (Ga 2 O 3 ) and Diamond, etc. In the circuit topology of the power module of the present invention, in order to make the series and parallel relationships of the components in the circuit diagram clear, the body-diode in the switching tube power electronic chip or the anti-paralleled free-wheeling diode are omitted.

[0035] Figure 1 FIG. is a schematic diagram of the overall architecture design of the power module according to an embodiment of the present invention. The power module includes a bottom plate 10, a "DC+" power electrode 1, a "DC-" power electrode 2, a first power unit and a second power unit connected in parallel and sequentially in series, and a series connection structure 70 for realizing the series connection between the first power unit and the second power unit.

[0036] Figure 2 FIG. is a schematic cross-sectional structure diagram of the power module according to an embodiment of the present invention. From bottom to top, there are successively a bottom plate 10, a first solder layer 11, a first / second power unit DBC structure 30, a main second solder layer 12, a main switching tube power electronic chip 40, an auxiliary switching tube power electronic chip 50, and a clamping capacitor 60. The power unit DBC structure 30 includes a lower copper foil 31, an intermediate ceramic layer 32, and an upper copper foil 33.

[0037] Figure 3Schematic diagram of the structure of the first power unit in the power module according to an embodiment of the present invention, which includes the gate signal terminal 101 and source signal terminal 102 of the main switch tube of the first basic circuit unit, the gate signal terminal 103 and source signal terminal 104 of the auxiliary switch tube of the first basic circuit unit, the gate signal terminal 105 and source signal terminal 106 of the main switch tube of the second basic circuit unit, the gate signal terminal 107 and source signal terminal 108 of the auxiliary switch tube of the second basic circuit unit, the power electronic chip 40 of the main switch tube, the power electronic chip 50 of the auxiliary switch tube, the clamping capacitor 60, the high-potential voltage sampling terminal 16 and 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 low-potential voltage sampling terminal 19 of the clamping capacitor of the second basic circuit unit.

[0038] Figure 4 Schematic diagram of the structure of the second power unit in the power module according to an embodiment of the present invention, which includes the gate signal terminal 201 and source signal terminal 202 of the main switch tube of the third basic circuit unit, the gate signal terminal 203 and source signal terminal 204 of the auxiliary switch tube of the third basic circuit unit, the gate signal terminal 205 and source signal terminal 206 of the main switch tube of the fourth basic circuit unit, the gate signal terminal 207 and source signal terminal 208 of the auxiliary switch tube of the fourth basic circuit unit, the power electronic chip 40 of the main switch tube, the power electronic chip 50 of the auxiliary switch tube, the clamping capacitor 60, the high-potential voltage sampling terminal 26 and low-potential voltage sampling terminal 27 of the clamping capacitor of the third basic circuit unit, and the high-potential voltage sampling terminal 28 and low-potential voltage sampling terminal 29 of the clamping capacitor of the fourth basic circuit unit.

[0039] Figure 5Schematic diagram of the circuit topology of the first / second power units in a power module according to an embodiment of the present invention. The first power unit is formed by connecting a first basic circuit unit and a second basic circuit unit in series, and the second power unit is formed by connecting a third basic circuit unit and a fourth basic circuit unit in series. The circuit topologies of the first basic circuit unit, the second basic circuit unit, the third basic circuit unit, and the fourth basic circuit unit are all the same. Therefore, the circuit topology of the first power unit is the same as that of the second power unit. The circuit topology of the basic circuit unit is formed by connecting a main branch and an active clamping branch in parallel. The main branch of the basic circuit unit is the path from the drain (D) to the source (S) of the main switch Q1. The active clamping branch of the basic circuit unit is formed by connecting an auxiliary switch Q2 and a clamping capacitor C1 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. The main branch of the first power unit sequentially passes through the source of the first basic circuit unit, the drain of the second basic circuit unit, and reaches the source of the second basic circuit unit from the drain of the first basic circuit unit. The main branch of the second power unit sequentially passes through the source of the third basic circuit unit, the drain of the fourth basic circuit unit, and reaches the source of the fourth basic circuit unit from the drain of the third basic circuit unit.

[0040] Figure 6 Schematic diagram of the circuit topology of a power module according to an embodiment of the present invention. In the figure, the series connection mode of the first power unit and the second power unit is sequential series connection. The so-called sequential series connection means that the source of the first power unit is connected to the drain of the second power unit, and the drain of the second power unit is connected to the source of the first power unit. The so-called source of the first power unit refers to the source of the second basic circuit unit in the first power unit. The so-called drain of the first power unit refers to the drain of the first basic circuit unit in the first power unit. The so-called source of the second power unit refers to the source of the fourth basic circuit unit in the second power unit. The so-called drain of the second power unit refers to the drain of the third basic circuit unit in the second power unit.

[0041] Figure 7Schematic diagram of the design of the first DBC structure according to an embodiment of the present invention. The upper copper foil of the DBC structure in the figure includes: gate bar 110 and source bar 120 for laying out the gate-source path of the main switch power electronic chip of the first basic circuit unit, source bar 111 and source bar 121 for laying out the gate-source path of the auxiliary switch power electronic chip of the first basic circuit unit, area 130 for laying out the main switch power electronic chip of the first basic circuit unit, area 131 for laying out the auxiliary switch power electronic chip of the first basic circuit unit, gate bar 210 and source bar 220 for laying out the gate-source path of the main switch power electronic chip of the second basic circuit unit, gate bar 211 and source bar 221 for laying out the gate-source path of the auxiliary switch power electronic chip, area 230 for laying out the main switch power electronic chip of the second basic circuit unit, area 231 for laying out the auxiliary switch power electronic chip of the second basic circuit unit, and area 250 for laying out the source of the second basic circuit unit. Among them, the upper copper foil area 230 is in an overall "F" shape, the upper copper foil areas 131 and 231 are both in an "L" shape, and the upper copper foil area 250 is also in an "L" shape overall.

