Power module and packaging method thereof

Abstract

The invention discloses a power module and a packaging method thereof, the power module comprises an insulating substrate, the insulating substrate comprises a conductive structure located on the front surface of the insulating substrate, the conductive structure comprises four independent conductive structures, each conductive structure is provided with a power unit group, each power unit group comprises a plurality of power units, and the power units are arranged on the conductive structures. And the plurality of power units of at least one power unit group in the first to fourth power unit groups are distributed in a bilateral symmetry manner. According to the invention, the size of the power module is obviously reduced, the layout is more compact, the cost is reduced, the stray inductance of various commutation loops is reduced, the current balance degree in the power module is improved, and the electrical performance is optimized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more specifically, to a power module and a packaging method thereof. Background Art

[0002] The power module is a new type of high-power power electronic device with the advantages of high current density, low saturation voltage and high voltage resistance. It is currently widely used in various fields such as production and life.

[0003] Power modules are power semiconductor devices that realize power conversion control in power electronic systems. Compared with two-level power modules, power modules using T-type neutral point clamped (TNPC) circuits can provide higher voltage and current quality, but have the disadvantage of long loop paths, and the corresponding loop inductance is much larger than that of traditional two-level circuits, resulting in unbalanced dynamic and static current distribution between power units, thus affecting the electrical performance of three-level power modules. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide a power module and a packaging method thereof, so as to improve the current distribution within the power module, reduce the stray inductance of various commutation circuits, and enhance the electrical performance of the power module.

[0005] The present invention provides a power module, comprising an insulating substrate, wherein the insulating substrate comprises a conductive structure located on the front side of the insulating substrate, wherein the conductive structure comprises a fourth conductive structure, a first conductive structure, a second conductive structure and a third conductive structure which are independently arranged in sequence from bottom to top; a fourth power unit group, a first power unit group, a third power unit group and a second power unit group, wherein the fourth power unit group is located on the fourth conductive structure, the first power unit group is located on the first conductive structure, the third power unit group is located on the third conductive structure and the second power unit group is located on the second conductive structure; wherein a plurality of power units of at least one power unit group among the first to fourth power unit groups are symmetrically distributed left and right.

[0006] Optionally, the power module also includes: an AC output terminal, a DC input positive terminal, a zero potential input terminal and a DC input negative terminal; the first power unit group is electrically connected to the AC output terminal and the DC input positive terminal, the second power unit group and the third power unit group are connected in sequence, the second power unit group is electrically connected to the zero potential input terminal, and the third power unit group is electrically connected to the AC output terminal; the fourth power unit group is electrically connected to the AC output terminal and the DC input negative terminal, thereby forming a T-type mid-point clamped three-level circuit.

[0007] Optionally, the fourth power unit group includes several fourth power units, the first power unit group includes several first power units, the third power unit group includes several third power units, and the second power unit group includes several second power units; the fourth power units are at least two, and the several power units of the fourth power units are symmetrically distributed on the left and right and the first power units are at least two, and the several power units of the first power units are symmetrically distributed on the left and right; or, the third power units are at least two, and the several power units of the third power units are symmetrically distributed on the left and right and the second power units are at least two, and the several power units of the second power units are symmetrically distributed on the left and right.

[0008] Optionally, the number of the fourth power unit, the first power unit, the third power unit and the second power unit is equal, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

[0009] Optionally, the number of the fourth power unit is equal to that of the first power unit, the number of the third power unit is equal to that of the second power unit, the number of the fourth power unit is less than the number of the third power unit, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

[0010] Optionally, the number of the fourth power unit is equal to that of the first power unit, the number of the third power unit is equal to that of the second power unit, the number of the fourth power unit is greater than the number of the third power unit, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

[0011] Optionally, the AC output terminal is located on the upper side of the power module; the zero potential input terminal, the DC input negative terminal and the DC input positive terminal are located on the lower side of the power module.

[0012] Optionally, the third end of the first power unit is electrically connected to the positive end of the DC input, and the second end of the first power unit is electrically connected to the AC output end; the third end of the second power unit is electrically connected to the zero potential, the second end of the second power unit is electrically connected to the second end of the third power unit, the third end of the third power unit is electrically connected to the AC output end, the third end of the fourth power unit is electrically connected to the AC output end, the second end of the fourth power unit is electrically connected to the negative end of the DC input, the first end of the first power unit receives a first control signal, the first end of the second power unit receives a second control signal, the first end of the third power unit receives a third control signal, and the first end of the fourth power unit receives a fourth control signal.

[0013] Optionally, the conductive structure also includes: a fifth conductive structure and a sixth conductive structure, the fifth conductive structure and the sixth conductive structure are respectively located on the left and right sides of the insulating substrate; the first conductive structure, the second conductive structure, the third conductive structure, and the fourth conductive structure are located between the fifth conductive structure and the sixth conductive structure; a seventh conductive structure, the seventh conductive structure is located below the fourth conductive structure; the first conductive structure to the seventh conductive structure are independent of each other.

