Power conversion device

Abstract

The embodiment of the utility model provides power conversion equipment, and relates to the technical field of energy, the power conversion equipment comprises an equipment shell, a radiator, a circuit board, a power module and a pressing piece, and the radiator is at least partially located outside or in the equipment shell; the circuit board is located in the equipment shell; the power module is located in the equipment shell, the power module is used for converting direct current into alternating current, the power module comprises a packaging shell and pins extending out of the packaging shell, the packaging shell is located between the circuit board and the radiator, the packaging shell is connected with the radiator, and the pins are fixed to the circuit board; the abutting piece is fixed to the circuit board or the radiator, the circuit board is provided with an opening, one part of the abutting piece is located on the side, away from the radiator, of the circuit board, and the other part of the abutting piece penetrates through the opening and abuts against the surface, facing the circuit board, of the packaging shell. According to the technical scheme, the gap between the power module and the radiator can be reduced, the thermal resistance between the power module and the radiator is reduced, and heat dissipation of the power module is facilitated.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to a power conversion device. Background Technology

[0002] In scenarios such as photovoltaic power generation, energy storage, and charging stations, power conversion equipment is typically required to transform the input power. For example, it can convert direct current (DC) from photovoltaic modules or energy storage batteries into alternating current (AC), or it can convert AC from the power grid into DC. Power modules are the core components of this power conversion equipment.

[0003] To dissipate heat from the power module, power conversion equipment typically includes a heat sink. However, after the power module and heat sink are assembled, the gap between them is large, resulting in high thermal resistance between the power module and the heat sink. This leads to poor heat dissipation of the power module and poor long-term reliability of the power conversion equipment. Utility Model Content

[0004] This application provides a power conversion device that can reduce the gap between the power module and the heat sink, reduce the thermal resistance between the power module and the heat sink, and facilitate the heat dissipation of the power module.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a power conversion device, which includes a device housing, a heat sink, a circuit board, a power module, and a retaining member. The heat sink is at least partially located outside the device housing, or the heat sink is located inside the device housing. The circuit board is located inside the device housing. The power module is located inside the device housing and is used to convert direct current from photovoltaic modules or energy storage batteries into alternating current. The power module includes a package shell and pins extending outside the package shell. The package shell is located between the circuit board and the heat sink and is connected to the heat sink. The pins are fixed to the circuit board. The retaining member is fixed to the circuit board or the heat sink. The circuit board has an opening. A portion of the retaining member is located on the side of the circuit board away from the heat sink, and another portion of the retaining member passes through the opening and abuts against the surface of the package shell facing the circuit board.

[0007] The power module is mounted on a circuit board, with its pins fixedly connected to the board. Furthermore, a portion of a pressure-bearing component passes through an opening and presses against the power module's package housing. This pressure-bearing component applies pressure to the package housing, bringing it closer to and connecting it to the heatsink, thus reducing the gap between the package housing and the heatsink and decreasing the thermal resistance between them. Since the power module's substrate and die are all housed within the package housing, the package housing is the part of the power module that generates the most heat. This application reduces the thermal resistance between the package housing and the heatsink through the above method, facilitating heat transfer from the package housing to the heatsink, resulting in better heat dissipation of the power module and improved long-term reliability of the power conversion equipment.

[0008] In one optional embodiment, the power conversion device further includes a threaded rod and a limiting block. The limiting block is fixed to the end of the threaded rod and protrudes radially outward from the threaded rod. The pressing member has a first through hole, and the circuit board has a second through hole. The threaded rod passes through the first through hole and the second through hole and is threadedly connected to the heat sink. The pressing member is clamped between the limiting block and the circuit board.

[0009] The threaded rod and the limiting block are fixed together to form at least part of a fastening structure (e.g., bolts, screws, etc.). When a pressure-retaining component needs to be installed, the threaded rod is screwed onto the heat sink. The threaded connection between the threaded rod and the heat sink causes the limiting block to press against the pressure-retaining component, which in turn presses the housing onto the heat sink, reducing the gap between the power module and the heat sink. Furthermore, the threaded rod has a self-locking function. Not only does the threaded rod ensure reliable assembly of the pressure-retaining component and the heat sink, but the tightness of the contact between the housing and the heat sink can also be adjusted by rotating the threaded rod, making the position of the power module more suitable for the heat sink. When it is necessary to remove the pressure-retaining component, the threaded rod is loosened in the opposite direction, and the threaded rod and the limiting block are removed from the pressure-retaining component. Without the restriction of the limiting block, the pressure-retaining component can be removed freely.

[0010] In one alternative embodiment, in the thickness direction of the circuit board, there is a gap between the surface of the pressing member closest to the circuit board and the circuit board.

[0011] After the pressing component has pressed the package onto the heat sink (the package is connected to the heat sink), there is still a gap between the pressing component and the circuit board. This gap is the reserved spare gap. With the spare gap, the user or operator can further tighten the threaded rod as needed (for example, further tighten the threaded rod for individual power modules) to make the contact between the package and the heat sink tighter and reduce the possibility of the package and the heat sink detaching.

[0012] In one optional embodiment, the power conversion device further includes a support platform fixed to the surface of the heat sink facing the circuit board, the support platform being used to support the circuit board.

[0013] The power module's pins are fixed to the circuit board. When the pressure component applies pressure to the package housing, the package housing exerts a pulling force on the pins, causing the pins to also exert a pulling force on the circuit board (pulling the circuit board towards the heat sink). During the tightening of the threaded rod, as the threaded rod tightens further, the pulling force of the pins on the circuit board increases continuously. The support platform supports the circuit board, reducing the possibility of excessive deformation under the pulling force of the pins and minimizing the risk of circuit board damage. In other words, the circuit board is protected by setting a support platform on the heat sink.

[0014] In one alternative embodiment, the support platform has a threaded hole that is threadedly connected to a threaded rod.

[0015] Since the threaded rod needs to be fixed to the heatsink, when a support platform is fixed to the heatsink, the threaded rod can be threaded into the threaded hole of the support platform. The support platform serves both as the connection point for the threaded rod and as a support and protection for the circuit board, thus enriching its functionality. In one case, since the support platform already has a threaded hole, there is no need to drill a new threaded hole on the heatsink, reducing processing steps. In another case, the heatsink will also have a connecting hole (with internal threads), and this connecting hole communicates with the threaded hole in the support platform. The support platform essentially extends the connecting hole on the heatsink, making the connection between the threaded rod and the heatsink more secure.

