Power conversion device and power supply cabinet
Patent Information
- Application Number
- PCT/CN2025/113267
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-19
- Filing Date
- 2025-08-07
- Publication Date
- 2026-08-27
Smart Images
Figure CN2025113267_27082026_PF_FP_ABST
Abstract
Description
Power conversion devices and power supply cabinets
[0001] This application claims priority to Chinese patent application filed on February 19, 2025, with application number 202520269918.X and entitled "Power Conversion Device and Power Supply Cabinet", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of energy technology, and in particular to a power conversion device and a power supply cabinet. Background Technology
[0003] As electronic products move towards higher frequencies and higher densities, surface-mount devices (SMDs) are gradually replacing through-hole devices due to their smaller parasitic parameters and higher production efficiency. For example, power devices in power conversion equipment can exist in the form of SMDs and are soldered onto pads on the circuit board.
[0004] Heat dissipation is particularly important for power conversion devices. In related technologies, multiple through-holes are set on the pads of the circuit board to transfer the heat from the power devices to the heat sink. However, multiple through-holes will increase the void ratio of the solder surface of the power devices, thereby reducing the effective heat conduction area of the power devices and resulting in poor heat dissipation.
[0005] Utility Model Content
[0006] This application provides a power conversion device and a power cabinet including the power conversion device, which can improve the heat dissipation effect of power devices.
[0007] To achieve the above objectives, this application adopts the following technical solution:
[0008] A first aspect of this application provides a power conversion device for converting input electrical energy into power and outputting it. The power conversion device includes a device housing, a first circuit board, a substrate, a power device, and a heat sink. The first circuit board is fixed inside the device housing and includes a receiving groove, the opening of which is located on one surface of the first circuit board. The substrate is fixed inside the device housing and is located on one side of the first circuit board, blocking the receiving groove. The substrate includes a first wiring layer, a first insulating layer, and a first metal layer. The first insulating layer is fixed between the first wiring layer and the first metal layer. The first wiring layer faces the receiving groove and is electrically connected to the first circuit board. The power device is fixed to the first wiring layer and is at least partially located inside the receiving groove. The heat sink is located inside the device housing or partially extends outside the device housing. The heat sink is located on the side of the substrate away from the first circuit board and is fixed to the substrate.
[0009] The power conversion device converts input electrical energy by switching the switching transistors in the power devices. A first trace layer on the substrate houses the power devices, which are electrically connected to a first circuit board via this layer. Furthermore, a receiving slot in the first circuit board accommodates the power devices, thereby reducing the distance between the circuit board and the substrate. The first metal layer of the substrate has good thermal conductivity, allowing heat from the power devices to be transferred outwards, thus achieving heat dissipation. In addition, the first insulating layer of the substrate separates the first trace layer from the first metal layer, reducing the possibility of interconnection between traces in the first trace layer. In this application, the heat from the power devices is directly transferred outwards through the thermally conductive substrate, effectively improving the heat dissipation of the power devices.
[0010] In one embodiment of this application, the first circuit board further includes a third metal layer, and the power device is located between the third metal layer and the first metal layer.
[0011] Electromagnetic compatibility (EMC) is particularly important for power device applications. The high-frequency switching of power devices can introduce EMC interference, especially when they are surface-mount devices. Since power devices lack external leads, it's impossible to attach ferrite cores (used to mitigate EMC interference) to these cores. Using extensive external absorption circuitry to address EMC issues often leads to a degradation in the device's performance.
[0012] Therefore, in this application, the power device is disposed between the third metal layer of the first circuit board and the first metal layer of the substrate. By using the third metal layer and the first metal layer located on both sides of the power device, a good electromagnetic shielding effect is achieved, thereby improving the EMC performance and anti-external interference capability of the power device.
[0013] In one embodiment of this application, the orthographic projection of the power device onto the surface of the third metal layer is located inside the outer edge of the surface of the third metal layer.
[0014] By using a larger third metal layer to cover the location of the power device, the shielding area of the third metal layer is wider, which further optimizes the EMC performance and the ability to resist external interference of the power device.
[0015] In one embodiment of this application, a third metal layer is exposed on the side of the first circuit board away from the substrate.
[0016] Exposing the third metal layer outside the first circuit board increases the distance between the third metal layer and the substrate, allowing for a longer dimension of the receiving groove in the thickness direction of the first circuit board. This results in a larger internal space for the receiving groove, improving its capacity. For example, the receiving groove can accommodate larger power devices, reducing the possibility of interference from the inner surface of the groove during device mounting. Furthermore, the receiving groove can hold more thermally conductive material, further enhancing the heat dissipation capacity of the power devices.
[0017] In one embodiment of this application, a third metal layer is fixed to the inner surface of the receiving groove facing the substrate.
[0018] The receiving groove is equivalent to a recess created on the first circuit board. A third metal layer is disposed on the inner surface of the receiving groove facing the substrate. For example, a layer of metal is electroplated on the inner surface of the receiving groove as the third metal layer; alternatively, the internal wiring layer exposed after the receiving groove is cut out of the first circuit board can also be used as the third metal layer. By placing the third metal layer inside the first circuit board, the surface of the first circuit board facing away from the substrate does not need to have a third metal layer. The portion of the first circuit board facing away from the substrate and opposite to the power devices can then be arbitrarily configured with pads, wiring layers, terminals, etc., as needed. This reduces the impact of the third metal layer on the surface layout of the first circuit board and improves the flexibility of the surface layout of the first circuit board.
[0019] In one embodiment of this application, the third metal layer is located between the surface of the first circuit board away from the substrate and the surface of the receiving groove facing the substrate.