[0014] Optionally, it is characterized in that: the third conductive structure is located at the upper part of the insulating substrate; the first conductive structure is located at the lower part of the insulating substrate; the first conductive structure semi-surrounds the fourth conductive structure and the seventh conductive structure, the first conductive structure is led to the lower side of the insulating substrate and forms the first end of the first conductive structure and the second end of the first conductive structure respectively, the first end of the first conductive structure and the second end of the first conductive structure are symmetrically arranged on the lower side of the insulating substrate, an opening of the first conductive structure is formed between the first end of the first conductive structure and the second end of the first conductive structure, the opening of the first conductive structure faces the lower side of the insulating substrate, the first end of the first conductive structure serves as a first connection end of the DC input positive terminal, the second end of the first conductive structure serves as a second connection end of the DC input positive terminal, the first end of the first conductive structure and the second end of the first conductive structure are electrically connected to the DC input positive terminal; the seventh conductive structure is located at the first conductive At the opening of the structure, the seventh conductive structure is led out to the lower side of the insulating substrate and forms the first end of the seventh conductive structure, and the seventh conductive structure is electrically connected to the DC input negative terminal; the third conductive structure surrounds the second conductive structure; the third conductive structure is electrically connected to the AC output terminal; the second conductive structure is electrically connected to the fifth conductive structure and the sixth conductive structure, the first end of the fifth conductive structure is led out to the lower side of the insulating substrate, the first end of the fifth conductive structure serves as the first connection end of the DC input negative terminal, the first end of the sixth conductive structure is led out to the lower side of the insulating substrate, the first end of the sixth conductive structure serves as the second connection end of the DC input negative terminal, the first end of the fifth conductive structure and the first end of the sixth conductive structure are electrically connected to the zero potential input terminal; the first end of the fifth conductive structure, the first end of the first conductive structure, the first end of the seventh conductive structure, the first end of the second conductive structure and the first end of the sixth conductive structure are sequentially arranged on the lower side of the insulating substrate.

[0015] Optionally, the third end of the first power unit is electrically connected to the DC input positive end via the first conductive structure, and the second end of the first power unit is electrically connected to the AC output end via the third conductive structure; the third end of the second power unit is electrically connected to the zero potential via the fifth conductive structure and the sixth conductive structure, the second end of the second power unit is electrically connected to the second end of the third power unit, the third end of the third power unit is electrically connected to the AC output end via the third conductive structure, the drain of the fourth power unit is electrically connected to the AC output end via the fourth conductive structure and the third conductive structure, the second end of the fourth power unit is electrically connected to the DC input negative end via the seventh conductive structure, the first end of the first power unit receives a first control signal, the first end of the second power unit receives a second control signal, the first end of the third power unit receives a third control signal, and the first end of the fourth power unit receives a fourth control signal.

[0016] Optionally, the power module also includes a signal end, and the signal end includes: a first end lead-out terminal of the first power unit, a second end lead-out terminal of the first power unit, and a third end lead-out terminal of the first power unit; a first end lead-out terminal of the second power unit, and a second end lead-out terminal of the second power unit; a first end lead-out terminal of the third power unit, a second end lead-out terminal of the third power unit, and a third end lead-out terminal of the third power unit; a first end lead-out terminal of the fourth power unit, a second end lead-out terminal of the fourth power unit, and a third end lead-out terminal of the fourth power unit.

[0017] Optionally, the current of the first commutation loop flows through the power module, through the DC input positive terminal, the first power unit, the fourth power unit, and the DC input negative terminal.

[0018] Optionally, it is characterized in that the current path on the power module in the first commutation loop is bilaterally symmetrical to form two parallel first commutation loops.

[0019] Optionally, the current of the second commutation loop flows through the power module, the DC input positive terminal, the first power unit, the third power unit, the second power unit, and the zero potential input terminal.

[0020] Optionally, it is characterized in that the current path on the power module in the second commutation loop is bilaterally symmetrical to form two parallel second commutation loops.

[0021] Optionally, the current of the third commutation loop flows through the power module, through the zero potential input terminal, the second power unit, the third power unit, the fourth power unit, and the DC input negative terminal.

[0022] Optionally, it is characterized in that the current path on the power module in the third commutation loop is bilaterally symmetrical to form two third commutation loops in parallel.

[0023] Optionally, it further includes: a shell, and the insulating substrate, the conductive structure, and a plurality of power unit groups are located on one side of the shell.

[0024] Optionally, it further includes: a cover plate, which is located on one side of the shell, and the shell and the cover plate cover the insulating substrate, the conductive structure, and a plurality of power units.

[0025] Optionally, it further includes: a heat dissipation substrate, which is located at the other side of the shell, and the back side of the insulating substrate is connected to the heat dissipation substrate.

[0026] Optionally, the back surface of the insulating substrate is connected to the heat dissipation substrate by welding or sintering.

[0027] Optionally, the insulating substrate is a DBC copper-clad substrate.

[0028] Optionally, the power module further includes a signal terminal, the signal terminal is perpendicular to the insulating substrate, and at least a portion of the top end of the signal terminal passes through the cover plate.

[0029] Optionally, a thermistor is further arranged on the insulating substrate, and two ends of the thermistor are led out of the housing of the power module.

[0030] Optionally, the number of the fourth power units is greater than or equal to six, the number of the first power units is greater than or equal to six, the number of the third power units is greater than or equal to 6, and the number of the second power units is greater than or equal to 6.

[0031] Optionally, the DC input positive terminal, the zero potential input terminal and the DC input negative terminal are located at the lower side of the power module, and the DC input positive terminal, the zero potential input terminal and the DC input negative terminal are located in different planes.

[0032] Optionally, it is characterized in that: the first to fourth power units are one of a metal oxide semiconductor field effect transistor power tube, a silicon carbide metal oxide semiconductor field effect transistor, a parallel structure of an insulated gate field effect transistor and a parallel freewheeling diode, or an RC-IGBT; when the power unit is a metal oxide semiconductor field effect transistor or a silicon carbide metal oxide semiconductor field effect transistor, the first end of the power unit is the gate, the second end of the first power unit is the source, and the third end of the first power unit is the drain; when the power unit is a parallel structure of an insulated gate field effect transistor and a parallel freewheeling diode, or the power unit is an RC-IGBT, the first end of the power unit is the base, the second end of the power unit is the collector, and the third end of the power unit is the emitter; the parallel structure of the insulated gate field effect transistor and the parallel freewheeling diode is that the collector of the insulated gate field effect transistor is connected to the anode of the diode, and the emitter of the insulated gate field effect transistor is connected to the cathode of the diode.

