Power module and power converter

Abstract

The application relates to the technical field of power converters, in particular to a power module and a power converter. The application aims to solve the technical problem that the stress between a pin and a package of a power module is too large and the reliability of the power module is reduced. The power module provided by the application comprises a power chip and a package, the power chip is packaged in the package, a support and a pin are arranged on the package, the end of the pin away from the package is used for being fixed with a circuit board, the support is arranged on the side of the pin protruding from the package, the support is used for abutting against the circuit board, so that the power module can be directly contacted with the circuit board through the support, the support can replace the pin to bear the pressure from the circuit board to the power module, and the pressure is avoided from being concentrated on the pin. The support abuts against the circuit board, so that the pressure from the circuit board to the power module directly acts on the package, the stress between the package and the pin is reduced, and the reliability of the power module is improved.

Description

Technical Field

[0001] This application relates to the field of power converter technology, specifically to a power module and a power converter. Background Technology

[0002] Power converters such as inverters and rectifiers generally consist of a power module, a circuit board, and a heat sink. The power module is positioned between the circuit board and the heat sink and is electrically connected to the circuit board via pins. Because the circuit board deforms during operation, the stress generated by this deformation acts on the pins of the power module. This excessive stress between the pins and the power module's package can easily lead to moisture ingress, reducing the reliability of the power module. Utility Model Content

[0003] This application provides a power module and a power converter that can reduce the stress between the pins and the package of the power module, thereby improving the reliability of the power module.

[0004] In a first aspect, the power module provided in the embodiments of this application includes a power chip and a package. The power chip is packaged in the package. The package is provided with a support and pins. The ends of the pins away from the package are used to fix them to the circuit board. The support is provided on the side where the pins protrude from the package and is used to abut against the circuit board.

[0005] The ends of the pins facing away from the package are used to secure the power chip to the circuit board, enabling electrical connection between the power chip and the circuit board. A support member is mounted on the package and positioned on the side where the pins protrude from the package, abutting against the circuit board. This allows the power module to directly contact the circuit board via the support member, avoiding a connection solely through the pins. The support member absorbs the pressure from the circuit board on the power module, preventing pressure concentration on the pins. The contact between the support member and the circuit board ensures that the pressure exerted by the circuit board on the power module acts directly on the package, reducing stress between the package and the pins and improving the reliability of the power module.

[0006] In some embodiments that may include the above embodiments, the package includes a first surface perpendicular to the thickness direction of the power module, the first surface being oriented toward the circuit board, and a support member disposed on the first surface.

[0007] The support is disposed on a first surface perpendicular to the thickness direction of the power module. The first surface is parallel to the extension direction of the circuit board. Since the first surface faces the circuit board, the distance between the support and the circuit board is shorter, which can reduce the manufacturing difficulty and cost of the support.

[0008] In some embodiments that may include the above embodiments, the first surface includes four edge points, and the support is located at at least one edge point.

[0009] The support is located at at least one edge point, which can increase the support span of the support and improve the stability of the connection between the circuit board and the support, thereby improving the reliability of the power module.

[0010] In some embodiments that may include the above embodiments, the distance between the edge point with the support and the pin is smaller than the distance between the edge point without the support and the pin.

[0011] The distance between the edge point with the support and the pin is smaller than the distance between the edge point without the support and the pin. In other words, the support is placed near the edge point of the pin. The support bears the stress in the area near the pin, further reducing the stress on the pin, preventing pin deformation, and improving the reliability of the power module.

[0012] In some embodiments that may include the above embodiments, there are multiple supports, and the multiple supports are spaced apart on the first surface.

[0013] The presence of multiple support components increases the contact area between the support components and the circuit board, thereby increasing the area over which the support components bear pressure and further reducing the impact of pressure on them. Multiple support components can distribute the pressure from the circuit board onto the power module, reducing the pressure on each support component, decreasing wear and tear, and extending their lifespan.

[0014] The spaced arrangement of multiple support components helps prevent localized stress concentration on the power module. Furthermore, since the support components abut against the circuit board, the spaced arrangement of multiple support components improves the stability of the connection between the power module and the circuit board.

[0015] In some embodiments that may include the above embodiments, the support and the package are an integral structure.

[0016] Integrating the support component and the package into a single structure reduces the manufacturing difficulty and cost of the support component. Furthermore, this integrated structure increases the strength of the support component and extends its service life.

[0017] In some embodiments that may include the above embodiments, the side of the support facing away from the pin has a drainage surface.

[0018] The side of the support component away from the pin has a flow-guiding surface. Since the support component is located on the side of the package body closer to the pin, the injection molding direction of the package body is from the end away from the pin to the end closer to the pin. During injection molding, the fluid can enter the mold and the position corresponding to the support component under the guidance of the flow-guiding surface, thereby realizing the production of the support component, ensuring the integrity of the support component, and improving the production yield of the package body.