[0020] This design ensures that the third metal layer is neither exposed outside the first circuit board nor inside the receiving groove. For example, a portion of the middle trace layer of the first circuit board (multilayer circuit board) can serve as the third metal layer, eliminating the need for an additional third metal layer on the first circuit board. This reduces processing steps and facilitates the manufacturing of the first circuit board. Furthermore, the surface of the first circuit board facing away from the substrate and opposite the power devices can be arbitrarily configured with pads, trace layers, terminals, and other structures as needed, increasing the flexibility of the first circuit board's surface layout.
[0021] In one embodiment of this application, the power conversion device further includes an auxiliary device. The auxiliary device encapsulates at least one of a driving circuit, a protection circuit, and a snubber circuit. The driving circuit is used to drive the power device, the protection circuit is used to detect the current of the input or output power device, and the snubber circuit is used to clamp the voltage between the first and second poles of the power device. The first circuit board further includes a second trace layer, which is fixed to the inner surface of the receiving groove facing the substrate. The second trace layer is electrically connected to the first trace layer, and the auxiliary device is fixed to the second trace layer.
[0022] Inside the receiving groove of the first metal layer, a trace layer for fixing (e.g., soldering) auxiliary devices can be provided, so that the receiving groove can not only accommodate power devices, but also fix auxiliary devices related to the power devices. For example, the auxiliary devices can encapsulate the drive circuit, protection circuit, or snubber circuit of the power device, etc. This enables a stacked design in a limited space, improving the utilization rate of the receiving groove and the density of devices within the first circuit board. In addition, the loop length around the power device can be reduced, thereby reducing parasitic inductance and improving the performance of the power device.
[0023] In one embodiment of this application, the power conversion device further includes at least one first conductor, a portion of each first conductor being located within a first circuit board, one end of each first conductor protruding from the surface of the first circuit board toward the substrate and connected to a first metal layer, and the other end of each first conductor being connected to a third metal layer.
[0024] The first conductor provides electrical connection between the third metal layer of the first circuit board and the first metal layer of the substrate. Furthermore, either the third or first metal layer can be connected to a point in the circuit where the potential does not change abruptly, or to ground, achieving good electromagnetic shielding. In addition, when either the third or first metal layer is connected to the electrical network of the power conversion device, besides achieving good electromagnetic shielding, the three metal layers can also enhance current carrying capacity, effectively reducing line losses and improving the efficiency and stability of power transmission.
[0025] Furthermore, since the first conductor connects the third metal layer and the first metal layer, the first conductor is located on the outside of the power device. The first conductor is metal, which can also improve the side interference immunity of the power device, further improving the EMC performance and external interference immunity of the power device.
[0026] In one embodiment of this application, a plurality of first conductors are provided, and the plurality of first conductors surround the outer periphery of the power device.
[0027] Multiple first conductors surround the power device. The power device is wrapped by the third metal layer, the first metal layer and the multiple first conductors connecting the two, achieving a good electromagnetic shielding effect and further optimizing the EMC performance of the power device.
[0028] In one embodiment of this application, the power conversion device further includes a second conductor, a portion of which is located within a first circuit board. The first circuit board further includes a third trace layer disposed away from the substrate. One end of the second conductor extends from the surface of the first circuit board toward the substrate and is connected to the first trace layer, while the other end of the second conductor is connected to the third trace layer.
[0029] The electrical connection between the first trace layer and the first circuit board is achieved through the second conductor. In other words, the electrical connection between the power device and the first circuit board can be achieved through the second conductor and the first trace layer, so that current can flow between the power device and the first circuit board.
[0030] In one embodiment of this application, the power conversion device further includes a heat sink, which is located inside the device housing or partially extends outside the device housing. The heat sink is located on the side of the substrate away from the first circuit board and is fixed to the substrate.
[0031] The substrate allows heat from the power device to be transferred to the heat sink, which then dissipates heat from the power device, improving its heat dissipation efficiency. In this application, the heat from the power device is directly transferred to the heat sink through the substrate, eliminating the need to pass through the first circuit board, thus shortening the heat transfer path and effectively improving the heat dissipation performance of the power device.
[0032] In one embodiment of this application, the substrate further includes a second insulating layer and a second metal layer, the second insulating layer being fixed between the first metal layer and the second metal layer, and the heat sink being fixedly connected to the second metal layer.
[0033] In addition to the first insulating layer, the substrate also includes a second insulating layer, which improves the substrate's insulation performance. The second insulating layer is located between the heat sink and the first metal layer, achieving mutual insulation between the heat sink and the first metal layer. Furthermore, the second metal layer, situated between the heat sink and the second insulating layer, not only enhances the substrate's thermal conductivity but also provides a mounting position for the heat sink. For example, the heat sink can be soldered onto the second metal layer, or it can be bolted to the second metal layer. By incorporating both the second insulating layer and the second metal layer, the insulation performance of the substrate is improved, and the connection between the heat sink and the substrate is also facilitated.
[0034] In one embodiment of this application, the receiving groove is filled with potting compound, and the potting compound is connected to the substrate.
[0035] Filling the containment tank with potting compound enhances the insulation of power devices. Furthermore, it improves the thermal conductivity of the containment tank, allowing heat from the power devices to be rapidly transferred outwards through the potting compound. For example, heat from the power devices is transferred to the substrate through the potting compound, and then to the heat sink through the substrate, achieving efficient heat dissipation for the power devices. In addition, the potting compound also provides waterproofing, and power devices encased in it exhibit enhanced reliability, improving the operational stability of the power conversion device.
[0036] In one embodiment of this application, the power conversion device further includes a second circuit board, which is fixed inside the device housing. A first circuit board is fixed to the second circuit board, and the surface of the first circuit board is perpendicular to the surface of the second circuit board. The surface of the first circuit board facing the substrate includes an insulating region, which is at least partially located between the substrate and the second circuit board.
