Power conversion device and power supply cabinet

Abstract

The embodiment of the utility model provides a power conversion device and a power supply cabinet comprising the same, and relates to the technical field of energy. Wherein the power conversion device is used for performing power conversion on input electric energy and then outputting the electric energy, the power conversion device comprises a device shell, a circuit board, a power device and a substrate, and the circuit board is fixed in the device shell; the power device is fixed on the circuit board; the substrate is located in the device shell and comprises a first metal layer, a second metal layer and a first insulating layer fixed between the first metal layer and the second metal layer, and the first metal layer is connected with the circuit board or the power device; the substrate further comprises a through hole and an electric conductor, the through hole penetrates through the first metal layer and the first insulating layer, and the electric conductor penetrates through the through hole and is connected with the first metal layer and the second metal layer; under the condition that the power conversion device operates, the voltage to ground of the part, used for being connected with the first metal layer, of the circuit board or the power device is unchanged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy, in particular to a power conversion device and a power cabinet. BACKGROUND

[0002] The power conversion device is widely used in various power systems, wherein, the power device is the core of the hardware design of the power conversion device, but in the process of running of the power conversion device, the power device generates more heat.

[0003] In the related art, in order to effectively dissipate heat of the power device, a substrate for auxiliary heat dissipation is connected to the circuit board, and in order to make the structure connected with the substrate (for example, a further auxiliary heat dissipation structure) not directly electrified, the substrate is set as a multi-layer structure, and two metal layers of the substrate are isolated by an insulating layer.

[0004] However, the area of the two metal layers of the substrate facing each other is large, which will generate a large parasitic capacitance, and the changing voltage on the circuit board will be conducted to the structure connected with the substrate through the parasitic capacitance of the substrate, resulting in a jump voltage of the substrate and the structure connected to the substrate, which will interfere with the signals (for example, signals used by the driving circuit to drive the power device; for example, signals used by the control circuit to control the power device) in the power conversion device. CONTENT OF THE INVENTION

[0005] The present application provides a power conversion device and a power cabinet comprising the power conversion device, which reduces the interference with the internal signals of the power conversion device under the condition of effectively dissipating heat of the power device.

[0006] To achieve the above object, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a power conversion device for converting input electrical energy and outputting, the power conversion device comprising a device shell, a circuit board, a power device and a substrate, the circuit board being fixed in the device shell; the power device is fixed on the circuit board; the substrate is located in the device shell, and the substrate comprises a first metal layer, a second metal layer and a first insulating layer fixed between the first metal layer and the second metal layer, the first metal layer being connected with the circuit board or the power device; the substrate further comprises a through hole and a conductive body, the through hole penetrating the first metal layer and the first insulating layer, and the conductive body penetrating the through hole and connecting the first metal layer and the second metal layer; in the case of running of the power conversion device, the part of the circuit board or the power device connected with the first metal layer has a constant ground voltage.

[0008] The power conversion device realizes power conversion on input electric energy through power devices on the circuit board. In the process of operation of the power conversion device, the power devices generate a large amount of heat. The substrate can assist the power devices in heat dissipation. The first metal layer and the second metal layer in the substrate have strong heat conduction capacity (metal has good heat conduction capacity). The heat of the power devices can be transferred outward through the substrate, effectively improving the heat dissipation effect of the power devices. For example, when the substrate is connected with the power devices, the heat of the power devices is transferred to the substrate and then transferred outward through the substrate. For another example, when the substrate is connected with the circuit board, the heat of the power devices is transferred to the circuit board, and then the heat is transferred to the substrate through the circuit board, and the heat is transferred outward through the substrate. In addition, the first insulating layer of the substrate can separate the first metal layer and the second metal layer, reducing the possibility of mutual conduction of the first metal layer and the second metal layer.

[0009] The substrate further has an electric conductor. The electric conductor passes through the first metal layer and the first insulating layer, and the electric conductor connects the first metal layer and the second metal layer. Since the first metal layer is connected with the circuit board or the power devices, the second metal layer can be electrically connected with the circuit board or the power devices through the electric conductor. The part of the circuit board and the power devices for connecting the first metal layer has a constant ground voltage (stable voltage level without jump voltage), so that the voltage level of the second metal layer (or a structure connected to the second metal layer) is stable, the interference to the internal signals of the power conversion device (for example, signals for driving the power devices by a driving circuit; for another example, signals for controlling the power devices by a control circuit) is reduced, and the electromagnetic compatibility (EMC) of the power conversion device is improved.

[0010] In summary, the substrate of the present application can assist the power devices in heat dissipation. In the case of effectively dissipating the heat of the power devices, the risk of jump voltage of the second metal layer (or a structure connected to the second metal layer) interfering with the internal signals of the power conversion device is reduced.

[0011] In an embodiment of the present application, the substrate is located on the side of the circuit board away from the power devices. The circuit board includes a wiring layer facing the substrate. The wiring layer is connected with the first metal layer. The part of the wiring layer for connecting the first metal layer has a constant ground voltage.

[0012] The conductive body connects the first metal layer and the second metal layer, and the first metal layer is connected to the trace layer of the circuit board. That is, by means of the conductive body and the first metal layer, the second metal layer is electrically connected to the trace layer. By connecting the first metal layer to the part of the trace layer where the ground voltage is constant, the level of the second metal layer (or the structure connected to the second metal layer) can be stabilized. In addition, the trace layer of the circuit board is connected to the first metal layer of the substrate. The material of the trace layer is metal, and the metal trace layer can be soldered to the metal first metal layer, which facilitates the stable connection of the substrate and the circuit board and reduces the possibility of separation of the substrate and the circuit board. In the case where the trace layer of the circuit board facing the substrate is soldered to the first metal layer of the substrate, the solder used for soldering serves as a thermal interface material (TIM), which has a small thermal resistance, so that the thermal resistance between the substrate and the circuit board is small, which is conducive to heat transfer between the substrate and the circuit board.

[0013] In an embodiment of the present application, the substrate is located on the side of the power device away from the circuit board; the power device includes a package shell, a die, and a metal plate, the die is located in the package shell and is electrically connected to the metal plate, the metal plate protrudes from the package shell to the side of the package shell away from the circuit board, the metal plate is connected to the first metal layer, and the ground voltage of the metal plate is constant.

