A power module and packaging structure with low inductance structure

Abstract

This invention provides a power module and its packaging structure with a low inductance structure, including a heat dissipation substrate and a power module body. The heat dissipation substrate is divided into a first heat dissipation section and a second heat dissipation section from left to right. The power module body includes a copper-clad ceramic substrate and at least two busbar terminals. The copper-clad ceramic substrate is disposed on the first heat dissipation section. One end of each of the at least two busbar terminals is connected to the copper-clad ceramic substrate, and the other end extends upwards towards the second heat dissipation section to form a connection portion for connecting an external capacitor. The connection portion is spaced a specified distance from the second heat dissipation section. According to this invention, the problem of existing power modules neglecting the space utilization between the busbar terminals and the heat dissipation substrate, resulting in large power module size, low integration, limited heat dissipation and inductance reduction effects, and easy damage to external capacitors under high power or high current conditions can be solved.

Description

Technical Field

[0001] This utility model belongs to the field of power module technology, and more specifically, relates to a power module with a low inductance structure and its packaging structure. Background Technology

[0002] Power modules are core components in fields such as new energy vehicle inverters, industrial frequency converters, and photovoltaic power supplies, and their performance directly affects the reliability and efficiency of the system. When a power module is packaged with an external capacitor, induced electromotive force is generated inside the module, at the connection points, and inside the capacitor when the current changes, forming parasitic inductance. Parasitic inductance can easily cause voltage spikes during high-frequency switching operations, leading to overvoltage damage to devices, while also increasing switching losses, thereby shortening the lifespan of the power module and limiting its performance in high-frequency, high-power applications.

[0003] Existing power modules typically employ a busbar stacked structure, as disclosed in patent CN115513163A, to reduce parasitic inductance. However, this approach neglects the space utilization between the busbar terminals and the heat sink, resulting in a large power module size, low integration, and limited heat dissipation, making it susceptible to damage to external capacitors under high power or current conditions. Furthermore, while the longer busbar terminal design meets bolt connection requirements, it increases parasitic inductance, weakening the inductance reduction effect of existing power modules. Therefore, this application proposes a low-inductance power module structure to effectively reduce its size, achieve miniaturization and high integration, and improve its overall performance. Utility Model Content

[0004] The purpose of this invention is to solve the problem that existing power modules neglect the space utilization between the busbar terminals and the heat dissipation substrate, resulting in large power module size, low integration, limited heat dissipation and inductance reduction effects, and easy damage to external capacitors under high power or high current.

[0005] To achieve the above objectives, this utility model provides a power module and its packaging structure with a low inductance structure.

[0006] According to a first aspect of the present invention, a power module with a low inductance structure is provided, comprising a heat dissipation substrate and a power module body;

[0007] The heat dissipation substrate is divided into a first heat dissipation section and a second heat dissipation section from left to right;

[0008] The power module body includes a copper-clad ceramic substrate and at least two busbar terminals. The copper-clad ceramic substrate is disposed on the first heat dissipation section. One end of each of the at least two busbar terminals is connected to the copper-clad ceramic substrate, and the other end extends upward toward the second heat dissipation section to form a connection portion for connecting an external capacitor.

[0009] The connection portion is spaced at a specified distance from the second heat dissipation section so that when each busbar terminal is energized, the second heat dissipation section can generate an induced current in the opposite direction to the current in each busbar terminal, thereby reducing the parasitic inductance of each busbar terminal.

[0010] Optionally, the specified distance can be less than 1 mm.

[0011] Alternatively, the connection portion is formed by bending the other end of each busbar terminal toward the direction of the second heat dissipation section and then extending horizontally above the second heat dissipation section.

[0012] Optionally, the side of the connecting portion facing the second heat dissipation segment is formed with a protrusion that is spaced at a specified distance from the second heat dissipation segment.

[0013] Optionally, the upper surface of the second heat dissipation section is formed with a stepped portion that is spaced a specified distance from the connecting portion.

