A power module, power converter and photovoltaic power generation system

Abstract

The application provides a power module, a power converter and a photovoltaic power generation system. The power module comprises a substrate, a power device, a package and at least two pins. The power device is electrically connected to the substrate. The package encapsulates the substrate and the power device. The pins are electrically connected to the substrate and pass through the package to extend out of the power module and be connected to a circuit board. The package is provided with a protrusion or a groove on a side facing away from the substrate, and the protrusion or the groove is at least partially located between two adjacent pins. When the pins are in conduction, even if the distance between the two adjacent pins is shortened, the protrusion or the groove between the two pins can increase the creepage distance between the two pins, thereby improving the working performance and safety performance of the power module.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to a power module, a power converter, and a photovoltaic power generation system. Background Technology

[0002] A power module is a functional module that combines power devices according to certain functions and then encapsulates or pots them into a whole. It is widely used in equipment such as servo motors, frequency converters, or inverters. Common packaging forms for power modules include housing packages and molding packages. These mainly involve assembling and soldering the substrate, chip, and pins, and then pouring in encapsulation materials to protect the components.

[0003] To ensure the safety of power modules, the creepage distances between multiple pins of the power module must meet safety regulations. As the voltage level of the power module continues to increase, the creepage distances between these pins need to be gradually increased. However, increasing the creepage distance reduces the mutual inductance when current flows through the pins, increases the parasitic parameters of the circuit, and causes voltage spikes during the substation process. Utility Model Content

[0004] This application provides a power module, a power converter, and a photovoltaic power generation system to improve the performance of the power module by shortening the spacing between two adjacent pins and increasing the creepage distance between the two pins.

[0005] In a first aspect, this application provides a power module. The power module includes a substrate, a power device, a package, and at least two pins. Specifically, the power device is disposed on one side surface of the substrate and is electrically connected to the substrate. The package encapsulates the substrate and the power device. The aforementioned at least two pins are respectively electrically connected to the substrate, and the aforementioned at least two pins pass through the package and extend from the surface of the package opposite to the substrate. The side of the package opposite to the substrate has a protrusion or groove, and the protrusion or groove may be at least partially located between two adjacent pins of the aforementioned at least two pins.

[0006] The power module of this application can be applied to high-voltage power converters. In the power module, pins extend from one side relative to the substrate and connect to the power converter's circuit board. When the power module is operating, current flows through the pins, and a protrusion or groove is provided between adjacent pins. Therefore, even if the spacing between the two pins is shortened, the protrusion or groove between the two pins can increase the creepage distance between the two pins, thereby improving the operating performance and safety performance of the power module.

[0007] In one implementation, a protrusion or groove is provided on the surface of the package body facing away from the substrate, and the protrusion or groove is located between the two pins. In this implementation, the protrusion or groove can be directly provided on the outer surface of the package body, and can be formed simultaneously with the package body during the manufacturing process of the power module, thereby reducing the manufacturing cost of the power module.

[0008] In one implementation, the height of the protrusion can be less than the length of the two adjacent pins extending out of the power module. Therefore, when the power module is assembled with the power converter's circuit board, these two pins are directly connected to the circuit board. Since the height of the protrusion is less than the length of the pin between the package and the circuit board, the protrusion does not affect the connection between the pin and the circuit board, and the end of the pin furthest from the package can be directly connected to the circuit board.

[0009] In one implementation, the height of the protrusion is greater than the length of the two pins extending out of the power module. One end of the protrusion is connected to the package and is parallel to the two pins. The end of the protrusion away from the package is located on the side of the two pins away from the package and extends in a direction parallel to the plane of the package. In this implementation, the height of the protrusion is greater than the length of the pins between the package and the circuit board, which can further increase the creepage distance between the two pins. In this case, the circuit board of the power converter can be provided with a notch to accommodate the protrusion.

[0010] In one implementation, the package includes a cover and a molding compound, the molding compound encapsulating the power device, and the cover being disposed on a surface of the molding compound facing away from the substrate. The cover at least partially covers this surface of the molding compound. In this implementation, the power module can be encapsulated in a plastic shell; specifically, the cover can completely cover the surface of the molding compound and be connected to the substrate, with the molding compound located within the space between the cover and the substrate. Alternatively, the power module can be molded; specifically, a portion of the surface of the molding compound is covered by the cover, while another portion is exposed outside the cover.