[0014] In the case where the first metal layer of the substrate is connected to the power device, the heat of the power device can be directly transferred to the substrate (without passing through the circuit board) and transferred outward through the substrate, shortening the heat dissipation path of the power device and making the heat dissipation effect of the power device better. In the case where the ground voltage of the metal plate is constant, the first metal layer is connected to the metal plate, and the first metal layer and the second metal layer are connected by the conductive body, which can stabilize the level of the second metal layer (or the structure connected to the second metal layer) and reduce the interference with the signal.

[0015] In addition, the metal plate of the power device can also assist the power device in dissipating heat outward, so that the heat inside the package shell is quickly transferred to the outside of the power package shell, that is, the heat inside the package shell is quickly transferred to the substrate, improving the heat dissipation efficiency of the power device.

[0016] In an embodiment of the present application, the die includes a switch tube, the drain or collector of the switch tube is electrically connected to the metal plate, and the metal plate is electrically connected to the negative bus of the power conversion circuit in the power conversion device.

[0017] Generally, the drain or collector of the switch tube in the die is electrically connected to the metal plate. When the metal plate is electrically connected to the negative bus and the ground voltage of the metal plate is constant, the substrate connected to the metal plate is also in a stable state, reducing the risk of interference with the signal in the power conversion device.

[0018] In an embodiment of the present application, the power conversion device further comprises a heat sink, the heat sink is located in the device shell or at least partially located outside the device shell, the heat sink comprises a heat conduction plate and a plurality of fins, the heat conduction plate is located on the side of the substrate away from the power device and connected with the second metal layer, and the plurality of fins are fixed to the surface of the heat conduction plate away from the substrate.

[0019] The second metal layer of the substrate is connected with the heat sink (HSK), and since the second metal layer has a stable level, the heat sink is also in a level stable state, reducing the possibility of jump voltage existing between the substrate and the heat sink, and reducing the risk of interference to the internal signals of the power conversion device.

[0020] The heat sink can assist the substrate in heat dissipation, and after the heat of the power device is transmitted to the substrate, it is transmitted to the heat conduction plate of the heat sink through the substrate, the heat of the heat conduction plate is transmitted to the plurality of fins, and the gap between adjacent two fins is beneficial to heat exchange between the fins and the air, thereby improving the heat dissipation efficiency of the power device.

[0021] In addition, if the substrate is directly formed with a boss (similar to the structure of the fin), it may be limited by the substrate manufacturing equipment, resulting in a shorter length (size in the thickness direction of the second metal layer) of the boss, affecting the heat dissipation effect of the power device. Moreover, in order to make the length of the boss meet the heat dissipation demand of the power device, the manufacturing cost will inevitably be greatly increased by using the above design method. However, by using the method of additionally setting the heat sink, the heat sink can be produced separately according to the demand, so that the size and shape of the heat sink are more flexible, which is beneficial to production and manufacturing, and reduces the manufacturing cost on the basis of effectively dissipating heat of the power device.

[0022] In an embodiment of the present application, the through hole also penetrates the second metal layer, and one end of the conductive body away from the circuit board is connected with the heat sink.

[0023] The through hole penetrates the first metal layer, the first insulating layer and the second metal layer, that is, the through hole penetrates the entire substrate, facilitating the processing of the through hole. In addition, in the case that the through hole penetrates the entire substrate, the conductive body can also pass through the second metal layer and be connected with the heat sink, further improving the stability of the electrical connection between the heat sink, the second metal layer and the first metal layer.

[0024] In an embodiment of the present application, the substrate further comprises a filler, the conductive body is annular and fixed to the inner surface of the through hole, and the filler is used to fill the space surrounded by the conductive body.

[0025] The conductive body is fixed to the inner wall of the through hole to form a metal hole. In this case, the conductive body is a metal layer in the through hole, and the space surrounded by the conductive body is the space inside the through hole. The filler is arranged in the space surrounded by the conductive body, so as to block the through hole. By blocking the through hole with the filler, in the case that the substrate needs to be connected to a circuit board or a heat sink by welding, the possibility of solder between the circuit board and the substrate or solder between the substrate and the heat sink entering the through hole is reduced, which is conducive to the stable connection of the substrate to the circuit board or the heat sink.

[0026] In an embodiment of the present application, the filler includes a metal block, and an end of the metal block away from the circuit board is connected to the heat sink; or the filler includes resin.

[0027] In the case that the filler is a metal block, since the material of the metal block is metal, the heat conduction capacity is strong, so that the metal block can quickly conduct the heat on the substrate to the heat sink, improving the heat dissipation efficiency of the power device. In the case that the filler is resin, the heat conduction capacity of resin is also stronger than that of air, so that the heat can be quickly transmitted through the resin, improving the heat transmission speed.

[0028] In an embodiment of the present application, the substrate further includes a second insulating layer and a third metal layer between the first insulating layer and the second metal layer, the second insulating layer is fixed between the second metal layer and the third metal layer; the through hole further penetrates the second insulating layer and the third metal layer, and the conductive body is further connected to the third metal layer.

[0029] One side of the substrate needs to be connected to a power board device or a circuit board, and the other side of the substrate can be connected to a heat sink or other auxiliary heat dissipation structure, so that the materials of the first metal layer, the second metal layer and the third metal layer can be selected respectively, for example, the materials of the metal layers on both sides of the substrate (the material of the first metal layer and the material of the second metal layer) are materials conducive to welding (for example, copper), the material of the metal layer in the middle of the substrate (the material of the third metal layer) is a material with lower cost (for example, aluminum), or the material of the third metal layer is a material with lighter weight, etc.

[0030] The substrate includes a plurality of metal layers (the first metal layer, the second metal layer and the third metal layer), different materials can be selected for different metal layers according to requirements, in the case of facilitating the connection (for example, welding) of the substrate to other structures, the cost, weight, heat conduction capacity and other aspects of the substrate are also taken into account, so that the design of the substrate is more flexible. In addition, in the case that the substrate has a plurality of metal layers, a plurality of insulating layers (the first insulating layer and the second insulating layer) are arranged, which reduces the possibility of mutual conduction between adjacent metal layers.

[0031] And, in the case that the substrate has multiple metal layers, the via at least penetrates the first metal layer, the first insulating layer, the third metal layer and the second insulating layer, so that the conductor can connect the first metal layer, the second metal layer and the third metal layer, and in the case that the structure connected by the first metal layer has a constant ground voltage, the second metal layer and the third metal layer can be in a stable state.

[0032] In an embodiment of the present application, the thickness of the first metal layer and the thickness of the second metal layer are both greater than the thickness of the first insulating layer.