[0019] The flow-guiding surface can reduce the manufacturing difficulty of the support component, ensure complete filling, reduce surface defects, and guarantee the quality of the support component. At the same time, the flow-guiding surface can guide the fluid flow to the cavity through a smooth transition structure, reduce the abrupt resistance of the flow path, and make the fluid injection pressure lower, thereby reducing mold wear and equipment energy consumption.

[0020] In some embodiments that may include the above embodiments, the package body is provided with a through hole and a limiting flange. The center line of the through hole is parallel to the thickness direction of the package body. The limiting flange is wrapped around the through hole. The height of the limiting flange along the thickness direction of the package body is greater than the height of the support member along the thickness direction of the package body. The limiting flange is used to be embedded in the limiting hole on the circuit board.

[0021] Bolts can pass through through holes and mate with threaded holes on the radiator. Tightening the bolts into the threaded holes on the radiator connects the radiator to the power module, allowing the radiator to cool the power module.

[0022] The limiting flange is wrapped around the through hole. The limiting flange can be embedded in the limiting hole on the circuit board to realize the positioning between the power module and the circuit board, which facilitates the subsequent connection of the power module pins to the circuit board.

[0023] At the same time, the limiting flange can increase the distance between the circuit board and the bolt, so that there is sufficient electrical clearance and creepage distance between the bolt and the live components on the circuit board, preventing high voltage breakdown or leakage, and avoiding the bolt from contacting the conductive layer on the circuit board, which could cause a short circuit or arc discharge.

[0024] In some embodiments that may include the above embodiments, a stop portion is provided on the limiting flange. The stop portion is used to abut against the surface of the circuit board facing the package. The height of the stop portion along the thickness direction of the package is equal to the height of the support member along the thickness direction of the package.

[0025] The limiting flange is provided with an abutting part, which abuts against the surface of the circuit board facing the package. The abutting part can support the circuit board, determine the distance between the circuit board and the power module, ensure that the circuit board and the package are parallel, and improve the stability of the connection between the circuit board and the power module.

[0026] Meanwhile, the height of the contact part along the thickness direction of the package is equal to the height of the support member along the thickness direction of the package, so that when the circuit board contacts the package, the circuit board is parallel to the power chip, thereby making the stress on the package more uniform, avoiding local stress on the package, and improving the reliability of the power module.

[0027] In some embodiments that may include the above embodiments, the power chip includes a first power chip and a second power chip, and the power module further includes a first pin and a second pin. The first pin and the second pin are disposed at one end of the package body along the thickness direction perpendicular to the power module and close to the support member. The first pin is electrically connected to the first power chip, and the second pin is electrically connected to the second power chip.

[0028] The first and second pins are positioned close to the support, which can bear the stress in the vicinity of the first and second pins, further reducing the stress on the first and second pins and preventing deformation of the first and second pins.

[0029] The first and second power chips are packaged together in a package, which can improve the integration of the power module, reduce the area of ​​the circuit board, save space for the power converter, and increase the power density of the power converter.

[0030] The first and second pins are located at one end of the package along the thickness direction perpendicular to the power module. The first pin is electrically connected to the first power chip, and the second pin is electrically connected to the second power chip. This can shorten the connection distance between the first and second pins and the circuit board, reduce the trace distance on the circuit board, reduce the area of ​​the circuit board, and reduce the parasitic inductance on the circuit board.

[0031] In some embodiments that may include the above embodiments, the first pin includes a first sub-pin and a second sub-pin. Along the pin arrangement direction, the second sub-pin is disposed closer to the support, and the first sub-pin is disposed farther from the support. There is a voltage difference between the first sub-pin and the second sub-pin, and a first isolation groove is provided on the package between the first sub-pin and the second sub-pin.

[0032] A first isolation groove is provided on the package between the first sub-pin and the second sub-pin. The first isolation groove can increase the creepage distance and electrical clearance between the first sub-pin and the second sub-pin, and prevent arcing or leakage current from occurring between the first sub-pin and the second sub-pin due to high voltage.

[0033] In addition, the first sub-pin generates high heat when carrying a large current. The first isolation groove can increase the distance between the first sub-pin and the second sub-pin, reduce the conduction of heat to the second sub-pin, and avoid local temperature rise affecting the reliability of the power module.

[0034] The second pin includes a third sub-pin and a fourth sub-pin. Along the pin arrangement direction, the fourth sub-pin is positioned closer to the support, and the third sub-pin is positioned further away from the support. There is a voltage difference between the third and fourth sub-pins, and a second isolation groove is provided on the package between the third and fourth sub-pins.