[0033] According to the power module provided by the present invention, all power units in the T-type midpoint clamped three-level circuit are encapsulated in the same encapsulation structure, the power units of the same power unit group are connected in parallel with each other, and the power units of the several power units of the same power unit group are symmetrically distributed in the power module. The present invention significantly reduces the volume of the power module, makes the power module package more compact, and reduces the cost. At the same time, the encapsulation of the power module can ensure that the stray inductance of various commutation circuits in the three-level circuit topology is similar and small. The power units of the same power unit group in the power module are symmetrically distributed in the power unit placement area, and the connection end adopts a double-end structure. In particular, each power unit placement area has a pair of symmetrical return paths for forming two parallel commutation circuits, which can significantly reduce the overall stray inductance of the commutation circuit, help reduce the circuit commutation area, and significantly improve the current balance of the power unit in the power module, and optimize the electrical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0035] Figure 1 A circuit diagram of a power module of the present invention is shown;

[0036] Figure 2 A schematic diagram showing a packaging of a power module according to a first embodiment of the present invention;

[0037] Figure 3 A bottom view showing a package of a power module according to a first embodiment of the present invention;

[0038] Figure 4A schematic diagram showing the packaging of the power module of the first embodiment of the present invention without the cover plate;

[0039] Figure 5 A schematic diagram showing a packaging of a power module according to a second embodiment of the present invention;

[0040] Figure 6 A schematic diagram showing a packaging insulating substrate of a power module according to a first embodiment of the present invention;

[0041] Figure 7 A schematic diagram showing the internal layout of a power module package according to a first embodiment of the present invention;

[0042] Figure 8 A schematic diagram showing a first commutation loop inside a package of a power module according to a first embodiment of the present invention;

[0043] Fig. 9 A schematic diagram showing a second commutation loop inside a package of a power module according to a first embodiment of the present invention;

[0044] Fig.10 A schematic diagram showing a third commutation loop inside a package of a power module according to a first embodiment of the present invention;

[0045] Fig.11 A schematic diagram showing the internal layout of a power module package according to a third embodiment of the present invention;

[0046] Fig.12 A schematic diagram showing the internal layout of a power module package according to a fourth embodiment of the present invention;

[0047] Fig.13 A schematic diagram showing the internal layout of a power module package according to a fifth embodiment of the present invention is shown. DETAILED DESCRIPTION

[0048] The present invention will be described in more detail below with reference to the accompanying drawings. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown. Many specific details of the present invention are described below, but as those skilled in the art will appreciate, the present invention may not be implemented in accordance with these specific details.

[0049] The present invention may be embodied in various forms, some examples of which will be described below.

[0050] Figure 1 A circuit diagram of a power module according to a first embodiment of the present invention is shown.

[0051] like Figure 1 As shown, the power module includes:

[0052] AC output terminal AC, DC input positive terminal P, zero potential input terminal 0 and DC input negative terminal N; the AC output terminal AC is located on the upper side of the power module; the zero potential input terminal 0, DC input negative terminal N and DC input positive terminal P are located on the lower side of the power module.

[0053] Several power cells of the power cells of at least one of the first to fourth power cell groups are symmetrically distributed. The first power cell group T1, the second power cell group T2, the third power cell group T3 and the fourth power cell group T4, the first power cell group T1 is electrically connected to the AC output terminal AC and the DC input positive terminal P, the second power cell group T2 and the third power cell group T3 are connected in sequence, the second power cell group is electrically connected to the zero potential input terminal 0, the third power cell group T4 is electrically connected to the AC output terminal AC; the fourth power cell group T4 is electrically connected to the AC output terminal AC and the DC input negative terminal N, thereby forming a T-type midpoint clamped three-level circuit. For the convenience of illustration and description, Figure 1 In the description, the first to fourth power unit groups are respectively equivalent to a single MOSFET as an example. In fact,

[0054] The first power unit group includes I first power units, the second power unit group includes J second power units, the third unit group includes K third power units, and the fourth unit group includes L fourth power units. The fourth power unit group, the first power unit group, the third power unit group, and the second power unit group are arranged in sequence from bottom to top. The I first power units of the first power unit group are arranged horizontally from left to right, the J second power units of the second power unit group are arranged horizontally from left to right, the K third power units of the third power unit group are arranged horizontally from left to right, and the L fourth power units of the fourth power unit group are arranged horizontally from left to right. Among I, J, K, L, I, J, K, and L are positive integers, and at least I and L are positive integers greater than or equal to 2, or at least J and K are positive integers greater than or equal to 2.

[0055] The power unit of each power unit group is a metal oxide semiconductor field effect transistor (MOSFET), a silicon carbide metal oxide semiconductor field effect transistor (SiC MOSFET), an insulated gate field effect transistor (IGBT) power unit and a parallel freewheeling diode (FRD) structure, or a power unit in an RC-IGBT, etc. For convenience, the embodiments of each power unit of the first to fourth power unit groups in the present invention are described exemplarily using a metal oxide semiconductor field effect transistor (MOSFET) as an example, but this exemplary description does not limit the type of each power unit of this patent.