[0033] Since the first metal layer and the second metal layer in the substrate both have strong heat conduction capacity, and the first insulating layer that plays a shielding role has weak heat conduction capacity, in some cases, the thickness of the first metal layer and the second metal layer can be increased, and the thickness of the first insulating layer can be reduced, so as to improve the heat conduction capacity of the substrate and facilitate heat dissipation of the power device.

[0034] In an embodiment of the present application, the material of the first insulating layer includes polypropylene.

[0035] Polypropylene (PP) has good insulation performance, and has stronger heat conduction capacity than other insulating materials (for example, polyimide). By making the first insulating layer of the substrate include polypropylene, the thermal resistance between the first metal layer and the second metal layer is reduced, and the heat dissipation capacity of the substrate is improved, while achieving insulation between the first metal layer and the second metal layer.

[0036] In a second aspect of the present application, a power cabinet is provided, which includes a cabinet body and the power conversion device described above. The plurality of power conversion devices are located in the cabinet body, and the plurality of power conversion devices are connected in parallel.

[0037] The power conversion device in the cabinet body can perform power conversion on the input electric energy and output the power conversion result. The substrate can assist the power device in heat dissipation, and also reduces the risk that the second metal layer (or a structure connected to the second metal layer) has a jump voltage and interferes with the internal signal of the power conversion device. The power cabinet provided in the present application includes the power conversion device described above, so the power cabinet provided in the present application and the power conversion device of the technical solution described above can solve the same technical problems and have the same technical effects, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A structural schematic diagram of a power conversion device provided in an embodiment of the present application is shown in the figure;

[0039] Figure 2 A structural schematic diagram of a power cabinet provided in an embodiment of the present application is shown in the figure;

[0040] Figure 3Another structure schematic view of a power supply cabinet provided by the embodiment of the present application;

[0041] Figure 4 An internal structure schematic view of a power conversion device provided by the embodiment of the present application;

[0042] Figure 5 Another internal structure schematic view of a power conversion device provided by the embodiment of the present application;

[0043] Figure 6 A structure and position schematic view of a substrate provided by the embodiment of the present application;

[0044] Figure 7 A structure schematic view of a via hole and a conductor provided by the embodiment of the present application;

[0045] Figure 8 A structure schematic view of a filler provided by the embodiment of the present application;

[0046] Figure 9 A structure and position schematic view of a heat sink provided by the embodiment of the present application;

[0047] Figure 10 Another internal structure schematic view of a power conversion device provided by the embodiment of the present application;

[0048] Figure 11 Another internal structure schematic view of a power conversion device provided by the embodiment of the present application;

[0049] Figure 12 A structure schematic view of a heat dissipation hole provided by the embodiment of the present application;

[0050] Figure 13 Another position schematic view of a substrate provided by the embodiment of the present application;

[0051] Figure 14 Structure schematic views of two power devices provided by the embodiment of the present application;

[0052] Figure 15 A topology view of a direct-current-direct-current power conversion circuit provided by the embodiment of the present application;

[0053] Figure 16 Another position schematic view of a heat sink provided by the embodiment of the present application;

[0054] Figure 17 Another position schematic view of a substrate provided by the embodiment of the present application;

[0055] Figure 18 Another structure schematic view of a substrate provided by the embodiment of the present application;

[0056] Figure 19 Another schematic structural diagram of a substrate is provided in an embodiment of the present application.

[0057] Reference signs:

[0058] 100 - power conversion device; 1 - device shell; 11 - opening; 2 - circuit board; 21 - wiring layer; 22 - heat dissipation hole; 3 - power device; 31 - package shell; 32 - die; 321 - switch tube; 33 - metal plate; 34 - pin; 35 - mounting plate; 36 - conductive structure; 4 - mainboard; 5 - substrate; 51 - first metal layer; 52 - first insulating layer; 53 - second metal layer; 54 - through hole; 55 - conductor; 56 - filler; 57 - second insulating layer; 58 - third metal layer; 59 - boss; 6 - heat sink; 61 - heat conduction plate; 62 - fin; 7 - solder; 8 - DC-DC power conversion circuit; 81 - positive bus; 82 - negative bus; 200 - power supply cabinet; 201 - cabinet body; 202 - circuit breaker; 203 - charging gun; 204 - cable. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application.

[0060] In the present application, the terms "first", "second", and the like are used only for the purpose of description and are intended to distinguish one element from another, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features.

[0061] In addition, in the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present relevant concepts in a concrete manner.

[0062] In the drawings of the embodiments of the present application, the entity structures of components, assemblies, and the like are represented by guide lines; the structures composed of multiple components are represented by guide lines in brackets or with solid arrows; the hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows.

[0063] The power conversion device 100 provided by the embodiments of the present application can be an inverter, a rectifier, an on-board charger (OBC), a power module (for example, a DC-DC module, an AC-DC module) in a charging pile, a small charging device, etc. Figure 1 An exemplary structure of a power conversion device 100 is shown in FIG. 1, and the structure of the power conversion device 100 is described in detail with reference to FIG. 1. Figure 1 The power conversion device 100 can be a rectifier.

[0064] In addition, the power conversion device 100 can also be used in a power supply cabinet 200, for example, Figure 2 An exemplary structure of a power supply cabinet 200 is shown in FIG. 2, and the structure of the power supply cabinet 200 is described in detail with reference to FIG. 2. Figure 2 The power supply cabinet 200 can be a cabinet-type uninterruptible power supply (UPS), wherein the power supply cabinet 200 includes a cabinet body 201, a plurality of parallel power conversion devices 100, and a plurality of circuit breakers 202, etc. The plurality of power conversion devices 100 can include a plurality of AC-DC modules, or the plurality of power conversion devices 100 can include a plurality of DC-DC modules and a plurality of AC-DC modules. The plurality of power conversion devices 100 are stacked in the cabinet body 201 along the height direction of the cabinet body 201, and the plurality of circuit breakers 202 are located above the plurality of power conversion devices 100.

[0065] For another example, Figure 3 An exemplary structure of another power supply cabinet 200 is shown in FIG. 3, and the structure of the power supply cabinet 200 is described in detail with reference to FIG. 3. Figure 3 The power supply cabinet 200 can also be a charging pile, and the power supply cabinet 200 includes a cabinet body 201, a plurality of parallel power conversion devices 100, at least one charging gun 203 (a plurality of charging guns 203 are shown in FIG. 3) and at least one cable 204 (a plurality of cables 204 are shown in FIG. 3), etc. The plurality of parallel power conversion devices 100 are located in the cabinet body 201 of the power supply cabinet 200, and the charging gun 203 is electrically connected to the output end of the plurality of power conversion devices 100 through the corresponding cable 204. Figure 3 Figure 3 An exemplary internal structure of a power conversion device 100 is shown in FIG. 4, and the internal structure of the power conversion device 100 is described in detail with reference to FIG. 4.

