Power device and power conversion apparatus

Abstract

The embodiment of the invention provides a power device and a power conversion device comprising the same, and relates to the technical field of power conversion. The power conversion device comprises a circuit board, a radiator, a power device and a supporting piece, wherein one board surface of the circuit board faces the radiator; the power device comprises a packaging shell and pins, the packaging shell is located between the circuit board and the radiator, the packaging shell comprises a bottom surface facing the circuit board, a top surface facing the radiator and a peripheral surface located between the bottom surface and the top surface, and the pins extend out of the peripheral surface and are inserted into the circuit board; the supporting piece is used for supporting the packaging shell to enable at least part of the top surface to be in contact with the radiator; wherein the pin comprises a plurality of bends, the pin further comprises a plurality of pin sections separated by the bends, and orthographic projections of at least two pin sections on the circuit board are overlapped. According to the technical scheme, by changing the pin structure, the packaging shell of the power device can be attached to the radiator more tightly, and heat dissipation of the power device is facilitated.

Description

TECHNICAL FIELD

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

[0002] The power device in the power conversion device is usually plugged on the circuit board through its pin, wherein the power device is a high-heat device, and the power device generates a lot of heat during the operation of the power conversion device. Therefore, the power device needs to be lifted up by the support so that the power device can be attached to the heat sink for heat dissipation.

[0003] However, due to the tolerance accumulation of the power device, the circuit board, the support and the heat sink, the power device cannot be completely attached to the heat sink. For example, under the action of the support, the corners of the package shell of the power device are on the heat sink, and most of the surface of the package shell facing the heat sink cannot be attached to the heat sink. This makes the heat dissipation effect of the power device poor, resulting in damage to the power conversion device and other problems. SUMMARY

[0004] The present application provides a power device and a power conversion device comprising the power device. By changing the structure of the pin, the package shell of the power device can be more closely attached to the heat sink, which is beneficial to the heat dissipation of the power device.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a power conversion device, comprising a circuit board, a heat sink, a power device and a support: one surface of the circuit board faces the heat sink; the power device comprises a package shell and a pin, the package shell is located between the circuit board and the heat sink, the package shell comprises a bottom surface facing the circuit board, a top surface facing the heat sink, and a peripheral surface between the bottom surface and the top surface, the pin extends from the peripheral surface and is plugged into the circuit board; the support contacts the circuit board and the bottom surface, and the support is used to support the package shell so that at least part of the top surface contacts the heat sink; wherein the pin comprises a plurality of bends, and the pin further comprises a plurality of pin segments separated by the plurality of bends, and the normal projections of at least two pin segments in the plurality of pin segments on the circuit board have an overlap.

[0007] The power conversion device can perform power conversion on the input current and output the power conversion result. The power device is one of the core devices of the power conversion device. The pins of the power device are inserted into the circuit board to connect the power device and the circuit board. Since the die (or wafer) of the power device is packaged in the package shell, the package shell of the power device generates more heat. In order to dissipate the heat of the package shell, the package shell is lifted by the support to contact the heat sink. The top surface of the package shell is in full or partial contact with the heat sink, and the heat on the package shell is transferred to the heat sink for heat dissipation.

[0008] Due to the tolerance accumulation of the power device, the circuit board, the support, the heat sink and the like, after the support applies an external force to the package shell, the edge of the top surface close to the pin will first abut against the heat sink. The package shell needs to continuously move towards the heat sink to make more areas of the top surface contact the heat sink. During the movement of the package shell under stress, the package shell will apply a pressure to the pin towards the circuit board. If the pin has high rigidity, the pin is not easy to deform, and thus cannot absorb the external force, and the package shell cannot move towards the heat sink. If only the force applied by the support to the power device is increased, the package shell will be stressed seriously, and long-term extrusion will also damage the power device.

[0009] Therefore, the pins of the power device are bent multiple times, and the normal projections of at least two pin segments of the pin on the circuit board have overlaps in the thickness direction of the circuit board. The pin of the application has better elasticity than the pin bent once, reduces the rigidity of the pin, and enables the pin to absorb part of the external force and deform to a greater extent (compared with the pin bent once). After the support applies an external force to the package shell, more areas of the top surface of the package shell can be in contact with the heat sink, which is conducive to the heat dissipation of the power device.

[0010] In an optional embodiment, the plurality of pin segments include a first pin segment, a second pin segment and a third pin segment. The first pin segment is in a strip shape and extends from the peripheral surface towards the outside of the peripheral surface. The third pin segment is in a strip shape and extends in the thickness direction of the circuit board. The third pin segment is inserted into the circuit board. The normal projections of the first pin segment and the second pin segment on the circuit board have overlaps, or the second pin segment includes at least one bend. The normal projections of a plurality of portions in the second pin segment on the circuit board have overlaps.

[0011] The extending direction of the first pin segment is different from the extending direction of the third pin segment, and the second pin segment is located between the first pin segment and the third pin segment, thus, the part between the first pin segment and the second pin segment needs to be bent, and the part between the second pin segment and the third pin segment also needs to be bent. Through the multiple bends on the pin, the orthogonal projection of the first pin segment and the second pin segment on the circuit board has overlap, or the orthogonal projection of multiple parts in the second pin segment on the circuit board has overlap, the rigidity of the pin is reduced, and the pin can absorb part of the external force and deform.

[0012] In an optional embodiment, in the first direction, the distance between the bend between the second pin segment and the third pin segment and the package shell is smaller than the distance between the bend between the first pin segment and the second pin segment and the package shell; wherein the first direction is parallel to the arrangement direction of the pin and the package shell, and is perpendicular to the thickness direction of the circuit board.

[0013] Among the two bends, the bend between the third pin segment and the second pin segment is closer to the package shell, which makes the third pin segment closer to the package shell. The third pin segment is used to plug the circuit board, and if the third pin segment is closer to the package shell, the resistance arm will be shorter, which is beneficial to the support to lift the package shell, so that the top surface of the package shell is more closely attached to the heat sink, further improving the heat dissipation effect of the power device.

[0014] In an optional embodiment, the second pin segment is in a strip shape, and in the first direction, the distance between the end of the second pin segment facing the circuit board and the package shell is smaller than the distance between the end of the second pin segment away from the circuit board and the package shell.

[0015] The strip-shaped second pin segment is inclined towards the package shell, so that the second pin segment and the first pin segment form an acute angle, and the orthogonal projection of the second pin segment and the first pin segment on the circuit board has overlap. The pin with such structure reduces the rigidity of the pin, so that the pin can absorb part of the external force. After the support applies external force to the package shell, the package shell will apply pressure to the pin towards the circuit board. After the pin absorbs part of the external force, the pin deforms to a large extent, which can improve the attachment of the package shell to the heat sink. In addition, the second pin segment inclined towards the package shell can also make the end of the second pin segment away from the first pin segment closer to the package shell. The end of the second pin segment away from the first pin segment is connected to the third pin segment through one of the bends, so that the third pin segment is closer to the package shell, which makes the resistance arm shorter, which is beneficial to the support to lift the package shell, so that the top surface of the package shell is more closely attached to the heat sink. In addition, the multiple bends of the pin can be realized by some commonly used bending tools, which is convenient for processing the pin and has low processing cost.

[0016] In an alternative embodiment, the second pin section comprises at least one bend when the first pin section and the second pin section have an overlap in the orthographic projection on the circuit board.

[0017] The second pin section is also a bent structure, so that there are more bends on the whole pin, and the rigidity of the pin is reduced. When the support applies an external force to the package shell, the package shell will apply a pressure to the pin towards the circuit board. The pin with lower rigidity will deform to a larger extent after absorbing part of the external force, so that the top surface of the package shell is more closely attached to the heat sink.

[0018] In an alternative embodiment, the second pin section further comprises a plurality of sub-sections separated by the at least one bend. Each of the sub-sections is in a strip shape, and the plurality of sub-sections are arranged along the thickness direction of the circuit board. The bend connecting any two adjacent sub-sections is bent from the sub-section closest to the first pin section among the two connected sub-sections towards the package shell.

[0019] There are more bends on the whole pin, and each of the bends on the second pin section is bent towards the side where the package shell is located. Therefore, the overlap area of the orthographic projection of the pin on the circuit board is larger, so that the rigidity of the pin is reduced and the pin can deform to a larger extent under stress.