[0037] The first circuit board can be vertically mounted on the second circuit board. Since the surface of the first circuit board is perpendicular to the surface of the second circuit board, the substrate on the first circuit board is closer to the second circuit board. An insulating region is provided between the substrate and the second circuit board, reducing the possibility of electrical continuity between them. For example, when the first metal layer is connected to the electrical network of the power conversion device, the possibility of arcing between the substrate and the second circuit board is reduced. Furthermore, the possibility of electrical continuity between the substrate and the first circuit board, as well as between the substrate and the pins of the first circuit board (used to connect to the second circuit board), is also reduced, meeting safety requirements.
[0038] A second aspect of this application provides a power supply cabinet, including a cabinet body and multiple power conversion devices, wherein the multiple power conversion devices are located inside the cabinet body and are connected in parallel.
[0039] A power conversion device is installed inside the cabinet. This device converts the input electrical energy into power. The power conversion device's housing contains interconnected power devices and a substrate. Heat from the power devices is transferred outwards through the substrate, effectively improving heat dissipation. Furthermore, the power cabinet provided in this application includes the aforementioned power conversion device. Therefore, the power cabinet provided in this application solves the same technical problem and achieves the same technical effect as the power conversion device in the above-mentioned technical solution, and will not be elaborated further here. Attached Figure Description
[0040] Figure 1 is a schematic diagram of a power conversion device provided in an embodiment of this application;
[0041] Figure 2 is a structural schematic diagram of a power cabinet provided in an embodiment of this application;
[0042] Figure 3 is a schematic diagram of the internal structure of a power conversion device provided in an embodiment of this application;
[0043] Figure 4 is a schematic diagram of the internal structure of another power conversion device provided in an embodiment of this application;
[0044] Figure 5 is a schematic diagram of the internal structure of another power conversion device provided in an embodiment of this application;
[0045] Figure 6 is a schematic diagram of the internal structure of another power conversion device provided in an embodiment of this application;
[0046] Figure 7 is a schematic diagram of a first circuit board and a substrate provided in an embodiment of this application;
[0047] Figure 8 is a schematic diagram of another substrate provided in an embodiment of this application;
[0048] Figure 9 is a schematic diagram of another first circuit board provided in an embodiment of this application;
[0049] Figure 10 is a projection diagram of a power device on the surface of a third metal layer according to an embodiment of this application;
[0050] Figure 11 is a schematic diagram of the structure of a second conductor provided in an embodiment of this application;
[0051] Figure 12 is a schematic diagram of another first circuit board provided in an embodiment of this application;
[0052] Figure 13 is a schematic diagram of another first circuit board provided in an embodiment of this application;
[0053] Figure 14 is a schematic diagram of another first circuit board provided in an embodiment of this application;
[0054] Figure 15 is a schematic diagram of a potting compound provided in an embodiment of this application;
[0055] Figure 16 is a schematic diagram of the structure of two types of potting holes provided in the embodiments of this application;
[0056] Figure 17 is a schematic diagram of the structure of an insulating region provided in an embodiment of this application.
[0057] Reference numerals: 100-Power conversion device; 1-Device housing; 11-Opening; 2-First circuit board; 21-Receiving groove; 211-Potent; 22-Third metal layer; 23-Second wiring layer; 24-Third wiring layer; 25-Potent hole; 27-Pin; 27-Insulating area; 3-Substrate; 31-First wiring layer; 32-First insulating layer; 33-First metal layer; 34-Second insulating layer; 35-Second metal layer; 4-Heat sink; 41-Heat conduction plate; 42-Fin; 5-Power device; 6-Second circuit board; 7-First conductor; 8-Second conductor; 9-Auxiliary device; 200-Power cabinet; 201-Cabinet; 202-Circuit breaker. Detailed Implementation
[0058] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0059] In this application, unless otherwise expressly specified and limited, the terms "upper", "lower", "front", "back", "left", "right", etc., indicating orientation or positional relationship may be defined relative to the orientation of the components schematically placed in the accompanying drawings. These directional terms may be relative concepts, used for relative description and clarification, and may change accordingly depending on the orientation of the components in the accompanying drawings. They should not be construed as limitations on this application.
[0060] In this application, the terms "first," "second," etc., are used for descriptive purposes only to distinguish one element from another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.
[0061] In this application, unless otherwise expressly stated and limited, "multiple" means two or more.
[0062] Furthermore, in this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0063] In the accompanying drawings of the embodiments of this application, solid structures such as components and assemblies are represented by guide lines; structures composed of multiple components are represented by guide lines with parentheses or solid arrows; and hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows.
[0064] This application provides a power conversion device 100, which is used to convert input electrical energy into power and output it. For example, the power conversion device 100 can convert direct current (DC) to alternating current (AC); or, for example, it can convert AC to DC; or it can perform voltage boosting or bucking. The power conversion device 100 of this application can be an inverter, a rectifier, an on-board charger (OBC), a power module (e.g., a DC-DC module, an AC-DC module) within a charging device, etc. Figure 1 exemplarily illustrates the structure of a power conversion device 100. Referring to Figure 1, the power conversion device 100 is a photovoltaic inverter.
[0065] Furthermore, Figure 2 exemplarily illustrates a power cabinet 200 including power conversion devices 100. For example, the power cabinet 200 is a cabinet-type uninterruptible power supply (UPS), wherein the power cabinet 200 includes a cabinet body 201, multiple power conversion devices 100, and multiple circuit breakers 202, etc. The multiple power conversion devices 100 are stacked in the cabinet body 201 along the height direction of the cabinet body 201, and the multiple power conversion devices 100 are connected in parallel, with the multiple circuit breakers 202 located above the multiple power conversion devices 100. As another example, the power cabinet 200 can also be a charging pile, with multiple parallel power conversion devices 100 located in the cabinet of the charging pile, and the charging gun is electrically connected to the multiple power conversion devices 100 through cables.