[0042] Figure 8 Schematic diagram of the design of the second DBC structure according to an embodiment of the present invention. The upper copper foil of the DBC structure in the figure includes: gate bar 310 and source bar 320 for laying out the gate-source path of the main switch power electronic chip of the third basic circuit unit, source bar 311 and source bar 321 for laying out the gate-source path of the auxiliary switch power electronic chip of the third basic circuit unit, area 330 for laying out the main switch power electronic chip of the third basic circuit unit, area 331 for laying out the auxiliary switch power electronic chip of the third basic circuit unit, gate bar 410 and source bar 420 for laying out the gate-source path of the main switch power electronic chip of the fourth basic circuit unit, gate bar 411 and source bar 421 for laying out the gate-source path of the auxiliary switch power electronic chip of the fourth basic circuit unit, area 430 for laying out the main switch power electronic chip of the fourth basic circuit unit, area 431 for laying out the auxiliary switch power electronic chip of the fourth basic circuit unit, and area 450 for laying out the source of the fourth basic circuit unit. Among them, the upper copper foil area 430 is in an overall "F" shape, the upper copper foil areas 331 and 431 are both in an "L" shape, and the upper copper foil area 450 is also in an "L" shape overall.

[0043] Figure 9 Schematic diagram for comparing the symmetry relationship between the first DBC structure and the second DBC structure according to an embodiment of the present invention. In the figure, the upper copper foil pattern of the first power unit DBC structure and the upper copper foil pattern of the second power unit second DBC structure are in a mirror symmetry relationship, and the symmetry mirror plane is parallel to the short axis center line of the first power unit or the second power unit and perpendicular to the horizontal plane where the power module is located.

[0044] Figure 10 It is a schematic diagram of the projection of the internal structure of the power module according to an embodiment of the present invention on the horizontal plane of the module. In the figure, two first power units and one second power unit are connected in series in sequence and are arranged side by side on the long axis center line of the power module. The "DC+" power electrode is arranged on the first basic circuit unit of the first of the side-by-side first power units, and the "DC-" power electrode is arranged on the fourth basic circuit unit of the last of the side-by-side second power units.

[0045] Figure 11 It is a schematic diagram of the overall path characteristics presented after the projection of the main power branch path of the power module according to an embodiment of the present invention on the horizontal plane of the power module. The main power branch starts from the "DC+" power electrode, sequentially passes through the side-by-side first power unit and second power unit, then the first power unit and second power unit, and then directly connects from the second basic circuit unit of the last of the side-by-side first power units to the "DC-" power electrode. The main power branch is overall in the shape of a "rectangular wave", and this "rectangular wave" path unfolds along the long axis center line of the power module, and the part perpendicular to the short axis center line of the power unit in the path is arranged next to the right side of the power unit.

[0046] An embodiment of the present invention proposes a power module based on the series connection of power electronic chips, such as Figure 1 and Figure 2 shown, which is characterized in that it includes: a bottom plate 10; a first solder layer 11 located on the upper surface of the bottom plate 10; a first power unit, such as Figure 3As shown, it includes a first DBC structure 100, a second solder layer 12, a main switch power electronic chip 40, an auxiliary switch power electronic chip 50, a clamping capacitor 60, main switch gate signal terminals 101 and 105, main switch source signal terminals 102 and 106, auxiliary switch gate signal terminals 103 and 107, auxiliary switch source signal terminals 104 and 108, voltage sampling signal terminals 16, 17, 18, and 19. The first DBC structure 100 includes a lower copper foil 31, an intermediate ceramic layer 32, and an upper copper foil 33. The lower copper foil 31 is located on the upper surface of the first solder layer 11 and is used to connect to the bottom plate 10. The circuit topology of the first power unit includes a first basic circuit unit and a second basic circuit unit connected in series therewith. Each of the first basic circuit unit or the second basic circuit unit includes a main switch power electronic chip 40 and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip 50 and the clamping capacitor 60 connected in series therewith. The main branch of the first power unit includes the main switch power electronic chip of the first basic circuit unit and the main switch power electronic chip of the second basic circuit unit connected in series therewith; a second power unit, such as Figure 4As shown in the figure, it includes a second DBC structure 200, a second solder layer 12, a main switch power electronic chip 40, an auxiliary switch power electronic chip 50, a clamping capacitor 60, main switch gate signal terminals 201 and 205, main switch source signal terminals 202 and 206, auxiliary switch gate signal terminals 203 and 207, auxiliary switch source signal terminals 204 and 208, voltage sampling signal terminals 26, 27, 28 and 29. The second DBC structure 200 includes a lower copper foil 31, an intermediate ceramic layer 32 and an upper copper foil 33. The lower copper foil is located on the upper surface of the first solder layer 11 and is used to connect to the bottom plate 10. The circuit topology of the second power unit includes a third basic circuit unit and a fourth basic circuit unit connected in series therewith. Both the third basic circuit unit and the fourth basic circuit unit include a main switch power electronic chip 40 and an active clamping branch connected in parallel therewith. The active clamping branch includes an auxiliary switch power electronic chip 50 and the clamping capacitor 60 connected in series therewith. The main branch of the second power unit includes the main switch power electronic chip of the third basic circuit unit and the main switch power electronic chip of the fourth basic circuit unit connected in series therewith; a series connection structure 70, located on the upper copper foils of the first DBC structure 100 and the second DBC structure 200, for realizing the series connection of the first power unit and the second power unit; power electrodes, including a "DC+" power electrode 1 and a "DC-" power electrode 2; and inside the power module, the first power unit and the second power unit are arranged in parallel in sequence and connected together through the series connection structure 70. The "DC+" power electrode 1 is located on the first basic circuit unit of the first power unit in the first parallel position, and the "DC-" power electrode 2 is located on the second basic circuit unit of the last first power unit in the parallel arrangement or the fourth basic circuit unit of the second power unit; in the module formed by sequentially connecting multiple first power units and second power units in series, the first basic circuit unit, the second basic circuit unit, the third basic circuit unit and the fourth basic circuit unit are also connected in series in sequence.