[0020] In an alternative embodiment, the plurality of sub-sections comprises a first sub-section and a second sub-section arranged in sequence from the package shell to the circuit board. The first sub-section extends along the thickness direction of the circuit board. In the first direction, the distance between the end of the second sub-section towards the circuit board and the package shell is smaller than the distance between the end of the second sub-section away from the circuit board and the package shell.

[0021] The orthographic projection of the first pin section and the second sub-section on the circuit board has an overlap, that is, the orthographic projection of the first pin section and the second pin section on the circuit board has an overlap. Therefore, the rigidity of the pin is reduced and the pin can deform to a larger extent under stress. Moreover, the second sub-section is arranged obliquely, so that the distance between the second sub-section and the first pin section is increased, and the deformation degree (compression degree) of the pin is also increased. In addition, the third pin section is also arranged close to the package shell, so that the resistance arm is reduced, which is beneficial to the support to lift the package shell, and the top surface of the package shell is more closely attached to the heat sink.

[0022] In addition, the pin has three bends in total, and the number of bends is appropriate. Therefore, the structure of the pin after processing is closer to the expectation during design, and the processing of the pin is also facilitated.

[0023] In an alternative embodiment, the plurality of sub-sections include a first sub-section, a second sub-section and a third sub-section arranged in sequence along a direction from the package shell to the circuit board; in the first direction, a distance between an end of the first sub-section facing the circuit board and the package shell is greater than a distance between an end of the first sub-section away from the circuit board and the package shell, a distance between an end of the second sub-section facing the circuit board and the package shell is less than a distance between an end of the second sub-section away from the circuit board and the package shell; and an extending direction of the third sub-section is parallel to an extending direction of the first pin section.

[0024] By bending the second pin section of the pin multiple times, the elasticity of the pin is better, and the rigidity of the pin is further reduced, so that the pin can better absorb external force.

[0025] In an alternative embodiment, the second pin section is arc-shaped and protrudes in a direction away from the package shell.

[0026] The arc-shaped second pin section causes the multiple parts in the second pin section to have overlapping orthographic projections on the circuit board, and the second pin section can also have overlapping orthographic projections with the first pin section on the circuit board, so that the rigidity of the pin is reduced, which is conducive to the pin absorbing external force and deforming to a greater extent.

[0027] In an alternative embodiment, in the first direction, a distance between a position of the circuit board for inserting the pin and an edge of the top surface close to the pin is less than a distance between a position of the bottom surface for contacting the support member and the edge; wherein the first direction is parallel to an arrangement direction of the pin and the package shell, and perpendicular to a thickness direction of the circuit board.

[0028] After the support member applies external force to the bottom surface of the package shell, the edge of the top surface close to the pin will first abut against the heat sink, and the distance between the position of the bottom surface for contacting the support member and the edge of the top surface close to the pin in the first direction is a power arm, and the distance between the position of the circuit board for inserting the pin and the edge of the top surface close to the pin in the first direction is a resistance arm. After the edge of the top surface close to the pin abuts against the heat sink, the package shell needs to move towards the heat sink in order to make more areas of the top surface contact the heat sink. By adjusting the sizes of the resistance arm and the power arm, the resistance arm is smaller than the power arm, which is conducive to the support member lifting the package shell, so that the top surface of the package shell is more closely attached to the heat sink, and the heat dissipation effect of the power device is further improved.

[0029] In an alternative embodiment, the power conversion device further includes a threaded member, one end of the support member is connected to the circuit board through the threaded member, the other end of the support member supports the bottom surface, and a portion of the support member between the two ends contacts the circuit board.

[0030] One end of the support component is connected to the circuit board via a threaded connector. The threaded connector drives one end of the support component to move towards the circuit board. This can be understood as the circuit board applying a pulling force to this end of the support component, causing the other end of the support component to "lift up" and exert a force on the bottom surface of the package shell towards the heat sink. This ensures that the top surface of the package shell is wholly or partially in contact with the heat sink, transferring heat from the package shell to the heat sink, which then dissipates heat from the power devices.

[0031] In one optional embodiment, the support includes a base and a mounting plate. The mounting plate is located on the side of the base away from the circuit board. One end of the base and one end of the mounting plate are both connected to the circuit board via threaded parts. The other end of the base and the other end of the mounting plate both support the bottom surface. The end of the base used to support the bottom surface is located on the side of the mounting plate used to support the bottom surface away from the threaded parts. A portion of the base between its two ends contacts the circuit board, and a portion of the mounting plate between its two ends contacts the base.

[0032] Both the base and the mounting plate form levers and, together with the threaded parts, support the bottom surface of the package. The base supports the area on the bottom surface closer to the pins, while the mounting plate supports the area on the bottom surface farther from the pins. This allows the bottom surface of the package to be stressed in multiple places, resulting in a higher fit between the top surface of the package and the heat sink, further improving the heat dissipation effect of the power device.

[0033] A second aspect of this application provides a power device for a power conversion apparatus, the power conversion apparatus including a circuit board, a heat sink, and a support member, one side of the circuit board facing the heat sink. The power device includes a package and pins. The package includes a bottom surface facing the circuit board, a top surface facing the heat sink, and a peripheral surface located between the bottom and top surfaces, with pins extending from the peripheral surface. The package is located between the circuit board and the heat sink, and the pins are inserted into the circuit board. The support member contacts the circuit board and the bottom surface, and the support member supports the package so that at least a portion of the top surface contacts the heat sink. The pins include multiple bends, and the pins also include multiple pin segments separated by the multiple bends, at least two of the pin segments having overlapping orthographic projections on the circuit board.

[0034] The power device of this application has multiple bends in its pins, and at least two pin segments have overlapping projections on the circuit board along the thickness direction of the circuit board, which improves the elasticity of the pins, reduces the rigidity of the pins, and allows the pins to absorb some external force and undergo a large degree of deformation. After the support applies external force to the package shell, the top surface of the package shell can have more area to contact the heat sink, which is beneficial to the heat dissipation of the power device.

[0035] In one optional embodiment, the plurality of pin segments include a first pin segment, a second pin segment, and a third pin segment; the first pin segment is elongated and extends from the circumferential surface toward the outer side of the circumferential surface, the third pin segment is elongated and extends along the thickness direction of the circuit board, and the third pin segment is inserted into the circuit board; the orthographic projections of the first pin segment and the second pin segment on the circuit board overlap, or the second pin segment includes at least one bend, and the orthographic projections of multiple portions of the second pin segment on the circuit board overlap.

[0036] The extension direction of the first pin segment is different from that of the third pin segment, and the second pin segment is located between the first and third pin segments. Therefore, the portion between the first and second pin segments needs to be bent, and the portion between the second and third pin segments also needs to be bent. By bending the pins multiple times, the orthographic projections of the first and second pin segments on the circuit board overlap, or multiple portions of the second pin segment overlap on the circuit board, thereby reducing the pin rigidity and enabling the pin to absorb some external force and deform.

[0037] In one alternative embodiment, in the first direction, the bend between the second pin segment and the third pin segment is closer to the package housing than the bend between the first pin segment and the second pin segment; wherein, the first direction is parallel to the arrangement direction of the pins and the package housing and perpendicular to the thickness direction of the circuit board.

[0038] Of the two bends, the bend between the third and second pin segments is closer to the package housing, which also makes the third pin segment closer to the package housing. The third pin segment is used to connect to the circuit board. If the third pin segment is closer to the package housing, the resistance arm is shorter, which helps the support to lift the package housing, allowing the top surface of the package housing to fit more tightly against the heat sink, further improving the heat dissipation of the power device.

[0039] In one alternative implementation, if the first pin segment and the second pin segment overlap in their orthographic projections on the circuit board, the second pin segment includes at least one bend.

[0040] The second pin segment is also a bent structure, which increases the number of bends on the entire pin and reduces the pin's rigidity. After the support applies external force to the package shell, the package shell will apply pressure to the pin towards the circuit board. The pin with lower rigidity absorbs part of the external force and undergoes a greater degree of deformation, making the top surface of the package shell fit more tightly with the heat sink.

[0041] In one optional embodiment, the second pin segment further includes a plurality of sub-segments separated by at least one bend, each sub-segment being elongated and the plurality of sub-segments being arranged along the thickness direction of the circuit board; the bend connecting any two adjacent sub-segments bends from the sub-segment closest to the first pin segment among the two connected sub-segments toward the package housing.