[0066] Figure 3 illustrates an exemplary internal structure of a power conversion device 100. Referring to Figure 3, the power conversion device 100 includes a device housing 1, which can be any housing with a receiving function. Furthermore, the power conversion device 100 also includes a first circuit board 2, a substrate 3, a heat sink 4, and a power device 5. The substrate 3 is located between the first circuit board 2 and the heat sink 4, and the power device 5 is connected to the substrate 3 and is at least partially located within the first circuit board 2 (this will be described in detail later). In the embodiment shown in Figure 3, the first circuit board 2, substrate 3, heat sink 4, and power device 5 are all located within the device housing 1.
[0067] Figure 4 illustrates the internal structure of another power conversion device 100. Referring to Figure 4, an opening 11 is provided on the device housing 1. The first circuit board 2, the substrate 3, and the power device 5 are all located inside the device housing 1. The heat sink 4 passes through the opening 11, with one part of the heat sink 4 located inside the device housing 1 and connected to the substrate 3, and the other part extending outside the device housing 1. Figure 5 illustrates the internal structure of yet another power conversion device 100. Referring to Figure 5, the first circuit board 2, the substrate 3, and the power device 5 are all located inside the device housing 1. The heat-conducting plate 41 of the heat sink 4 is integrally formed with the device housing 1, and the fins 42 of the heat sink 4 are located outside the device housing 1.
[0068] Furthermore, Figure 6 also exemplarily illustrates the internal structure of another power conversion device 100. Referring to Figure 6, the power conversion device 100 further includes a second circuit board 6. The first circuit board 2 can be vertically mounted on the second circuit board 6, meaning that any surface of the first circuit board 2 is perpendicular to any surface of the second circuit board 6 (not absolutely perpendicular, allowing an error of ±10°). Electrically connecting the first circuit board 2 and the second circuit board 6 enables the flow of current between them. In some other embodiments, the first circuit board 2 can also be mounted horizontally on the second circuit board 6, meaning that any surface of the first circuit board 2 is parallel to any surface of the second circuit board 6 (not absolutely parallel, allowing an error of ±10°).
[0069] In the embodiment shown in FIG6, the first circuit board 2, the substrate 3, the heat sink 4, the power device 5, and the second circuit board 6 are all located inside the device housing 1. If the power conversion device 100 also includes the second circuit board 6, the heat sink 4 may also partially extend outside the device housing 1.
[0070] In some other embodiments, the power conversion device 100 may not include a heat sink 4 connected to the substrate 3.
[0071] Figure 7 exemplarily illustrates the structure of a first circuit board 2 and a substrate 3. Referring to Figure 7, the first circuit board 2 includes a receiving groove 21, the opening of which is located on the surface of the first circuit board 2 facing the substrate 3. The substrate 3 is located on one side of the first circuit board 2 and blocks the receiving groove 21. The substrate 3 includes a first wiring layer 31, a first insulating layer 32, and a first metal layer 33. The first insulating layer 32 is fixed between the first metal layer 33 and the first wiring layer 31, with the first wiring layer 31 facing the receiving groove 21. The first insulating layer 32 of the substrate 3 can separate the first wiring layer 31 and the first metal layer 33, reducing the possibility that different wirings in the first wiring layer 31 can conduct to each other through the first metal layer 33.
[0072] The first trace layer 31 is electrically connected to the first circuit board 2, allowing current to flow between the first trace layer 31 and the first circuit board 2. For example, the power conversion device 100 also includes a second conductor 8. Multiple second conductors 8 can be provided, or only one second conductor 8 can be provided; this application does not impose specific limitations on this. Referring to Figure 7, a portion of the second conductor 8 is located within the first circuit board 2. The first circuit board 2 includes a third trace layer 24 disposed away from the substrate 3. One end of the second conductor 8 extends from the surface of the first circuit board 2 toward the substrate 3 and is connected to the first trace layer 31. The other end of the second conductor 8 is connected to the third trace layer 24. The end of the second conductor 8 connected to the third trace layer 24 can extend from the surface of the first circuit board 2 away from the substrate 3, or it can remain outside the first circuit board 2, as long as the second conductor 8 can connect the third trace layer 24 and the first trace layer 31. Through the second conductor 8, an electrical connection between the first trace layer 31 and the first circuit board 2 can be achieved.
[0073] The second conductor 8 can be any structure capable of conducting electricity. For example, the second conductor 8 can be a metal pillar, or it can be a metal part inside a conductive hole on the first circuit board 2.
[0074] The first wiring layer 31 on the substrate 3 is used to mount the power device 5 and fix the power device 5 to the first wiring layer 31. Since the first wiring layer 31 is electrically connected to the first circuit board 2, the power device 5 can be electrically connected to the first circuit board 2 through the first wiring layer 31. When the power device 5 is fixed to the first wiring layer 31, the power device 5 is at least partially located in the receiving groove 21. The receiving groove 21 in the first circuit board 2 can accommodate the power device 5, thereby reducing the distance between the first circuit board 2 and the substrate 3.
[0075] Referring to FIG7, the heat sink 4 is located on the side of the substrate 3 away from the first circuit board 2 and is fixed to the substrate 3. In the embodiment shown in FIG7, the heat sink 4 is fixedly connected to the first metal layer 33 of the substrate 3 (e.g., by welding or by bolting).