[0035] A second isolation groove is provided on the package between the third and fourth sub-pins. The second isolation groove can increase the creepage distance and electrical clearance between the third and fourth sub-pins, and prevent arcing or leakage current from occurring between the third and fourth sub-pins due to high voltage.

[0036] In addition, the third sub-pin generates high heat when carrying a large current. The second isolation slot can increase the distance between the third and fourth sub-pins, reduce the conduction of heat to the fourth sub-pin, and avoid local temperature rise affecting the reliability of the power module.

[0037] Secondly, embodiments of this application provide a power converter, including a circuit board and the aforementioned power module. Along the thickness direction of the power module, the power module is connected to the circuit board via pins, and a support member is used to abut against the circuit board.

[0038] The power converter provided in this application includes the power module in any of the above embodiments, so both can solve the same technical problem and achieve the same technical effect. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the power converter structure in related technologies;

[0040] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0041] Figure 3 This is a schematic diagram of the power converter provided in the embodiments of this application;

[0042] Figure 4 This is a schematic diagram of the power module provided in the embodiments of this application;

[0043] Figure 5 A side view of the power module provided in an embodiment of this application;

[0044] Figure 6 for Figure 4 BB-direction sectional view;

[0045] Figure 7 The diagram shows the structure of the first power chip and the second power chip provided in the embodiments of this application.

[0046] Explanation of reference numerals in the attached figures:

[0047] 10: Power converter; 11: Circuit board; 111: Limiting hole; 12: Heat sink; 121: Groove; 122: Threaded hole; 13: Ceramic plate; 14: Bolt; 15: Gasket; 20: Power module; 21: Pin; 22: Power chip; 23: Package; 231: First surface; 232: Through hole; 24: Support; 241: Draining surface; 25: Limiting flange; 26: Edge point; 31: First pin; 311: First sub-pin; 312: Second sub-pin; 32: Second pin; 321: Third sub-pin; 322: Fourth sub-pin; 41: First isolation groove; 42: Second isolation groove. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0050] Furthermore, in the embodiments of this application, directional terms such as "up," "down," "left," "right," "horizontal," and "vertical" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0051] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0052] It should be noted that, in the description of the embodiments of this application, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection or an integral connection; they can also refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0053] Please refer to Figure 1 This application provides a power converter 10, including a circuit board 11, a heat sink 12, and a power module 20. Along the thickness direction of the power module 20, the power module 20 is disposed between the circuit board 11 and the heat sink 12, and the power module 20 is connected to the circuit board 11 through pins 21.

[0054] One end of the power converter 10 can be connected to the power grid, and the other end can be connected to devices such as batteries to process the current from the power grid to meet charging and discharging needs.

[0055] This application does not limit the power converter 10. For example, the power converter 10 may include an inverter, a rectifier, a power conversion system (PCS), a switching power supply, a server power supply, etc.

[0056] In embodiments where the power converter 10 includes an inverter, the power converter 10 can convert the direct current (DC) from the battery into alternating current (AC) and transmit it to the power grid. In embodiments where the power converter 10 includes a rectifier, the power converter 10 can convert the AC from the power grid into DC and store it in the battery.

[0057] In addition to the power converter 10 mentioned above, the power module 20 can also be installed on the power conversion circuit of the new energy vehicle to convert the DC power of the battery into AC power to power the motor; it can also convert the DC power of the battery into DC power with a lower voltage to power low-voltage equipment such as vehicle lights and instruments.

[0058] Since the power module 20 generates a lot of heat during operation, the temperature of the power module 20 is relatively high. The heat sink 12 is located on the side of the power module 20 away from the circuit board 11, which can accelerate the cooling speed of the power module 20, improve the heat dissipation capacity of the power module 20, and ensure the normal use of the power module 20.

[0059] Continue to refer to Figure 1 In some embodiments, a groove 121 is typically provided on the surface of the heat sink 12 near the power module 20, and a ceramic plate 13 is disposed within the groove 121. The ceramic plate 13 has high thermal conductivity, which can further improve the heat dissipation rate of the power module 20. The side of the power module 20 near the heat sink 12 is connected (e.g., in contact) to the ceramic plate 13. The heat of the power module 20 can be transferred to the heat sink 12 through the ceramic plate 13, thereby achieving heat dissipation of the power module 20.

[0060] This application does not limit the heat sink 12. For example, the heat sink 12 can be an air-cooled heat sink or a liquid-cooled heat sink. In embodiments where the heat sink 12 includes an air-cooled heat sink, the heat sink 12 may include a fan and heat sink fins disposed inside the power converter 10. The heat sink fins can contact the power module 20, and the fan is used to drive airflow through the heat sink fins to cool the heat sink fins, thereby achieving cooling of the power module 20.