[0014] Alternatively, the length of the connecting portion along its extending direction is less than the length of the second heat dissipation section.

[0015] Alternatively, the connection between the connecting part and the external capacitor can be achieved by laser connection.

[0016] Alternatively, the heat dissipation substrate can be a copper pin-type heat dissipation substrate or a copper flat-bottom heat dissipation substrate.

[0017] According to a second aspect of the present invention, a packaging structure is also provided, comprising a power module with a low inductance structure as described above, wherein the packaging structure further comprises:

[0018] An external capacitor has a connection terminal at one end that is adapted to the connection portion.

[0019] The beneficial effects of this utility model are as follows:

[0020] This invention proposes a power module with a low-inductance structure. A copper-clad ceramic substrate is placed on a first heat dissipation section. At least two busbar terminals have one end connected to the copper-clad ceramic substrate, and the other end extends upwards towards a second heat dissipation section to form a connection portion for connecting an external capacitor. A specified distance is maintained between the connection portion and the second heat dissipation section. When each busbar terminal is energized, the second heat dissipation section generates an induced current in the opposite direction to the current in each busbar terminal, thereby reducing the parasitic inductance of each busbar terminal. Compared to existing power modules, this invention effectively reduces the parasitic inductance of each busbar terminal while also making efficient use of the space between the busbar terminals and the heat dissipation substrate, thus reducing the overall size of the power module and achieving miniaturization and high integration. Furthermore, by maintaining a specified distance between the connection portion and the second heat dissipation section, the heat dissipation path of the busbar terminals is shortened, effectively improving the heat dissipation efficiency of the busbar terminals. This reduces the possibility of damaging external capacitors under high power or high current conditions, thereby improving the overall performance of the power module.

[0021] Furthermore, the length of the connecting portion along its extension direction is less than the length of the second heat dissipation section, and it is laser-connected to the external capacitor. This significantly shortens the length of the busbar terminals, thereby significantly reducing the parasitic inductance at the connection between the power module and the external capacitor, and enhancing the inductance reduction effect of the power module.

[0022] The packaging structure of this utility model belongs to the same general inventive concept as the power module with the low inductance structure mentioned above, and has at least the same beneficial effects as the power module with the low inductance structure mentioned above. The beneficial effects will not be repeated here.

[0023] As can be seen from the above, this utility model can effectively solve the problem that existing power modules neglect the space utilization between the busbar terminals and the heat dissipation substrate, resulting in large power module size, low integration, limited heat dissipation and inductance reduction effects, and easy damage to external capacitors under high power or high current.

[0024] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] This invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts.

[0026] Figure 1 A cross-sectional view of a power module with a low-inductance structure according to a first embodiment of the present invention is shown;

[0027] Figure 2A cross-sectional view of a power module with a low-inductance structure according to a second specific embodiment of the present invention is shown;

[0028] Figure 3 A cross-sectional view of a power module with a low-inductance structure according to a third embodiment of the present invention is shown;

[0029] Figure 4 A schematic diagram of the packaging structure according to an embodiment of the present invention is shown;

[0030] Figure 5 A cross-sectional view of the packaging structure according to an embodiment of the present invention is shown.

[0031] Figure label:

[0032] 1-Heat dissipation substrate;

[0033] 11-First heat dissipation section;

[0034] 12-Second heat dissipation section;

[0035] 121 - Step section;

[0036] 2-Copper-clad ceramic substrate;

[0037] 3-Busbar terminal;

[0038] 31-Connecting part;

[0039] 311 - Protrusion;

[0040] 4-External capacitor;

[0041] 41 - Connecting terminal;

[0042] 5-Plastics;

[0043] 6-Shell;