[0076] In some other embodiments, FIG8 exemplarily illustrates another structure of the substrate 3. Referring to FIG8, the substrate 3 further includes a second insulating layer 34, which is located between the heat sink 4 and the first metal layer 33, thereby achieving mutual insulation between the heat sink 4 and the first metal layer 33. In this embodiment, the substrate 3 includes a second insulating layer 34 in addition to the first insulating layer 32, which improves the insulation performance of the substrate 3. Furthermore, referring to FIG8, the substrate 3 also includes a second metal layer 35, with the second insulating layer 34 fixed between the first metal layer 33 and the second metal layer 35, i.e., the second metal layer 35 is disposed facing the heat sink 4. The second metal layer 35, disposed between the heat sink 4 and the second insulating layer 34, not only enhances the thermal conductivity of the substrate 3 but also provides a mounting position for the heat sink 4. For example, the heat sink 4 can be soldered onto the second metal layer 35, or the heat sink 4 can be bolted to the second metal layer 35, facilitating the installation of the heat sink 4 and the substrate 3.
[0077] The substrate 3 includes at least a first metal layer 33 (in some embodiments, the substrate 3 also includes a second metal layer 35), giving the substrate 3 good thermal conductivity. The heat from the power device 5 can be transferred to the heat sink 4 through the metal layers of the substrate 3 (e.g., the first metal layer 33, or, for example, the first metal layer 33 and the second metal layer 35), and the heat sink 4 dissipates heat from the power device 5. In this application, the heat from the power device 5 is directly transferred to the heat sink 4 through the substrate 3, without needing to pass through the first circuit board 2, shortening the heat transfer path and effectively improving the heat dissipation effect of the power device 5.
[0078] In the embodiments shown in Figures 7 and 8, the heat sink 4 is an air-cooled heat sink, comprising a heat-conducting plate 41 and a plurality of fins 42. The heat-conducting plate 41 is fixedly connected to the substrate 3 (e.g., by bonding, welding, bolting, etc.), and the plurality of fins 42 are fixed on the side of the heat-conducting plate 41 facing away from the first circuit board 2. In some other embodiments, the heat sink 4 may further comprise a plurality of heat dissipation fins fixed between adjacent fins 42. In some other embodiments, the heat sink 4 may also be a liquid-cooled heat sink. The embodiments shown in the following figures all exemplify an air-cooled heat sink 4.
[0079] Since the substrate 3 has strong thermal conductivity, even if the power conversion device 100 does not include the heat sink 4 connected to the substrate 3, the heat of the power device 5 can be directly transferred to the outside through the substrate 3 with strong thermal conductivity, which can also achieve good heat dissipation of the power device 5.
[0080] The power conversion device 100 of this application converts input electrical energy by switching the switching transistor in the power device 5. Electromagnetic compatibility (EMC) is particularly important for the application of the power device 5. The high-frequency switching of the power device 5 can cause EMC interference, especially when the power device 5 is a surface-mount device. Without outward-extending leads, it's impossible to attach ferrite cores (used to address EMC interference) to the leads of the power device 5. If numerous absorption circuits are used externally to address the EMC issues of the power device 5, it often leads to a degradation in the performance of the power device 5 itself.
[0081] To address the aforementioned issues, in some embodiments, the first circuit board 2 further includes a third metal layer 22. FIG9 exemplarily illustrates another structure of the first circuit board 2. Referring to FIG9, the power device 5 is disposed between the third metal layer 22 of the first circuit board 2 and the first metal layer 33 of the substrate 3. Through the third metal layer 22 and the first metal layer 33 located on both sides of the power device 5, a good electromagnetic shielding effect can be achieved, thereby improving the EMC performance and anti-external interference capability of the power device 5.
[0082] In the embodiment shown in FIG9, the third metal layer 22 is fixed (e.g., bonded or electroplated) to the inner surface (B1) of the receiving groove 21 facing the substrate 3. The receiving groove 21 is equivalent to a recess formed on the first circuit board 2. The third metal layer 22 is provided on the inner surface of the receiving groove 21 facing the substrate 3. For example, a layer of metal is electroplated on the inner surface (B1) of the receiving groove 21 as the third metal layer 22; or, for another example, the internal wiring layer exposed after the receiving groove 21 is cut out of the first circuit board 2 can also be used as the third metal layer 22. That is, the third metal layer 22 can be part of the internal wiring layer of the first circuit board 2 (multilayer circuit board).
[0083] By placing the third metal layer 22 inside the first circuit board 2, the portion of the first circuit board 2 facing away from the substrate 3 and opposite to the power device 5 (the area where the dashed box is located in Figure 9) can be equipped with pads, trace layers, terminals, etc. as needed, which reduces the impact of setting the third metal layer 22 on the surface layout of the first circuit board 2 and improves the flexibility of the traces on the surface of the first circuit board 2.
[0084] In the case where the power conversion device 100 includes a third metal layer 22, in one embodiment, the area covered by the third metal layer 22 is relatively large. For example, FIG10 exemplarily shows a projection of a power device 5 onto the surface of the third metal layer 22. Referring to FIGS. 9 and 10, the orthographic projection of the power device 5 onto the surface of the third metal layer 22 (any surface, such as the surface facing the power device 5) is located inside the outer edge of the surface of the third metal layer 22. By using a larger third metal layer 22 to cover the location of the power device 5, the shielding area of the third metal layer 22 is wider, further optimizing the EMC performance and immunity to external interference of the power device 5.
[0085] Furthermore, in some embodiments, referring back to FIG9, the power conversion device 100 further includes at least one first conductor 7, through which the third metal layer 22 of the first circuit board 2 and the first metal layer 33 of the substrate 3 are electrically connected. For example, a portion of each first conductor 7 is located within the first circuit board 2, one end of each first conductor 7 protrudes from the first circuit board 2 toward the surface of the substrate 3, the portion of each first conductor 7 protruding outside the first circuit board 2 passes through the first wiring layer 31 and the first insulating layer 32 of the substrate 3, and is connected to the first metal layer 33 of the substrate 3, and the other end of each first conductor 7 is connected to the third metal layer 22.