[0011] In one implementation, an insulating pad is disposed between the cover plate and the molding compound. A protrusion is provided on the surface of the insulating pad facing the cover plate, extending through the cover plate and beyond the power module. Two pins pass through the protrusion and extend beyond the power module. In this implementation, the protrusion is disposed on the insulating pad. Specifically, the protrusion of the insulating pad extends from the side of the cover plate located inside the power module to the other side located outside the power module. The pins pass through the protrusion, i.e., the protrusion covers the portion of the pins extending outside the power module. Thus, the creepage distance between two adjacent pins includes both the cover plate surface and the protrusion surface between the two pins, thereby increasing the creepage distance.

[0012] In one implementation, an insulating layer is provided on the surface of the protrusion or groove to increase the comparative tracking index (CTI) of the protrusion or groove surface, thereby further improving the insulation performance of the protrusion or groove.

[0013] In one implementation, the current directions of the two pins are opposite. When the power module is connected to the circuit board and powered on, the potentials of the two adjacent pins can be different. In this way, the distance between the two pins can be shortened without affecting safety, thereby increasing the mutual inductance when the pins are carrying current, thus reducing the risk of parasitic inductance and voltage spikes.

[0014] Secondly, this application also provides a power converter. The power converter includes a circuit board and a power module as described in the first aspect. The circuit board is located on the side of the package facing away from the substrate, and at least two pins are connected to the circuit board. In the power converter of this application, the spacing between two adjacent pins of the power module is short, and the creepage distance is large, resulting in better operating performance and safety performance of the power module.

[0015] In one implementation, a protrusion is provided on the side of the package facing away from the substrate. The protrusion is located between two adjacent pins, and the height of the protrusion is greater than the length of the two pins extending out of the power module. A notch is provided on the surface of the circuit board facing the power module. The end of the protrusion near the package is parallel to the two pins, and the end of the protrusion away from the package is located within the notch. In this implementation, the height of the protrusion is greater than the length of the pins between the power module and the circuit board, which can further increase the creepage distance between the two pins. In this case, the circuit board of the power converter can be provided with a notch to accommodate the protrusion.

[0016] Thirdly, this application also provides a photovoltaic power generation system. The photovoltaic power generation system includes photovoltaic modules and, as a second aspect, a power converter. The photovoltaic modules are connected to the power converter, which converts the direct current output from the photovoltaic modules into power. In the photovoltaic power generation system of this application, the spacing between adjacent pins of the power module in the power converter is short, and the creepage distance is large, resulting in better operating performance and safety performance of the power module. Attached Figure Description

[0017] Figure 1 A schematic diagram of a photovoltaic power generation system provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of a power converter provided in one embodiment of this application;

[0019] Figure 3 A schematic diagram of a power converter provided in one embodiment of this application;

[0020] Figure 4 A schematic diagram of a power converter provided in one embodiment of this application;

[0021] Figure 5 A schematic diagram of a power converter provided in another embodiment of this application;

[0022] Figure 6 A schematic diagram of a power converter provided in another embodiment of this application;

[0023] Figure 7 A schematic diagram of a power converter provided in another embodiment of this application;

[0024] Figure 8 for Figure 4 Schematic diagram of a medium power module;

[0025] Figure 9 for Figure 5 Schematic diagram of a medium power module;

[0026] Figure 10 A schematic diagram of a power module provided in one embodiment of this application;

[0027] Figure 11 A schematic diagram of a power converter provided in another embodiment of this application;

[0028] Figure 12 for Figure 11 A schematic diagram of a medium-power module.

[0029] Figure label:

[0030] 10-Photovoltaic Power Generation System

[0031] 11-Photovoltaic Modules

[0032] 12-Power Converter

[0033] 13-Power Grid

[0034] 14-Load

[0035] 20-Power Module

[0036] 21-pin

[0037] 22-Substrate

[0038] 23-Power Devices

[0039] 24-package

[0040] 25-protrusion

[0041] 26-groove

[0042] 121-Circuit Board

[0043] 241-Encapsulated Body

[0044] 242-Cover Plate

[0045] 243-Insulating Pad Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0047] To facilitate understanding of the power module, power converter, and photovoltaic power generation system provided in the embodiments of this application, their application scenarios are described below. Power converters are widely used in photovoltaic power generation systems, energy storage systems, or powertrain systems of new energy vehicles to convert current or voltage in the application system. Power converters may include inverters or microinverters in photovoltaic power generation systems, converters in energy storage systems, or motor controllers in the powertrain of new energy vehicles.