[0061] In embodiments where the radiator 12 includes a liquid-cooled radiator, the radiator 12 may include a liquid-cooled plate, one side of which contacts the power module 20. The liquid-cooled plate forms a cavity in which coolant is disposed. The radiator 12 also includes a cooling pump, cooling pipes, and a fan. The cooling pipes are disposed within the cavity, and coolant flows within the cooling pipes. The cooling pump is disposed inside the liquid-cooled plate and connected to the cooling pipes, ensuring that the coolant flows in a predetermined direction within the cavity. The fan is disposed on the side of the cooling pipes away from the power module 20, which can reduce the temperature of the coolant and ensure the cooling effect of the coolant on the power module 20.

[0062] When the coolant flows to the part where the liquid cooling plate contacts the power module 20, it absorbs heat from the power module 20, thus cooling the power module 20. The coolant temperature rises after absorbing heat and continues to flow along the cooling pipes away from the power module 20. When the coolant flows near the fan, the fan can lower the coolant temperature, and the cooled coolant continues to be used to cool the power module 20.

[0063] The power module 20 includes a power chip 22, pins 21, and a package 23. The power chip 22 is disposed within the package 23, a portion of the pins 21 is within the package 23, and the remainder of the pins 21 is outside the package 23. One end of the pins 21 can be electrically connected to the power chip 22 within the power module 20, and the other end of the pins 21 can be connected to the circuit board 11, thereby realizing the electrical connection between the power chip 22 and the circuit board 11.

[0064] To ensure a tight connection between pin 21 and circuit board 11, pin 21 and circuit board 11 are usually interference-fitted. After pin 21 is connected to circuit board 11, circuit board 11 will deform during operation. The stress generated by the deformation of circuit board 11 will act on pin 21 of power module 20, causing pin 21 to be subjected to downward pressure.

[0065] Since the circuit board 11 and the power module 20 are connected only through pin 21, the stress of the circuit board 11 is concentrated on pin 21, resulting in excessive stress between pin 21 and package 23, and forming a gap between pin 21 and package 23 (e.g., Figure 2 As shown in the figure, moisture can easily enter the gaps, reducing the reliability of the power module 20.

[0066] Please refer to Figure 3 The power module 20 provided in this application embodiment includes a power chip 22 and a package 23. The power chip 22 is packaged in the package 23. The package 23 is provided with a support member 24 and pins 21. The end of the pins 21 that is away from the package 23 is used to fix them to the circuit board 11. The support member 24 is provided on the side of the pins 21 that protrudes from the package 23 and is used to abut against the circuit board 11.

[0067] Here, power module 20 refers to an integrated power electronic device that can package multiple power chips 22, drive circuits, protection circuits, etc. together to achieve efficient and reliable power conversion (such as AC-DC conversion, voltage boosting and scaling, frequency conversion control, etc.).

[0068] This application does not limit the power chip 22. For example, the power chip 22 can be a diode, silicon carbide (SiC) transistor, metal-oxide-semiconductor field-effect transistor (MOSFET), gallium nitride (GaN) transistor, thyristor, or insulated-gate bipolar transistor (IGBT).

[0069] Here, package 23 refers to a protective shell formed by injection molding, which can be used to enclose the power chip 22, leads, and other internal structures. This application embodiment does not limit the material of package 23; for example, the material of package 23 can be epoxy resin, polyimide, etc.

[0070] The end of pin 21 facing away from the package 23 is used to fix it to the circuit board 11, enabling electrical connection between the power chip 22 and the circuit board 11. A support member 24 is disposed on the package 23 and on the side where pin 21 protrudes from the package 23, abutting against the circuit board 11. This allows the power module 20 to directly contact the circuit board 11 through the support member 24, avoiding the connection between the power module 20 and the circuit board 11 solely through pin 21. The support member 24 bears the pressure from the circuit board 11 on the power module 20, preventing stress concentration on pin 21.

[0071] The support member 24 abuts against the circuit board 11, so that the pressure of the circuit board 11 on the power module 20 is directly applied to the package 23, which reduces the stress between the package 23 and the pin 21 and improves the reliability of the power module 20.

[0072] Please refer to Figure 4In some embodiments, the package 23 includes a first surface 231 perpendicular to the thickness direction z of the power module 20, the first surface 231 being oriented toward the circuit board 11, and a support member 24 being disposed on the first surface 231.

[0073] The support member 24 is disposed on a first surface 231 that is perpendicular to the thickness direction z of the power module 20. The first surface 231 is parallel to the extension direction of the circuit board 11. Since the first surface 231 faces the circuit board 11, the distance between the support member 24 and the circuit board 11 is short, which can reduce the manufacturing difficulty of the support member 24 and reduce the manufacturing cost of the support member 24.