[0086] Connecting either the third metal layer 22 or the first metal layer 33 to a point in the circuit where the potential does not change abruptly or to a ground point can achieve a good electromagnetic shielding effect. Furthermore, when either the third metal layer 22 or the first metal layer 33 is connected to the electrical network of the power conversion device 100, in addition to achieving a good electromagnetic shielding effect, the third metal layer 22 and the first metal layer 33 can also enhance current carrying capacity, effectively reduce line losses, and improve the efficiency and stability of power transmission.
[0087] The first conductor 7 can be any conductive structure. For example, the first conductor 7 can be a metal pillar, and a portion of the first conductor 7 is located within the receiving groove 21. Alternatively, the first conductor 7 can also include the metal portion of a conductive hole on the first circuit board 2. Since the first conductor 7 is located outside the power device 5 and is made of metal, it can also enhance the side-side anti-interference capability of the power device 5, further improving the EMC performance of the power device 5.
[0088] In some embodiments, the EMC performance of the power device 5 can be improved by increasing the number of first conductors 7. For example, referring to FIG10, multiple first conductors 7 can be provided, with multiple first conductors 7 surrounding the outer periphery of the power device 5. By wrapping the power device 5 with the third metal layer 22, the first metal layer 33, and the multiple first conductors 7 connecting the two, the power device 5 has a shielding structure on both sides and the outer periphery, achieving a good electromagnetic shielding effect and further optimizing the EMC performance of the power device 5.
[0089] Furthermore, if the power conversion device 100 includes a third metal layer 22, and if multiple second conductors 8 are provided, the multiple second conductors 8 can surround the outer periphery of the third metal layer 22. For example, FIG11 exemplarily shows a structure of a second conductor 8. In the example shown in FIG11, multiple second conductors 8 surround the outer periphery of the metal third metal layer 22.
[0090] In some other embodiments, the third metal layer 22 may be exposed on the outside of the first circuit board 2, that is, the distance between the third metal layer 22 and the substrate 3 may be greater, so that the dimension of the receiving groove 21 in the thickness direction of the first circuit board 2 may be larger. For example, FIG12 exemplarily illustrates another structure of the first circuit board 2. Referring to FIG12, the third metal layer 22 is exposed on the side of the first circuit board 2 facing away from the substrate 3. In this embodiment, the surface (B2) of the third metal layer 22 facing the substrate 3 may serve as the inner surface of the receiving groove 21, that is, the receiving groove 21 extends to the location of the third metal layer 22. In some other embodiments, the receiving groove 21 does not extend to the location of the third metal layer 22 on the first circuit board 2, that is, there is a certain distance between the inner surface of the receiving groove 21 facing the substrate 3 and the third metal layer 22.
[0091] Referring to Figure 12, the receiving groove 21 is made longer in the thickness direction of the first circuit board 2, resulting in a larger internal space and thus improving its carrying capacity. For example, a larger receiving groove 21 can accommodate a larger power device 5, reducing the possibility of interference between the inner surface of the receiving groove 21 and the installation of the power device 5. Furthermore, a larger receiving groove 21 can accommodate more thermally conductive material (e.g., thermally conductive adhesive), thereby further improving the heat dissipation capacity of the power device 5.
[0092] Furthermore, in the embodiment shown in FIG12, the power conversion device 100 may also include a plurality of first conductors 7, through which the first circuit board 2 is electrically connected to the third metal layer 22 and the first metal layer 33. The first conductors 7 in FIG12 are intended to illustrate that, when the power conversion device 100 includes first conductors 7, the first conductor 7 may be partially located within the receiving groove 21 (the first conductor 7 on the right in FIG12), and this type of first conductor 7 may be a metal pillar; alternatively, the first conductor 7 may be entirely located outside the receiving groove 21 (the first conductor 7 on the left in FIG12), and this type of first conductor 7 may be a metal pillar passing through the first metal layer 33, and this type of first conductor 7 may also include the metal portion of a conductive hole on the first circuit board 2.
[0093] In other embodiments, the third metal layer 22 can also be located in other suitable locations. For example, FIG13 exemplarily illustrates another structure of the first circuit board 2. Referring to FIG13, the third metal layer 22 is located within the first circuit board 2, and the third metal layer 22 is located between the surface of the first circuit board 2 facing away from the substrate 3 and the surface of the receiving groove 21 facing the substrate 3. With this design, the third metal layer 22 is neither exposed outside the first circuit board 2 nor exposed inside the receiving groove 21. For example, a portion of any intermediate trace layer of the first circuit board 2 (multilayer circuit board) can be used as the third metal layer 22, eliminating the need for an additional metal shielding structure in the first circuit board 2, reducing processing steps, and facilitating the manufacturing of the first circuit board 2. Furthermore, the portion of the first circuit board 2 facing away from the substrate 3 and opposite to the power device 5 (the area within the dashed box in FIG13) can be arbitrarily structured as needed (e.g., pads, trace layers, terminals, etc. can be provided), reducing the impact of the third metal layer 22 on the surface layout of the first circuit board 2 and improving the flexibility of the surface layout of the first circuit board 2.
[0094] In the embodiment shown in FIG13, the power conversion device 100 can also electrically connect the third metal layer 22 of the first circuit board 2 and the first metal layer 33 of the substrate 3 via the first conductor 7. In FIG13, the first conductor 7 is entirely located outside the receiving groove 21. This first conductor 7 can be a metal pillar or include the metal portion of a conductive hole on the first circuit board 2. In some other embodiments, the first conductor 7 may be partially located within the receiving groove 21.