[0042] The entire pin has a lot of bending, and each bend on the second pin segment bends towards the side where the package is located, making the overlapping area of ​​the pin's orthogonal projection on the circuit board larger. This reduces the pin's rigidity and allows the pin to deform to a greater extent under stress.

[0043] In one optional embodiment, the plurality of segments include a first segment and a second segment arranged sequentially along the direction from the package shell to the circuit board. The first segment extends along the thickness direction of the circuit board. In the first direction, the distance between the end of the second segment facing the circuit board and the package shell is less than the distance between the end of the second segment away from the circuit board and the package shell.

[0044] The first and second pin segments overlap on the circuit board, reducing pin rigidity and allowing for greater deformation under stress. Furthermore, the tilted design of the second sub-segment increases the distance between it and the first pin segment, thus increasing the allowable degree of pin deformation (compression). This pin configuration also allows the third pin segment to be closer to the package housing, reducing the drag arm and facilitating the support component to lift the package housing, resulting in a tighter fit between the top surface of the package housing and the heatsink.

[0045] In one alternative embodiment, in a first direction, the distance between the position of the circuit board for inserting the pin and the edge of the top surface near the pin is less than the distance between the position of the bottom surface for contacting the support and the edge; wherein, the first direction is parallel to the arrangement direction of the pin and the package shell and perpendicular to the thickness direction of the circuit board.

[0046] After the top edge near the pins abuts against the heat sink, the package needs to move towards the heat sink so that more of the top surface can contact the heat sink. By adjusting the size of the resistance arm and the power arm, making the resistance arm smaller than the power arm, the support can lift the package, making the top surface of the package fit more tightly against the heat sink, further improving the heat dissipation effect of the power device. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of a photovoltaic energy storage system provided in an embodiment of this application;

[0048] Figure 2 This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0049] Figure 3 A topology diagram of a power conversion device provided in an embodiment of this application;

[0050] Figure 4 A schematic diagram of a circuit board structure provided in an embodiment of this application;

[0051] Figure 5 This is a schematic diagram of the structure of a heat sink provided in an embodiment of this application;

[0052] Figure 6 This is a schematic diagram of another heat sink provided in an embodiment of this application;

[0053] Figure 7 This is a schematic diagram of the structure of a power device provided in an embodiment of this application;

[0054] Figure 8 This is a schematic diagram of the structure of a support member provided in an embodiment of this application;

[0055] Figure 9 This is a schematic diagram of another support member provided in an embodiment of this application;

[0056] Figure 10 This is a schematic diagram of the structure of a base and a mounting plate provided in an embodiment of this application;

[0057] Figure 11 This is a schematic diagram of another support member provided in an embodiment of this application;

[0058] Figure 12 This is a schematic diagram of the power device structure in the related technology of this application;

[0059] Figure 13 A schematic diagram of a pin structure provided in an embodiment of this application;

[0060] Figure 14 A schematic diagram of a resistance arm provided for an embodiment of this application;

[0061] Figure 15 This is a schematic diagram of another power device provided in an embodiment of this application;

[0062] Figure 16 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0063] Figure 17 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0064] Figure 18 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0065] Figure 19This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0066] Figure 20 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0067] Figure 21 This is a schematic diagram of another pin structure provided in an embodiment of this application;

[0068] Figure 22 This is a schematic diagram of a power arm provided in an embodiment of this application.

[0069] Figure label:

[0070] 100-Photovoltaic-Storage System; 10-Photovoltaic Module; 20-Power Conversion Device; 201-Inverter; 202-Energy Storage Converter; 30-Grid; 40-Energy Storage Battery; 1-Power Conversion Circuit; 11-DC-DC Circuit; 12-DC-AC Circuit; 2-Device Housing; 21-Port; 3-Circuit Board; 4-Power Device; 41-Encapsulation Housing; 411-Bottom Surface; 412-Top Surface; 4121-Edge; 413-Perimeter Surface; 42-Lead 420 - Bend; 4200 - Pin segment; 4201 - First bend; 4202 - Second bend; 421 - First pin segment; 422 - Second pin segment; 4220 - Sub-segment; 4221 - First sub-segment; 4222 - Second sub-segment; 4223 - Third sub-segment; 423 - Third pin segment; 5 - Heat sink; 51 - Heat conduction plate; 52 - Fin; 6 - Heat sink cover; 7 - Support; 71 - Base; 72 - Mounting plate; 8 - Threaded part. Detailed Implementation

[0071] 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.

[0072] In this application, the terms "first," "second," etc., are used for descriptive purposes only to distinguish one element from another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0073] In this application, unless otherwise expressly stated and limited, "multiple" means two or more.

[0074] Furthermore, in this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0075] The X-axis, Y-axis, and Z-axis are three mutually perpendicular coordinate axes in a three-dimensional coordinate system.

[0076] In the accompanying drawings of the embodiments of this application, solid structures such as components and assemblies are represented by guide lines; structures composed of multiple components are represented by guide lines with parentheses or solid arrows; and hollow structures such as openings, holes, spaces, and cavities are represented by guide lines with hollow arrows.

[0077] Figure 1 An exemplary structure of a photovoltaic energy storage system 100 (solar photovoltaic energy storage power generation system) is shown, including a photovoltaic system and an energy storage system. (Refer 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 cells connected in series or parallel to achieve a certain output power. Inverter 201 converts the direct current (DC) from photovoltaic modules 10 into alternating current (AC) and transmits the AC to the power grid 30 (or load). Alternatively, inverter 201 sends the AC to a corresponding prefabricated substation for voltage transformation. The prefabricated substation converts the low-voltage AC output from inverter 201 into medium-voltage AC and then transmits the AC to a step-up substation before supplying it to the power grid 30 (or load).

[0078] In energy storage systems, refer to Figure 1 The energy storage battery 40 can store unstable electrical energy. The energy storage battery 40 converts direct current (DC) to alternating current (AC) through a power conversion system (PCS) 202. After passing through a prefabricated substation corresponding to the energy storage battery 40, it delivers stable electrical energy to the power grid 30 (or load). Alternatively, the power conversion system 202 can also convert AC power from the power grid 30 to DC power to charge the energy storage battery 40, and then store the electrical energy within the energy storage battery 40. Or, the energy storage battery 40 can convert DC power to AC power through an inverter 201 to deliver stable electrical energy to the power grid 30 (or load).

[0079] This application provides a power conversion device 20, Figure 2 An exemplary structure of a power conversion device 20 is shown, with reference to Figure 2The power conversion device 20 is used to convert one of alternating current (AC) and direct current (DC) to the other. In one embodiment, the power conversion device 20 is an inverter 201 (auxiliary reference). Figure 1 In one embodiment, the power conversion device 20 can be used in a photovoltaic system to convert direct current (DC) from the photovoltaic module 10 into alternating current (AC); the power conversion device 20 can also be used in an energy storage system to convert DC from the energy storage battery 40 into AC. In another embodiment, the power conversion device 20 is an energy storage converter 202 used in an energy storage system (see auxiliary reference). Figure 1 The power conversion device 20 is used to convert the direct current from the energy storage battery 40 into alternating current.

[0080] Reference Figure 2 The power conversion device 20 includes a power conversion circuit 1 and a device housing 2 for housing the power conversion circuit 1. The device housing 2 can be any suitable housing or equipment box, and this application does not impose any limitations on it. Figure 3 An exemplary topology diagram of a power conversion device 20 is shown, with reference to... Figure 3 The power conversion circuit 1 of the power conversion device 20 (two-stage mode) includes at least one DC-DC circuit 11 (direct current to direct current conversion circuit) and at least one DC-AC circuit 12 (direct current to alternating current conversion circuit), for example, in Figure 3 In the illustrated embodiment, the power conversion circuit 1 includes multiple DC-DC circuits 11 and one DC-AC circuit 12. The input terminal of each DC-DC circuit 11 is connected to a photovoltaic module 10 (or an energy storage battery 40), and the output terminal of each DC-DC circuit 11 is electrically connected to the input terminal of the DC-AC circuit 12. The output terminal of the DC-AC circuit 12 is connected to the power grid 30 (or a load). The DC-DC circuits 11 are used to convert direct current (DC) power, for example, to boost or buck the voltage. The DC-AC circuit 12 is used to convert DC power to alternating current (AC), for example, it is a three-phase inverter circuit.