[0047] As Figure 3 , Figure 4 and Figure 1As shown, the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure 100, and the source electrode of the third basic circuit unit and the drain electrode of the fourth basic circuit unit are electrically interconnected through the upper copper foil of the second DBC structure 200; when the first power unit and the second power unit are connected in series in sequence, the short-axis centerlines of the first power unit and the second power unit are both parallel to the long-axis centerline of the power module. The drain electrode of the third basic circuit unit in the second power unit and the source electrode of the second basic circuit unit of the previous first power unit connected in series are electrically interconnected through the series connection structure 70, and the source electrode of the fourth basic circuit unit in the second power unit and the drain electrode of the first basic circuit unit of the next first power unit connected in series are also electrically interconnected through the series connection structure 70. After series connection, the sum of the numbers of the first power unit and the second power unit in the power module is N, and N is a natural number greater than or equal to 2. The withstand voltage of the power module is equal to 2N times the withstand voltage of the first power unit or the second power unit.

[0048] As Figure 5 shown, the parallel numbers of the main switch power electronic chip 40 (or Q1), the auxiliary switch power electronic chip 50 (or Q2), and the clamping capacitor 60 (or C1) are all greater than or equal to 1, and the sizes of the clamping capacitors can be different. The main switch power electronic chip or the auxiliary switch power electronic chip can also be anti-parallel connected with a freewheeling diode chip accordingly. The so-called anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain electrode of the switch power electronic chip, and the anode of the freewheeling diode chip is connected to the source electrode of the switch power electronic chip.

[0049] The first basic circuit unit and the second basic circuit unit are respectively located on both sides of the short-axis centerline of the first power unit (as Figure 10As shown, the gate signal terminal 101 and the source signal terminal 102 of the main switch tube, and the gate signal terminal 103 and the source signal terminal 104 of the auxiliary switch tube in the first basic circuit unit are close to the short-axis center line of the first power unit and are arranged on the same side of the short-axis center line. The gate signal terminal 105 and the source signal terminal 106 of the main switch tube, and the gate signal terminal 107 and the source signal terminal 108 of the auxiliary switch tube in the second basic circuit unit are also close to the short-axis center line of the first power unit and are arranged on the other side of the short-axis center line. The layout positions of the second basic circuit signal terminals and the first basic circuit signal terminals are symmetrically distributed with respect to the short-axis center line of the first power unit. The clamping capacitors and the voltage sampling terminals of the clamping capacitors in the first basic circuit unit and the second basic unit are respectively arranged in the corresponding outer side regions of the short sides of the first power unit. The power electronic chips of the main switch tube and the auxiliary switch tube in the first basic circuit unit are arranged in the middle region between the signal terminals and the layout regions of the capacitors and their sampling terminals. The power electronic chips of the main switch tube and the auxiliary switch tube in the second basic circuit unit are also arranged in the middle region between the signal terminals and the layout regions of the capacitors and their sampling terminals. Moreover, the drain of the second basic circuit unit is connected to the source of the first basic circuit unit through the upper copper foil of the first DBC structure of the first power unit.

[0050] As Figure 4As shown, the third basic circuit unit and the fourth basic circuit unit are respectively located on both sides of the short-axis center line of the second power unit. In the third basic circuit unit, the gate signal terminal 201 and the source signal terminal 202 of the main switching transistor, and the gate signal terminal 203 and the source signal terminal 204 of the auxiliary switching transistor are all arranged close to the short-axis center line of the second power unit on the same side of the short-axis center line. In the fourth basic circuit unit, the gate signal terminal 205 and the source signal terminal 206 of the main switching transistor, and the gate signal terminal 207 and the source signal terminal 208 of the auxiliary switching transistor are also all arranged close to the short-axis center line of the second power unit and on the other side of the center line. The layout positions of the fourth basic circuit signal terminal and the third basic circuit signal terminal are symmetrically distributed with respect to the short-axis center line of the second power unit. The clamping capacitors and the voltage sampling terminals of the clamping capacitors in the third basic circuit unit and the fourth basic circuit unit are respectively arranged in the outer side area of the corresponding short side of the second power unit. The power electronic chips of the main switching transistor and the auxiliary switching transistor in the third basic circuit unit are arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal. The power electronic chips of the main switching transistor and the auxiliary switching transistor in the fourth basic circuit unit are also arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal. Moreover, the drain of the fourth basic circuit unit is connected to the source of the third basic circuit unit through the upper copper foil of the second DBC structure, and the drain of the third basic circuit unit is connected to the source of the second basic circuit unit of the first power unit through a series connection structure.