[0056] The third end (drain) D1 of the first power unit T1 is electrically connected to the DC input positive terminal P, and the second end (source) S1 of the first power unit is electrically connected to the AC output terminal AC; the third end (drain) D2 of the second power unit T2 is electrically connected to the zero potential 0, the second end (source) of the second power unit T2 is electrically connected to the second end (source) S3 of the third power unit T3, the third end (drain) D3 of the third power unit T3 is electrically connected to the AC output terminal AC, the third end (drain) D4 of the fourth power unit T4 is electrically connected to the AC output terminal AC, the second end (source) S4 of the fourth power unit T4 is electrically connected to the DC input negative terminal N, the first end (gate) G1 of the first power unit T1 receives the first control signal, the first end (gate) G2 of the second power unit T2 receives the second control signal, the first end (gate) G3 of the third power unit T3 receives the third control signal, and the first end (gate) G4 of the fourth power unit T1 receives the fourth control signal.

[0057] The power module further includes a thermistor RT, wherein, specifically, one end of the thermistor RT is connected to the end R1 , and the other end of the thermistor RT is connected to the end R2 .

[0058] like Figure 1 As shown, by controlling the gate G1 of the first power unit T1, the gate G2 of the second power unit T2, the gate G3 of the third power unit T3 and the gate G4 of the fourth power unit T4, the first power unit T1 is turned on, the second power unit T2 and the third power unit T3 are turned off, and the fourth power unit T4 is turned on, so as to achieve the following Figure 1 The first commutation loop shown in the figure, the current of the first commutation loop passes through the DC input positive terminal P to the DC input negative terminal N; similarly, the first power unit T1, the second power unit T2 and the third power unit are turned on, and the fourth power unit T4 is turned off, so as to achieve the following Figure 1 The second commutation circuit shown in the figure, the current of the second commutation circuit passes through the DC input positive terminal P to the second commutation circuit of zero potential 0; similarly, the first power unit T1 is turned off, and the second power unit T2, the third power unit T3 and the fourth power unit T4 are turned on, so as to achieve the following Figure 1 The third commutation circuit shown in the figure has a third commutation circuit in which the current of the third commutation circuit passes through the zero potential 0 to the negative terminal N of the DC input.

[0059] Figure 2The schematic diagram of the packaging of the power module of the first embodiment of the present invention is shown; the packaging of the power module includes a housing 100, a cover plate 200, an insulating substrate (not shown in the figure, blocked), a heat dissipation substrate 400, a signal terminal 500, an AC output terminal 610, a zero potential input terminal 620, a DC input positive terminal 630 and a DC input negative terminal 640. Among them, the copper busbars corresponding to each end of the AC output terminal 610, the zero potential input terminal 620, the DC input positive terminal 630 and the DC input negative terminal 640 are all embedded in the housing 100 and are integrally injection molded with the housing 100. The heat dissipation substrate and the insulating substrate are located in the housing 100. Figure 1 The first to fourth power units and thermistor are all located on the front side of the insulating substrate, and the back side of the insulating substrate is connected to the back side of the heat dissipation substrate 400 by welding, sintering or similar methods. The front side of the heat dissipation substrate 400 can be a flat plate, or it can be provided with heat dissipation fins such as pin fins or fins to obtain a better heat dissipation effect.

[0060] The upper side of the housing 100 has an AC output terminal 610 extending therefrom. Figure 1 The lower side of the housing 100 has a zero potential input terminal 620, a DC input positive terminal 630 and a DC input negative terminal 640 extending from left to right in sequence. The zero potential input terminal 620, the DC input positive terminal 630 and the DC input negative terminal 640 can be arranged in any order on the lower side of the housing 100 without being affected by Figure 1 The limit, where the zero potential input terminal 620 and Figure 1 The zero potential 0 in the DC input positive terminal 630 corresponds to Figure 1 The DC input positive terminal P corresponds to the DC input negative terminal 640. Figure 1 The DC input positive terminal P, the zero potential input terminal 0 and the DC input negative terminal N are located at the lower side of the power module and the DC input positive terminal P, the zero potential input terminal 0 and the DC input negative terminal N are located at different planes; specifically, Figure 3 As shown in the bottom view of the device, the zero potential input terminal 620, the DC input positive terminal 630 and the DC input negative terminal 640 are located in different planes.

[0061] See also Figure 2 The package also includes a plurality of signal terminals 500, wherein R1, R2, D2, G2, S3, G3, G1, S1, G4, S4, D4, D3, and D1 in the signal terminals 500 are respectively connected to Figure 1 In one-to-one correspondence, specifically, the first end (gate) of the first power unit T1 leads to the terminal G1, the second end (source) S1 of the first power unit leads to the terminal, and the third end (drain) of the first power unit T1 leads to the terminal D1;

[0062] The first end (gate) of the second power unit T2 leads to the terminal G2, and the second end (source) of the second power unit S2 leads to the terminal;

[0063] A first end (gate) lead-out terminal G3 of the third power unit T3, a second end (source) lead-out terminal S3 of the third power unit T3, and a third end (drain) lead-out terminal D3 of the third power unit T2;

[0064] The first end (gate) of the fourth power unit T4 leads to the terminal G4, the second end (source) of the fourth power unit T4 leads to the terminal S4, and the third end (drain) of the fourth power unit T4 leads to the terminal D4.