[0081] In another embodiment, the power conversion circuit 1 of the power conversion device 20 (single-stage mode) includes at least one DC-AC circuit 12, but does not include a DC-DC circuit 11. In this embodiment, the input terminal of the DC-AC circuit 12 is used to connect to the photovoltaic module 10 or the energy storage battery 40, and the output terminal of the DC-AC circuit 12 is used to connect to the power grid 30 (or the load).

[0082] It should be noted that, Figure 3 The topology diagram of the power conversion device 20 shown is only an example and is not intended to limit the power conversion device 20 of this application.

[0083] In some other embodiments, in addition to the power conversion circuit 1, the power conversion device 20 also includes other circuits.

[0084] To form the circuitry within the power conversion device 20, the power conversion device 20 includes at least one circuit board 3 and multiple components fixed to the circuit board 3. Figure 4 An exemplary structure of a circuit board 3 is shown. The circuit board 3 can be a printed circuit board (PCB). In one embodiment, multiple circuit boards 3 are provided. For example, the multiple circuit boards 3 include a first circuit board and a second circuit board, with some components disposed on the first circuit board and others disposed on the second circuit board. In another embodiment, only one circuit board 3 is provided. The circuit board 3 and the components on it are all fixed within the device housing 2. The structure of the device housing 2 is shown in the auxiliary reference. Figure 2 .

[0085] Reference Figure 4 The multiple devices include at least one power device 4; that is, there can be one power device 4 or multiple power devices 4. Figure 4 This illustrates the case where multiple power devices 4 are configured. Figure 4 The dashed boxes in the diagram represent other components. Each power device 4 is fixed to and electrically connected to the circuit board 3, and is used for power conversion.

[0086] Return to reference Figure 3 In one embodiment, the power device 4 is a single power transistor (a power device in a single package), which encapsulates a power transistor, such as an insulated-gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET), or a power diode, such as a silicon carbide (SiC) diode. In another embodiment, the power device 4 is a power module, which encapsulates multiple power semiconductors (e.g., IGBTs, MOSFETs), and in some cases, the power device 4 also encapsulates at least one of a drive circuit, a protection circuit, and a sensor.

[0087] During the operation of the power conversion device 20, the power device 4 generates a lot of heat. In order to dissipate heat from the power device 4, the power conversion device 20 may also include a heat sink 5. One side of the circuit board 3 faces the heat sink 5, and the heat sink 5 provides targeted heat dissipation for the power device 4. Figure 5An exemplary structure of a heat sink 5 is shown, with reference to Figure 5 The radiator 5 is an air-cooled radiator. The radiator 5 is integrally connected to the device housing 2. For example, the radiator 5 includes a heat-conducting plate 51 and multiple fins 52. The heat-conducting plate 51 is integrally connected to the device housing 2. The multiple fins 52 are fixed to the heat-conducting plate 51 and protrude from the heat-conducting plate 51 toward the device housing 2. There is a gap between two adjacent fins 52.

[0088] Figure 6 An exemplary diagram shows the structure of another heat sink 5, with reference to Figure 6 The heat sink 5 includes a heat-conducting plate 51 and multiple fins 52. The heat-conducting plate 51 is located inside the device housing 2 and is used to connect to the power device 4. The multiple fins 52 are fixed to the surface of the heat-conducting plate 51 facing away from the power device 4. The device housing 2 is provided with a through-hole 21, through which the multiple fins 52 extend to the outside of the device housing 2. In another embodiment, both the heat-conducting plate 51 and the multiple fins 52 of the heat sink 5 are located outside the device housing 2. In this example, the power device 4 is connected to the heat-conducting plate 51 through the through-hole 21.

[0089] When the heat sink 5 is an air-cooled heat sink, the heat from the power device 4 can be transferred to the heat-conducting plate 51, and then through the heat-conducting plate 51 to the fins 52. The heat on the fins 52 is then dissipated by heat exchange with the air, thereby cooling the power device 4. Furthermore, in some examples, refer to... Figure 6 The power conversion device 20 may also include a heat sink 6, which is located outside the device housing 2 and fixed on the device housing 2. The heat sink 6 can cover multiple fins 52 of the heat sink 5. In order to facilitate heat dissipation, the heat sink 6 is also provided with multiple air vents, such as multiple air inlets and multiple air outlets.

[0090] In another embodiment, the radiator 5 is a liquid-cooled radiator, and the radiator 5 is located inside the device housing 2 and fixed to the power device 4, that is, the radiator 5 does not extend outside the device housing 2, and a coolant (e.g., water) flows inside the radiator 5. In another embodiment, the radiator 5 is a two-phase working fluid radiator, and the radiator 5 contains a working fluid that can be interconverted between gaseous and liquid states.

[0091] In one embodiment, when multiple power devices 4 are provided, a heat sink 5 is connected to multiple power devices 4 and simultaneously dissipates heat for multiple power devices 4. In another embodiment, multiple heat sinks 5 are also provided, with each heat sink 5 dissipating heat for a corresponding device. In this application, there are no specific limitations on the number of power devices 4 or the number of heat sinks 5.

[0092] This application also provides a power device 4, Figure 7 An exemplary structure of a power device 4 is shown, with reference toFigure 7 The power device 4 includes a package 41 and at least one pin 42, for example, in Figure 7 In the illustrated embodiment, multiple pins 42 are provided, and the package 41 includes a bottom surface 411, a top surface 412, and a peripheral surface 413 located between the bottom surface 411 and the top surface 412, with the pins 42 extending out of the peripheral surface 413.

[0093] Since the bare die (or wafer) of the power device 4 is packaged in the package 41, the package 41 of the power device 4 generates a lot of heat. In order to dissipate heat from the package 41 of the power device 4, the package 41 is pushed (or pressed) against the heat sink 5 by external force, so that the package 41 and the heat sink 5 come into contact.

[0094] The power conversion device 20 also includes a support member 7. The support member 7 contacts the bottom surface 411 of the circuit board 3 and the package shell 41. The support member 7 can support the package shell 41, so that the top surface 412 of the package shell 41 is at least partially (partially or entirely) in contact with the heat sink 5. The heat on the package shell 41 can be transferred to the heat sink 5 and dissipated through the heat sink 5. Figure 8 An exemplary structure of a support member 7 is shown. Figure 8 Pin 42 in Figure 7 Side view of pin 42, see reference Figure 8 The support member 7 lifts the package 41 to contact the heat sink 5. Figure 8 The top and bottom directions are reversed ( Figure 8 Rotating 180°, the support member 7 presses down on the encapsulation shell 41, causing it to contact the heat sink 5. It's important to understand that the terms "lifting" and "pressing down" in this application are not absolute, but rather refer to the actual state of the power conversion device 20. The support member 7 applies pressure to the power device 4, enabling it to contact the heat sink 5. In other words, the support member 7 applies pressure to the power device 4, causing it to press against the heat sink 5, thus allowing for better heat transfer from the power device 4 to the heat sink 5.

[0095] Reference Figure 8 The package 41 is located between the circuit board 3 and the heat sink 5. The bottom surface 411 of the package 41 faces the circuit board 3, and the top surface 412 of the package 41 faces the heat sink 5. The pins 42 of the package 41 are inserted into the circuit board 3. The power conversion device 20 also includes a threaded component 8 (e.g., a bolt). The threaded component 8 passes through one end (D1 end) of the support component 7. One end (D1 end) of the support component 7 is connected to the circuit board 3 through the threaded component 8. By rotating the threaded component 8, one end (D1 end) of the support component 7 can be moved toward the circuit board 3. Figure 8The leftmost of the three dashed arrows points in the direction of the force applied to one end (D1) of the support member 7. The other end (D2) of the support member 7 contacts the bottom surface 411 of the package 41. A portion (D3) of the support member 7 located between its two ends (D1 and D2) contacts the circuit board 3. After one end (D1) of the support member 7 is subjected to force, the other end (D2) of the support member 7 "lifts up" and applies a force towards the heat sink 5 to the bottom surface 411 of the package 41. Figure 8 The direction pointed to by the middle dashed arrow among the three dashed arrows is the direction of the force exerted by the other end (D2 end) of the support member 7 on the bottom surface 411.