[0066] Figure 4 Figure 4 ​​The power conversion device 100 includes a device housing 1, which can be any housing with a containing function. Furthermore, the power conversion device 100 also includes a circuit board 2 and a power device 3 fixed to the circuit board 2. For example, the circuit board 2 is a printed circuit board (PCB), and the power device 3 is fixed (e.g., soldered) to the circuit board 2 and connected to traces on the surface of the circuit board 2. Both the circuit board 2 and the power device 3 are located within the device housing 1.

[0067] In some embodiments, the power device 3 can be in the form of a surface-mount device, which is beneficial for the miniaturization and high density of the power device 3, and can also improve the reliability of the power device 3. The surface-mount power device 3 can be soldered onto the pads of the circuit board 2 (the pads can be the exposed portion of the traces on the circuit board 2), and the pins of the power device 3 are fixedly connected to the surface of the pads facing the power device 3. In other embodiments, the power device 3 can also be other suitable packaged devices.

[0068] exist Figure 4 In the illustrated embodiment, the power conversion circuit in the power conversion device 100 is at least partially disposed on the circuit board 2, wherein the power conversion circuit includes a power device 3, a drive circuit for driving the power device 3, a control circuit for controlling the power device 3, and so on.

[0069] Figure 5 An exemplary internal structure of another power conversion device 100 is shown, with reference to Figure 5 ,and Figure 4 The illustrated embodiment differs in that the circuit board 2, to which the power device 3 is fixed, is attached to another circuit board (which may be designated motherboard 4) via an adapter structure (e.g., pins or metal fittings). Figure 5 In the illustrated embodiment, a portion of the power devices 3 in the power conversion circuit are disposed on the circuit board 2, and other devices of the power conversion circuit, such as inductors, capacitors, etc., are disposed on another circuit board (main board 4). In addition, the other circuit board 2 (main board 4) is also provided with a control circuit for controlling the power devices 3, etc.

[0070] The circuit board 2, which houses the power device 3, can be mounted at any suitable angle to another circuit board (main board 4), for example, in... Figure 5In the shown embodiment, the circuit board 2 on which the power device 3 is fixed is fixed perpendicularly to another circuit board (the main board 4), that is, any surface of the circuit board 2 on which the power device 3 is fixed is perpendicular to any surface of the another circuit board (the main board 4) (here, "perpendicular" is not absolute perpendicular, and an error of ±10° is allowed). In other embodiments, the circuit board 2 on which the power device 3 is fixed is parallel to another circuit board (the main board 4), that is, any surface of the circuit board 2 on which the power device 3 is fixed is parallel to any surface of the another circuit board (the main board 4) (here, "parallel" allows an error of ±10°).

[0071] During the operation of the power conversion device 100, the power device 3 generates a large amount of heat, and therefore, in the present application, the power conversion device 100 further comprises a substrate 5, and the substrate 5 assists the power device 3 in heat dissipation. Figure 6 An example is shown to illustrate the structure and position of the substrate 5, with reference to Figure 6 The substrate 5 is located in the device shell 1 (the structure of the device shell 1 can be referred to Figure 4 or Figure 5 ). With reference to Figure 6 The substrate 5 comprises a first metal layer 51, a first insulating layer 52 and a second metal layer 53, the first insulating layer 52 is fixed between the first metal layer 51 and the second metal layer 53, and the first metal layer 51 is connected to the circuit board 2.

[0072] The material of the first metal layer 51 and the material of the second metal layer 53 are both metal, which has strong heat conduction capacity. The heat of the power device 3 is transferred to the circuit board 2, and then transferred to the substrate 5 through the circuit board 2. The heat is transferred outward through the substrate 5 which has strong heat conduction capacity. The material of the first metal layer 51 and the material of the second metal layer 53 can be any suitable metal material respectively, and the material of the first metal layer 51 and the material of the second metal layer 53 can be the same or different, as long as the material of the first metal layer 51 and the material of the second metal layer 53 are both metal. In some embodiments, if the first metal layer 51 needs to be welded with the circuit board 2, the material of the first metal layer 51 can be a metal material that is conducive to welding, for example, copper. In other embodiments, if it is necessary to control the cost or weight, the material of the second metal layer 53 can be a material that meets the design requirements, for example, aluminum. In other embodiments, if it is necessary to connect other structures (for example, structures that assist in heat dissipation) on the second metal layer 53, the material of the second metal layer 53 can be a metal material that is conducive to welding, for example, copper, or the material of the second metal layer 53 can be a metal material that is not conducive to welding (the material is selected for other purposes, for example, cost, weight, heat conduction capacity, etc.), and the surface of the second metal layer 53 that needs to be welded with other structures (for example, the surface of the second metal layer 53 away from the first insulating layer 52) is electroplated, so that the surface of the second metal layer 53 is electroplated with a layer of material that is conducive to welding, facilitating the welding and fixation of the second metal layer 53 with other structures.

[0073] In addition, the first insulating layer 52 of the substrate 5 can separate the first metal layer 51 and the second metal layer 53, reducing the possibility of mutual conduction of the first metal layer 51 and the second metal layer 53. The material of the first insulating layer 52 can also be any suitable insulating material, for example, the material of the first insulating layer 52 includes polypropylene (PP), that is, the first insulating layer 52 is a PP layer. The polypropylene has good insulation performance, and has stronger heat conduction capacity compared to other insulating materials (for example, polyimide). By including polypropylene in the first insulating layer 52 of the substrate 5, the thermal resistance between the first metal layer 51 and the second metal layer 53 is reduced while achieving mutual insulation of the first metal layer 51 and the second metal layer 53, thereby improving the heat dissipation capacity of the substrate 5.

[0074] Since the first metal layer 51 and the second metal layer 53 in the substrate 5 both have strong heat conduction capacity, and the first insulating layer 52 used to separate the first metal layer 51 and the second metal layer 53 has weak heat conduction capacity, in some embodiments, referring to Figure 6The thickness of the first metal layer 51 and the thickness of the second metal layer 53 can be made thicker, and the thickness of the first insulating layer 52 can be made thinner, so as to improve the heat conduction capacity of the substrate 5. For example, the thickness of the first metal layer 51 and the thickness of the second metal layer 53 are both greater than the thickness of the first insulating layer 52. In other embodiments, the thickness of the first metal layer 51 and the thickness of the first insulating layer 52 can also be equal, or the thickness of the first metal layer 51 is less than the thickness of the first insulating layer 52.