[0048] Taking photovoltaic (PV) power generation systems as an example, PV power generation systems can be used in applications such as residential power stations and industrial PV power stations. PV power generation systems are used to convert solar energy into electrical energy and supply the electrical energy to the power grid or loads. Figure 1 This is a schematic diagram of a photovoltaic power generation system provided in an embodiment of this application. Figure 1 As shown, the photovoltaic power generation system 10 may include a photovoltaic module 11 and a power converter 12. The output terminal of the photovoltaic module 11 is connected to the input terminal of the power converter 12. The power converter 12 is used to convert the DC power output from the photovoltaic module 11 into power and output it to the power grid 13 or the load 14.

[0049] Figure 2 This is a schematic diagram of a power converter provided in one embodiment of this application. Figure 2 As shown, the power converter 12 includes a circuit board 121 and a power module 20, wherein the power module 20 is disposed on one side of the circuit board 121 and electrically connected to the circuit board 121. Specifically, the power module 20 includes at least two pins 21, the portions of which extend outside the power module 20 are connected to the circuit board 121.

[0050] To ensure the safety of the power module, the creepage distance between two adjacent pins must meet safety regulations. It should be noted that creepage distance refers to the charged area between two conductive components measured along the insulating surface. Under different usage conditions, this area is formed because the insulating material around the conductor becomes electrically charged, and is typically determined according to safety regulations. In the embodiments of this application, the creepage distance refers to the distance between two adjacent pins along the outer surface of the power module. Therefore, the spacing between two adjacent pins along the outer surface of the power module should meet the creepage distance requirements.

[0051] As the voltage levels of power modules continue to increase, the creepage distance gradually increases. However, the increase in creepage distance leads to an increase in the spacing between two adjacent pins, thereby reducing the mutual inductance between the two pins when current is flowing, and increasing the parasitic parameters of the power circuit, causing voltage spikes during the substation process.

[0052] In view of this, this application provides a power module, a power converter, and a photovoltaic power generation system, which can increase the creepage distance between two adjacent pins while shortening the spacing between the two pins, thereby improving the working performance and safety performance of the power module.

[0053] It should be noted that the terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0054] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0055] In this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0056] Furthermore, in this article, directional terms such as "top," "bottom," "upper," and "lower" are defined relative to the orientation of the structure as shown in the attached drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the structure.

[0057] like Figure 2 As shown, the power module 20 also includes a substrate 22, a power device 23, and a package 24. Specifically, the power device 23 is disposed on one side of the surface of the substrate 22 and is electrically connected to the substrate 22. The package 24 is used to encapsulate the substrate 22 and the power device 23. The aforementioned at least two pins 21 are respectively electrically connected to the substrate 22. The aforementioned at least two pins 21 penetrate the package 24 and extend from the surface of the package 24 away from the substrate 22, for connection to the circuit board 121. The side of the package 24 away from the substrate 22 may be provided with a protrusion 25, and the protrusion 25 or groove 26 may be at least partially located between two adjacent pins 21 of the aforementioned at least two pins 21. Figure 3 A schematic diagram of a power converter provided for another embodiment of this application. (See diagram below.) Figure 3 As shown, a groove 26 may also be provided on the side of the package body 24 away from the substrate 22, and the groove 26 may be at least partially located between two adjacent pins 21 of the aforementioned at least two pins 21.

[0058] It should be noted that the package 24 may only have a protrusion 25, or the package 24 may only have a groove 26, or the package 24 may have both a protrusion 25 and a groove 26. The embodiments of this application are not limited.

[0059] The power module 20 described above can be applied to a high-voltage power converter 12. In the power module 20, pins 21 extend from one side relative to the substrate 22 and connect to the circuit board 121 of the power converter 12. When the power module 20 is operating, current flows through the pins 21, wherein a protrusion 25 or a groove 26 is provided between two adjacent pins 21. Therefore, even if the distance between the two pins 21 is shortened, the protrusion 25 or the groove 26 between the two pins 21 can increase the creepage distance between the two pins 21, thereby improving the operating performance and safety performance of the power module 20.