[0051] As Figure 7As shown, the source bars 120 and gate bars 110 of the gate-source path of the main switch power electronic chip of the first basic circuit unit, and the source bars 121 and gate bars 111 of the gate-source path of the auxiliary switch power electronic chip are all close to the short-axis center line of the DBC structure and are arranged on the same side of the center line. The source bars 220 and gate bars 210 of the gate-source path of the main switch power electronic chip of the second basic circuit unit, and the source bars 221 and gate bars 211 of the gate-source path of the auxiliary switch power electronic chip are also close to the short-axis center line of the first DBC structure 100 and are arranged on the other side of the center line. The source bars 220 and gate bars 210 of the gate-source path of the main switch power electronic chip of the second basic circuit unit and the source bars 120 and gate bars 110 of the gate-source path of the main switch power electronic chip of the first basic circuit unit are symmetric with each other with respect to the plane perpendicular to the plane of the first DBC structure where the short-axis center line is located; in the direction from the short-axis center line of the first DBC structure to the short outer side, the area adjacent to the source bar 120 and gate bar 110 of the gate-source path of the main switch power electronic chip of the first basic circuit unit is the area for arranging the main switch power electronic chip 40 of the first basic circuit unit, and this area 130 is in an "L" shape. The area adjacent to the source bar 121 and gate bar 111 of the gate-source path of the auxiliary switch power electronic chip of the first basic circuit unit is the area 131 for arranging the auxiliary switch power electronic chip 50 of the first basic circuit unit, and this area 131 is also in an "L" shape. The area adjacent to the source bar 220 and gate bar 210 of the gate-source path of the main switch power electronic chip of the second basic circuit unit is the area 230 for arranging the main switch power electronic chip of the second basic circuit unit, and this area is integrally set in an "F" shape. The area adjacent to the source bar 221 and gate bar 211 of the gate-source path of the auxiliary switch power electronic chip of the second basic circuit unit is the area 231 for arranging the auxiliary switch power electronic chip of the second basic circuit unit, and this area is also in an "L" shape; the "L" shaped area 131 for arranging the auxiliary switch power electronic chip of the first basic circuit unit and the "L" shaped area 231 for arranging the auxiliary switch power electronic chip of the second basic circuit unit are both located in the left-side area of the first power unit DBC structure; the area 230 in an "F" shape for arranging the drain of the second basic circuit unit is located in the right-side area of the first power unit DBC structure.

[0052] The region for laying out the low-voltage pins of the clamping capacitors of the second basic circuit unit, the region for laying out the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors, and the region for laying out the sources of the second basic circuit unit in the upper copper foil of the first DBC structure form a single connected region 250. The single connected region 250 is overall in an "L" shape and is characterized by a low-voltage potential in the circuit topology of the first power unit; the region for laying out the power electronic chips of the main switching transistors of the second basic circuit unit, the region for laying out the low-potential voltage pins of the clamping capacitors of the first basic circuit unit, the region for laying out the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors of the first basic circuit unit, and the region for laying out the sources of the power electronic chips of the main switching transistors of the first basic circuit unit in the upper copper foil of the first DBC structure form a single connected region 230. The single connected region is an "F" shaped region, which is also used as the main branch path between the source of the first basic circuit unit and the drain of the second basic circuit unit through the upper copper foil of the first DBC structure.

[0053] Such as Figure 8As shown, the source bars 320 and gate bars 310 of the gate-source path of the main switch power electronic chip of the third basic circuit unit, and the source bars 321 and gate bars 311 of the gate-source path of the auxiliary switch power electronic chip are all arranged close to the short-axis center line of the second DBC structure on the same side of the short-axis center line. The source bars 420 and gate bars 410 of the gate-source path of the main switch power electronic chip of the fourth basic circuit unit, and the source bars 421 and gate bars 411 of the gate-source path of the auxiliary switch power electronic chip are also arranged close to the short-axis center line of the second DBC structure and on the other side of the short-axis center line. The source bars 420 and gate bars 410 of the gate-source path of the main switch power electronic chip of the fourth basic circuit unit and the source bars 320 and gate bars 310 of the gate-source path of the main switch power electronic chip of the third basic circuit unit are symmetric with each other with respect to the plane perpendicular to the plane of the second DBC structure where the short-axis center line is located; from the short-axis center line of the second DBC structure towards the short outer side, adjacent to the source bars 320 and gate bars 310 of the gate-source path of the main switch power electronic chip of the third basic circuit unit is the area 330 for arranging the main switch power electronic chip of the third basic circuit unit and this area is in an "L" shape. Adjacent to the source bars 321 and gate bars 311 of the gate-source path of the auxiliary switch power electronic chip of the third basic circuit unit is the area 331 for arranging the auxiliary switch power electronic chip of the third basic circuit unit and this area is also in an "L" shape. And adjacent to the source bars 420 and gate bars 410 of the gate-source path of the main switch power electronic chip of the fourth basic circuit unit is the area 430 for arranging the main switch power electronic chip of the fourth basic circuit unit and this area is in an overall "F" shape. Adjacent to the source bars 421 and gate bars 411 of the gate-source path of the auxiliary switch power electronic chip of the fourth basic circuit unit is the area 431 for arranging the auxiliary switch power electronic chip of the fourth basic circuit unit and this area is also in an "L" shape; the "L" shaped area 431 for arranging the auxiliary switch power electronic chip of the fourth basic circuit unit and the "L" shaped area 331 for arranging the auxiliary switch power electronic chip of the third basic circuit unit are both located in the left side area of the second DBC structure; the area 430 in the "F" shape for arranging the drain of the fourth basic circuit unit is located in the right side area of the second DBC structure; the upper copper foil pattern of the second DBC structure and the upper copper foil pattern of the first DBC structure are in a mirror symmetry relationship, as Figure 9 shown, the mirror is parallel to the short-axis center line of the first DBC structure and perpendicular to the plane where the first DBC structure is located.