[0075] It should be noted that the thickness of the first metal layer 51, the thickness of the first insulating layer 52, and the thickness of the second metal layer 53 all refer to the size of the three in the X direction of their own thickness direction. Figure 6

[0076] However, the area directly opposite between the first metal layer 51 and the second metal layer 53 of the substrate 5 is large, which can generate a large parasitic capacitance. The changing voltage on the circuit board 2 can be conducted to the structure connected with the substrate 5 through the parasitic capacitance of the substrate 5, resulting in a jump voltage of the substrate 5 and the structure connected with the substrate 5, which can interfere with the signals in the power conversion device 100 (for example, the signals used by the driving circuit to drive the power device 3; for example, the signals used by the control circuit to control the power device 3).

[0077] Therefore, the substrate 5 further comprises a through hole 54 and a conductive body 55, Figure 7 An exemplary structure of the through hole 54 and the conductive body 55 is shown, the through hole 54 penetrates the first metal layer 51 and the first insulating layer 52, and the conductive body 55 is arranged in the through hole 54 and connects the first metal layer 51 and the second metal layer 53. Moreover, in the case that the power conversion device 100 is running, the part of the circuit board 2 used to connect the first metal layer 51 has a constant voltage to ground (for example, the potential difference between the charged body and the ground with the ground as the reference point). In the present application, the constant voltage to ground means that the voltage level is stable and does not jump.

[0078] Referring to Figure 7 , the conductive body 55 connects the first metal layer 51 and the second metal layer 53. Since the first metal layer 51 is connected with the circuit board 2, the second metal layer 53 can be electrically connected with the circuit board 2 through the conductive body 55 and the first metal layer 51. Since the part of the circuit board 2 used to connect the first metal layer 51 has a constant voltage to ground, the voltage level of the second metal layer 53 (or the structure connected with the second metal layer 53) is also in a stable state, which reduces the interference with the signals in the power conversion device 100 and improves the electromagnetic compatibility of the power conversion device 100.

[0079] ​That is, by using the substrate 5 of the present application, the risk of the second metal layer 53 (or the structure connected to the second metal layer 53) existing a jump voltage and interfering with the internal signals of the power conversion device 100 is reduced while effectively dissipating heat from the power device 3.

[0080] The electrically conductive body 55 can be any suitable metal structure, in some embodiments, referring to Figure 7 The electrically conductive body 55 is annular and fixed to the inner surface of the through hole 54, so that the inner surface of the through hole 54 forms a metal layer, the through hole 54 combines with the electrically conductive body 55 to form a metal hole, the electrically conductive body 55 connects the first metal layer 51 and the second metal layer 53, and in some embodiments, the end of the electrically conductive body 55 away from the second metal layer 53 extends to the outside of the substrate 5 and is connected to the circuit board 2. In other embodiments, the electrically conductive body 55 can be a metal column, a metal block or other conductive structure, and the electrically conductive body 55 can be connected to the second metal layer 53 at one end and to the first metal layer 51 at the other end.

[0081] It should be noted that in some embodiments, there can be multiple metal layers between the first insulating layer 52 and the circuit board 2, and the multiple metal layers are all connected to the circuit board 2, wherein the multiple metal layers are insulated from each other and form a structure similar to a trace on the surface of the substrate 5, for example, Figure 6 The multiple metal layers between the first insulating layer 52 and the circuit board 2 in the above-mentioned embodiment include the first metal layer 51, a metal layer a and a metal layer b, etc. However, the first metal layer 51 of the present application refers to the metal layer provided with the through hole 54 and having the electrically conductive body 55. In other embodiments, the metal layer between the first insulating layer 52 and the circuit board 2 is only the first metal layer 51.

[0082] The part of the circuit board 2 for connecting the first metal layer 51 can be a trace on the circuit board 2 with relatively stable voltage level, for example, the circuit board 2 includes a trace layer 21 (including multiple traces) facing the substrate 5, the first metal layer 51 is connected to the trace layer 21, and the part of the trace layer 21 for connecting the first metal layer 51 has constant ground voltage. It can be understood that the above-mentioned trace layer 21 is the trace layer 21 of the circuit board 2 facing the substrate 5, in addition, the circuit board 2 also includes traces for connecting the power device 3, in some embodiments, the circuit board 2 is a multi-layer circuit board 2, and the circuit board 2 includes multiple layers of traces.

[0083] In the case where the substrate 5 needs to be connected to the circuit board 2 by welding, the through hole 54 can also be plugged in some embodiments, wherein the substrate 5 further includes a filler 56, Figure 8 An exemplary structure of the filler 56 is shown, which plugs the through hole 54 by the filler 56, referring to Figure 8The conductor 55 is a metal layer inside the through-hole 54, and the space enclosed by the conductor 55 is the internal space of the through-hole 54. By placing the filler 56 within the space enclosed by the conductor 55, the through-hole 54 can be sealed, reducing the possibility of solder 7 entering the through-hole 54 between the circuit board 2 and the substrate 5, thus enabling the substrate 5 to be stably connected to the trace layer 21 of the circuit board 2. The filler 56 can be made of any suitable material, such as a metal block or resin that facilitates heat transfer.

[0084] In some other embodiments, the through hole 54 may not be filled with filler 56, and the through hole 54 may be filled by conductor 55.

[0085] In some embodiments, a structure for heat dissipation of the auxiliary substrate 5 may also be provided. For example, the power conversion device 100 includes a heat sink 6. Figure 9 An exemplary location of a heat sink 6 is shown, wherein, Figure 9 The substrate 5 is located on the side of the circuit board 2 away from the power device 3. The heat sink 6 includes a heat-conducting plate 61 and a plurality of fins 62. The heat-conducting plate 61 is located on the side of the substrate 5 away from the power device 3 and is fixed to the substrate 5. For example, the heat-conducting plate 61 is fixed to the second metal layer 53, and the plurality of fins 62 are fixed to the surface of the heat-conducting plate 61 away from the substrate 5.

[0086] The substrate 5 can be connected to the heat-conducting plate 61 of the heat sink 6 in any way, such as by welding the substrate 5 to the heat-conducting plate 61. This relatively simple connection method allows the heat sink 6 to be stably connected to the substrate 5 and assists the substrate 5 in heat dissipation. After the heat from the power device 3 is transferred to the substrate 5, it is transferred through the substrate 5 to the heat-conducting plate 61 of the heat sink 6. The heat from the heat-conducting plate 61 is then transferred to multiple fins 62. The gap between adjacent fins 62 facilitates heat exchange between the fins 62 and the air, improving the heat dissipation efficiency of the power device 3.