[0065] Figure 4 A schematic diagram showing the packaging of the power module of the first embodiment of the present invention without the cover plate; Figure 4 It can be seen that the insulating substrate 300 is located in the housing 100, and the insulating substrate 300 is provided with a thermistor RT, a first power unit group T1, a second power unit group T2, a third power unit group T3 and a fourth power unit group T4. Specifically, the thermistor RT is located in the upper left corner area of ​​the insulating substrate 300, and the thermistor RT is assembled to the insulating substrate 300 by a connection process such as welding or sintering; the signal terminal 500 is assembled to the insulating substrate 300 by an ultrasonic welding process; the back of the insulating substrate 300 is assembled to the heat dissipation substrate 400 by welding, sintering and other processes;

[0066] From the AC output terminal 610 to the zero potential input terminal 620, the DC input positive terminal 630 and the DC input negative terminal 640, the second power unit group T2, the third power unit group T3, the first power unit group T1 and the fourth power unit group T4 are arranged in sequence.

[0067] The zero potential input terminal 620 is connected to the insulating substrate 300 through the zero potential first connection terminal 6201 and the zero potential second connection terminal 6202 on the inner side of the shell 100; the DC input positive terminal 630 is connected to the insulating substrate 300 through the DC input positive terminal first connection terminal 6301 and the DC input positive terminal second connection terminal 6302 on the inner side of the shell 100; the DC input negative terminal 640 is connected to the insulating substrate 300 through the DC input negative terminal first connection terminal 6401 and the DC input negative terminal second connection terminal 6402 on the inner side of the shell 100.

[0068] Figure 5A schematic diagram of the packaging of a power module according to a second embodiment of the present invention is shown; in the second embodiment, the zero potential input terminal 620, the DC input positive terminal 630 and the DC input negative terminal 640 are all located on the lower side of the housing 100, wherein the DC input positive terminal 630 is located in the middle area of ​​the lower side, and the zero potential input terminal 620 has two connection terminals symmetrically arranged on the left and right sides of the DC input positive terminal 630; the DC input negative terminal 640 is arranged on both sides of the zero potential input terminal 620, that is, in the packaging of the power module according to the second embodiment, the zero potential input terminal 620 and the DC input negative terminal 640 below the housing 100 are symmetrically designed, and are connected and inputted by two symmetrical connection terminals.

[0069] Figure 6 FIG. 1 is a schematic diagram showing a packaging insulating substrate of a power module according to a first embodiment of the present invention; Figure 6 As shown, a conductive structure is disposed on the front side of the insulating substrate 300, and the conductive structure includes a fifth conductive structure 310, a sixth conductive structure 370, a first conductive structure 320, a fourth conductive structure 330, a third conductive structure 340, a second conductive structure 350 and a seventh conductive structure 360, wherein the first conductive structure 320, the fourth conductive structure 330, the third conductive structure 340 and the second conductive structure 350 are all power unit placement areas, such as Figure 6 As shown, a first power unit group T1 is located on the first conductive structure 330 , a second power unit group T2 is located on the second conductive structure 350 , a third power unit group T3 is located on the third conductive structure 340 , and a fourth power unit group T4 is located on the fourth conductive structure 330 ;

[0070] The fifth conductive structure 310, the sixth conductive structure 370 and the seventh conductive structure 360 ​​are used for conduction and auxiliary routing; the power cells of each power cell group are mounted on the corresponding conductive area (power cell placement area) through the drain and are electrically connected thereto. Specifically, the first power cell group T1 is arranged on the first conductive structure 320, the second power cell group T2 is arranged on the second conductive structure 350, the third power cell group T3 is arranged on the third conductive structure 340, and the fourth power cell group T4 is arranged on the fourth conductive structure 330.

[0071] The fifth conductive structure 310 and the sixth conductive structure 370 are, for example, strip-shaped and are respectively located at left and right side regions of the insulating substrate 300 .

[0072] The first conductive structure 320 , the second conductive structure 350 , the third conductive structure 340 , and the fourth conductive structure 330 are located between the fifth conductive structure 310 and the sixth conductive structure 370 ;

[0073] The seventh conductive structure 360 ​​is located below the fourth conductive structure 330 .

[0074] The first to seventh conductive structures are independent of each other.

[0075] The third conductive structure 340 is located on the upper portion of the insulating substrate;

[0076] The first conductive structure 320 is located at the lower portion of the insulating substrate;

[0077] The first conductive structure 320 semi-surrounds the fourth conductive structure 330 and the seventh conductive structure 360. The first conductive structure 320 is led out to the lower side of the insulating substrate and forms a first end of the first conductive structure 320 and a second end of the first conductive structure respectively. The first end of the first conductive structure 320 and the second end of the first conductive structure 320 are symmetrically arranged on the lower side of the insulating substrate. An opening of the first conductive structure is formed between the first end of the first conductive structure 320 and the second end of the first conductive structure 320. The opening of the first conductive structure 320 faces the lower side of the insulating substrate. The first end of the first conductive structure serves as a first connection end 6301 of a DC input positive terminal, and the second end of the first conductive structure serves as a second connection end 6302 of a DC input positive terminal. The first end of the first conductive structure 320 and the second end of the first conductive structure 320 are electrically connected to the DC input positive terminal P.

[0078] The seventh conductive structure 360 ​​extends out of a first end of the seventh conductive structure 360 ​​through the opening of the first conductive structure 320 , and the seventh conductive structure 360 ​​is electrically connected to the DC input negative terminal N;

[0079] The third conductive structure 340 surrounds the second conductive structure;

[0080] The third conductive structure 340 is electrically connected to the AC output terminal 610;

[0081] The second conductive structure 350 is electrically connected to the fifth conductive structure 310 and the sixth conductive structure 370. The first end of the fifth conductive structure serves as the first connection end 6401 of the DC input negative terminal. The first end of the sixth conductive structure serves as the second connection end 6402 of the DC input negative terminal. The first end of the fifth conductive structure 350 and the first end of the sixth conductive structure 370 are electrically connected to the zero potential input terminal 0.