[0060] Figure 4 This is a schematic diagram of a power converter provided in another embodiment of this application. Figure 5 A schematic diagram of a power converter provided for another embodiment of this application. (See diagram below.) Figure 4 and Figure 5 As shown, the package 24 includes a molding compound 241 and a cover plate 242. The molding compound 241 encapsulates the power device 23, and the cover plate 242 is disposed on the surface of the molding compound 241 facing away from the substrate 22, and the cover plate 242 at least partially covers the surface of the molding compound 241 facing away from the substrate 22. Protrusions 25 and / or recesses 26 may be provided on the cover plate 242.

[0061] like Figure 4 As shown, in one embodiment, the power module 20 can be molded, specifically, the molded package 241 includes two opposing sides, one side encapsulating the substrate 22 and the power device 23, and the other side encapsulating the cover plate 242. That is, the cover plate 242 covers a portion of the surface of the molded package 241 facing away from the substrate 22, and another portion of that surface is exposed outside the cover plate 242.

[0062] Figure 6 This is a schematic diagram of a power converter provided in another embodiment of this application. Figure 7 A schematic diagram of a power converter provided for another embodiment of this application. (See diagram below.) Figure 6 and Figure 7 As shown, the power module 20 can be housed in a plastic shell. Specifically, the plastic shell 241 encapsulates the substrate 22 and the power device 23, and the cover plate 242 is disposed on the side of the plastic shell 241 away from the substrate 22 and completely covers the plastic shell 241.

[0063] The following explanation uses the molded power module 20 as an example.

[0064] Figure 8 for Figure 4 Schematic diagram of a medium power module. Figure 9 for Figure 5 A schematic diagram of a medium-power module. (Example) Figure 8 and Figure 9 As shown, an insulating pad 243 is provided between the cover plate 242 and the molding compound 241. The insulating pad 243 can be used to increase the heat dissipation area between the power device 23 and the cover plate 242 to achieve temperature uniformity of the cover plate 242. In addition, the insulating pad 243 can prevent high-voltage breakdown between the power device 23 and the cover plate 242 to reduce the risk of short circuit.

[0065] like Figure 8 and Figure 9As shown, in some embodiments, the protrusion 25 or the groove 26 can be directly disposed on the outer surface of the cover plate 242, and the protrusion 25 or the groove 26 is located between two pins 21. In this case, the creepage distance between two adjacent pins 21 is as follows: Figure 8 and Figure 9 As shown by the bold solid line in the figure. When manufacturing the power module 20, the protrusions 25 or grooves 26 can be formed simultaneously with the production of the cover plate 242 by injection molding, thereby reducing the manufacturing cost of the cover plate 242.

[0066] Figure 10 This is a schematic diagram of a power module provided in one embodiment of this application. Figure 10 As shown, protrusions 25 can also be provided on the insulating pad 243. Specifically, protrusions 25 are provided on the surface of the insulating pad 243 facing the cover plate 242, and the protrusions 25 pass through the cover plate 242 and extend out of the power module 20. Pins 21 pass through the protrusions 25 and extend out of the power module 20.

[0067] In this embodiment, the protrusion 25 of the insulating pad 243 extends from one side of the cover plate 242 located inside the power module 20 to the other side located outside the power module 20. The pin 21 passes through the protrusion 25, meaning the protrusion 25 covers the portion of the pin 21 extending outside the power module 20. At this time, the creepage distance between two adjacent pins 21 is as follows: Figure 10 As shown by the bold solid line in the figure. Thus, the creepage distance between two adjacent pins 21 includes the surface of the cover plate 242 and the surface of the protrusion 25 between the two pins 21, thereby increasing the creepage distance.

[0068] Of course, in other embodiments, the insulating pad 243 may be provided with protrusions 25, and the cover plate 242 may be provided with protrusions 25 and / or grooves 26.

[0069] In the above embodiments, the surfaces of the protrusion 25 and the groove 26 may be provided with an insulating layer to improve the comparative tracking index (CTI) of the surface of the protrusion 25, thereby further improving the insulation performance of the protrusion 25.