[0087] Furthermore, if a fin-like structure 62 is directly formed on the substrate 5, the length of this structure (the dimension in the thickness direction of the second metal layer 53) may be relatively short due to limitations in the substrate 5 manufacturing equipment, affecting the heat dissipation effect of the power device 3. Therefore, in order for the fin-like structure 62 on the substrate 5 to meet the heat dissipation requirements of the power device 3, it is necessary to extend the length of the structure through other means, which increases manufacturing costs. However, by using an additional heat sink 6, the heat sink 6 can be produced separately as needed, making the size and shape of the heat sink 6 more flexible, which is beneficial to manufacturing. This effectively dissipates heat from the power device 3 while reducing manufacturing costs.

[0088] In some embodiments, refer to Figure 9The through hole 54 also penetrates the second metal layer 53. In this case, the through hole 54 penetrates the first metal layer 51, the first insulating layer 52, and the second metal layer 53, that is, the through hole 54 penetrates the entire substrate 5, facilitating the processing of the through hole 54. In addition, in the case where the through hole 54 penetrates the entire substrate 5, the conductive body 55 can also pass through the second metal layer 53, and the end of the conductive body 55 away from the circuit board 2 is connected to the heat sink 6, further improving the stability of the electrical connection among the heat sink 6, the first metal layer 51, and the second metal layer 53. In the case where the first metal layer 51 is connected to the circuit board 2, the heat sink 6, the first metal layer 51, and the second metal layer 53 are all electrically connected to the circuit board 2. Since the part of the circuit board 2 used to connect the first metal layer 51 has a constant ground voltage, the heat sink 6 has a stable voltage level, so the heat sink 6 is also in a stable voltage level state, reducing the possibility of voltage jumping between the substrate 5 and the heat sink 6, and thus reducing the risk of interference with the internal signals of the power conversion device 100.

[0089] In the case where the substrate 5 is connected to the heat sink 6, the through hole 54 can be provided with a filler 56. In the case where the filler 56 is a metal block, the end of the metal block away from the circuit board 2 is connected to the heat sink 6. Since the material of the metal block is metal, the heat conduction ability is strong, so the metal block can quickly conduct the heat on the substrate 5 to the heat sink 6, improving the heat dissipation efficiency of the power device 3. In addition, the metal block can also be connected at one end to a wire with a constant ground voltage of the circuit board 2 and at the other end to the heat sink 6, making the electrical connection between the heat sink 6 and the circuit board 2 more stable. In addition, in the case where the filler 56 is resin, the heat conduction ability of the resin is stronger than that of air, and the heat can also be quickly transferred through the resin, improving the heat transfer speed.

[0090] In some embodiments, in the case where the substrate 5 is not connected to the heat sink 6, the through hole 54 can also penetrate the entire substrate 5.

[0091] In the case where the power device 3 further includes the heat sink 6, the position of the heat sink 6 relative to the device shell 1 can be set according to requirements, for example, Figure 10 An exemplary internal structure diagram of another power conversion device 100 is shown, which is described with reference to Figure 10 The heat sink 6 is located inside the device shell 1. For another example, Figure 11 An exemplary internal structure diagram of another power conversion device 100 is shown, which is described with reference to Figure 11 The device shell 1 is provided with an opening 11, and a part of the heat sink 6 is located inside the device shell 1, and another part (for example, the plurality of fins 62) of the heat sink 6 extends out of the device shell 1 through the opening 11.

[0092] In some embodiments, the heat transfer speed between the power device 3 and the substrate 5 can be further improved by means of a hole, for example, the circuit board 2 comprises a heat dissipation hole 22, Figure 12 An example is shown in FIG. 2, which shows a structure of the heat dissipation hole 22, Figure 12 The heat dissipation hole 22 is located between the power device 3 and the substrate 5, one end of the heat dissipation hole 22 is directed to the power device 3, and the other end of the heat dissipation hole 22 is directed to the substrate 5, which can accelerate the heat conduction between the power device 3 and the substrate 5, so that the heat of the power device 3 can be quickly transferred to the substrate 5 through the circuit board 2, and then transferred outward through the substrate 5, thereby improving the heat dissipation efficiency of the power device 3.

[0093] The heat dissipation hole 22 can be any suitable hole structure, for example, referring to Figure 12 The heat dissipation hole 22 is a metal hole, and the inner surface of the heat dissipation hole 22 is provided with a metal layer. In addition, the heat dissipation hole 22 can also be filled with a material with high heat conduction capacity, which can further improve the heat transfer speed. In addition, filling some materials in the heat dissipation hole 22 can also seal the heat dissipation hole 22, for example, in the case that the heat dissipation hole 22 penetrates the solder pad on the circuit board 2, filling the heat dissipation hole 22 can reduce the possibility of the solder material on the solder pad entering the heat dissipation hole 22, which is beneficial to stably connecting the power device 3 to the circuit board 2.

[0094] In other embodiments, the substrate 5 can also be connected to the power device 3, for example, Figure 13 Another example is shown in FIG. 3, which shows another position of the substrate 5, Figure 13 The substrate 5 is located on the side of the power device 3 away from the circuit board 2, and the first metal layer 51 of the substrate 5 is connected to the power device 3. The heat of the power device 3 is directly transferred to the substrate 5 (without passing through the circuit board 2), and then transferred outward through the substrate 5, thereby shortening the heat dissipation path of the power device 3 and improving the heat dissipation effect of the power device 3.

[0095] Referring to Figure 13 The substrate 5 also comprises a through hole 54 and a conductive body 55, and the through hole 54 penetrates the first metal layer 51 and the first insulating layer 52, and the conductive body 55 is arranged in the through hole 54 and connects the first metal layer 51 and the second metal layer 53. In the case that the power conversion device 100 is running, the part of the power device 3 for connecting the first metal layer 51 has a constant ground voltage, the first metal layer 51 is connected to the second metal layer 53 through the conductive body 55, so that the level of the second metal layer 53 is stable, thereby reducing the interference to the signal. Figure 13 In the embodiment shown in FIG. 4, the through hole 54 is provided with a filler 56, and in other embodiments, the through hole 54 can also not be provided with the filler 56.