[0016] In one optional embodiment, the pressing member includes a connecting rod and a pressing block. The connecting rod is located on the side of the circuit board away from the heat sink, and the length direction of the connecting rod is parallel to the surface of the circuit board. The pressing block is fixed to the surface of the connecting rod facing the circuit board. A part of the pressing block is located on the side of the circuit board away from the heat sink, and the other part of the pressing block passes through the opening and abuts against the surface of the encapsulation shell facing the circuit board. In the length direction of the connecting rod, the length of the connecting rod is greater than the length of the pressing block.

[0017] If the retaining component needs to be fixed to the circuit board or the heat sink, additional fastening structures (such as threaded rods and limiting blocks) are required to secure it. By employing the aforementioned structure, the connecting rod of the retaining component extends to a certain length, thus providing more space for the fastening structures to connect, facilitating the fixing of the retaining component to the heat sink (or circuit board).

[0018] In one alternative embodiment, the package has a bottom surface facing the circuit board and a peripheral surface surrounding the bottom surface; the pins include a first segment, a second segment, and a third segment connected in sequence, the first segment extending from the peripheral surface of the package to the outside of the package, the second segment bending from the first segment toward the circuit board, and the third segment extending toward the circuit board and fixed to the circuit board; a portion of the first segment or a portion of the third segment is inclined toward the package in the direction from the heat sink to the circuit board.

[0019] After the first segment of the pin extends from the circumference of the package, it is bent at the second segment and then secured to the circuit board via the third segment (e.g., the third segment is soldered to the circuit board). In one case, a portion of the first segment is inclined toward the package in the direction from the heat sink to the circuit board, thus bending the first segment. After the pressure member applies pressure to the package in the direction of the heat sink, the first segment deforms as the package moves (e.g., the first segment deforms towards straightening). The bent first segment has a larger deformation range (a larger allowable deformation), which is beneficial for the package to move toward the heat sink. In another case, a portion of the third segment is inclined toward the package in the direction from the heat sink to the circuit board, thus bending the third segment. After the pressure member applies pressure to the package in the direction of the heat sink, the third segment deforms as the package moves (e.g., the third segment deforms towards straightening). The bent third segment has a larger deformation range, which is beneficial for the package to move toward the heat sink.

[0020] In other words, by setting an inclined section in the first or third section, more bending points are made on the pin, increasing the deformation space of the pin (the allowable deformation is greater). When the package is subjected to external force, the larger deformation space of the pin can reduce the possibility of the pin falling off the circuit board.

[0021] In one optional embodiment, the first segment includes a first part and a second part, the first part extending from the circumferential surface of the package shell to the outside of the package shell, and the second part connecting the first part and the second segment, the second part tilting from the second segment toward the circuit board.

[0022] The second part of the first segment can be understood as the inclined portion of the first segment. Connecting the second part to the second segment (the part where the pin bends towards the circuit board) concentrates the bending portion of the pin, facilitating pin production. For example, from a packaging process perspective, this design only requires minor modifications to the original pin forming process to achieve the production of the pins in this application.

[0023] In one alternative embodiment, the third segment includes a third part and a fourth part, the third part being fixed to the circuit board, the fourth part being connected between the third part and the second segment, and the fourth part being inclined from the second segment toward the package shell.

[0024] The fourth part of the third segment can be understood as the inclined part of the third segment. Connecting the fourth part with the second segment (the second segment is the part where the pin bends towards the circuit board) concentrates the part of the pin that needs to be bent together. Only minor modifications are needed to the original forming process of the pin to realize the production of the pin of this application, making the production and processing of the pin more convenient.

[0025] In one alternative embodiment, the package has a bottom surface facing the circuit board and a peripheral surface surrounding the bottom surface; the pins include a connected fourth segment and a fifth segment, the fourth segment extending from the peripheral surface of the package to the outside of the package, at least a portion of the fourth segment being inclined toward the side opposite to the package in the direction from the heat sink to the circuit board, and the fifth segment extending toward the circuit board and fixed to the circuit board.

[0026] In some cases, the pressure exerted on the package by the retaining component is relatively large. Under the pressure of the retaining component, the package exerts a large pulling force on the pins, resulting in a large deformation of the pins. Therefore, after the package moves towards the heat sink to a certain extent, the pins are at least partially tilted towards the circuit board due to deformation. For example, under the pulling force of the package (the package moves closer to the heat sink), the fourth segment of the pin tilts from the package towards the circuit board. Due to the deformation of the pin, the package can fit tightly against the heat sink, reducing the gap between the package and the heat sink, which is beneficial for the heat dissipation of the power module.

[0027] In one alternative embodiment, the power module further includes a protrusion fixed to the pin, the protrusion being located on the side of the circuit board facing the heat sink, and the protrusion contacting the circuit board.

[0028] In cases with installation errors, if the heatsink is too close to the circuit board, the heatsink will apply reverse pressure to the package, causing the package to move towards the circuit board. Under the pressure of the package, the pins will also deform and apply pressure towards the circuit board. The protrusions support the pins, reducing the possibility of the pins separating from the circuit board during the process of being pressed down by the package, thus making the connection between the pins and the circuit board more stable. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a photovoltaic energy storage system provided in an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0031] Figure 3 This is a schematic diagram of the structure of a heat sink provided in an embodiment of this application;

[0032] Figure 4 This is a schematic diagram of another heat sink provided in an embodiment of this application;

[0033] Figure 5 This is a schematic diagram of another heat sink provided in an embodiment of this application;

[0034] Figure 6 This application provides a topology diagram of a power conversion device according to an embodiment of the present application.

[0035] Figure 7 This is a schematic diagram of the structure of a power module provided in an embodiment of this application;

[0036] Figure 8 This is a schematic diagram of the structure of a power module in related technologies;

[0037] Figure 9 This is a schematic diagram of the structure of a pressing member provided in an embodiment of this application;

[0038] Figure 10 A schematic diagram of a threaded rod and a limiting block provided in an embodiment of this application;

[0039] Figure 11 This is a schematic diagram of another pressing member provided in an embodiment of this application;

[0040] Figure 12 This is a schematic diagram of the structure of a support platform provided in an embodiment of this application;

[0041] Figure 13 A diagram showing the positional relationship between a support platform and a circuit board, provided in an embodiment of this application;

[0042] Figure 14 This is a schematic diagram of another type of pressing member provided in an embodiment of this application;

[0043] Figure 15 This is a schematic diagram of another type of pressing member provided in an embodiment of this application;

[0044] Figure 16 A schematic diagram of a pin structure provided in an embodiment of this application;

[0045] Figure 17 for Figure 16 Enlarged view at point A in the middle;

[0046] Figure 18 This is a schematic diagram of the structure of a pin in related technologies;

[0047] Figure 19 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0048] Figure 20 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0049] Figure 21 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0050] Figure 22 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0051] Figure 23 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0052] Figure 24 This is a schematic diagram of another power module provided in an embodiment of this application;

[0053] Figure 25 This is a schematic diagram of a protrusion structure provided in an embodiment of this application.