[0070] like Figure 8 and Figure 10 As shown, the height of the protrusion 25 can be less than the length of the two adjacent pins 21 extending out of the power module 20. Therefore, when the power module 20 is assembled with the circuit board 121 of the power converter 12, the two pins 21 are directly connected to the circuit board 121. Since the height of the protrusion 25 is less than the length of the pins 21 between the package 24 and the circuit board 121, the protrusion 25 does not affect the connection between the pins 21 and the circuit board 121, and the end of the pin 21 away from the package 24 can be directly connected to the circuit board 121.

[0071] Figure 11 This is a schematic diagram of a power converter provided in another embodiment of this application. Figure 12 for Figure 11 A schematic diagram of a medium-power module. (Example) Figure 11 and Figure 12 As shown, the height of the protrusion 25 is greater than the length of the two pins 21 extending out of the power module 20. One end of the protrusion 25 is connected to the package 24 and is parallel to the two pins 21. The end of the protrusion 25 away from the package 24 is located on the side of the two pins 21 away from the package 24 and extends in a direction parallel to the plane of the cover plate 242. In this implementation, the height of the protrusion 25 is greater than the length of the pins 21 between the package 24 and the circuit board 121, which can further increase the creepage distance between the two pins 21. In this case, the circuit board 121 of the power converter 12 can be provided with a notch to accommodate the protrusion 25.

[0072] In some embodiments, the current directions of the two pins 21 can be opposite. Therefore, when the power module 20 is connected to the circuit board 121 and energized, the potentials of the two adjacent pins 21 are different. In this way, the spacing between the two pins 21 can be shortened without affecting safety, thereby increasing the mutual inductance when current flows through the pins 21 to reduce parasitic inductance and the risk of voltage spikes.

[0073] The above are merely specific embodiments 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 module, characterized by Includes substrate, power devices, and package, wherein: The power device is disposed on one side of the surface of the substrate, and the power device is electrically connected to the substrate; The package encapsulates the substrate and the power device; the power module further includes at least two pins, which are electrically connected to the substrate, and the at least two pins pass through the package and extend from the surface of the package away from the substrate. The package body has a protrusion or groove on the side opposite to the substrate, and the protrusion or groove is at least partially located between two adjacent pins of the at least two pins.

2. The power module of claim 1, wherein, The surface of the package body facing away from the substrate has the protrusion or the groove, and the protrusion or the groove is located between the two pins.

3. The power module of claim 2, wherein, The height of the protrusion is less than the length of the two pins extending out of the power module.

4. The power module of claim 2, wherein, The height of the protrusion is greater than the length of the two pins extending out of the power module; the end of the protrusion connected to the package body is parallel to the two pins, the end of the protrusion away from the package body is located on the side of the two pins away from the package body, and extends in a direction parallel to the plane of the package body.

5. The power module of any one of claims 1 to 4, wherein, The package includes a cover plate and a molding compound, the molding compound encapsulating the power device, the cover plate being disposed on the surface of the molding compound facing away from the substrate, and the cover plate at least partially covering the surface of the molding compound.

6. The power module of claim 5, wherein, An insulating pad is provided between the cover plate and the encapsulated body. The surface of the insulating pad facing the cover plate has the protrusion. The protrusion passes through the cover plate and extends out of the power module. The two pins pass through the protrusion and extend out of the power module.

7. The power module of any one of claims 1 to 6, wherein, The surface of the protrusion or the groove is provided with an insulating layer.

8. The power module of any one of claims 1 to 7, wherein, The current flows in opposite directions on the two pins.

9. A power converter, characterized by The package includes a circuit board and a power module as described in any one of claims 1 to 8, wherein the circuit board is located on the side of the package opposite to the substrate, and the at least two pins are connected to the circuit board.

10. The power converter of claim 9, wherein, The package body has the protrusion on the side opposite to the substrate, the protrusion is located between the two pins, and the height of the protrusion is greater than the length of the two pins extending out of the power module; The circuit board has a notch on the side facing the power module. The end of the protrusion near the package is parallel to the two pins, and the end of the protrusion away from the package is located inside the notch.

11. A photovoltaic power system, characterized by, It includes a photovoltaic module and a power converter as described in claim 9 or 10, wherein the photovoltaic module is connected to the power converter, and the power converter is used to convert the direct current output by the photovoltaic module into power.

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