[0096] Figure 9 An exemplary embodiment shows another structure of support member 7, with reference to Figure 9 One end (D1 end) of the support member 7 is connected to the circuit board 3 via a threaded part 8. By rotating the threaded part 8, one end (D1 end, i.e., the part of the support member 7 located within the dashed frame D1) can move towards the circuit board 3. The other end (D2 end, i.e., the part of the support member 7 located within the dashed frame D2) supports the bottom surface 411 of the encapsulation shell 41. A portion of the support member 7 between its two ends (D3 portion) contacts the circuit board 3. The support member 7 includes a base 71 and a mounting plate 72. Figure 10 An exemplary structure of a base 71 and a mounting plate 72 is shown, with reference to Figure 10 The mounting piece 72 is located on the side of the base 71 away from the circuit board 3. One end (D11 end) of the base 71 and one end (D12 end) of the mounting piece 72 are both connected to the circuit board 3 through the threaded part 8. The other end (D21 end) of the base 71 and the other end (D22 end) of the mounting piece 72 both support the bottom surface 411. The end of the base 71 used to support the bottom surface 411 (D21 end) is located on the side of the mounting piece 72 used to support the bottom surface 411 (D22 end) away from the threaded part 8. A portion of the base 71 between its two ends (D31 portion) contacts the circuit board 3, and a portion of the mounting piece 72 between its two ends (D32 portion) contacts the base 71.

[0097] exist Figure 9 and Figure 10In the illustrated embodiment, it can be understood that the entire support member 7 is a lever, allowing one end (D1 end) to be pressed down while the other end (D2 end) is raised. The other end (D2 end) of the entire support member 7 is the other end (D21 end) of the base 71. The support member 7 itself includes two levers (base 71 and mounting plate 72). In addition to the base 71, there is also a mounting plate 72 that can apply pressure to the bottom surface 411 of the package shell 41. Both the base 71 and the mounting plate 72 form levers, and together they support the bottom surface 411 of the package shell 41 under the action of the threaded part 8. The base 71 is used to support the area of ​​the bottom surface 411 that is closer to the pin 42, and the mounting plate 72 is used to support the area of ​​the bottom surface 411 that is farther away from the pin 42. This causes the bottom surface 411 of the package shell 41 to be subjected to multiple forces. As a result, the contact between the top surface 412 of the package shell 41 and the heat sink 5 will be higher, further improving the heat dissipation effect of the power device 4.

[0098] In one embodiment, the base 71 and the mounting piece 72 are connected by a snap-fit, and the mounting piece 72 can move relative to the base 71 under the drive of the threaded part 8. In another embodiment, the support member 7 includes the base 71, the mounting piece 72, and insulating paper. A portion of the insulating paper is located between the D21 end of the base 71 and the encapsulation shell 41, and another portion of the insulating paper is located between the D22 end of the mounting piece 72 and the encapsulation shell 41. The base 71 and the mounting piece 72 support the bottom surface 411 of the encapsulation shell 41 by supporting the insulating paper.

[0099] also, Figure 11 An exemplary embodiment shows the structure of another support member 7, with reference to Figure 11 The support member 7 is a spring-like structure. It is fixed to the circuit board 3 and, under elastic force, applies a force toward the heat sink 5 to the bottom surface 411 of the package 41. In another embodiment, the support member 7 is a spring located between the package and the circuit board, and it applies a force toward the heat sink 5 to the bottom surface 411 of the package 41.

[0100] In related technologies, the pin 42 of power device 4 is bent once and forms an "L" shape. Figure 12 An exemplary diagram illustrates the structure of power device 4 in the related art, with reference to Figure 12 Due to the accumulated tolerances in the power device 4, circuit board 3, support 7, heat sink 5, etc., after the support 7 applies external force to the package shell 41, the edge 4121 of the top surface 412 near the pin 42 will first abut against the heat sink 5. The package shell 41 needs to continuously move towards the heat sink 5 so that more of the top surface 412 can contact the heat sink 5. During the process of the package shell 41 moving under force, the package shell 41 will apply pressure to the pin 42 towards the circuit board 3, causing the pin 42 to press down on the circuit board 3.Figure 12 The rightmost arrow of the three dashed arrows indicates the direction of force on circuit board 3. If pin 42 adopts the solution in the relevant technology, pin 42 will be more rigid and less prone to deformation, thus unable to absorb external force. As a result, package 41 cannot move toward heat sink 5, and a large gap will always exist between package 41 and heat sink 5. For example, only the edge 4121 of the top surface 412 of package 41 is in contact with the heat sink 5, and other parts of the top surface 412 are not in contact with the heat sink 5.

[0101] However, if only the force exerted on the power device 4 by the support member 7 is increased, the package shell 41 will be severely stressed if it cannot move toward the heat sink 5, and prolonged compression will also damage the power device 4.

[0102] To address the aforementioned issues, the pin 42 provided in this application includes multiple (two or more) bends 420, for example, referring to the reference. Figure 7 The pin 42 shown has bends 420 on it, which are the bent portions of the pin 42. The pin 42 includes multiple bends 420, meaning that multiple portions of the pin 42 are bent. By having multiple bends 420, the orthographic projections (projected onto the circuit board 3 along a direction parallel to the X-axis) of multiple (two or more) portions of the pin 42 overlap on the circuit board 3. That is, the pin 42 also includes multiple pin segments 4200 separated by multiple bends 420, where each pin segment 4200 is a segment of the pin 42. Multiple pin segments 4200 are separated by bends 420, meaning that a bend 420 connects two adjacent pin segments. At least two pin segments 4200 have overlapping orthographic projections on the circuit board 3, for example, referring to... Figure 11 The upper and lower parts of pin 42 within the dashed box (the horizontally extending pin segment 4200 and the obliquely extending pin segment 4200) have overlapping orthographic projections on the circuit board 3.

[0103] By changing the structure of pin 42, the rigidity of pin 42 is reduced, and the elasticity of pin 42 is better than that of pin 42 in related technologies that bends only once. This allows pin 42 to absorb some external force and undergo a greater degree of deformation (the degree of deformation is greater than that of pin 42 in related technologies that bends only once). After the support member 7 applies external force to the package shell 41, the package shell 41 will apply pressure to pin 42 toward the circuit board 3. During this process, pin 42 absorbs external force and deforms, for example, pin 42 is compressed. The orthogonal projection on the circuit board 3 has multiple overlapping pin segments 4200 that move closer to each other. In this way, the package shell 41 can also move a certain distance toward the heat sink 5. The top surface 412 of the package shell 41 can have more area to fit with the heat sink 5, which is beneficial to the heat dissipation of the power device 4.

[0104] Pin 42 includes some suitable structures, for example, Figure 13 An exemplary structure for pin 42 is shown. Figure 13 Pin 42 in Figure 7 Side view of pin 42, see reference Figure 13 The pin 42 has multiple bends 420, including two first bends 4201. The pin 42 also includes a first pin segment 421, a second pin segment 422, and a third pin segment 423 separated by the two first bends 4201. That is, the multiple pin segments 4200 include a first pin segment 421, a second pin segment 422, and a third pin segment 423. The first pin segment 421, the second pin segment 422, and the third pin segment 423 are arranged sequentially along the direction from the package housing 41 to the circuit board 3. Figure 13 The direction indicated by the middle arrow X1. One first bend 4201 connects between the first pin segment 421 and the second pin segment 422, and the other first bend 4201 connects between the second pin segment 422 and the third pin segment 423. The first pin segment 421 is elongated and extends from the peripheral surface 413 toward the outside of the peripheral surface 413, and the third pin segment 423 is elongated and extends along the thickness direction of the circuit board 3 (parallel to the X-axis), wherein the third pin segment 423 is inserted into the circuit board 3.

[0105] Reference Figure 13 Since the extension direction of the first pin segment 421 is different from that of the third pin segment 423, and the second pin segment 422 is located between the first pin segment 421 and the third pin segment 423, the portion between the first pin segment 421 and the second pin segment 422 needs to be bent (one first bend 4201), and the portion between the second pin segment 422 and the third pin segment 423 also needs to be bent (another first bend 4201). The first bend 4201 between the first pin segment 421 and the second pin segment 422 bends from the first pin segment 421 toward the circuit board 3, so that the second pin segment 422 is located on the side of the first pin segment 421 facing the circuit board 3. The first bend 4201 between the second pin segment 422 and the third pin segment 423 bends from the second pin segment 422 toward the circuit board 3, so that the third pin segment 423 is located on the side of the second pin segment 422 facing the circuit board 3.