[0096] Figure 14 Two power device structures 3 are illustrated exemplarily, with reference to Figure 13 and Figure 14 In (a), the power device 3 includes a package 31, a die 32, and a metal plate 33. The die 32 is located inside the package 31 and is fixed to the metal plate 33. Each die 32 includes at least one switching transistor 321, which can be an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET). Each switch 321 includes a control electrode, a first electrode, and a second electrode. For example, when the switch 321 is an insulated gate bipolar transistor (IGBT), the first electrode of the switch 321 is the collector (C), the second electrode of the switch 321 is the emitter (E), and the control electrode of the switch 321 is the base (B). As another example, when the switch 321 is a metal-oxide-semiconductor field-effect transistor (MOSFET), the first electrode of the switch 321 is the drain (D), the second electrode of the switch 321 is the source (S), and the control electrode of the switch 321 is the gate (G).

[0097] Reference Figure 13 and Figure 14 In (a), the metal plate 33 protrudes from inside the package shell 31 to outside the package shell 31 (on the side opposite to the circuit board 2), and the portion of the metal plate 33 protruding outside the package shell 31 is connected to the first metal layer 51. Since the die 32 is fixed on the metal plate 33, the first or second pole of the die 32 will be electrically connected to the metal plate 33, and the metal plate 33 will be charged. When the voltage of the metal plate 33 to ground remains unchanged, the first metal layer 51 is connected to the metal plate 33, and the first metal layer 51 and the second metal layer 53 are connected through the conductor 55, which can stabilize the voltage level of the second metal layer 53 and reduce interference to the signal.

[0098] In addition, the metal plate 33 of the power device 3 can also help the power device 3 dissipate heat to the outside, so that the heat inside the package shell 31 can be quickly transferred to the outside of the power package shell 31 through the metal plate 33. That is, the heat inside the package shell 31 can be quickly transferred to the substrate 5, thereby improving the heat dissipation efficiency of the power device 3.

[0099] Continue to refer to Figure 13 and Figure 14 In (a), the power device 3 also includes a plurality of pins 34 for connection to the circuit board 2, and at least one pin 34 is connected to the metal plate 33.

[0100] In some other embodiments, reference is made to Figure 13 and Figure 14In (b), the metal plate 33 may not be the plate used to fix the bare die 32. Instead, the bare die 32 is fixed to a dedicated mounting plate 35, for example, a direct-copper-bonded (DCB) ceramic plate. In this embodiment, the metal plate 33 is electrically connected to the mounting plate 35 via a conductive structure 36. In this way, the metal plate 33 achieves electrical connection with the bare die 32 through the conductive structure 36 and the mounting plate 35, and therefore, the voltage level of the second metal layer 53 is in a stable state.

[0101] In this circuit, power device 3 can be any suitable power device 3 in the power conversion circuit, as long as the voltage of metal plate 33 to ground remains constant. For example, consider a DC-DC power conversion circuit (a type of power conversion circuit). Figure 15 An exemplary DC-DC power conversion circuit 8 is shown, with reference to Figure 15 The DC-DC power conversion circuit 8 includes a first bridge arm disposed between the positive bus 81 and the negative bus 82. The first bridge arm includes a first switch Q1 and a second switch Q2 (two switches 321 with the same freewheeling direction) connected in series. The drain or collector of the second switch Q2 is connected to the negative bus 82, and the drain or collector level of the second switch Q2 is stable.

[0102] Reference Figure 14 and Figure 15 This allows the switching transistor 321 of the bare die 32 in the power device 3 to include the aforementioned second switching transistor Q2. The drain or collector of the switching transistor 321 is electrically connected to the metal plate 33, for example, in... Figure 14 In the power device 3 shown in (a), the drain or collector of the switching transistor 321 is fixed to and electrically connected to the metal plate 33; for example, in Figure 14 In the power device 3 shown in (b), the drain or collector of the switching transistor 321 is fixed on the mounting plate 35. The metal plate 33 is electrically connected to the mounting plate 35 through the conductive structure 36, so that the metal plate 33 is electrically connected to the drain or collector of the switching transistor 321. When the metal plate 33 is connected to the negative bus 82, the voltage level of the metal plate 33 is in a stable state, that is, the voltage of the metal plate 33 to ground remains unchanged.

[0103] Furthermore, when the power device 3 is connected to the substrate 5, the substrate 5 may also be provided with a heat sink 6. Figure 16 An exemplary location of another heatsink 6 is shown, with reference to Figure 16The heat sink 6 is connected (welded) to the second metal layer 53 of the substrate 5 to assist the substrate 5 in heat dissipation. The heat sink 6 can be entirely located inside the device housing 1, or a portion of the heat sink 6 can be located inside the device housing 1 and the other portion can extend outside the device housing 1 through the opening 11. This application does not impose specific limitations on this.

[0104] exist Figure 16 In the illustrated embodiment, the through-hole 54 penetrates the entire substrate 5, and a filler 56 is provided within the through-hole 54. The filler 56 seals the through-hole 54, reducing the possibility of solder 7 between the heat sink 6 and the substrate 5 entering the through-hole 54, thus facilitating a stable connection of the heat sink 6 to the substrate 5. In some other embodiments, the filler 56 may not be provided within the through-hole 54. In other embodiments, when the substrate 5 is connected to a heat sink 6, the through-hole 54 may not penetrate the entire substrate 5, for example... Figure 13 The through hole is in the form of 54.

[0105] Furthermore, in some embodiments, two substrates 5 may be provided. Figure 17 An exemplary view shows the position of another substrate 5, with reference to Figure 17 One of the substrates 5 ( Figure 17 The substrate 5 in the lower middle section is located on the side of the circuit board 2 away from the power device 3, and the first metal layer 51 of the substrate 5 is connected to the circuit board 2. Another substrate 5 ( Figure 17 The upper substrate 5 is located on the side of the power device 3 away from the circuit board 2, and the first metal layer 51 of the substrate 5 is connected to the power device 3. The voltage to ground of the portion of the circuit board 2 used to connect to the lower substrate 5 remains constant, and the voltage to ground of the portion of the power device 3 used to connect to the upper substrate 5 also remains constant.

[0106] In embodiments where there are multiple substrates 5, a single heat sink 6 may be provided, and the heat sink 6 may be connected to one of the substrates 5; alternatively, multiple heat sinks 6 may be provided, for example, referring to... Figure 17 Each substrate 5 has a heat sink 6 fixed on the side opposite to the power device 3.