[0054] Figure label:

[0055] 100-Photovoltaic-Storage System; 10-Photovoltaic Module; 20-Power Conversion Equipment; 201-Photovoltaic Inverter; 202-Energy Storage Converter; 203-DC-DC Conversion Circuit; 204-DC-AC Conversion Circuit; 30-Box-type Substation; 40-Step-up Substation; 50-Grid; 60-Energy Storage Battery; 1-Equipment Housing; 11-Port; 2-Circuit Board; 21-Opening; 22-Second Through Hole; 3-Power Module; 31-Substrate; 32-Barrel Die; 33-Package Housing; 331-Bottom Surface; 332-Peripheral Surface; 34-Pin; 341-First Segment; 3411-First Part; 3412-Second Part 342 - Second section; 343 - Third section; 3431 - Third part; 3432 - Fourth part; 344 - Fourth section; 3441 - Fifth part; 3442 - Sixth part; 345 - Fifth section; 346 - Sixth section; 4 - Radiator; 41 - Heat-conducting plate; 42 - Fins; 43 - Heat dissipation channel; 44 - Connecting hole; 5 - Heat dissipation cover; 51 - Air outlet; 6 - Pressing component; 61 - Connecting rod; 62 - Pressing block; 63 - First through hole; 64 - Support column; 65 - Adjusting bolt; 7 - Fastening structure; 71 - Threaded rod; 72 - Limiting block; 8 - Support platform; 81 - Threaded hole; 9 - Protrusion. Detailed Implementation

[0056] 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.

[0057] 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 (or multiple parts) 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.

[0058] Figure 1 An exemplary structure of an optical storage system 100 is shown, with reference to Figure 1 In a photovoltaic system, photovoltaic modules 10 utilize the photovoltaic effect to directly convert solar energy into electrical energy. Photovoltaic modules 10 typically include multiple (in this application, multiple refers to two or more) solar cells connected in series or parallel to achieve a certain rated output power and voltage. A photovoltaic inverter 201 converts the direct current (DC) from the photovoltaic modules 10 into alternating current (AC). After passing through a switch box for on / off control, the AC is fed into a prefabricated substation 30 corresponding to the photovoltaic inverter 201 for voltage transformation. The prefabricated substation 30, corresponding to the photovoltaic inverter 201, converts the low-voltage AC output from the photovoltaic inverter 201 into medium-voltage AC, and then transmits the AC to a step-up substation 40 and then to the power grid 50. Alternatively, the prefabricated substation 30 corresponding to the photovoltaic inverter 201 feeds the AC to a prefabricated substation 30 corresponding to an energy storage battery 60, where the electrical energy is stored.

[0059] Reference Figure 1 In the energy storage system, the energy storage battery 60 is used to store the unstable electrical energy from the photovoltaic module 10, and outputs stable electrical energy to the grid 50 through the energy storage converter 202 (Power Conversion System, PCS) and the corresponding box-type substation 30.

[0060] This application provides a power conversion device 20, which is used to convert alternating current (AC) and direct current (DC) into the other. In one example, refer to... Figure 1 The power conversion device 20 can be a photovoltaic inverter 201. In this example, the power conversion device 20 is used in a photovoltaic system and is used to convert the direct current from the photovoltaic module 10 into alternating current and output it to the grid 50 or other loads.

[0061] In another example, refer to Figure 1 The power conversion device 20 can be an energy storage converter 202. In this example, the power conversion device 20 is used in an energy storage system, and it is used to convert DC power from the energy storage battery 60 into AC power and output it to the grid 50 or other loads. In addition, the power conversion device 20 (energy storage converter 202) can also convert AC power from the grid 50 into DC power to charge the energy storage battery 60.

[0062] Figure 2 An exemplary external structure of a power conversion device 20 is shown. Figure 3 An example is shown Figure 2 The internal structure of the medium power conversion device 20 is shown in reference. Figure 2 and Figure 3 The power conversion device 20 includes a housing 1, a circuit board 2, and a power module 3. The housing 1 can be any suitable enclosure or equipment box, and this application does not impose any limitations on it. The housing 1 has internal space for housing devices and apparatus. The circuit board 2 can be a printed circuit board (PCB), and it is fixed within the internal space of the housing 1. The power module 3 is located inside the housing 1 and fixed to the circuit board 2. That is, both the circuit board 2 and the power module 3 are located inside the housing 1. The power module 3 is used to convert direct current (DC) from the photovoltaic module 10 or the energy storage battery 60 into alternating current (AC).

[0063] To dissipate heat from the power module 3, the power conversion device 20 may further include a heat sink 4, wherein... Figure 3 The diagram shows the structure of a heat sink 4. Figure 3 In the example shown, the heat sink 4 is an air-cooled heat sink. The heat sink 4 includes a heat-conducting plate 41 and multiple fins 42. The heat-conducting plate 41 is located inside the device housing 1 and is used to connect to the power module 3. The multiple fins 42 are fixed to the surface of the heat-conducting plate 41 facing away from the power module 3, and there is a gap between two adjacent fins 42. The device housing 1 is provided with a through-hole 11, through which the multiple fins 42 extend to the outside of the device housing 1.

[0064] In some other examples, the heat-conducting plate 41 and multiple fins 42 of the heat sink 4 are located outside the device housing 1. In this example, the power module 3 extends into the port 11 of the device housing 1 and is connected to the heat-conducting plate 41.

[0065] When the heat sink 4 is an air-cooled heat sink, the heat from the power module 3 can be transferred to the heat conduction plate 41, and then transferred to the fins 42 through the heat conduction plate 41. The heat on the fins 42 is then dissipated by heat exchange with the air, thereby cooling the power module 3. Furthermore, in some examples, refer to... Figure 2 and Figure 3 The power conversion device 20 may also include a heat sink 5, which is located outside the device housing 1 and fixed to the device housing 1. The heat sink 5 can cover multiple fins 42 of the heat sink 4. In order to facilitate heat dissipation, the heat sink 5 is also provided with multiple air vents 51, such as multiple air inlets and multiple air outlets.

[0066] In some other examples, a portion of the heat sink 4 is integrally formed with a portion of the device housing 1, for example, Figure 4 An exemplary diagram shows another structure of the heat sink 4, with reference to Figure 4 The heat-conducting plate 41 of the radiator 4 is integrally set with the equipment housing 1, and multiple fins 42 are located outside the equipment housing 1 and fixed on the heat-conducting plate 41.