[0106] By making multiple bends 420 on pin 42, the orthographic projections of the first pin segment 421 and the second pin segment 422 on the circuit board 3 overlap, thereby reducing the rigidity of pin 42 and enabling pin 42 to absorb some external force and deform.

[0107] In some embodiments, by reducing the resistance arm, the package 41 is subjected to greater force, which can further improve the fit between the top surface 412 of the package 41 and the heat sink 5. For example, Figure 14 An exemplary schematic diagram of a power arm and a resistance arm is shown, in a first direction (parallel to the Y-axis), the bend 420 (one of the first bends 4201) between the second pin segment 422 and the third pin segment 423 is closer to the package housing 41 than the bend 420 (another first bend 4201) between the first pin segment 421 and the second pin segment 422. That is, Figure 13 L1 is less than L2.

[0108] The first direction (parallel to the Y-axis) is parallel to the arrangement direction of the pins 42 and the package 41, and perpendicular to the thickness direction of the circuit board 3.

[0109] Of the two first bends 4201, the first bend 4201 located between the third pin segment 423 and the second pin segment 422 is closer to the package housing 41, which also makes the third pin segment 423 closer to the package housing 41. The third pin segment 423 is used to insert the circuit board 3. If the third pin segment 423 is closer to the package housing 41, it will cause the resistance arm (e.g., Figure 14 If the L1 in the circuit is shorter, and if pin 42 does not bend between the second pin segment 422 and the third pin segment 423, but instead bends between the first pin segment 421 and the second pin segment 422 and extends directly downwards to be inserted into the circuit board 3 (i.e., without the third pin segment 423), then the resistance arm is longer (e.g., Figure 14 (L2 in the example). Therefore, the shorter resistance arm in this application is more conducive to the support 7 lifting the package 41, making the top surface 412 of the package 41 fit more tightly with the heat sink 5, further improving the heat dissipation effect of the power device 4. It is understandable that... Figure 13 L3 is the power arm.

[0110] The shape of the second pin segment 422 between the two first bends 4201 can be configured as needed. In one embodiment, refer to... Figure 13The second pin segment 422 is not bent; that is, the second pin segment 422 is elongated. In the first direction (parallel to the Y-axis), the distance between the end of the second pin segment 422 facing the circuit board 3 (D4 end) and the package shell 41 is less than the distance between the end of the second pin segment 422 away from the circuit board 3 (D5 end) and the package shell 41. It can be understood that the end of the second pin segment 422 facing the circuit board 3 (D4 end) is used to connect the first bend 4201 between the second pin segment 422 and the third pin segment 423, and the end of the second pin segment 422 away from the circuit board 3 (D5 end) is used to connect the first bend 4201 between the first pin segment 421 and the second pin segment 422. The distances of the second pin segment 422's respective ends (D4 end and D5 end) from the circuit board 3 and the package shell 41 in the first direction can be used as a reference. Figure 14 The distance between the two first bends 4201 and the package shell 41 in the first direction is referenced. Figure 13 and Figure 14 It is easy to see that the end of the second pin segment 422 facing the circuit board 3 (D4 end) is closer to the package shell 41 in the first direction. That is, the second pin segment 422 is inclined from the first bend 4201 (the first bend 4201 between the first pin segment 421 and the second pin segment 422) toward the side where the package shell 41 is located, so that the angle between the extension direction of the first pin segment 421 and the extension direction of the second pin segment 422 is an acute angle, and the angle between the extension direction of the second pin segment 422 and the extension direction of the third pin segment 423 is an obtuse angle.

[0111] Reference Figure 13 and Figure 14 The second pin segment 422 and the first pin segment 421 overlap in their orthographic projection on the circuit board 3. This structure reduces the rigidity of the pin 42, allowing it to absorb some external force. After the support member 7 applies external force to the package shell 41, the package shell 41 applies pressure to the pin 42 towards the circuit board 3. After absorbing some external force, the pin 42 undergoes a significant deformation, which improves the fit between the package shell 41 and the heat sink 5. Furthermore, the second pin segment 422, which is inclined towards the package shell 41, allows the end of the second pin segment 422 away from the first pin segment 421 to be closer to the package shell 41. The end of the second pin segment 422 away from the first pin segment 421 is connected to the third pin segment 423 through one of the first bends 4201, making the third pin segment 423 closer to the package shell 41. This results in a shorter resistance arm (L1), which helps the support member 7 to lift the package shell 41, making the top surface 412 of the package shell 41 fit more tightly against the heat sink 5.

[0112] In another embodiment, the second pin segment 422 is also a bent structure and has been bent at least once; that is, the second pin segment 422 includes at least one bend 420. Figure 15 An exemplary structure of another power device 4 is shown, which increases the number of bending points on the entire pin 42, further reducing the rigidity of the pin 42. After the support 7 applies external force to the package shell 41, the top surface 412 of the package shell 41 fits more tightly with the heat sink 5. The multiple bends 420 of the pin 42 can be processed using some commonly used bending fixtures, making the processing of the pin 42 convenient and cost-effective. Where the second pin segment 422 includes at least one bend 420, the orthographic projections of the first pin segment 421 and the second pin segment 422 on the circuit board 3 may overlap, or they may not overlap.

[0113] Figure 16 An exemplary configuration of another pin 42 is shown. Figure 16 Pin 42 in Figure 15 Side view of pin 42, see reference Figure 16 The bends 420 on the second pin segment 422 include at least one second bend 4202. That is, the bent portion of the entire pin 42 includes multiple first bends 4201 and at least one second bend 4202, increasing the number of bends on the pin 42. All the second bends 4202 are located in the second pin segment 422, so that the second pin segment 422 also includes multiple elongated sub-segments 4220 separated by at least one second bend 4202. A second bend 4202 connects any two adjacent sub-segments 4220, that is, every two adjacent sub-segments 4220 are separated by a second bend 4202.

[0114] Furthermore, each second bend 4202 bends from the sub-segment 4220 closest to the first pin segment 421 among the two connected sub-segments 4220 toward the package housing 41. That is, each second bend 4202 bends toward the side where the package housing 41 is located, making the overlap area between the orthographic projection of the first pin segment 421 on the circuit board 3 and the orthographic projection of the second pin segment 422 on the circuit board 3 larger. This can reduce the rigidity of the pin 42 and allow the pin 42 to deform to a greater extent under stress.

[0115] by Figure 16 Taking pin 42 as an example, multiple segments 4220 include those along the direction from the package 41 to the circuit board 3. Figure 16The first sub-segment 4221 and the second sub-segment 4222 are arranged sequentially in the direction indicated by the middle arrow X1. A second bend 4202 connects the first sub-segment 4221 and the second sub-segment 4222. The first sub-segment 4221 extends along the thickness direction of the circuit board 3 (parallel to the X-axis). In the first direction (parallel to the Y-axis), the distance between the end of the second sub-segment 4222 facing the circuit board 3 (D6 end) and the package shell 41 is less than the distance between the end of the second sub-segment 4222 away from the circuit board 3 (D7 end) and the package shell 41. It can be understood that the end of the second sub-segment 4222 facing the circuit board 3 (D6 end) is used to connect the first bend 4201 between the second pin segment 422 and the third pin segment 423, and the end of the second sub-segment 4222 away from the circuit board 3 (D7 end) is used to connect the second bend 4202. (Refer to...) Figure 16 It is easy to see that the end of the second segment 4222 facing the circuit board 3 (D6 end) is closer to the package shell 41 in the first direction. That is, the second segment 4222 is located on the side of the first segment 4221 facing the circuit board 3, and the second segment 4222 is inclined from the side of the second bend 4202 facing the package shell 41.

[0116] In this design, the second bend 4202 bends from the first sub-segment 4221 toward the side where the package shell 41 is located, so that the second sub-segment 4222 is located on the side of the second bend 4202 toward the package shell 41. This design allows the orthographic projections of the first pin segment 421 and the second sub-segment 4222 on the circuit board 3 to overlap, reducing the rigidity of the pin 42 and allowing it to deform under stress. Furthermore, the inclined arrangement of the second sub-segment 4222 increases the distance between the second sub-segment 4222 and the first pin segment 421, thus increasing the allowable degree of deformation (compression) of the pin 42. In other words, when the pin 42 is subjected to stress, the second sub-segment 4222 is less likely to contact the first pin segment 421 as it moves toward it.