[0054] The starting point and the ending point of the series connection of the first power unit and the second power unit are the "DC+" power electrode 1 and the "DC-" power electrode 2 respectively. The main power branch path of the power module from the "DC+" power electrode 1 to the "DC-" power electrode 2 is formed by the series connection of the main branch of the first power unit and the main branch of the second power unit. As Figure 1 shown, the figure contains two first power units and one second power unit. The projection of the main power branch path of the power module on the horizontal plane of the power module is overall in the shape of a "rectangular wave" and is distributed along the long-axis center line of the power module. As Figure 11 shown, the path parts perpendicular to the long-axis center line of the power module in the "rectangular wave" shape are all located in the right-side area of the first power unit or the second power unit where they are located.

[0055] A power module and its structural design, comprising: a first power unit, which includes a first DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 DBC structure includes a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The circuit topology of the first power unit includes a first basic circuit unit and a second basic circuit unit connected in series therewith. Each of the first basic circuit unit or the second basic circuit unit includes a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the first power unit includes the main switch power electronic chip of the first basic circuit unit and the main switch power electronic chip of the second basic circuit unit connected in series therewith; a second power unit, which includes a second DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 second DBC structure includes a lower copper foil, an intermediate ceramic layer, and an upper copper foil. The circuit topology of the second power unit includes a third basic circuit unit and a fourth basic circuit unit connected in series therewith. Each of the third basic circuit unit or the fourth basic circuit unit includes a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the second power unit includes the main switch power electronic chip of the third basic circuit unit and the main switch power electronic chip of the fourth basic circuit unit connected in series therewith; a series connection structure, located on the upper copper foils of the first DBC structure and the second DBC structure, for realizing the series connection of the first power unit and the second power unit; power electrodes, including a "DC+" power electrode and a "DC-" power electrode; and inside the power module, the first power unit and the second power unit are arranged in parallel in sequence and connected together through the series connection structure. The "DC+" power electrode is located on the first basic circuit unit of the first first power unit in the parallel arrangement, and the "DC-" power electrode is located on the second basic circuit unit of the last first power unit in the parallel arrangement or the fourth basic circuit unit of the second power unit; in the module formed by sequentially connecting in series multiple of the first power units and the second power units, the first basic circuit unit, the second basic circuit unit, the third basic circuit unit, and the fourth basic circuit unit are also connected in series in sequence;

[0056] In the power module, the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure, and the source electrode of the third basic circuit unit and the drain electrode of the fourth basic circuit unit are electrically interconnected through the upper copper foil of the second DBC structure; when the first power unit and the second power unit are connected in series in sequence, the short-axis centerlines of the first power unit and the second power unit are both parallel to the long-axis centerline of the power module. The drain electrode of the third basic circuit unit in the second power unit and the source electrode of the second basic circuit unit of the previous first power unit connected in series are electrically interconnected through a series connection structure, and the source electrode of the fourth basic circuit unit in the second power unit and the drain electrode of the first basic circuit unit of the next first power unit connected in series are also electrically interconnected through a series connection structure. After series connection, the sum of the numbers of the first power unit and the second power unit in the power module is N, and N is a natural number greater than or equal to 2. The withstand voltage of the power module is equal to 2N times the withstand voltage of the first power unit or the second power unit;

[0057] In the first power unit, the first basic circuit unit and the second basic circuit unit are respectively located on both sides of the short-axis centerline of the first power unit. The gate signal terminal and the source signal terminal of the main switch tube, and the gate signal terminal and the source signal terminal of the auxiliary switch tube in the first basic circuit unit are close to the short-axis centerline of the first power unit and are arranged on the same side of the short-axis centerline. The gate signal terminal and the source signal terminal of the main switch tube, and the gate signal terminal and the source signal terminal of the auxiliary switch tube in the second basic circuit unit are also close to the short-axis centerline of the first power unit and are arranged on the other side of the short-axis centerline. The layout positions of the second basic circuit signal terminal and the first basic circuit signal terminal are symmetrically distributed with respect to the short-axis centerline of the first power unit; the clamping capacitors and the voltage sampling terminals of the clamping capacitors in the first basic circuit unit and the second basic unit are respectively arranged in the corresponding outer side regions of the short side of the first power unit. The main switch tube power electronic chip and the auxiliary switch tube power electronic chip in the first basic circuit unit are arranged in the middle region between the signal terminal and the layout regions of the capacitor and its sampling terminal. The main switch tube power electronic chip and the auxiliary switch tube power electronic chip in the second basic circuit unit are also arranged in the middle region between the signal terminal and the layout regions of the capacitor and its sampling terminal. And the drain electrode of the second basic circuit unit is connected to the source electrode of the first basic circuit unit through the upper copper foil of the first DBC structure of the first power unit;