[0044] 7-Chip. Detailed Implementation

[0045] To enable those skilled in the art to more fully understand the technical solution of this utility model, exemplary embodiments of this utility model will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of this utility model described below are merely one or more specific ways to implement the technical solution of this utility model, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solution of this utility model, and it should not be limited to the embodiments described exemplary. Based on one or more embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0046] Example: Figure 1 A cross-sectional view of a power module with a low-inductance structure according to a first embodiment of the present invention is shown; Figure 2 A cross-sectional view of a power module with a low-inductance structure according to a second specific embodiment of the present invention is shown; Figure 3 A cross-sectional view of a power module with a low-inductance structure according to a third embodiment of the present invention is shown; Figure 4 A schematic diagram of the packaging structure according to an embodiment of the present invention is shown; Figure 5 A cross-sectional view of the packaging structure according to an embodiment of the present invention is shown.

[0047] Reference Figure 1-3 An embodiment of this utility model provides a power module with a low inductance structure, including a heat dissipation substrate 1 and a power module body;

[0048] The heat dissipation substrate 1 is divided into a first heat dissipation section 11 and a second heat dissipation section 12 from left to right;

[0049] The main body of the power module includes a copper-clad ceramic substrate 2 and at least two busbar terminals 3. The copper-clad ceramic substrate 2 is disposed on the first heat dissipation section 11. One end of each of the at least two busbar terminals 3 is connected to the copper-clad ceramic substrate 2, and the other end extends upward to the second heat dissipation section 12 to form a connection portion 31 for connecting an external capacitor 4.

[0050] The connection part 31 and the second heat dissipation section 12 are spaced at a specified distance so that when each busbar terminal 3 is energized, the second heat dissipation section 12 can generate an induced current that is opposite to the current direction in each busbar terminal 3, so as to reduce the parasitic inductance of each busbar terminal 3.

[0051] In one specific embodiment, the heat dissipation substrate 1 is a copper pin-type heat dissipation substrate or a copper flat-bottom heat dissipation substrate.

[0052] Specifically, a specified distance is maintained between the connecting part and the second heat dissipation section, so that an induced current opposite to the current direction in each busbar terminal can be generated in the second heat dissipation section, thereby reducing the voltage drop at each busbar terminal.

[0053] Each busbar terminal in a powered state generates a changing magnetic field in its surrounding space. When the connection part and the second heat dissipation section are spaced a specified distance apart, the second heat dissipation section induces a circular current in the magnetic field, opposite in direction to the current in each busbar terminal. The magnetic field generated by the induced current is opposite in direction to the magnetic field generated by the current in each busbar terminal, thus partially canceling out the magnetic field strength around the busbar terminal. According to the principle of electromagnetic induction, parasitic inductance is proportional to magnetic field strength; a decrease in magnetic field strength directly leads to a decrease in parasitic inductance. Therefore, the parasitic inductance of the busbar terminals can be effectively reduced, thereby improving the high-frequency performance and efficiency of the power module.

[0054] In one specific embodiment, the copper-clad ceramic substrate 2 is an AMB copper-clad ceramic substrate.

[0055] In one embodiment, the specified distance is less than 1 mm.

[0056] The power module with a low inductance structure of this utility model has the following three specific embodiments:

[0057] In a first specific embodiment, the connecting portion 31 is formed by bending from the other end of each busbar terminal 3 toward the direction close to the second heat dissipation section 12, and then extending horizontally above the second heat dissipation section 12. Figure 1 As shown.

[0058] In a second specific embodiment, a protrusion 311 is formed on the side of the connecting portion 31 facing the second heat dissipation section 12, such that it is spaced at a specified distance from the second heat dissipation section 12. Figure 2 As shown.

[0059] In a third specific embodiment, the upper surface of the second heat dissipation section 12 is formed with a stepped portion 121 that is spaced a specified distance from the connecting portion 31, such as... Figure 3 As shown.