[0067] In some other examples, radiator 4 can also be a liquid-cooled radiator. Figure 5 An exemplary embodiment shows the structure of another heat sink 4, with reference to Figure 4 In this example, the heat sink 4 is located inside the device housing 1 and fixed to the power module 3; that is, the heat sink 4 does not extend outside the device housing 1. A heat dissipation channel 43 is formed inside the heat sink 4, allowing coolant (e.g., water) to flow through it. When the heat sink 4 is a liquid-cooled heat sink, heat from the power module 3 can be transferred to the heat sink 4. As the coolant flows through the heat dissipation channel 43, it carries away the heat from the power module 3, achieving liquid cooling of the power module 3.

[0068] In this application, one or more power modules 3 can be provided, and each power module 3 is fixed to and electrically connected to the circuit board 2. When multiple power modules 3 are provided, one heat sink 4 can be connected to multiple power modules 3 simultaneously and dissipate heat for multiple power modules 3 at the same time. Alternatively, when multiple power modules 3 are provided, multiple heat sinks 4 can also be provided, with each heat sink 4 dissipating heat for a corresponding power module 3. This application does not impose specific limitations on the number of power modules 3 or the number of heat sinks 4.

[0069] Power module 3 can be any device capable of converting alternating current (AC) and direct current (DC) to the other. Figure 6 An exemplary topology diagram of a power conversion device 20 is shown, with reference to... Figure 6 The power conversion device 20 includes multiple DC-DC conversion circuits 203 and one DC-AC conversion circuit 204. The multiple DC-DC conversion circuits 203 are all boost circuits, and the DC-AC conversion circuit 204 is a three-phase inverter circuit. The power module 3 may contain a switching transistor, for example... Figure 5 The switching transistor within the dashed box a can be packaged within a power module 3 (the switching transistor within the dashed box a is only a part of the power module 3). Multiple switching transistors can also be packaged within the power module 3, for example... Figure 5 The multiple switching transistors within the dashed box b can be packaged within a power module 3, and this application does not impose specific restrictions on this.

[0070] Figure 7 An exemplary internal structure of a power module 3 is shown, with reference to... Figure 7The power module 3 includes a substrate 31, a die 32, and a package 33. The substrate 31 can be any plate structure capable of supporting the die 32; for example, the substrate 31 can be a direct-bonding ceramic substrate (DBC). In other examples, the substrate 31 can also be a copper plate, an aluminum plate, etc. The die 32 can be one of several types, such as an insulated-gate bipolar transistor (IGBT), a diode, a silicon carbide (SiC) transistor, a metal-oxide-semiconductor field-effect transistor (MOSFET), a gallium nitride (GaN) transistor, or a thyristor. The die 32 is fixed to the substrate 31. Figure 7 In the example shown, both substrate 31 and die 32 are located within package 33, which encapsulates substrate 31 and die 32. Furthermore, refer to... Figure 7 The power module 3 also includes multiple pins 34 extending out of the package housing 33.

[0071] Figure 8 An exemplary structure of a power module 3 in the related art is shown, with reference to Figure 8 Pin 34 is fixed on circuit board 2. After circuit board 2 and power module 3 are installed, there is a gap between package 33 and heat sink 4. Figure 8 (The gap between the two dashed lines). Since the power module 3's substrate 31 and die 32 are all housed within the package 33 (auxiliary reference). Figure 7 Therefore, the package shell 33 of the power module 3 is the part of the power module 3 that generates more heat. Even if thermally conductive adhesive or other thermally conductive structures are filled in the gap between the package shell 33 and the heat sink 4, the thermal resistance between the package shell 33 and the heat sink 4 will still be high, resulting in poor heat dissipation of the power module 3.

[0072] The power conversion device 20 provided in this application further includes a pressing member 6. Figure 9 An exemplary structure of a pressing member 6 is shown, wherein, Figure 9 The structure shown, including the pressure-bearing component 6, circuit board 2, power module 3, and heat sink 4, is disassembled to allow for independent observation of each structure. Figure 10 An example is shown Figure 9 The situation after combining multiple structures. (Refer to...) Figure 9 and Figure 10Pin 34 is fixed on circuit board 2, package shell 33 is located between circuit board 2 and heat sink 4, and pressing member 6 is fixed on heat sink 4. Circuit board 2 has opening 21. Part of pressing member 6 is located on the side of circuit board 2 away from heat sink 4, and the other part of pressing member 6 passes through opening 21 and abuts against the surface of package shell 33 facing circuit board 2. Pressure is applied to package shell 33 of power module 3 by pressing member 6. Under the pressure of pressing member 6, package shell 33 of power module 3 is connected to heat sink 4. For example, package shell 33 of power module 3 is brought into contact with heat sink 4, or package shell 33 of power module 3 is pressed tightly onto heat sink 4.

[0073] The pressing member 6 can be any suitable structure, for example, in Figure 9 In the example shown, the pressing member 6 includes a connecting rod 61 and a pressing block 62. The extending direction of the connecting rod 61 is parallel to the surface of the circuit board 2 (with an allowable error within ±10°). The pressing block 62 is fixed to the connecting rod 61 and is located on the side of the connecting rod 61 facing the power module 3. In the length direction of the connecting rod 61, the length of the connecting rod 61 is greater than the length of the pressing block 62. (Refer to...) Figure 9 and Figure 10 After the pressure member 6 is installed, the connecting rod 61 is located on the side of the circuit board 2 away from the heat sink 4, a part of the pressure block 62 is located on the side of the circuit board 2 away from the heat sink 4, and the other part of the pressure block 62 passes through the opening 21 and abuts against the package shell 33. The surface of the package shell 33 that is pressed by the pressure block 62 is the surface of the package shell 33 facing the circuit board 2.

[0074] Applying pressure to the power module 3 by the pressing member 6 reduces the gap between the package shell 33 and the heat sink 4, thereby reducing the thermal resistance between them. This facilitates heat transfer from the package shell 33 to the heat sink 4, resulting in better heat dissipation of the power module 3 and improved long-term reliability of the power conversion device 20. It should be noted that, under the design concept of this application, if thermally conductive adhesive is further filled between the package shell 33 and the heat sink 4 after the power module 3 has been pressed firmly onto the heat sink 4, this also falls under the category of the connection between the package shell 33 and the heat sink 4 described in this application.