[0074] Continue to refer to Figure 4 In some embodiments, the first surface 231 includes four edge points 26, and the support 24 is located at at least one edge point 26.

[0075] The support member 24 is located at at least one edge point 26, which can increase the support span of the support member 24 and improve the circuit board 11. Figure 3 The stability of the connection between the power module 20 and the support member 24 (as shown) is improved, thereby enhancing the reliability of the power module 20.

[0076] Continue to refer to Figure 4 In some embodiments, the distance between the edge point 26 where the support member 24 is provided and the pin 21 is smaller than the distance between the edge point 26 where the support member 24 is not provided and the pin 21.

[0077] The distance between the edge point 26 with the support member 24 and the pin 21 is smaller than the distance between the edge point 26 without the support member 24 and the pin 21. In other words, the support member 24 is located near the edge point 26 of the pin 21. The support member 24 bears the stress in the area near the pin 21, further reducing the stress on the pin 21, preventing the pin 21 from deforming, and improving the reliability of the power module 20.

[0078] Continue to refer to Figure 4 In some embodiments, there are multiple support members 24, which are spaced apart on the first surface 231.

[0079] This application embodiment does not limit the arrangement of the multiple support members 24 on the first surface 231. For example, the multiple support members 24 can be spaced apart along the length direction y (length direction y of the power module 20) of the first surface 231, or spaced apart along the width direction x (width direction x of the power module 20) of the first surface 231. The multiple support members 24 can also be arranged in a rectangular pattern on the first surface 231.

[0080] There are multiple support members 24, such that the support members 24 are connected to the circuit board 11. Figure 3The increased contact area between the components (as shown) increases the area over which the support 24 bears pressure, further weakening the effect of pressure on the support 24. Multiple support components 24 can distribute the pressure of the circuit board 11 on the power module 20, reducing the pressure on each support component 24, decreasing wear and tear, and extending its service life.

[0081] The spaced arrangement of multiple support members 24 can prevent localized stress concentration on the power module 20. At the same time, since the support members 24 abut against the circuit board 11, the spaced arrangement of multiple support members 24 can improve the stability of the connection between the power module 20 and the circuit board 11.

[0082] Continue to refer to Figure 4 In some embodiments, the support 24 is disposed on the first surface 231 near one end of the pin 21.

[0083] Since the power module 20 is connected to the circuit board 11 through the support member 24 and the pin 21, the pin 21 will be subjected to some of the pressure from the circuit board 11. The support member 24 is set close to the pin 21, which can further reduce the pressure on the pin 21 and further reduce the stress between the pin 21 and the package 23, thus ensuring the reliability of the power module 20.

[0084] Continue to refer to Figure 3 and Figure 4 In some embodiments, the support 24 and the package 23 are an integral structure.

[0085] The support member 24 and the package 23 are integrated into one structure, which reduces the manufacturing difficulty and cost of the support member 24. At the same time, the integrated structure of the support member 24 and the package 23 can improve the strength of the support member 24 and extend its service life.

[0086] Please refer to Figure 5 In the above embodiment, the side of the support member 24 facing away from the pin 21 has a drainage surface 241.

[0087] The package 23 is typically injection molded, and the support 24 is an integral structure with the package 23, meaning that the support 24 is also injection molded. When manufacturing the package 23, the injection direction is usually parallel to the width direction x of the package 23 (the width direction x of the power module 20), pointing from the end furthest from the pin 21 to the end closest to the pin 21.

[0088] Because the support member 24 is located at the bottom of the injection mold and is not parallel to the injection direction, it is difficult for the fluid to enter the mold at the position corresponding to the support member 24. The side of the support member 24 facing away from the pin 21 has a flow-guiding surface 241. During injection molding, the fluid can enter the mold at the position corresponding to the support member 24 under the guidance of the flow-guiding surface 241, thus realizing the fabrication of the support member 24, ensuring the integrity of the support member 24, and improving the production yield of the package 23.

[0089] The flow-guiding surface 241 can reduce the manufacturing difficulty of the support 24, ensure complete filling, reduce surface defects of the support 24, and guarantee the quality of the support 24. At the same time, the flow-guiding surface 241 can guide the fluid to the cavity through a smooth transition structure, reduce the abrupt resistance of the flow path, and make the injection pressure of the fluid lower, thereby reducing mold wear and equipment energy consumption.

[0090] Continue to refer to Figure 4 and Figure 6 In some embodiments, the package 23 is provided with a through hole 232 and a limiting flange 25, and the center line of the through hole 232 ( Figure 4 The dashed line in the diagram is parallel to the thickness direction z of the package 23 (the thickness direction z of the power module 20). The limiting flange 25 is wrapped around the through hole 232. The height of the limiting flange 25 along the thickness direction z of the package 23 is greater than the height of the support member 24 along the thickness direction z of the package 23. The limiting flange 25 is used to be embedded in the limiting hole 111 on the circuit board 11.