[0058] In the second power unit, the third basic circuit unit and the fourth basic circuit unit are respectively located on both sides of the short-axis center line of the second power unit. In the third basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are all closely arranged on the same side of the short-axis center line of the second power unit along the short-axis center line. In the fourth basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are also all closely arranged along the short-axis center line of the second power unit and on the other side of the center line. The layout positions of the fourth basic circuit signal terminal and the third basic circuit signal terminal are symmetrically distributed with respect to the short-axis center line of the second power unit; the clamping capacitors and the voltage sampling terminals of the clamping capacitors in the third basic circuit unit and the fourth basic circuit unit are respectively arranged in the corresponding outer side area of the short side of the second power unit. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the third basic circuit unit are arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the fourth basic circuit unit are also arranged in the middle area between the signal terminal and the layout area of the capacitor and its sampling terminal. Moreover, the drain of the fourth basic circuit unit is connected to the source of the third basic circuit unit through the upper copper foil of the second DBC structure, and the drain of the third basic circuit unit is connected to the source of the second basic circuit unit of the first power unit through a series connection structure;

[0059] In the first DBC structure, the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the first basic circuit unit and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all close to the short-axis center line of the DBC structure and are arranged on the same side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the second basic circuit unit and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also close to the short-axis center line of the DBC structure and are arranged on the other side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the second basic circuit unit and the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the first basic circuit unit are symmetric with each other with respect to the plane perpendicular to the DBC structure plane where the short-axis center line is located. In the direction from the short-axis center line of the first DBC structure to the short outer side, the area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip of the first basic circuit unit is the area for arranging the main switch power electronic chip of the first basic circuit unit and this area is in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip of the first basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the first basic circuit unit and this area is also in an "L" shape. The area adjacent to the source bar and gate bar of the gate-source path of the main switch power electronic chip of the second basic circuit unit is the area for arranging the main switch power electronic chip of the second basic circuit unit and this area is set as an overall "F" shape. The area adjacent to the source bar and gate bar of the gate-source path of the auxiliary switch power electronic chip of the second basic circuit unit is the area for arranging the auxiliary switch power electronic chip of the second basic circuit unit and this area is also in an "L" shape. The "L" shaped area for arranging the auxiliary switch power electronic chip of the first basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chip of the second basic circuit unit are both located in the left side area of the first power unit DBC structure. The area where the drain of the second basic circuit unit is in an "F" shape is located in the right side area of the first power unit DBC structure;

[0060] In the first DBC structure, the regions for laying out the low-voltage pins of the clamping capacitors of the second basic circuit unit, the regions for laying out the capacitor voltage sampling terminals for sampling the low-potential voltages of the sampling clamping capacitors, and the regions for laying out the sources of the second basic circuit unit in the upper copper foil of the first DBC structure form a single connected region. This single connected region is overall in an "L" shape and is characterized by a low-voltage potential in the circuit topology of the first power unit; the regions for laying out the power electronic chips of the main switching transistors of the second basic circuit unit, the regions for laying out the low-potential voltage pins of the clamping capacitors of the first basic circuit unit, the regions for laying out the capacitor voltage sampling terminals for sampling the low-potential voltages of the sampling clamping capacitors of the first basic circuit unit, and the regions for laying out the sources of the power electronic chips of the main switching transistors of the first basic circuit unit in the upper copper foil of the first DBC structure form a single connected region. This single connected region is an "F" - shaped region, which is also used as the main branch path realized through the upper copper foil of the first DBC structure between the source of the first basic circuit unit and the drain of the second basic circuit unit;

[0061] In the second DBC structure, the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all arranged close to the short-axis center line of the second DBC structure on the same side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also arranged close to the short-axis center line of the second DBC structure and on the other side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit are respectively symmetric to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit with respect to the plane perpendicular to the plane of the second DBC structure where the short-axis center line is located. From the short-axis center line of the second DBC structure towards the short outer side, the area close to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit is the area for arranging the main switch power electronic chips of the third basic circuit unit and this area is in an "L" shape. The area close to the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips of the third basic circuit unit is the area for arranging the auxiliary switch power electronic chips of the third basic circuit unit and this area is also in an "L" shape. The area close to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit is the area for arranging the main switch power electronic chips of the fourth basic circuit unit and this area is in an overall "F" shape. The area close to the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips of the fourth basic circuit unit is the area for arranging the auxiliary switch power electronic chips of the fourth basic circuit unit and this area is also in an "L" shape. The "L" shaped area for arranging the auxiliary switch power electronic chips of the fourth basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chips of the third basic circuit unit are both located in the left-side area of the second DBC structure. The area where the drain of the fourth basic circuit unit is in the "F" shape is located in the right-side area of the second DBC structure. The upper copper foil pattern of the second DBC structure is in a mirror symmetry relationship with the upper copper foil pattern of the first DBC structure, and the mirror plane is parallel to the short-axis center line of the first DBC structure and perpendicular to the plane where the first DBC structure is located.

[0062] In the power module, the starting point and the ending point of the series connection of the first power unit and the second power unit are the "DC+" power electrode and the "DC-" power electrode respectively. The main power branch path of the power module from the "DC+" power electrode to the "DC-" power electrode is formed by the series connection of the main branch of the first power unit and the main branch of the second power unit. The projection of the main power branch path of the power module on the horizontal plane of the power module is integrally distributed in a "rectangular wave" shape along the long-axis center line of the power module. All the path portions perpendicular to the long-axis center line in the "rectangular wave" shape path are located in the right-side area of the first power unit or the second power unit where they are located.