[0075] There are several ways to fix the pressure member 6 to the heat sink 4, for example, refer to Figure 9 and Figure 10 The power conversion device 20 also includes a fastening structure 7, through which the pressing member 6 is fixed to the heat sink 4. The fastening structure 7 includes a threaded rod 71 and a limiting block 72. The limiting block 72 is fixed to the threaded rod 71 and protrudes outward from the threaded rod 71. For example, the diameter of the limiting block 72 is larger than the diameter of the threaded rod 71; or, for another example, the radial length of the limiting block 72 in the threaded rod 71 is greater than the diameter of the threaded rod 71. Figure 9and Figure 10 In the example shown, the fastening structure 7 is a bolt, and the threaded rod 71 and the limiting block 72 form at least part of the bolt. In some other instances, the threaded rod 71 and the limiting block 72 may also form other fastening structures 7 (e.g., screws, etc.).

[0076] Reference Figure 9 The pressing member 6 has a first through hole 63. For example, in an example where the pressing member 6 includes a connecting rod 61 and a pressure block 62, the first through hole 63 is provided on the connecting rod 61. Furthermore, the circuit board 2 has a second through hole 22, which is located on one side of the opening 21. The heat sink 4 is provided with a connecting hole 44 (with internal threads). The threaded rod 71 passes through the first through hole 63 and the second through hole 22 and is threadedly connected to the connecting hole 44 of the heat sink 4. And, referring to… Figure 10 , Figure 10 The diagram shows the situation after the threaded rod 71 and the limiting block 72 are installed. The pressing member 6 is clamped between the limiting block 72 and the circuit board 2. That is, the limiting block 72 presses the pressing member 6 onto the circuit board 2.

[0077] When the pressure-retaining component 6 needs to be installed, the threaded rod 71 is passed through the first through hole 63 and the second through hole 22, and the threaded rod 71 is screwed onto the connecting hole 44 of the radiator 4. Through the threaded connection between the threaded rod 71 and the radiator 4, the limiting block 72 presses against the pressure-retaining component 6, and the pressure-retaining component 6 presses the encapsulation shell 33 onto the radiator 4, reducing the gap between the encapsulation shell 33 and the radiator 4. When the pressure-retaining component 6 needs to be removed, the threaded rod 71 is loosened in the opposite direction, and the threaded rod 71 and the limiting block 72 are removed from the pressure-retaining component 6. Without the restriction of the limiting block 72, the pressure-retaining component 6 can be removed at will.

[0078] In addition, the threaded rod 71 has a self-locking function. The threaded rod 71 can not only reliably connect the pressing part 6 and the heat sink 4, but also adjust the contact tightness between the package shell 33 and the heat sink 4 by rotating the threaded rod 71, so that the position of the power module 3 is more suitable for the heat sink 4.

[0079] The number of fastening structures 7 can be set as needed, for example, referring to... Figure 10 In one example, two threaded rods 71 ​​and two limiting blocks 72 are provided, with each threaded rod 71 fixedly connected to one limiting block 72. Furthermore, to accommodate the threaded rods 71, two first through holes 63, two second through holes 22, and two connecting holes 44 are also provided. In other examples, one threaded rod 71 and one limiting block 72 are provided, and to accommodate the threaded rods 71, one first through hole 63, one second through hole 22, and one connecting hole 44 are also provided.

[0080] exist Figure 10In the example shown, after the retaining member 6 is installed, it presses the package 33 onto the heat sink 4, and there is no gap between the portion of the retaining member 6 on the circuit board 2 facing away from the heat sink 4 and the circuit. For example, the pressing block 62 of the retaining member 6 presses the package 33 onto the heat sink 4, and there is no gap between the connecting rod 61 of the retaining member 6 and the circuit board 2. In some other examples, after the retaining member 6 is installed, there is a gap between the surface of the retaining member 6 closest to the circuit board 2 and the circuit board 2 in the thickness direction, for example, Figure 11 An exemplary diagram shows another structure of the pressing member 6, with reference to Figure 11 The pressing member 6 has pressed the package 33 onto the heat sink 4, and there is still a gap between the pressing member 6 and the circuit board 2. Figure 11 The gap between the two dotted lines is the reserved spare gap. With the spare gap, the user or staff can further tighten the threaded rod 71 as needed (for example, further tighten the threaded rod 71 for individual power modules 3) to make the contact between the package shell 33 and the heat sink 4 tighter and reduce the possibility of the package shell 33 and the heat sink 4 separating.

[0081] During the process of applying pressure to the pressing member 6 by rotating the threaded rod 71 and using the limiting block 72, since the pins 34 of the power module 3 are fixed to the circuit board 2, when the pressing member 6 applies pressure to the package shell 33, the package shell 33 will exert a pulling force on the pins 34, causing the pins 34 to also exert a pulling force on the circuit board 2 (the pins 34 pull the circuit board 2 towards the heat sink 4). In one example provided in this application, the circuit board 2 can be supported by setting a support structure. For example, the power conversion device 20 also includes a support platform 8. Figure 12 An exemplary structure of a support platform 8 is shown, which is fixed to the surface of the heat sink 4 facing the power module 3. Figure 13 An exemplary illustration shows the positional relationship between the support platform 8 and the circuit board 2, with reference to... Figure 13 The support platform 8 is fixed on the surface of the heat sink 4 facing the circuit board 2, and the support platform 8 is used to support the circuit board 2.

[0082] Reference Figure 13 During the tightening of the threaded rod 71, as the threaded rod 71 is further tightened, the pulling force of the pin 34 on the circuit board 2 also increases continuously. The support platform 8 can support the circuit board 2, reducing the possibility of excessive deformation of the circuit board 2 under the pulling force of the pin 34 and reducing the risk of damage to the circuit board 2. In other words, the circuit board 2 is protected by setting the support platform 8 on the heat sink 4.

[0083] In some examples, the support platform 8 can both support and protect the circuit board 2, and can also be threadedly connected to the threaded rod 71, thus enriching the function of the support platform 8. For example, refer to Figure 12 The support platform 8 has a threaded hole 81, and the threaded rod 71 passes through the first through hole 63 and the second through hole 22 and is threadedly connected to the threaded hole 81 (the structure of the first through hole 63 and the second through hole 22 can be referred to for further information). Figure 9 (Referring to) Figure 13 In the example where the radiator 4 is also provided with a connection hole 44, the connection hole 44 is connected to the threaded hole 81 in the support platform 8. The support platform 8 is equivalent to extending the connection hole 44 on the radiator 4, making the connection between the threaded rod 71 and the radiator 4 more stable.

[0084] In another example, since the support platform 8 already has a threaded hole 81, there is no need to open a connection hole 44 on the heat sink 4, which reduces the processing steps and facilitates the production and manufacturing of the heat sink 4.