[0082] The first end of the fifth conductive structure 310 , the first end of the first conductive structure 320 , the first end of the seventh conductive structure 360 ​​, the first end of the second conductive structure 350 and the first end of the sixth conductive structure 370 are sequentially arranged on the lower side of the insulating substrate.

[0083] Figure 7 FIG. 1 is a schematic diagram showing the internal layout of a power module package according to a first embodiment of the present invention; FIG. Figure 7It can be seen that the first power cell group T3, for example, includes 6 third power cells 301, and the 6 third power cells 301 are symmetrically arranged on the first conductive structure 320, three on the left and three on the right, and the third power cells 301 are connected in parallel; similarly, the second power cell group T2, the first power cell group T1 and the fourth power cell group T4 all include 6 power cells, which are also symmetrically arranged, three on the left and three on the right.

[0084] The third end (drain) D1 of the first power unit T1 is electrically connected to the DC input positive end P via the first conductive structure, and the second end (source) S1 of the first power unit is electrically connected to the AC output end AC via the third conductive structure; the third end (drain) D2 of the second power unit T2 is electrically connected to the zero potential 0 via the fifth conductive structure and the sixth conductive structure, the second end (source) of the second power unit T2 is electrically connected to the second end (source) S3 of the third power unit T3, and the third end (drain) D3 of the third power unit T3 is electrically connected to the AC output end AC via the third conductive structure. The third end (drain) D4 of the fourth power unit T4 is electrically connected to the AC output end AC via the fourth conductive structure and the third conductive structure, the second end (source) S4 of the fourth power unit T4 is electrically connected to the DC input negative end N via the seventh conductive structure, the first end (gate) G1 of the first power unit T1 receives the first control signal, the first end (gate) G2 of the second power unit T2 receives the second control signal, the first end (gate) G3 of the third power unit T3 receives the third control signal, and the first end (gate) G4 of the fourth power unit T1 receives the fourth control signal.

[0085] The layout of the power module significantly reduces the volume of the power module, making its layout more compact and reducing costs. The design that is symmetrical along the dotted line can make the stray inductance of each commutation loop similar, significantly reduce the stray inductance in the loop, improve the current balance, and optimize the electrical performance. By connecting multiple power units 301 in parallel, the current load can also be dispersed, the current carrying capacity of the entire power module can be enhanced, and the power level of the module can be improved.

[0086] Figures 8 to 10 Schematic diagrams respectively showing the first commutation loop to the third commutation loop inside the power module of the first embodiment of the present invention; Figure 8 The commutation circuits from P1 to N1 and P2 to N2 in Figure 1 Corresponding to the first commutation loop in the circuit, through the left-right symmetric design of each power unit, Figure 1 The first commutation loop in the module is divided into two symmetrical loops on the left and right. By connecting multiple power units in parallel, the current load can be dispersed, the current carrying capacity of the entire power module can be enhanced, and the power level of the module can be improved. Figure 4 The DC input positive terminal first connection terminal 6301 corresponds to N1. Figure 4The first connection terminal 6401 of the DC input negative terminal corresponds to P2. Figure 4 The DC input positive terminal second connection terminal 6302 corresponds to N2. Figure 4 The left-right symmetrical design can make the stray inductance of each commutation loop similar, significantly reduce the stray inductance in the loop, improve the current balance, and optimize the electrical performance.

[0087] Similarly, Fig. 9 The commutation circuits of P1 to 01 and P2 to 02 in Figure 1 The second commutation loop in corresponds to , where 01 and Figure 4 The first connection terminal 6201 of the zero potential input terminal corresponds to 02. Figure 4 Corresponding to the zero potential second connection terminal 6202.

[0088] Fig.10 The commutation circuits from 01 to N1 and from 02 to N2 in Figure 1 The third commutation loop in

[0089] Figures 11 to 13 Schematic diagrams showing the internal layout of the power modules of the third to fifth embodiments of the present invention are shown respectively; Fig.11 In the third embodiment shown, the difference from the first embodiment is that the number of power units in the second power unit group T2 is 4, and the 4 power units are grouped in two and are symmetrically distributed on the left and right; similarly, the number of power units in the third power unit group T3 is also 4, corresponding to the second power unit group T2, and the 4 power units are also grouped in two and are symmetrically distributed on the left and right.

[0090] Fig.12 The fourth embodiment shown is different from the third embodiment in that the number of semiconductor power units in the first power unit group T1 and the fourth power unit group T4 is also 4 respectively, and the power units in groups of 2 are distributed symmetrically on the left and right.

[0091] Fig.13 The fifth embodiment shown is different from the first embodiment in that the number of power units in the first power unit group T1 and the fourth power unit group T4 is 4 respectively, and the power units in groups of 2 are distributed symmetrically on the left and right.

[0092] In summary, the number of semiconductor power units in the above power units may be 2, 4, 6, 8, or 10, and the number of power units in the second power unit group T2 corresponds to the number of power units in the third power unit group T3.

[0093] According to the power module provided by the present invention, all power units in the T-type midpoint clamped three-level circuit are packaged on the same packaging structure, and the power units of the same power unit group are connected in parallel with each other, and several power units are symmetrically distributed on the left and right. The present invention significantly reduces the volume of the power module, makes the layout of the power module more compact, and reduces the cost. At the same time, the packaging structure of the power module can ensure that the stray inductance of each commutation circuit in the three-level circuit topology is similar and small. The semiconductor power units of the same power unit group in the power module are symmetrically distributed in the power unit placement area, and the connection ends thereof adopt a double-end structure to form two parallel commutation circuits. The overall stray inductance of the commutation circuit can be significantly reduced, which helps to reduce the circuit commutation area, and the current balance of the parallel semiconductor power units in the power module can be significantly improved to optimize the electrical performance.