[0091] The heat sink 12 has a threaded hole 122 on the side near the power module 20, and the package 23 has a through hole 232. The bottom of the bolt 14 has an external thread, allowing the bolt 14 to pass through the through hole 232 and engage with the threaded hole 122 on the heat sink 12. Tightening the bolt 14 with the threaded hole 122 on the heat sink 12 connects the heat sink 12 to the power module 20, enabling the heat sink 12 to cool the power module 20.

[0092] In other embodiments, the heat sink 12 may also have a blind hole on the side near the power module 20, and a locating pin may be used to connect the heat sink 12 and the power module 20.

[0093] The limiting flange 25 is wrapped around the through hole 232. The limiting flange 25 can be embedded in the limiting hole 111 on the circuit board 11 to realize the positioning between the power module 20 and the circuit board 11, which facilitates the subsequent connection of the pin 21 of the power module 20 to the circuit board 11.

[0094] Meanwhile, the height of the limiting flange 25 along the thickness direction z of the package 23 is greater than the height of the support member 24 along the thickness direction z of the package 23, which can further increase the distance between the circuit board 11 and the bolt 14, so that the bolt 14 and the live components on the circuit board 11 maintain sufficient electrical clearance and creepage distance, prevent high voltage breakdown or leakage, and avoid the bolt 14 from contacting the conductive layer on the circuit board 11, causing short circuit or arc discharge.

[0095] Continue to refer to Figure 6 In the above embodiment, a gasket 15 is provided between the bolt 14 and the power module 20. The gasket 15 can further improve the insulation performance between the circuit board 11 and the power module 20.

[0096] Continue to refer to Figure 4 In the above embodiment, the limiting flange 25 is provided with an abutment portion 251, which is used to abut against the circuit board 11. Figure 3 As shown, on the surface facing the package 23, the height of the contact portion 251 along the thickness direction z of the package 23 is equal to the height of the support member 24 along the thickness direction z of the package 23.

[0097] The limiting flange 25 is provided with an abutting part 251, which abuts against the surface of the circuit board 11 facing the package 23. The abutting part 251 can support the circuit board 11, determine the distance between the circuit board 11 and the power module 20, ensure that the circuit board 11 and the package 23 are parallel, and improve the stability of the connection between the circuit board 11 and the power module 20.

[0098] Meanwhile, the height of the contact portion 251 along the thickness direction z of the package 23 is equal to the height of the support member 24 along the thickness direction z of the package 23, so that when the circuit board 11 contacts the package 23, the circuit board 11 is parallel to the power chip 22, thereby making the stress of the circuit board 11 on the package 23 more uniform, avoiding local stress on the package 23, and improving the reliability of the power module 20.

[0099] Please refer to Figure 7 In some embodiments, the power chip 22 includes a first power chip 221 and a second power chip 222, and the pin 21 includes a first pin 31 and a second pin 32. The first pin 31 and the second pin 32 are disposed at one end of the package 23 along the thickness direction z perpendicular to the power module 20 and close to the support member 24. The first pin 31 is electrically connected to the first power chip 221, and the second pin 32 is electrically connected to the second power chip 222.

[0100] The first pin 31 and the second pin 32 are positioned close to the support member 24. The support member 24 can bear the stress in the area near the first pin 31 and the second pin 32, further reducing the stress on the first pin 31 and the second pin 32 and preventing deformation of the first pin 31 and the second pin 32.

[0101] The first power chip 221 and the second power chip 222 are packaged in the package 23, which can improve the integration of the power module 20, reduce the area of ​​the circuit board 11, save space for the power converter 10, and increase the power density of the power converter 10.

[0102] The first pin 31 and the second pin 32 are disposed at one end of the package 23 along the thickness direction z perpendicular to the power module 20. The first pin 31 is electrically connected to the first power chip 221 and the second pin 32 is electrically connected to the second power chip 222. This can shorten the connection distance between the first pin 31 and the second pin 32 and the circuit board 11, reduce the trace distance on the circuit board 11, reduce the area of ​​the circuit board 11, and reduce the parasitic inductance on the circuit board 11.

[0103] In addition, the first power chip 221 and the second power chip 222 can share the same ceramic plate, which reduces the size of the heat sink 12 and improves the heat dissipation performance of the power module 20.

[0104] Continue to refer to Figure 7 In the above embodiments, the first power chip 221 and the second power chip 222 are arranged at intervals. The arrangement of the first power chip 221 and the second power chip 222 at intervals can reduce electromagnetic interference between the first power chip 221 and the second power chip 222, and can also reduce thermal field overlap between the first power chip 221 and the second power chip 222, preventing local overheating.