[0085] In other examples, a pressure member 6 can press the package shells 33 of multiple power modules 3 onto the heat sink 4, for example, Figure 14 An exemplary embodiment shows the structure of another type of pressing member 6, with reference to Figure 14 Multiple power modules 3 are fixed on the circuit board 2. The pressing component 6 includes a connecting rod 61 and multiple pressing blocks 62, each pressing block 62 passing through the circuit board 2 and pressing against the corresponding package shell 33. Figure 14 In the example shown, multiple fastening structures 7 are provided, that is, multiple threaded rods 71 ​​and multiple limiting blocks 72 are provided. Each threaded rod 71 is fixedly connected to one limiting block 72. In addition, multiple first through holes 63 and multiple second through holes 22 are provided to adapt to the threaded rods 71 ​​(the structures such as threaded rods 71, limiting blocks 72, first through holes 63, and second through holes 22 can be used as auxiliary references). Figure 9 Each power module 3 has a fastening structure 7 on each side, and the fastening structure 7 between two adjacent power modules 3 is shared by the power modules 3 on both sides.

[0086] In other examples, the fastening structure 7 can be a rivet, a clip, or a welded material, etc.

[0087] In some other examples, the pressure member 6 can also be fixed to the circuit board 2, for example, Figure 15 An exemplary embodiment shows the structure of another type of pressing member 6, with reference to Figure 15The pressing member 6 includes a support post 64, a connecting rod 61, and a pressing block 62. The support post 64 is fixedly connected to the circuit board 2 (e.g., bonded). One end of the connecting rod 61 is fixed to the support post 64, and the other end of the connecting rod 61 is fixed to the pressing block 62. There is a gap between the connecting rod 61 and the circuit board 2. Both the connecting rod 61 and the support post 64 are located on the side of the circuit board 2 away from the heat sink 4. A portion of the pressing block 62 is located on the side of the circuit board 2 away from the heat sink 4, and another portion of the pressing block 62 extends through the circuit board 2 to the side of the circuit board 2 facing the package shell 33. The pressing block 62 is used to abut against the package shell 33.

[0088] exist Figure 15 In the example shown, the power conversion device 20 may also include an adjusting bolt 65, which passes through the connecting rod 61 and is threadedly connected to the circuit board 2. By tightening the adjusting bolt 65, the pressure block 62 can be moved toward the heat sink 4, thereby pressing the package shell 33 onto the heat sink 4. In some other examples, the pressing member 6 is fixedly connected to the circuit board 2 by the adjusting bolt 65, and the support column 64 is no longer fixedly connected to the circuit board 2.

[0089] In some other examples, the retaining member 6 is elastic. The portion of the retaining member 6 located on the side of the circuit board 2 away from the heat sink 4 is fixedly connected to the circuit board 2. Under the elastic action of the retaining member 6, the other portion of the retaining member 6 passes through the opening 21 and abuts against the package shell 33. That is, in this example, the retaining member 6 applies pressure to the package shell 33 through its own elastic force.

[0090] Furthermore, pin 34 can be any suitable structure; in one example, Figure 16 An exemplary structure of pin 34 is shown. Figure 17 for Figure 16 An enlarged view at point A in the middle, refer to Figure 17 At least one pin 34 includes a first segment 341, a second segment 342, and a third segment 343 connected in sequence. For example, one end of the second segment 342 is integrally connected to the first segment 341, and the other end of the second segment 342 is integrally connected to the third segment 343. Figure 17The two dashed lines in the diagram exemplarily divide the first segment 341, the second segment 342, and the third segment 343 described above. The package 33 has a bottom surface 331 facing the circuit board 2 and a peripheral surface 332 surrounding the bottom surface 331. The first segment 341 extends from the peripheral surface 332 of the package 33 to the outside of the package 33. The second segment 342 bends from the first segment 341 toward the circuit board 2. The third segment 343 extends toward the circuit board 2 and is fixed to the circuit board 2; for example, the third segment 343 passes through the circuit board 2 and is soldered onto the circuit board 2. That is, after the first segment 341 of the pin 34 extends from the peripheral surface 332 of the package 33, it is bent at the second segment 342 and then fixed to the circuit board 2 via the third segment 343.

[0091] Reference Figure 16 and Figure 17 When the pressure member 6 applies pressure to the package housing 33, the package housing 33 will move towards the heat sink 4. During this process, the pin 34 will be subjected to a pulling force towards the heat sink 4, causing the pin 34 to deform. In some examples, the structure of the pin 34 can be modified to allow for a greater deformation, which helps the package housing 33 to move towards the heat sink 4.

[0092] For example, refer to Figure 17 A portion of the first segment 341 is inclined toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction) (B1 portion is the inclined portion of the first segment 341), that is, the first segment 341 is bent. After the pressure member 6 applies pressure to the package housing 33 toward the heat sink 4, the first segment 341 will deform as the package housing 33 moves. For example, the first segment 341 will deform toward a straightening tendency. Because the first segment 341 is bent, the first segment 341 has a larger deformation space (a larger allowable deformation), which is beneficial for the package housing 33 to move toward the heat sink 4.

[0093] Can Figure 17 The example shown is compared with pin 34 in related technologies, wherein, Figure 18 An exemplary structure of pin 34 in the related art is shown. Figure 18 The two dashed lines in the diagram exemplarily divide the first segment 341, the second segment 342, and the third segment 343. Figure 17 The example shown is the same as Figure 18 By comparing the examples shown, it can be seen more intuitively that... Figure 17 In the example shown, pin 34 has a larger deformation range, and the deformation of pin 34 can reduce the possibility of pin 34 separating from circuit board 2 as the package 33 moves toward heat sink 4.

[0094] The portion of the first segment 341 that is inclined toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2 (part B1) can be located at any position of the first segment 341. Figure 17 In the example shown, the first segment 341 includes a first part 3411 and a second part 3412 (e.g., the first part 3411 and the second part 3412 are integrally connected and bent into shape). The first part 3411 extends from the peripheral surface 332 of the package 33 to the outside of the package 33. The second part 3412 connects the first part 3411 and the second segment 342. In the direction away from the peripheral surface 332, the second part 3412 is inclined from the first part 3411 toward the heat sink 4 (or, the second part 3412 is inclined from the second segment 342 toward the circuit board 2). The second part 3412 of the first segment 341 can be understood as the inclined part (B1 part) of the first segment 341. Connecting the second part 3412 with the second segment 342 (the second segment 342 is the part of the pin 34 that is bent toward the circuit board 2) concentrates the area on the pin 34 that needs to be bent, which is convenient for the production of the pin 34. For example, from the perspective of packaging technology, this design method only requires minor modifications to the original forming process of pin 34 to achieve the production of pin 34 of this application.