[0095] In addition, in some embodiments, other electronic components may be disposed in the receiving slot 21. For example, FIG14 exemplarily shows the structure of another first circuit board 2. Referring to FIG14, the power conversion device 100 further includes an auxiliary device 9, which encapsulates at least one of a drive circuit, a protection circuit, and an absorption circuit.
[0096] The driving circuit amplifies the signal from the control circuit to drive the power device 5. The protection circuit is used to deal with unstable factors to prevent them from affecting the circuit performance. For example, the protection circuit detects the current of the input or output power device 5 and disconnects the switching transistor in the power device 5 when the current is large (e.g., by disconnecting the switching transistor in the power device 5 through the driving circuit). The absorption circuit (buffer circuit) reduces the voltage spikes and current surges generated by the power device 5 during switching to limit the voltage (clamping voltage) between the first and second terminals of the power device 5, thereby protecting the sensitive components in the circuit from damage. For example, the absorption circuit can be an RCD circuit (a circuit composed of a resistor Rs, a capacitor Cs, and a diode VDs), or an RC circuit (composed of a resistor and a capacitor).
[0097] It should be noted that the power device 5 can be an insulated-gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET). Each power device 5 includes a control electrode, a first electrode, and a second electrode. For example, in the case of an IGBT, the first electrode is the collector (C), the second electrode is the emitter (E), and the control electrode is the base (B). As another example, in the case of a MOSFET, the first electrode is the drain (D), the second electrode is the source (S), and the control electrode is the gate (G). Furthermore, when the auxiliary device 9 is packaged with a snubber circuit, the snubber circuit can clamp the voltage between the source and gate of the power device 5.
[0098] To accommodate the auxiliary device 9, a wiring layer for fixing (e.g., soldering) the auxiliary device 9 can be provided inside the receiving groove 21 of the first metal layer 33. For example, referring to FIG14, the first circuit board 2 also includes a second wiring layer 23. The second wiring layer 23 is fixed to the inner surface of the receiving groove 21 facing the substrate 3 and is electrically connected to the first wiring layer 31. The auxiliary device 9 is fixed to the second wiring layer 23. The receiving groove 21 can not only accommodate the power device 5, but also fix the auxiliary device 9 associated with the power device 5, thereby realizing a stacked design in a limited space, improving the utilization rate of the receiving groove 21 and the device density on the first circuit board 2. In addition, the loop length around the power device 5 can be reduced, thereby reducing parasitic inductance and improving the performance of the power device 5.
[0099] The electrical connection between the second wiring layer 23 and the first wiring layer 31 can be achieved in any suitable manner. For example, the second wiring layer 23 and the first wiring layer 31 can be connected by a third conductor (e.g., a metal pillar) disposed between them.
[0100] In some embodiments, the receiving groove 21 may also be filled with potting compound 211, and the potting compound 211 is connected to the substrate 3. Figure 15 illustrates an exemplary structure of potting compound 211. Referring to Figure 15, filling the receiving groove 21 with potting compound 211 can enhance the insulation of the power device 5. After sealing with potting compound 211, the electrical safety distance can be reduced, allowing for a higher density design inside the receiving groove 21. Furthermore, it can improve the thermal conductivity of the receiving groove 21, enabling the heat of the power device 5 to be quickly transferred outward through the potting compound 211. For example, the heat of the power device 5 is transferred to the substrate 3 through the potting compound 211, and then to the heat sink 4 (if the power conversion device 100 includes a heat sink 4), achieving efficient heat dissipation for the power device 5. In addition, the potting compound 211 can also serve a waterproof function. The power device 5 encased in the potting compound 211 has stronger reliability and environmental adaptability, improving the operational stability of the power conversion device 100.
[0101] When it is necessary to pot the receiving groove 21 with glue, the potting can be achieved by opening a potting hole 25 on the first circuit board 2 or the substrate 3, thus reducing the difficulty of potting the receiving groove 21. For example, FIG16(a) shows an exemplary structure of a potting hole 25. Referring to FIG16(a), the potting hole 25 is located on the first circuit board 2, and one end of the potting hole 25 faces the side of the first circuit board 2 away from the substrate 3 (the substrate 3 is shown in FIG15). The other end of the potting hole 25 is connected to the receiving groove 21 (the receiving groove 21 is shown in FIG15). The potting glue 211 can be potted into the receiving groove 21 through the potting hole 25. Wherein, when the first circuit board 2 includes a third metal layer 22, FIG16(a) takes the third metal layer 22 in FIG15 as an example, and the potting hole 25 also passes through the third metal layer 22.
[0102] For example, Figure 16(b) exemplarily shows another structure of the potting hole 25. Referring to Figure 16(b), the potting hole 25 is located on the substrate 3, and one end of the potting hole 25 faces the heat sink 4 (refer to Figure 15 for the heat sink), and the other end of the potting hole 25 is connected to the receiving groove 21 (refer to Figure 15 for the receiving groove). Potting compound 211 can also be poured into the receiving groove 21 from the side of the substrate 3 through the potting hole 25.
[0103] When the power conversion device 100 also includes a second circuit board 6 (for example, as shown in FIG. 6), the first circuit board 2 can be fixed to the second circuit board 6 in a vertical mounting manner. In this case, the surface of the first circuit board 2 is perpendicular to the surface of the second circuit board 6, which may result in the substrate 3 on the first circuit board 2 being closer to the second circuit board 6, or the substrate 3 being closer to the pins of the first circuit board 2.
[0104] Therefore, in some embodiments, the surface of the first circuit board 2 may further include an insulating region 27. FIG17 shows a structure of an insulating region 27 provided in an embodiment of this application. Referring to FIG17, the insulating region 27 is located on the surface of the first circuit board 2 facing the substrate 3, and the insulating region 27 is at least partially located between the substrate 3 and the second circuit board 6. For example, the insulating region 27 surrounds the outer periphery of the substrate 3; or, for another example, the insulating region 27 is in the shape of a straight strip, and the insulating region 27 is entirely located between the substrate 3 and the second circuit board 6.