[0117] Furthermore, adopt Figure 16 The pin 42 shown also allows the third pin segment 423 to be closer to the package shell 41, reducing the resistance arm and making it easier for the support member 7 to lift the package shell 41, so that the top surface 412 of the package shell 41 fits more tightly with the heat sink 5.

[0118] In some embodiments, when pin 42 is separated into a first pin segment 421, a second pin segment 422 and a third pin segment 423 by two first bends 4201, the multiple bends 420 on the second pin segment 422 can also cause the orthographic projections of multiple portions of the second pin segment 422 on the circuit board 3 to overlap, thereby reducing the rigidity of pin 42.

[0119] For example, Figure 17An exemplary embodiment shows another structure of pin 42, see reference. Figure 17 In the first direction (parallel to the Y-axis), the distance between the end of the first sub-segment 4221 facing the circuit board 3 and the package shell 41 is greater than the distance between the end of the first sub-segment 4221 away from the circuit board 3 and the package shell 41. That is, the end of the first sub-segment 4221 away from the circuit board 3 is closer to the package shell 41 in the first direction; or, the first sub-segment 4221 is located on the side of the first pin segment 421 facing the circuit board 3, and the first sub-segment 4221 is inclined from the first bend 4201 connected to it toward the side away from the package shell 41. Furthermore, in the first direction, the distance between the end of the second segment 4222 facing the circuit board 3 and the package shell 41 is less than the distance between the end of the second segment 4222 away from the circuit board 3 and the package shell 41. That is, the end of the second segment 4222 facing the circuit board 3 is closer to the package shell 41 in the first direction; or, the second segment 4222 is located on the side of the first segment 4221 facing the circuit board 3, and the second segment 4222 is inclined from the side of the second bend 4202 facing the package shell 41.

[0120] exist Figure 17 In the illustrated embodiment, the orthographic projections of multiple portions of the second pin segment 422 onto the circuit board 3 overlap; that is, the orthographic projections of the first sub-segment 4221 and the second sub-segment 4222 onto the circuit board 3 overlap. Furthermore, the orthographic projections of the second pin segment 422 and the first pin segment 421 onto the circuit board 3 also overlap.

[0121] For example, Figure 18 An exemplary embodiment shows another structure of pin 42, see reference. Figure 18 In the first direction (parallel to the Y-axis), the distance between the end of the first sub-segment 4221 facing the circuit board 3 and the package shell 41 is greater than the distance between the end of the first sub-segment 4221 away from the circuit board 3 and the package shell 41. That is, the end of the first sub-segment 4221 away from the circuit board 3 is closer to the package shell 41 in the first direction; or, the first sub-segment 4221 is located on the side of the first pin segment 421 facing the circuit board 3, and the first sub-segment 4221 tilts from the connected first bend 4201 towards the side away from the package shell 41. Furthermore, the extension direction of the second sub-segment 4222 is parallel to the extension direction of the first pin segment 421. It should be noted that this "parallelism" is not absolute; due to deformation caused by factors such as installation, an error of approximately ±5° is allowed. Figure 18 In the illustrated embodiment, the orthographic projections of multiple portions of the second pin segment 422 onto the circuit board 3 overlap; that is, the orthographic projections of the first sub-segment 4221 and the second sub-segment 4222 onto the circuit board 3 overlap. Furthermore, the orthographic projections of the second pin segment 422 and the first pin segment 421 onto the circuit board 3 also overlap.

[0122] exist Figure 15 to Figure 18 In the illustrated embodiment, the second pin segment 422 includes only one bend 420, and the entire pin 42 has three bends 420. The appropriate number of bends makes the fabricated structure of the pin 42 closer to the design expectation and also facilitates the fabrication of the pin 42.

[0123] In another embodiment, the second pin segment 422 includes a plurality of bends 420, for example, Figure 19 An exemplary embodiment shows another structure of pin 42, see reference. Figure 19 The plurality of segments 4220 include a first segment 4221, a second segment 4222, and a third segment 4223 arranged sequentially along the direction from the package housing 41 to the circuit board 3 (in the direction indicated by arrow X1). A second bend 4202 connects the first segment 4221 and the second segment 4222, bending from the first segment 4221 toward the side where the package housing 41 is located, such that the second segment 4222 is located on the side of the second bend 4202 facing the package housing 41. Another second bend 4202 connects the second segment 4222 and the third segment 4223, bending from the second segment 4222 toward the side where the package housing 41 is located, such that the third segment 4223 is located on the side of the second bend 4202 facing the package housing 41.

[0124] In the first direction (parallel to the Y-axis), the distance between the end of the first sub-segment 4221 facing the circuit board 3 and the package shell 41 is greater than the distance between the end of the first sub-segment 4221 away from the circuit board 3 and the package shell 41. That is, the end of the first sub-segment 4221 away from the circuit board 3 is closer to the package shell 41 in the first direction; or, the first sub-segment 4221 is located on the side of the first pin segment 421 facing the circuit board 3, and the first sub-segment 4221 is inclined from the first bend 4201 connected to it toward the side away from the package shell 41. Furthermore, in the first direction, the distance between the end of the second segment 4222 facing the circuit board 3 and the package shell 41 is less than the distance between the end of the second segment 4222 away from the circuit board 3 and the package shell 41. That is, the end of the second segment 4222 facing the circuit board 3 is closer to the package shell 41 in the first direction; or, the second segment 4222 is located on the side of the first segment 4221 facing the circuit board 3, and the second segment 4222 is inclined from the side of the second bend 4202 (located between the first segment 4221 and the second segment 4222) towards the package shell 41. In addition, the extension direction of the third segment 4223 is parallel to the extension direction of the first pin segment 421. It should be noted that this "parallelism" is not absolute; due to deformation caused by factors such as installation, an error of about ±5° is allowed.

[0125] exist Figure 17 to Figure 19 In the illustrated embodiment, the second pin segment 422 of pin 42 includes at least one bend 420, which improves the elasticity of pin 42, further reduces the rigidity of pin 42, and enables pin 42 to better absorb external forces.

[0126] In some embodiments, by making multiple bends on pin 42, three or more portions of the second pin segment 422 may have overlapping orthogonal projections on the circuit board 3.

[0127] In some embodiments, the second pin segment 422 is arc-shaped (an arc shape can be understood as a bend with indistinct edges). Figure 20 An exemplary embodiment shows another structure of pin 42, see reference. Figure 20 The second pin segment 422 is arc-shaped and protrudes in a direction away from the package housing 41. The arc shape of the second pin segment 422 causes multiple portions (B1 portion and B2 portion) of the second pin segment 422 to overlap in their orthographic projections on the circuit board 3, and in... Figure 20 In the illustrated embodiment, the second pin segment 422 also overlaps with the orthographic projection of the first pin segment 421 on the circuit board 3, which reduces the rigidity of the pin 42 and makes it easier for the pin 42 to absorb external forces and undergo greater deformation.

[0128] exist Figure 17 to Figure 20 In the illustrated embodiment, in the first direction (parallel to the Y-axis), the first bend 4201 between the second pin segment 422 and the third pin segment 423 is closer to the package housing 41 than the first bend 4201 between the first pin segment 421 and the second pin segment 422.

[0129] In another embodiment, with Figure 21 Taking another pin 42 structure as an example, refer to Figure 21 The second pin segment 422 is arc-shaped and protrudes in a direction away from the package shell 41. In the first direction, the distance between the first bend 4201 between the second pin segment 422 and the third pin segment 423 and the package shell 41 is equal to the distance between the first bend 4201 between the first pin segment 421 and the second pin segment 422 and the package shell 41. Figure 21 In the illustrated embodiment, the second pin segment 422 does not overlap with the orthographic projection of the first pin segment 421 on the circuit board 3. However, the orthographic projections of multiple portions (B1 portion and B2 portion) of the second pin segment 422 on the circuit board 3 overlap.

[0130] After the support member 7 applies an external force to the bottom surface 411 of the package 41, the edge 4121 of the top surface 412 near the pin 42 will first abut against the heat sink 5. The distance between the position of the bottom surface 411 that contacts the support member 7 and the edge 4121 of the top surface 412 near the pin 42 in the first direction is the power arm, and the distance between the position of the circuit board 3 that inserts the pin 42 and the edge 4121 of the top surface 412 near the pin 42 in the first direction is the resistance arm. In some embodiments, the top surface 412 of the package 41 can be made to fit more tightly against the heat sink 5 by changing the power arm and the resistance arm.