[0095] In some other examples, a portion of the first segment 341 may be semi-circular, "V"-shaped, wavy, or zigzag-shaped, as long as a portion of the first segment 341 is inclined toward the package 33 in the direction from the heat sink 4 to the circuit board 2.

[0096] For example, Figure 19 An exemplary embodiment shows another structure for pin 34, wherein, Figure 19 The two dashed lines in the diagram exemplarily divide the first segment 341, the second segment 342, and the third segment 343. (Refer to...) Figure 19 A portion of the third segment 343 is inclined toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction) (B2 is the inclined portion of the third segment 343), that is, the third segment 343 is bent. After the pressing member 6 applies pressure to the package housing 33 toward the heat sink 4, the third segment 343 will deform as the package housing 33 moves. For example, the third segment 343 will deform toward a straightening tendency. Because the third segment 343 is bent, the third segment 343 has a larger deformation space, which is beneficial for the package housing 33 to move toward the heat sink 4.

[0097] Will Figure 19 The example shown is the same as Figure 18 By comparing the examples shown, it can be seen more intuitively that... Figure 19In the example shown, pin 34 has a larger deformation range, and the deformation of pin 34 can reduce the possibility of pin 34 separating from circuit board 2 as the package 33 moves toward heat sink 4.

[0098] The portion of the third segment 343 that is inclined towards the package housing 33 in the direction from the heat sink 4 to the circuit board 2 (part B2) can be located at any position of the third segment 343. Figure 19 In the example shown, the third segment 343 includes a third part 3431 and a fourth part 3432 (e.g., the third part 3431 and the fourth part 3432 are integrally connected and bent into shape). The third part 3431 is fixed to the circuit board 2, and the fourth part 3432 is connected between the third part 3431 and the second segment 342. In the direction from the circuit board 2 to the heat sink 4, the fourth part 3432 is inclined from the third part 3431 toward the side away from the package housing 33 (or, the fourth part 3432 is inclined from the second segment 342 toward the package housing 33). In this example, the fourth part 3432 is the inclined portion (B2 portion) of the third segment 343. Connecting the fourth part 3432 to the second segment 342 (the second segment 342 is the portion of the pin 34 bent toward the circuit board 2) concentrates the area where the pin 34 needs to be bent, facilitating the production of the pin 34. For example, from the perspective of packaging technology, this design method only requires minor modifications to the original forming process of pin 34 to achieve the production of pin 34 of this application.

[0099] In other examples, a portion of the third segment 343 may be semi-circular, "V"-shaped, wavy, or zigzag-shaped, as long as a portion of the third segment 343 is inclined toward the package 33 in the direction from the heat sink 4 to the circuit board 2. For example, Figure 20 An exemplary embodiment shows another structure of pin 34, wherein, Figure 20 The two dashed lines in the diagram exemplify the division of the first segment 341, the second segment 342, and the third segment 343. (Refer to...) Figure 20 The third segment 343 is partly zigzag-shaped, wherein the third segment 343 includes a portion (B2 portion) that is inclined toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction).

[0100] In some examples, a portion of the first segment 341 can be tilted toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2, and a portion of the third segment 343 can be tilted toward the package housing 33 in the direction from the heat sink 4 to the circuit board 2, for example, Figure 21 An exemplary embodiment shows another structure of pin 34, wherein, Figure 21 The two dashed lines in the diagram exemplarily divide the first segment 341, the second segment 342, and the third segment 343. (Refer to...) Figure 21The first segment 341 includes a first part 3411 and a second part 3412. The first part 3411 extends from the peripheral surface 332 of the package shell 33 to the outside of the package shell 33. The second part 3412 is connected between the first part 3411 and the second segment 342, and the second part 3412 is inclined from the first part 3411 toward the heat sink 4. The third segment 343 includes a third part 3431 and a fourth part 3432. The third part 3431 is fixed to the circuit board 2. The fourth part 3432 is connected between the third part 3431 and the second segment 342, and the fourth part 3432 is inclined from the third part 3431 toward the side away from the package shell 33.

[0101] exist Figure 21 In the example shown, the second part 3412 of the first segment 341, the second segment 342 of the pin 34, and the fourth part 3432 of the third segment 343 are positioned together, so that the area of ​​the pin 34 that needs to be bent is concentrated together, which facilitates the production of the pin 34.

[0102] In addition, in some other examples, pin 34 can also be a "Z" pin, for example, Figure 22 An exemplary embodiment shows another structure of pin 34, wherein, Figure 22 The two dashed lines in the diagram exemplarily divide the first segment 341, the second segment 342, and the third segment 343. (Refer to...) Figure 22 In addition to the first segment 341, the second segment 342, and the third segment 343, pin 34 also includes a sixth segment 346. The third segment 343 and the sixth segment 346 are integrally formed (e.g., the entire pin 34 is bent into shape), the sixth segment 346 is soldered to the circuit board 2, and the third segment 343 is fixed to the circuit board 2 via the sixth segment 346. Figure 22 In the example shown, a portion of the first segment 341 is inclined toward the package 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction), for example, the second portion 3412 is inclined toward the heat sink 4 from the first portion 3411, and a portion of the third segment 343 is inclined toward the package 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction), for example, the fourth portion 3432 is inclined toward the package 33 from the second segment 342.

[0103] In other examples of "Z"-shaped pins 34, only a portion of the first segment 341 may be tilted toward the package 33 in the direction from the heat sink 4 to the circuit board 2, while the third segment 343 is not deliberately bent; or only a portion of the third segment 343 may be tilted toward the package 33 in the direction from the heat sink 4 to the circuit board 2 (C1 direction), while the first segment 341 is not deliberately bent.

[0104] In some examples, the pressure exerted by the retaining member 6 on the package housing 33 is relatively large, resulting in a large pulling force on the pin 34 by the package housing 33. This may cause significant deformation of the pin 34. For example, Figure 23 An exemplary embodiment shows another structure of pin 34, see reference. Figure 23 In the case where pin 34 includes a fourth segment 344 and a fifth segment 345 connected, the fourth segment 344 extends from the peripheral surface 332 of the package housing 33 to the outside of the package housing 33, and at least a portion of the fourth segment 344 is inclined toward the side away from the package housing 33 in the direction from the heat sink 4 to the circuit board 2, and the fifth segment 345 extends toward the circuit board 2 and is fixed to the circuit board 2 (for example, the third segment 343 passes through the circuit board 2 and is soldered to the circuit board 2).