[0094] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0095] As described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A power module, characterized in that: include, An insulating substrate, the insulating substrate comprising a conductive structure located on the front side of the insulating substrate, the conductive structure comprising a fourth conductive structure, a first conductive structure, a second conductive structure and a third conductive structure which are independently arranged in sequence from bottom to top; a fourth power unit group, a first power unit group, a third power unit group, and a second power unit group, wherein the fourth power unit group is located on the fourth conductive structure, the first power unit group is located on the first conductive structure, the third power unit group is located on the third conductive structure, and the second power unit group is located on the second conductive structure; Among them, the power units of at least one power unit group among the first to fourth power unit groups are symmetrically distributed.

2. The power module according to claim 1, characterized in that: The power module further includes: AC output terminal, DC input positive terminal, zero potential input terminal and DC input negative terminal; The first power unit group is electrically connected to the AC output end and the DC input positive end, the second power unit group and the third power unit group are connected in sequence, the second power unit group is electrically connected to the zero potential input end, and the third power unit group is electrically connected to the AC output end; the fourth power unit group is electrically connected to the AC output end and the DC input negative end, thereby forming a T-type mid-point clamped three-level circuit.

3. The power module according to claim 2, characterized in that: The fourth power unit group includes a plurality of fourth power units, the first power unit group includes a plurality of first power units, the third power unit group includes a plurality of third power units, and the second power unit group includes a plurality of second power units; There are at least two of the fourth power units, and several power units of the fourth power units are symmetrically distributed left and right and several power units of the first power units are symmetrically distributed left and right; or, there are at least two of the third power units, several power units of the third power units are symmetrically distributed left and right and several power units of the second power units are at least two, and several power units of the second power units are symmetrically distributed left and right.

4. The power module according to any of claims 3, characterized in that: The number of the fourth power unit, the first power unit, the third power unit and the second power unit is equal, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

5. The power module according to any claim of claim 3, characterized in that: The number of the fourth power unit is equal to that of the first power unit, the number of the third power unit and the second power unit is equal, the number of the fourth power unit is less than the number of the third power unit, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

6. The power module according to any claim of claim 3, characterized in that: The number of the fourth power unit is equal to that of the first power unit, the number of the third power unit and the second power unit is equal, the number of the fourth power unit is greater than the number of the third power unit, several power units of the fourth power unit are symmetrically distributed left and right, several power units of the first power unit are symmetrically distributed left and right, several power units of the third power unit are symmetrically distributed left and right, and several power units of the second power unit are symmetrically distributed left and right.

7. The power module according to any one of claims 2 to 6, characterized in that: The AC output terminal is located on the upper side of the power module; the zero potential input terminal, the DC input negative terminal and the DC input positive terminal are located on the lower side of the power module.

8. The power module according to any one of claims 3 to 6, characterized in that: The third end of the first power unit is electrically connected to the positive end of the DC input, and the second end of the first power unit is electrically connected to the AC output end; the third end of the second power unit is electrically connected to the zero potential, the second end of the second power unit is electrically connected to the second end of the third power unit, the third end of the third power unit is electrically connected to the AC output end, the third end of the fourth power unit is electrically connected to the AC output end, the second end of the fourth power unit is electrically connected to the negative end of the DC input, the first end of the first power unit receives a first control signal, the first end of the second power unit receives a second control signal, the first end of the third power unit receives a third control signal, and the first end of the fourth power unit receives a fourth control signal.

9. The power module according to any one of claims 8, characterized in that: The conductive structure further comprises: a fifth conductive structure and a sixth conductive structure, wherein the fifth conductive structure and the sixth conductive structure are respectively located on the left and right sides of the insulating substrate; and the first conductive structure, the second conductive structure, the third conductive structure and the fourth conductive structure are located between the fifth conductive structure and the sixth conductive structure; a seventh conductive structure, the seventh conductive structure being located below the fourth conductive structure; The first to seventh conductive structures are independent of each other.

10. The power module according to claim 9, characterized in that: The third conductive structure is located at the upper portion of the insulating substrate; The first conductive structure is located at the lower portion of the insulating substrate; The first conductive structure semi-surrounds the fourth conductive structure and the seventh conductive structure, the first conductive structure is led out to the lower side of the insulating substrate and forms a first end of the first conductive structure and a second end of the first conductive structure respectively, the first end of the first conductive structure and the second end of the first conductive structure are symmetrically arranged on the lower side of the insulating substrate, an opening of the first conductive structure is formed between the first end of the first conductive structure and the second end of the first conductive structure, the opening of the first conductive structure faces the lower side of the insulating substrate, the first end of the first conductive structure serves as a first connection end of the DC input positive terminal, the second end of the first conductive structure serves as a second connection end of the DC input positive terminal, and the first end of the first conductive structure and the second end of the first conductive structure are electrically connected to the DC input positive terminal; The seventh conductive structure is located at the opening of the first conductive structure, the seventh conductive structure is led out to the lower side of the insulating substrate and forms a first end of the seventh conductive structure, and the seventh conductive structure is electrically connected to the DC input negative terminal; The third conductive structure surrounds the second conductive structure; The third conductive structure is electrically connected to the AC output end; The second conductive structure is electrically connected to the fifth conductive structure and the sixth conductive structure, the first end of the fifth conductive structure is led out to the lower side of the insulating substrate, the first end of the fifth conductive structure serves as the first connection end of the DC input negative terminal, the first end of the sixth conductive structure is led out to the lower side of the insulating substrate, the first end of the sixth conductive structure serves as the second connection end of the DC input negative terminal, and the first end of the fifth conductive structure and the first end of the sixth conductive structure are electrically connected to the zero potential input terminal; The first end of the fifth conductive structure, the first end of the first conductive structure, the first end of the seventh conductive structure, the first end of the second conductive structure and the first end of the sixth conductive structure are sequentially arranged on the lower side of the insulating substrate.