[0105] In the above embodiments, ceramic sheet 13 ( Figure 6 The device (as shown) may include a first ceramic sheet and a second ceramic sheet, with the first ceramic sheet in contact with the first power chip 221 and the second ceramic sheet in contact with the second power chip 222.

[0106] The first ceramic plate and the second ceramic plate can improve the electrical isolation between the first power chip 221 and the second power chip 222, and reduce mutual interference.

[0107] Meanwhile, the first ceramic plate is in contact with the first power chip 221, and the second ceramic plate is in contact with the second power chip 222, so that the first power chip 221 and the second power chip 222 have independent heat dissipation paths, which can avoid heat concentration and improve heat dissipation efficiency.

[0108] Continue to refer to Figure 7In the above embodiment, the first pin 31 includes a first sub-pin 311 and a second sub-pin 312. The second sub-pin 312 is disposed close to the support member 24, and the first sub-pin 311 is disposed away from the support member 24. There is a voltage difference between the first sub-pin 311 and the second sub-pin 312. A first isolation groove 41 is provided on the package 23 between the first sub-pin 311 and the second sub-pin 312. The second pin 32 includes a third sub-pin 321 and a fourth sub-pin 322. The fourth sub-pin 322 is disposed close to the support member 24, and the third sub-pin 321 is disposed away from the support member 24. There is a voltage difference between the third sub-pin 321 and the fourth sub-pin 322. A second isolation groove 42 is provided on the package 23 between the third sub-pin 321 and the fourth sub-pin 322.

[0109] This application embodiment does not limit the voltage of the first sub-pin 311 and the second sub-pin 312. For example, the voltage of the first sub-pin 311 may be greater than the voltage of the second sub-pin 312, or the voltage of the first sub-pin 311 may be less than the voltage of the second sub-pin 312. This application embodiment does not limit the voltage of the third sub-pin 321 and the fourth sub-pin 322. For example, the voltage of the third sub-pin 321 may be greater than the voltage of the fourth sub-pin 322, or the voltage of the third sub-pin 321 may be less than the voltage of the fourth sub-pin 322.

[0110] Because there is a voltage difference between the first sub-pin 311 and the second sub-pin 312, either the first sub-pin 311 or the second sub-pin 312 is under high voltage during operation, which can easily generate arcing or corona discharge, increasing the risk of electrical faults. Providing a first isolation groove 41 between the first sub-pin 311 and the second sub-pin 312 can increase the creepage distance and clearance between them, preventing arcing or leakage current from occurring between the first sub-pin 311 and the second sub-pin 312.

[0111] In addition, when the first sub-pin 311 or the second sub-pin 312 carries a large current, it will generate high heat. The first isolation groove 41 can increase the distance between the first sub-pin 311 and the second sub-pin 312, reduce the conduction of heat to adjacent pins (second sub-pin 312 or first sub-pin 311), and avoid local temperature rise from affecting the reliability of the power module 20.

[0112] Similarly, due to the voltage difference between the third sub-pin 321 and the fourth sub-pin 322, either the third sub-pin 321 or the fourth sub-pin 322 is under high voltage during operation, which can easily generate arcing or corona discharge, increasing the risk of electrical faults. Providing a second isolation groove 42 between the third sub-pin 321 and the fourth sub-pin 322 can increase the creepage distance and clearance between them, preventing arcing or leakage current from occurring between them.

[0113] In addition, the third sub-pin 321 or the fourth sub-pin 322 will generate high heat when carrying a large current. The second isolation groove 42 can increase the distance between the third sub-pin 321 and the fourth sub-pin 322, reduce the conduction of heat to adjacent pins (fourth sub-pin 322 or third sub-pin 321), and avoid local temperature rise from affecting the reliability of the power module 20.

[0114] Continue to refer to Figure 7 In the above embodiment, the first sub-pin 311 is a power pin, and the second sub-pin 312 is a signal pin. The first sub-pin 311 is located away from the edge of the package 23, and the second sub-pin 312 is located close to the edge of the package 23. The third sub-pin 321 is a power pin, and the fourth sub-pin 322 is a signal pin. The third sub-pin 321 is located away from the edge of the package 23, and the fourth sub-pin 322 is located close to the edge of the package 23.

[0115] Since the first sub-pin 311 and the third sub-pin 321 are power pins, the voltages of the first sub-pin 311 and the third sub-pin 321 are relatively high, while the voltages of the second sub-pin 312 and the fourth sub-pin 322 are relatively low. The first sub-pin 311 and the third sub-pin 321 are located away from the edge of the package 23, while the second sub-pin 312 and the fourth sub-pin 322 are located close to the edge of the package 23. In other words, the first sub-pin 311 and the third sub-pin 321 are located in the middle of the package 23, while the second sub-pin 312 and the fourth sub-pin 322 are located on both sides.