[0105] Providing an insulating region 27 between the substrate 3 and the second circuit board 6 reduces the possibility of electrical continuity between them. For example, when the first metal layer 33 is connected to the electrical network of the power conversion device 100, it reduces the possibility of arcing between the substrate 3 and the second circuit board 6. Furthermore, it also reduces the possibility of arcing between the substrate 3 and the pins 26 of the first circuit board 2 (for connecting the second circuit board 6), meeting safety requirements. In embodiments where the insulating region 27 surrounds the outer periphery of the substrate 3, the insulating region 27 also reduces the risk of electrical continuity between the substrate 3 and the first circuit board 2.
[0106] When the power conversion device 100 includes an insulating region 27, the width of the insulating region 27 can be set according to requirements. For example, the width of the insulating region 27 can be between 0 and 10 mm. In the embodiment shown in FIG17, L1, L2, L3, and L4 in FIG17 represent the widths of the insulating region 27. The dimensions of L1, L2, L3, and L4 can be the same or different; this application does not impose specific limitations on this. In the embodiment shown in FIG17, if the width of the insulating region 27 is between 0 and 10 mm, then the dimensions of L1, L2, L3, and L4 are all between 0 and 10 mm. For example, the dimensions of L1 can be 3 mm, 5 mm, 6 mm, or 9 mm, etc.; the dimensions of L2 can be 2 mm, 7 mm, 8 mm, or 10 mm, etc.; the dimensions of L3 can be 1 mm, 4 mm, 6 mm, or 8.5 mm, etc.; and the dimensions of L4 can be 0.5 mm, 4 mm, 5 mm, or 9.5 mm, etc.
[0107] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power conversion device for converting input electrical energy into power and then outputting it, characterized in that, include: Device casing; A first circuit board is fixed inside the device housing. The first circuit board includes a receiving groove, the opening of which is located on one of the surfaces of the first circuit board. A substrate is fixed inside the device housing. The substrate is located on one side of the first circuit board and blocks the receiving groove. The substrate includes a first wiring layer, a first insulating layer and a first metal layer. The first insulating layer is fixed between the first wiring layer and the first metal layer. The first wiring layer faces the receiving groove and is electrically connected to the first circuit board. A power device, which is fixed to the first trace layer and is at least partially located within the receiving groove.
2. The power conversion device according to claim 1, characterized in that, The first circuit board further includes a third metal layer, and the power device is located between the third metal layer and the first metal layer.
3. The power conversion device according to claim 2, characterized in that, The orthographic projection of the power device onto the surface of the third metal layer is located inside the outer edge of the surface of the third metal layer.
4. The power conversion device according to claim 2 or 3, characterized in that, The third metal layer is exposed on the side of the first circuit board away from the substrate.
5. The power conversion device according to claim 2 or 3, characterized in that, The third metal layer is fixed to the inner surface of the receiving groove facing the substrate.
6. The power conversion device according to claim 2 or 3, characterized in that, The third metal layer is located between the surface of the first circuit board facing away from the substrate and the surface of the receiving groove facing the substrate.
7. The power conversion device according to claim 6, characterized in that, The power conversion device further includes an auxiliary device, which encapsulates at least one of a driving circuit, a protection circuit, and an absorption circuit. The driving circuit is used to drive the power device, the protection circuit is used to detect the input or output current of the power device, and the absorption circuit is used to clamp the voltage between the first and second terminals of the power device. The first circuit board further includes a second wiring layer, which is fixed to the inner surface of the receiving groove facing the substrate. The second wiring layer is electrically connected to the first wiring layer, and the auxiliary device is fixed to the second wiring layer.
8. The power conversion device according to claim 2, characterized in that, The power conversion device further includes at least one first conductor, a portion of each first conductor is located within the first circuit board, one end of each first conductor protrudes from the surface of the first circuit board toward the substrate and is connected to the first metal layer, and the other end of each first conductor is connected to the third metal layer.
9. The power conversion device according to claim 8, characterized in that, Multiple first conductors are provided, and the multiple first conductors surround the outer periphery of the power device.
10. The power conversion device according to any one of claims 1-3, characterized in that, The power conversion device further includes a second conductor, a portion of which is located within the first circuit board. The first circuit board further includes a third trace layer disposed away from the substrate. One end of the second conductor extends from the surface of the first circuit board toward the substrate and is connected to the first trace layer. The other end of the second conductor is connected to the third trace layer.
11. The power conversion device according to any one of claims 1-3, characterized in that, The power conversion device further includes a heat sink, which is located inside the device housing or partially extends outside the device housing. The heat sink is located on the side of the substrate opposite to the first circuit board and is fixed to the substrate.
12. The power conversion device according to claim 11, characterized in that, The substrate further includes a second insulating layer and a second metal layer, the second insulating layer being fixed between the first metal layer and the second metal layer, and the heat sink being fixedly connected to the second metal layer.
13. The power conversion device according to any one of claims 1-3, characterized in that, The receiving groove is filled with potting compound, which is connected to the substrate.
14. The power conversion device according to any one of claims 1-3, characterized in that, The power conversion device further includes a second circuit board, which is fixed inside the device housing. The first circuit board is fixed to the second circuit board. The surface of the first circuit board is perpendicular to the surface of the second circuit board. The surface of the first circuit board facing the substrate includes an insulating region, which is at least partially located between the substrate and the second circuit board.
15. A power supply cabinet, characterized in that, The device includes a cabinet and a plurality of power conversion devices as described in any one of claims 1-14, wherein the plurality of power conversion devices are located within the cabinet and are connected in parallel.