[0105] The fourth segment 344 can be tilted as a whole; for example, the fourth segment 344 can be tilted entirely from the package shell 33 towards the circuit board 2. Alternatively, only a portion of the fourth segment 344 can be tilted; for example, in... Figure 23 In the example shown, the fourth segment 344 includes a connected fifth part 3441 and a sixth part 3442, wherein the fifth part 3441 and the sixth part 3442 can be integrally connected. The extension direction of the fifth part 3441 is parallel to the surface of the circuit board 2, and the sixth part 3442 is inclined away from the package shell 33 in the direction from the heat sink 4 to the circuit board 2 (or, the sixth part 3442 is inclined from the fifth part 3441 toward the circuit board 2). That is, after the package shell 33 moves toward the heat sink 4 to a certain extent, under the tension of the package shell 33, the pin 34 is at least partially inclined toward the circuit board 2 due to deformation. Under the deformation of the pin 34, the package shell 33 can fit tightly against the heat sink 4, reducing the gap between the package shell 33 and the heat sink 4, which is beneficial to the heat dissipation of the power module 3.

[0106] Figure 23 The structure of one pin 34 of power module 3 is shown. It can be understood that power module 3 can use each pin 34. Figure 23 The structure shown indicates that the power module 3 can also employ only one or more pins 34. Figure 23 The structure shown.

[0107] Furthermore, in some cases, if the heat sink 4 is close to the circuit board 2, the heat sink 4 will apply reverse pressure to the package shell 33, causing the package shell 33 to move towards the circuit board 2. Under the pressure of the package shell 33, the pin 34 will also deform and apply pressure towards the circuit board 2, potentially causing the connection between the pin 34 and the circuit board 2 to fail. Therefore, in some examples, the structure of the pin 34 can be further modified to give the pin 34 a bidirectional deformable space, for example, Figure 24 An exemplary embodiment shows another structure of pin 34, see reference. Figure 24The power module 3 also includes a protrusion 9, which is fixed to the pin 34 (e.g., the protrusion 9 is soldered to the pin 34, or the protrusion 9 is integrally formed with the pin 34). The power module 3 includes multiple pins 34, and the protrusion 9 may be fixed on only one pin 34 or multiple pins 34 (multiple protrusions 9 may be provided). Furthermore, this application does not limit which pin or pins 34 the protrusion 9 is specifically fixed to; that is, the specific position and number of protrusions 9 can be flexibly adjusted according to the actual scenario.

[0108] Figure 25 An exemplary structure of protrusion 9 is shown, intended to illustrate the mating relationship between protrusion 9 and circuit board 2. (Refer to...) Figure 25 The protrusion 9 is located on the side of the circuit board 2 facing the heat sink 4, and the protrusion 9 contacts the circuit board 2. The protrusion 9 can support the pin 34, so that the pin 34 has a bidirectional deformable space, further increasing the tolerance range that the pin 34 can absorb, reducing the possibility of the pin 34 separating from the circuit board 2 during the process of being pressed down by the package shell 33, and making the connection between the pin 34 and the circuit board 2 more stable.

[0109] 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, characterized by, The power conversion device comprises: a device shell; a heat sink, which is at least partially located outside the device shell, or is located inside the device shell; a circuit board, which is located inside the device shell; a power module, which is located inside the device shell, is used to convert direct current from a photovoltaic assembly or an energy storage battery into alternating current, comprises a packaging shell and a pin extending out of the packaging shell, is located between the circuit board and the heat sink, is connected with the heat sink, and is fixed to the circuit board; a pressing piece, which is fixed to the circuit board or the heat sink, has an opening, and has one part located on a side of the circuit board away from the heat sink and another part passing through the opening and abutting against a surface of the packaging shell facing the circuit board.

2. The power conversion device of claim 1, wherein, The power conversion device further comprises a threaded rod and a limiting block, the limiting block is fixed to an end of the threaded rod and protrudes outward along a radial direction of the threaded rod; the pressing piece has a first through hole, the circuit board has a second through hole, the threaded rod passes through the first through hole and the second through hole and is screwed with the heat sink, and the pressing piece is clamped between the limiting block and the circuit board.

3. The power conversion device of claim 2, wherein, The power conversion device further comprises a support table, which is fixed to a surface of the heat sink facing the circuit board and is used to support the circuit board.

4. The power conversion device of claim 3, wherein, The support table has a threaded hole, which is screwed with the threaded rod.

5. The power conversion device according to any one of claims 1 to 4, characterized by, The pressing piece comprises a connecting rod and a pressing block, the connecting rod is located on a side of the circuit board away from the heat sink, a length direction of the connecting rod is parallel to a surface of the circuit board, the pressing block is fixed to a surface of the connecting rod facing the circuit board, one part of the pressing block is located on a side of the circuit board away from the heat sink, and another part of the pressing block passes through the opening and abuts against a surface of the packaging shell facing the circuit board; in the length direction of the connecting rod, a length of the connecting rod is greater than a length of the pressing block.

6. The power conversion device according to any one of claims 1 to 4, characterized by, The packaging shell has a bottom surface facing the circuit board and a circumferential surface surrounding the bottom surface; the pin comprises a first segment, a second segment and a third segment connected in sequence, the first segment extends out of the packaging shell from the circumferential surface of the packaging shell, the second segment is bent from the first segment toward the circuit board, and the third segment extends toward the circuit board and is fixed to the circuit board; a part of the first segment or a part of the third segment is inclined toward the packaging shell in a direction from the heat sink to the circuit board.

7. The power conversion device of claim 6, wherein, The first segment comprises a first part and a second part, the first part extends out of the packaging shell from the circumferential surface of the packaging shell, the second part is connected between the first part and the second segment, and the second part is inclined from the second segment toward the circuit board.

8. The power conversion device of claim 6, wherein, The third section includes a third part and a fourth part, the third part is fixed to the circuit board, the fourth part is connected between the third part and the second section, and the fourth part is inclined from the second section toward the package shell.

9. The power conversion device according to any one of claims 1 to 4, characterized by, The package shell has a bottom surface facing the circuit board and a peripheral surface surrounding the bottom surface; The pin includes a connected fourth section and a fifth section, the fourth section extends out of the package shell from the peripheral surface of the package shell, at least part of the fourth section is inclined toward a side away from the package shell in a direction from the heat sink to the circuit board, and the fifth section extends toward the circuit board and is fixed to the circuit board.

10. The power conversion device of any one of claims 1-4, wherein, The power module further includes a protrusion, the protrusion is fixed to the pin, the protrusion is located on a side of the circuit board facing the heat sink, and the protrusion is in contact with the circuit board.

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