[0116] The first sub-pin 311 and the third sub-pin 321 are located in the middle position, which can reduce the trace distance between the first sub-pin 311 and the third sub-pin 321, making it easier to achieve miniaturization of the package 23.

[0117] Continue to refer to Figure 7 In the above embodiment, the distance L1 between the first sub-pin 311 and the third sub-pin 321 is greater than the distance L2 between the first sub-pin 311 and the second sub-pin 312. The distance L1 between the first sub-pin 311 and the third sub-pin 321 is greater than the distance L3 between the third sub-pin 321 and the fourth sub-pin 322.

[0118] Here, the distance L2 between the first sub-pin 311 and the second sub-pin 312 is the width of the first isolation groove 41. The distance L3 between the third sub-pin 321 and the fourth sub-pin 322 is the width of the second isolation groove 42.

[0119] The embodiments of this application do not limit the size of L1, L2, and L3. Optionally, L1 can be 3mm, L2 can be 1mm, and L3 can be 0.8mm.

[0120] Since both the first sub-pin 311 and the third sub-pin 321 are power pins, the voltage on the first sub-pin 311 and the third sub-pin 321 is relatively large, and arcing is more likely to occur between them. Therefore, it is necessary to further increase the distance between them to increase the creepage distance between the first sub-pin 311 and the third sub-pin 321, so as to avoid arcing between the first sub-pin 311 and the third sub-pin 321 and reduce the risk of electrical faults.

[0121] Similarly, the distance L1 between the first sub-pin 311 and the third sub-pin 321 is greater than the distance L3 between the third sub-pin 321 and the fourth sub-pin 322, which further increases the creepage distance between the first sub-pin 311 and the third sub-pin 321, avoids the generation of electric arc between the first sub-pin 311 and the third sub-pin 321, and reduces the risk of electrical faults.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A power module, characterized in that, include: Power chip; The power chip is packaged in the package. The package has a support and pins. The ends of the pins away from the package are used to fix them to the circuit board. The support is located on the side where the pins protrude from the package and is used to abut against the circuit board. The side of the support member facing away from the pin has a drainage surface.

2. The power module according to claim 1, characterized in that, The package includes a first surface perpendicular to the thickness direction of the power module, the first surface being oriented toward the circuit board, and the support member being disposed on the first surface.

3. The power module according to claim 2, characterized in that, The first surface includes four edge points, and the support is located at at least one of the edge points.

4. The power module according to claim 3, characterized in that, The distance between the edge point where the support is provided and the pin is less than the distance between the edge point where the support is not provided and the pin.

5. The power module according to claim 2, characterized in that, There are multiple support members, which are spaced apart on the first surface.

6. The power module according to any one of claims 1-5, characterized in that, The support member and the encapsulation body are an integral structure.

7. The power module according to any one of claims 1-5, characterized in that, The package body is provided with a through hole and a limiting flange. The center line of the through hole is parallel to the thickness direction of the package body. The limiting flange is wrapped around the through hole. The height of the limiting flange along the thickness direction of the package body is greater than the height of the support member along the thickness direction of the package body. The limiting flange is used to be embedded in the limiting hole on the circuit board.

8. The power module according to claim 7, characterized in that, The limiting flange is provided with an abutting part, which is used to abut against the surface of the circuit board facing the package. The height of the abutting part along the thickness direction of the package is equal to the height of the support member along the thickness direction of the package.

9. The power module according to any one of claims 1-5, characterized in that, The power chip includes a first power chip and a second power chip, and the pins include a first pin and a second pin. The first pin and the second pin are disposed on one end of the package body along the thickness direction perpendicular to the power module and close to the support member. The first pin is electrically connected to the first power chip, and the second pin is electrically connected to the second power chip.

10. The power module according to claim 9, characterized in that, The first pin includes a first sub-pin and a second sub-pin. Along the pin arrangement direction, the second sub-pin is disposed close to the support member, and the first sub-pin is disposed away from the support member. There is a voltage difference between the first sub-pin and the second sub-pin. A first isolation groove is provided on the package between the first sub-pin and the second sub-pin. The second pin includes a third sub-pin and a fourth sub-pin. Along the pin arrangement direction, the fourth sub-pin is located close to the support member, and the third sub-pin is located away from the support member. There is a voltage difference between the third sub-pin and the fourth sub-pin. A second isolation groove is provided on the package between the third sub-pin and the fourth sub-pin.

11. A power converter, characterized in that, include: The circuit board and the power module according to any one of claims 1-10, wherein the power module is connected to the circuit board via pins along the thickness direction of the power module, and the support member is used to abut against the circuit board.

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