[0063] Although the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are descriptive and exemplary rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A power module based on a series topology structure, characterized in that, it comprises: a bottom plate; a first solder layer located on the upper surface of the bottom plate; a first power unit, which includes a first DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 DBC structure includes 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 first solder layer and is used to connect to the bottom plate. The circuit topology structure of the first power unit includes a first basic circuit unit and a second basic circuit unit connected in series therewith. Both the first basic circuit unit and the second basic circuit unit include a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the first power unit includes the main switch power electronic chip of the first basic circuit unit and the main switch power electronic chip of the second basic circuit unit connected in series therewith; a second power unit, which includes a second DBC structure, a second solder layer, a main switch power electronic chip, an auxiliary switch power electronic 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 second DBC structure includes 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 first solder layer and is used to connect to the bottom plate. The circuit topology structure of the second power unit includes a third basic circuit unit and a fourth basic circuit unit connected in series therewith. Both the third basic circuit unit and the fourth basic circuit unit include a main switch power electronic chip and an active clamping branch connected in parallel therewith. The active clamping branch includes the auxiliary switch power electronic chip and the clamping capacitor connected in series therewith. The main branch of the second power unit includes the main switch power electronic chip of the third basic circuit unit and the main switch power electronic chip of the fourth basic circuit unit connected in series therewith; a series connection structure located on the upper copper foils of the first DBC structure and the second DBC structure for realizing the series connection of the first power unit and the second power unit; power electrodes, including a "DC+" power electrode and a "DC-" power electrode; and Inside the power module, the first power unit and the second power unit are arranged in parallel in sequence and connected together through a series connection structure. The "DC+" power electrode is located on the first basic circuit unit of the first first power unit in the parallel arrangement, and the "DC-" power electrode is located on the second basic circuit unit of the last first power unit in the parallel arrangement or the fourth basic circuit unit of the second power unit; in the module formed by sequentially connecting multiple first power units and second power units in series, the first basic circuit unit, the second basic circuit unit, the third basic circuit unit, and the fourth basic circuit unit are also connected in series in sequence.

2. The power module according to claim 1, further characterized in that, the source electrode of the first basic circuit unit and the drain electrode of the second basic circuit unit are electrically interconnected through the upper copper foil of the first DBC structure, and the source electrode of the third basic circuit unit and the drain electrode of the fourth basic circuit unit are electrically interconnected through the upper copper foil of the second DBC structure; when the first power unit and the second power unit are sequentially connected in series, the short-axis centerlines of the first power unit and the second power unit are both parallel to the long-axis centerline of the power module. The drain electrode of the third basic circuit unit in the second power unit and the source electrode of the second basic circuit unit of the previous first power unit connected in series are electrically interconnected through a series connection structure, and the source electrode of the fourth basic circuit unit in the second power unit and the drain electrode of the first basic circuit unit of the next first power unit connected in series are also electrically interconnected through a series connection structure. After being connected in series, the sum of the numbers of the first power unit and the second power unit in the power module is N, and N is a natural number greater than or equal to 2. The withstand voltage of the power module is equal to 2N times the withstand voltage of the first power unit or the second power unit.

3. The power module according to claim 2, further characterized in that, the parallel numbers of the main switch power electronic chip, the auxiliary switch power electronic chip, and the clamping capacitor are all greater than or equal to 1, and the sizes of the clamping capacitors can be different. The main switch power electronic chip or the auxiliary switch power electronic chip can also be correspondingly anti-parallel connected with a freewheeling diode chip. The so-called anti-parallel connection means that the cathode of the freewheeling diode chip is connected to the drain electrode of the main switch power electronic chip, and the anode of the freewheeling diode chip is connected to the source electrode of the main switch power electronic chip.

4. The power module according to claim 2, characterized in that, The first basic circuit unit and the second basic circuit unit are respectively located on both sides of the short-axis center line of the first power unit. In the first basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are close to the short-axis center line of the first power unit and are arranged on the same side of the short-axis center line. In the second basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are also close to the short-axis center line of the first power unit and are arranged on the other side of the short-axis center line. The layout positions of the second basic circuit signal terminal and the first basic circuit signal terminal are symmetrically distributed with respect to the short-axis center line of the first power unit. The clamping capacitors and the voltage sampling terminals of the clamping capacitors in the first basic circuit unit and the second basic unit are respectively arranged in the corresponding outer side regions of the short sides of the first power unit. The power electronic chips of the main switching transistor and the auxiliary switching transistor in the first basic circuit unit are arranged in the intermediate region between the signal terminals and the layout regions of the capacitors and their sampling terminals. The power electronic chips of the main switching transistor and the auxiliary switching transistor in the second basic circuit unit are also arranged in the intermediate region between the signal terminals and the layout regions of the capacitors and their sampling terminals. Moreover, the drain of the second basic circuit unit is connected to the source of the first basic circuit unit through the upper copper foil of the first DBC structure of the first power unit.

5. The power module according to claim 2, characterized in that The third basic circuit unit and the fourth basic circuit unit are respectively located on both sides of the short-axis center line of the second power unit. In the third basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are all arranged close to the short-axis center line of the second power unit on the same side of the short-axis center line. In the fourth basic circuit unit, the gate signal terminal and the source signal terminal of the main switching transistor, and the gate signal terminal and the source signal terminal of the auxiliary switching transistor are also all arranged close to the short-axis center line of the second power unit and on the other side of the center line. The layout positions of the fourth basic circuit signal terminal and the third basic circuit signal terminal are symmetrically distributed with respect to the short-axis center line of the second power unit. The clamping capacitors and the voltage sampling terminals of the clamping capacitors in the third basic circuit unit and the fourth basic circuit unit are respectively arranged in the outer side regions of the corresponding short sides of the second power unit. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the third basic circuit unit are arranged in the intermediate region between the signal terminal and the layout regions of the capacitor and its sampling terminal. The main switching transistor power electronic chip and the auxiliary switching transistor power electronic chip in the fourth basic circuit unit are also arranged in the intermediate region between the signal terminal and the layout regions of the capacitor and its sampling terminal. And the drain of the fourth basic circuit unit is connected to the source of the third basic circuit unit through the upper copper foil of the second DBC structure, and the drain of the third basic circuit unit is connected to the source of the second basic circuit unit of the first power unit through a series connection structure.