11. The power module according to claim 10, characterized in that: The third end of the first power unit is electrically connected to the DC input positive end via the first conductive structure, and the second end of the first power unit is electrically connected to the AC output end via the third conductive structure; the third end of the second power unit is electrically connected to the zero potential via the fifth conductive structure and the sixth conductive structure, the second end of the second power unit is electrically connected to the second end of the third power unit, the third end of the third power unit is electrically connected to the AC output end via the third conductive structure, the drain of the fourth power unit is electrically connected to the AC output end via the fourth conductive structure and the third conductive structure, the second end of the fourth power unit is electrically connected to the DC input negative end via the seventh conductive structure, the first end of the first power unit receives a first control signal, the first end of the second power unit receives a second control signal, the first end of the third power unit receives a third control signal, and the first end of the fourth power unit receives a fourth control signal.

12. The power module according to claim 11, characterized in that: The power module further includes a signal terminal, and the signal terminal includes: The first end of the first power unit leads out, the second end of the first power unit leads out, and the third end of the first power unit leads out; The first end of the second power unit leads out, and the second end of the second power unit leads out; A first end lead-out terminal of the third power unit, a second end lead-out terminal of the third power unit, and a third end lead-out terminal of the third power unit; The first end of the fourth power unit is led out, the second end of the fourth power unit is led out, and the third end of the fourth power unit is led out.

13. The power module according to any claim of claim 10, characterized in that: The current of the first commutation loop flows through the power module, the DC input positive terminal, the first power unit, the fourth power unit, and the DC input negative terminal.

14. The power module according to claim 13, characterized in that The current path on the power module in the first commutation loop is bilaterally symmetrical to form two first commutation loops connected in parallel.

15. The power module according to any claim of claim 10, characterized in that: The current of the second commutation loop flows through the power module, the DC input positive terminal, the first power unit, the third power unit, the second power unit, and the zero potential input terminal.

16. The power module according to claim 15, characterized in that The current path on the power module in the second commutation loop is bilaterally symmetrical to form two parallel second commutation loops.

17. The power module according to any claim of claim 10, characterized in that: The current of the third commutation loop flows through the power module, the zero potential input terminal, the second power unit, the third power unit, the fourth power unit, and the DC input negative terminal.

18. The power module according to claim 17, characterized in that The current path on the power module in the third commutation loop is bilaterally symmetrical to form two third commutation loops connected in parallel.

19. The power module according to any one of claims 1 to 6, characterized in that: Also includes: The housing, the insulating substrate, the conductive structure, and a plurality of power unit groups are located on one side of the housing.

20. The power module according to claim 19, characterized in that: Also includes: A cover plate is located on one side of the shell, and the shell and the cover plate cover the insulating substrate, the conductive structure, and a plurality of power units.

21. The power module according to any one of claims 1 to 6, characterized in that: Also includes: A heat dissipation substrate is located at the other side of the housing, and the back side of the insulating substrate is connected to the heat dissipation substrate.

22. The power module according to claim 21, characterized in that: The back side of the insulating substrate is connected to the heat dissipation substrate by welding or sintering.

23. The power module according to any one of claims 1 to 6, characterized in that: The insulating substrate is a DBC copper-clad substrate.

24. The power module according to claim 20, characterized in that: The power module further includes a signal terminal, which is perpendicular to the insulating substrate and electrically connected to the insulating substrate, and at least a portion of the top end of the signal terminal passes through the cover plate.

25. The power module according to any one of claims 1 to 6, characterized in that: A thermistor is also arranged on the insulating substrate, and two ends of the thermistor are led out of the housing of the power module.

26. The power module according to any one of claims 3 to 6, characterized in that: The number of the fourth power units is greater than or equal to six, the number of the first power units is greater than or equal to six, the number of the third power units is greater than or equal to 6, and the number of the second power units is greater than or equal to 6.

27. The power module according to any one of claims 2 to 6, characterized in that: The DC input positive terminal, the zero potential input terminal and the DC input negative terminal are located at the lower side of the power module, and the DC input positive terminal, the zero potential input terminal and the DC input negative terminal are located in different planes.

28. The power module according to any one of claims 3 to 6, characterized in that: The first to fourth power units are one of a metal oxide semiconductor field effect transistor power tube, a silicon carbide metal oxide semiconductor field effect transistor, a parallel structure of an insulated gate field effect transistor and a parallel freewheeling diode, or an RC-IGBT; When the power unit is a metal oxide semiconductor field effect transistor or a silicon carbide metal oxide semiconductor field effect transistor, the first end of the power unit is a gate, the second end of the first power unit is a source, and the third end of the first power unit is a drain; When the power unit is a parallel structure of an insulated gate field effect transistor and a parallel freewheeling diode, or when the power unit is an RC-IGBT, the first end of the power unit is a base, the second end of the power unit is a collector, and the third end of the power unit is an emitter; The parallel structure of the insulated gate field effect transistor and the parallel freewheeling diode is that the collector of the insulated gate field effect transistor is connected to the anode of the diode, and the emitter of the insulated gate field effect transistor is connected to the cathode of the diode.

29. A method for packaging a power module, characterized in that: A power module as claimed in any one of claims 1 to 28 is packaged.

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