[0131] by Figure 15 and Figure 16 Taking the power device 4 shown as an example, Figure 22 An exemplary embodiment is shown, comprising a power arm and a resistance arm, with reference to... Figure 22 In the first direction (parallel to the Y-axis), the distance between the position (S1) of the circuit board 3 for inserting the pin 42 and the edge 4121 of the top surface 412 near the pin 42 is less than the distance between the position (S2) of the bottom surface 411 for contacting the support 7 and the edge 4121. That is, the power arm (L3) is greater than the resistance arm (L1).

[0132] In this process, after the support member 7 applies an external force to the bottom surface 411 of the package shell 41, the package shell 41 needs to move towards the heat sink 5 so that the top surface 412 can make more contact with the heat sink 5. By adjusting the size of the resistance arm and the power arm, making the resistance arm smaller than the power arm, it is beneficial for the support member 7 to lift the package shell 41, so that the top surface 412 of the package shell 41 fits more tightly with the heat sink 5, further improving the heat dissipation effect of the power device 4.

[0133] In some embodiments, by making multiple bends on pin 42, the orthogonal projections of three or more portions of pin 42 on circuit board 3 may overlap.

[0134] 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 in that, The power conversion device includes a circuit board, a heat sink, power devices, and a support component. One side of the circuit board faces the heat sink; The power device includes a package and pins. The package is located between the circuit board and the heat sink. The package includes a bottom surface facing the circuit board, a top surface facing the heat sink, and a peripheral surface located between the bottom surface and the top surface. The pins extend from the peripheral surface and are inserted into the circuit board. The support member contacts the circuit board and the bottom surface, and the support member is used to support the package housing so that at least a portion of the top surface contacts the heat sink; The pin includes multiple bends and multiple pin segments separated by the multiple bends, and at least two of the multiple pin segments have overlapping orthographic projections on the circuit board.

2. The power conversion device according to claim 1, characterized in that, The plurality of pin segments includes a first pin segment, a second pin segment, and a third pin segment; The first pin segment is elongated and extends from the peripheral surface toward the outer side of the peripheral surface, and the third pin segment is elongated and extends along the thickness direction of the circuit board. The third pin segment is inserted into the circuit board. The first pin segment and the second pin segment have overlapping projections on the circuit board. Alternatively, the second pin segment may include at least one bend, and multiple portions of the second pin segment may have overlapping orthographic projections on the circuit board.

3. The power conversion device according to claim 2, characterized in that, In a first direction, the distance between the bend between the second pin segment and the third pin segment and the package shell is less than the distance between the bend between the first pin segment and the second pin segment and the package shell; wherein, the first direction is parallel to the arrangement direction of the pins and the package shell and perpendicular to the thickness direction of the circuit board.

4. The power conversion device according to claim 3, characterized in that, The second pin segment is elongated. In the first direction, the distance between the end of the second pin segment facing the circuit board and the package shell is less than the distance between the end of the second pin segment away from the circuit board and the package shell.

5. The power conversion device according to claim 2 or 3, characterized in that, If the first pin segment and the second pin segment overlap in their orthographic projections on the circuit board, the second pin segment includes at least one bend.

6. The power conversion device according to claim 2 or 5, characterized in that, The second pin segment further includes a plurality of sub-segments separated by the at least one bend, each of the sub-segments being elongated, and the plurality of sub-segments being arranged along the thickness direction of the circuit board; The bend connecting any two adjacent segments bends from the segment closest to the first pin segment towards the package.

7. The power conversion device according to claim 6, characterized in that, The plurality of segments include a first segment and a second segment arranged sequentially along the direction from the package shell to the circuit board. The first segment extends along the thickness direction of the circuit board. In the first direction, the distance between the end of the second segment facing the circuit board and the package shell is less than the distance between the end of the second segment away from the circuit board and the package shell.

8. The power conversion device according to claim 5, characterized in that, The plurality of sub-segments include a first sub-segment, a second sub-segment, and a third sub-segment arranged sequentially along the direction from the package shell to the circuit board; In the first direction, the distance between the end of the first sub-segment facing the circuit board and the package shell is greater than the distance between the end of the first sub-segment facing away from the circuit board and the package shell, and the distance between the end of the second sub-segment facing the circuit board and the package shell is less than the distance between the end of the second sub-segment facing away from the circuit board and the package shell; The extension direction of the third sub-segment is parallel to the extension direction of the first pin segment.

9. The power conversion device according to claim 2 or 3, characterized in that, The second pin segment is arc-shaped and protrudes in a direction away from the package shell.

10. The power conversion device according to any one of claims 1-9, characterized in that, In a first direction, the distance between the position on the circuit board for inserting the pin and the edge of the top surface near the pin is less than the distance between the position on the bottom surface for contacting the support and the edge; wherein, the first direction is parallel to the arrangement direction of the pin and the package shell, and perpendicular to the thickness direction of the circuit board.

11. The power conversion device according to any one of claims 1-10, characterized in that, The power conversion device further includes a threaded component. One end of the support component is connected to the circuit board through the threaded component, and the other end of the support component supports the bottom surface. A portion of the support component located between its two ends contacts the circuit board.

12. The power conversion device according to claim 11, characterized in that, The support includes a base and a mounting plate. The mounting plate is located on the side of the base away from the circuit board. One end of the base and one end of the mounting plate are both connected to the circuit board via the threaded component. The other end of the base and the other end of the mounting plate both support the bottom surface. The end of the base that supports the bottom surface is located on the side of the mounting plate that supports the bottom surface away from the threaded component. A portion of the base between its two ends contacts the circuit board, and a portion of the mounting plate between its two ends contacts the base.

13. A power device for a power conversion apparatus, the power conversion apparatus comprising a circuit board, a heat sink, and a support member, wherein one surface of the circuit board faces the heat sink, characterized in that, The power device includes a package and pins. The package includes a bottom surface facing the circuit board, a top surface facing the heat sink, and a peripheral surface located between the bottom surface and the top surface. The pins extend from the peripheral surface. The package is located between the circuit board and the heat sink, and the pins are inserted into the circuit board; the support contacts the circuit board and the bottom surface, and the support is used to support the package so that at least a portion of the top surface contacts the heat sink; The pin includes multiple bends and multiple pin segments separated by the multiple bends, and at least two of the multiple pin segments have overlapping orthographic projections on the circuit board.

14. The power device according to claim 13, characterized in that, The plurality of pin segments includes a first pin segment, a second pin segment, and a third pin segment; The first pin segment is elongated and extends from the peripheral surface toward the outer side of the peripheral surface, and the third pin segment is elongated and extends along the thickness direction of the circuit board. The third pin segment is inserted into the circuit board. The first pin segment and the second pin segment have overlapping projections on the circuit board, or... The second pin segment includes at least one bend, and multiple portions of the second pin segment have overlapping orthographic projections on the circuit board.

15. The power device according to claim 14, characterized in that, In a first direction, the bend between the second pin segment and the third pin segment is closer to the package shell than the bend between the first pin segment and the second pin segment; wherein, the first direction is parallel to the arrangement direction of the pins and the package shell and perpendicular to the thickness direction of the circuit board.

16. The power device according to claim 14 or 15, characterized in that, If the first pin segment and the second pin segment overlap in their orthographic projections on the circuit board, the second pin segment includes at least one bend.

17. The power device according to claim 14 or 16, characterized in that, The second pin segment further includes a plurality of sub-segments separated by the at least one bend, each of the sub-segments being elongated, and the plurality of sub-segments being arranged along the thickness direction of the circuit board; The bend connecting any two adjacent segments bends from the segment closest to the first pin segment towards the package housing.

18. The power device according to claim 17, characterized in that, The plurality of segments include a first segment and a second segment arranged sequentially along the direction from the package shell to the circuit board. The first segment extends along the thickness direction of the circuit board. In the first direction, the distance between the end of the second segment facing the circuit board and the package shell is less than the distance between the end of the second segment away from the circuit board and the package shell.

19. The power device according to any one of claims 13-18, characterized in that, In a first direction, the distance between the position on the circuit board for inserting the pin and the edge of the top surface near the pin is less than the distance between the position on the bottom surface for contacting the support and the edge; wherein, the first direction is parallel to the arrangement direction of the pin and the package shell, and perpendicular to the thickness direction of the circuit board.

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