6. The power module according to claim 2, wherein, The source bars and gate bars of the gate-source paths of the main switch power electronic chips in the first basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all close to the short-axis center line of the first DBC structure and are arranged on the same side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips in the second basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also close to the short-axis center line of the second DBC structure and are arranged on the other side of the center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips in the second basic circuit unit and the source bars and gate bars of the gate-source paths of the main switch power electronic chips in the first basic circuit unit are symmetric to each other with respect to the plane perpendicular to the plane of the first DBC structure where the short-axis center line is located; in the direction from the short-axis center line of the first DBC structure to the short outer side, the area adjacent to the source bars and gate bars of the gate-source path of the main switch power electronic chip in the first basic circuit unit is the area for arranging the main switch power electronic chip in the first basic circuit unit and this area is in an "L" shape, the area adjacent to the source bars and gate bars of the gate-source path of the auxiliary switch power electronic chip in the first basic circuit unit is the area for arranging the auxiliary switch power electronic chip in the first basic circuit unit and this area is also in an "L" shape, while the area adjacent to the source bars and gate bars of the gate-source path of the main switch power electronic chip in the second basic circuit unit is the area for arranging the main switch power electronic chip in the second basic circuit unit, and the whole area of the main switch power electronic chip in the second basic circuit unit is set in an "F" shape, the area adjacent to the source bars and gate bars of the gate-source path of the auxiliary switch power electronic chip in the second basic circuit unit is the area for arranging the auxiliary switch power electronic chip in the second basic circuit unit and this area is also in an "L" shape; the "L" shaped area for arranging the auxiliary switch power electronic chip in the first basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chip in the second basic circuit unit are both located in the left-side area of the first DBC structure; the area in an "F" shape for arranging the drain of the second basic circuit unit is located in the right-side area of the first DBC structure.

7. The power module according to claim 6, characterized in that The region for laying out the low-voltage pins of the clamping capacitors of the second basic circuit unit, the region for laying out the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors, and the region for laying out the sources of the second basic circuit unit in the upper copper foil of the first DBC structure form a single connected region. This single connected region is overall in an "L" shape and is characterized by a low-voltage potential in the circuit topology of the first power unit; the region for laying out the power electronic chips of the main switch tubes of the second basic circuit unit, the region for laying out the low-potential voltage pins of the clamping capacitors of the first basic circuit unit, the region for laying out the capacitor voltage sampling terminals for sampling the low-potential voltage of the sampling clamping capacitors of the first basic circuit unit, and the region for laying out the sources of the power electronic chips of the main switch tubes of the first basic circuit unit form a single connected region. This single connected region is the so-called "F" shaped region, which is also used for the main branch path realized between the source of the first basic circuit unit and the drain of the second basic circuit unit through the upper copper foil of the first DBC structure.

8. The power module according to claim 2, characterized in that The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are all arranged close to the short-axis center line of the second DBC structure on the same side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit, and the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips are also arranged close to the short-axis center line of the second DBC structure and on the other side of the short-axis center line. The source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit are respectively symmetric to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit with respect to the plane perpendicular to the plane of the second DBC structure where the short-axis center line is located. From the short-axis center line of the second DBC structure towards the short outer side, the area adjacent to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the third basic circuit unit is the area for arranging the main switch power electronic chips of the third basic circuit unit and this area is in an "L" shape. The area adjacent to the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips of the third basic circuit unit is the area for arranging the auxiliary switch power electronic chips of the third basic circuit unit and this area is also in an "L" shape. And the area adjacent to the source bars and gate bars of the gate-source paths of the main switch power electronic chips of the fourth basic circuit unit is the area for arranging the main switch power electronic chips of the fourth basic circuit unit, and the overall area of the main switch power electronic chips of the second basic circuit unit is in an "F" shape. The area adjacent to the source bars and gate bars of the gate-source paths of the auxiliary switch power electronic chips of the fourth basic circuit unit is the area for arranging the auxiliary switch power electronic chips of the fourth basic circuit unit and this area is also in an "L" shape. The "L" shaped area for arranging the auxiliary switch power electronic chips of the fourth basic circuit unit and the "L" shaped area for arranging the auxiliary switch power electronic chips of the third basic circuit unit are both located in the left side area of the second DBC structure; The area where the drain of the fourth basic circuit unit is in the "F" shape is located in the right side area of the second DBC structure; The upper copper foil pattern of the second DBC structure is mirror-symmetric to the upper copper foil pattern of the first DBC structure, and the mirror plane is parallel to the short-axis center line of the first DBC structure and perpendicular to the plane where the first DBC structure is located.

9. The power module according to claim 2, characterized in that The starting point and the ending point connecting the first power unit and the second power unit are the "DC+" power electrode and the "DC-" power electrode respectively. The main power branch path of the power module from the "DC+" power electrode to the "DC-" power electrode is formed by connecting in series the main branches of the first power unit and the second power unit. The projection of the main power branch path of the power module on the horizontal plane of the power module is integrally in the shape of a "rectangular wave" and is distributed along the central axis of the long axis of the power module. The path portions perpendicular to the central axis of the long axis of the power module in the "rectangular wave" path are all located in the right side region of the first power unit or the second power unit where they are located.

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