[0107] Furthermore, when multiple substrates 5 and heat sinks 6 are provided, if two heat sinks 6 are located on different sides of the circuit board 2 (e.g., Figure 17 In the case shown, in one embodiment, both radiators 6 may be entirely located inside the device housing 1. In another embodiment, one of the radiators 6 is entirely located inside the device housing 1, while a portion of the other radiator 6 is located inside the device housing 1 and the other portion extends out of the device housing 1 through the opening 11.

[0108] In one embodiment, the substrate 5 may further include more insulating and metal layers; for example, the substrate 5 may further include a second insulating layer 57 and a third metal layer 58. Figure 18 An exemplary structure of another substrate 5 is shown, with reference to Figure 18 The second insulating layer 57 and the third metal layer 58 are both located between the first insulating layer 52 and the second metal layer 53, with the second insulating layer 57 fixed between the second metal layer 53 and the third metal layer 58. The material of the second insulating layer 57 can be any suitable insulating material, such as polypropylene (PP). This achieves mutual insulation between the second metal layer 53 and the third metal layer 58, reducing the thermal resistance between them and improving the heat dissipation capacity of the substrate 5.

[0109] Furthermore, the material of the third metal layer 58 can be any suitable material, as long as the material of the third metal layer 58 is metal. The materials of the first metal layer 51, the second metal layer 53, and the third metal layer 58 can be the same or different. In some cases, one side of the substrate 5 needs to be connected to the power device 3 or the circuit board 2, while the other side of the substrate 5 can be connected to an auxiliary heat dissipation structure such as a heat sink 6. Therefore, the materials of the first metal layer 51, the second metal layer 53, and the third metal layer 58 can be selected separately. For example, the materials of the first metal layer 51 and the second metal layer 53 can be materials that facilitate soldering (e.g., copper), the material of the third metal layer 58 can be a lower-cost material (e.g., aluminum), or the material of the third metal layer 58 can be a lighter material, and so on. That is, when the substrate 5 includes multiple metal layers (e.g., the first metal layer 51, the second metal layer 53, and the third metal layer 58), the materials of different metal layers can be selected according to requirements. This facilitates the connection of the substrate 5 with other structures (e.g., soldering) while also taking into account other aspects such as the cost, weight, and thermal conductivity of the substrate 5, making the design of the substrate 5 more flexible.

[0110] Among them, Figure 18 In the illustrated embodiment, large parasitic capacitances are generated between the first metal layer 51 and the third metal layer 58 of the substrate 5, as well as between the third metal layer 58 and the second metal layer 53. Therefore, the via 54 also penetrates the second insulating layer 57 and the third metal layer 58, and the conductor 55 is also connected to the third metal layer 58, thereby stabilizing the voltage levels of the substrate 5 and the heat sink 6 and reducing the possibility of interference with the internal signals of the power conversion device 100.

[0111] In some other embodiments, the substrate 5 also includes a plurality of protrusions 59 for auxiliary heat dissipation (which can be understood as a structure similar to fins 62). Figure 19 An exemplary embodiment shows the structure of another substrate 5, with reference toFigure 19 A plurality of protrusions 59 are arranged away from the circuit board 2, for example, on the side of the power device 3 facing the air. Figure 19 In the embodiment shown, the plurality of protrusions 59 are fixed (integrally connected or welded) to the second metal layer 53. After the heat of the power device 3 is transferred to the substrate 5, the gap between two adjacent protrusions 59 is conducive to heat exchange between the fins 62 and the air, thereby improving the heat dissipation efficiency of the power device 3.

[0112] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which shall be encompassed in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A power conversion device for converting input electrical energy into power and then outputting it, characterized in that, The power conversion device comprises: a device shell; a circuit board fixed in the device shell; a power device fixed on the circuit board; a substrate in the device shell, the substrate comprising a first metal layer, a second metal layer, and a first insulating layer fixed between the first metal layer and the second metal layer, the first metal layer connected to the circuit board or the power device; the substrate further comprising a through hole penetrating the first metal layer and the first insulating layer, and a conductive body penetrating the through hole and connected to the first metal layer and the second metal layer; when the power conversion device is in operation, the part of the first metal layer connected to the circuit board or the power device has a constant voltage to ground.

2. The power conversion device of claim 1, wherein, The substrate is located on the side of the circuit board away from the power device, and the circuit board comprises a wiring layer facing the substrate, the wiring layer connected to the first metal layer, and the wiring layer used to connect the part of the first metal layer having a constant voltage to ground.

3. The power conversion device of claim 1, wherein, The substrate is located on the side of the power device away from the circuit board; the power device comprising a package shell, a die, and a metal plate, the die located in the package shell and electrically connected to the metal plate, the metal plate protruding from the package shell to the side of the package shell away from the circuit board, the metal plate connected to the first metal layer, and the metal plate having a constant voltage to ground.

4. The power conversion device of claim 3, wherein, The die comprises a switch tube, the drain or collector of the switch tube electrically connected to the metal plate, and the metal plate electrically connected to the negative bus of the power conversion circuit in the power conversion device.

5. The power conversion device according to any one of claims 1 to 4, characterized by, The power conversion device further comprises a heat sink, the heat sink located in the device shell or at least partially located outside the device shell, the heat sink comprising a heat-conducting plate and a plurality of fins, the heat-conducting plate located on the side of the substrate away from the power device and connected to the second metal layer, and the plurality of fins fixed on the surface of the heat-conducting plate away from the substrate.

6. The power conversion device of claim 5, wherein, The through hole further penetrates the second metal layer, and one end of the conductive body away from the circuit board is connected to the heat sink.

7. The power conversion device of claim 6, wherein, The substrate further comprises a filler, the conductive body in the form of a ring and fixed on the inner surface of the through hole, and the filler used to fill the space surrounded by the conductive body; the filler comprising a metal block, one end of the metal block away from the circuit board connected to the heat sink; or the filler comprising a resin.

8. The power conversion device of any one of claims 1-4, wherein, The substrate further comprises a second insulating layer and a third metal layer between the first insulating layer and the second metal layer, the second insulating layer fixed between the second metal layer and the third metal layer; the through hole further penetrating the second insulating layer and the third metal layer, and the conductive body further connected to the third metal layer.

9. The power conversion device of any one of claims 1-4, wherein, The thickness of the first metal layer and the thickness of the second metal layer are both greater than the thickness of the first insulating layer.

10. A power cabinet characterized in that, The cabinet comprises a cabinet body and a plurality of power conversion devices according to any one of claims 1-9, the plurality of power conversion devices located in the cabinet body, and the plurality of power conversion devices connected in parallel.

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