[0060] In one specific embodiment, the length of the connecting portion 31 along its extending direction is less than the length of the second heat dissipation section 12. This reduces the length of the busbar terminal while increasing the proportion of the second heat dissipation section in the magnetic field of the busbar terminal, thereby further enhancing the inductance reduction effect.

[0061] In one specific embodiment, the connecting part 31 is covered by plastic 5 and encapsulated within the housing 6.

[0062] Specifically, the plastic serves to insulate the connection between the connector and the heat sink substrate. Furthermore, the upper surface of the connector exposes a welding surface for connection to an external capacitor.

[0063] In one specific embodiment, the connection between the connecting part 31 and the external capacitor 4 is a laser connection. Specifically, compared with the bolt connection, the laser connection can greatly shorten the length of the busbar terminals, thereby helping to reduce parasitic inductance.

[0064] In one specific embodiment, the polarities of adjacent busbar terminals 3 in at least two busbar terminals 3 are opposite.

[0065] In one embodiment, a plurality of chips 7 are arranged on the copper-clad ceramic substrate 2, and each of the plurality of chips 7 is electrically connected to each busbar terminal 4.

[0066] In one specific embodiment, each chip 7 is a SiC chip or a Si chip.

[0067] In one specific embodiment, the power module is a half-bridge power module, a single-phase full-bridge power module, or a three-phase full-bridge power module. It should be understood that this invention is not limited thereto, and any power module structure capable of achieving the same technical effect as this invention is within the protection scope of this invention.

[0068] This invention proposes a power module with a low-inductance structure. A copper-clad ceramic substrate is placed on a first heat dissipation section. At least two busbar terminals have one end connected to the copper-clad ceramic substrate, and the other end extends upwards towards a second heat dissipation section to form a connection portion for connecting an external capacitor. A specified distance is maintained between the connection portion and the second heat dissipation section. When each busbar terminal is energized, the second heat dissipation section generates an induced current in the opposite direction to the current in each busbar terminal, thereby reducing the parasitic inductance of each busbar terminal. Compared to existing power modules, this invention effectively reduces the parasitic inductance of each busbar terminal while also making efficient use of the space between the busbar terminals and the heat dissipation substrate, thus reducing the overall size of the power module and achieving miniaturization and high integration. Furthermore, by maintaining a specified distance between the connection portion and the second heat dissipation section, the heat dissipation path of the busbar terminals is shortened, effectively improving the heat dissipation efficiency of the busbar terminals. This reduces the possibility of damaging external capacitors under high power or high current conditions, thereby improving the overall performance of the power module.

[0069] Furthermore, the length of the connecting portion along its extension direction is less than the length of the second heat dissipation section, and it is laser-connected to the external capacitor. This significantly shortens the length of the busbar terminals, thereby significantly reducing the parasitic inductance at the connection between the power module and the external capacitor, and enhancing the inductance reduction effect of the power module.

[0070] Accordingly, refer to Figure 4-5 Based on any of the power modules with low inductance structures described above, embodiments of this utility model further provide a packaging structure, which includes:

[0071] An external capacitor 4 is provided at one end with a connecting terminal 41 that is adapted to the connecting part 31. This utility model does not limit the shape and material of the connecting terminal. Any shape and material of the connecting terminal that can achieve the same technical effect as this utility model is within the protection scope of this utility model.

[0072] Specifically, when the external capacitor is connected to the power module, one end of the connection terminal extends into the housing and overlaps the welding surface of the connection part, and then the connection between the two is achieved by laser welding technology.

[0073] While one or more embodiments of the present invention have been described above, those skilled in the art will recognize that the present invention can be implemented in any other form without departing from its spirit and scope. Therefore, the embodiments described above are illustrative and not restrictive, and many modifications and substitutions will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A power module having a low inductance structure, characterized by, Includes a heat dissipation substrate and the main body of the power module; The heat dissipation substrate is divided into a first heat dissipation section and a second heat dissipation section from left to right; The power module body includes a copper-clad ceramic substrate and at least two busbar terminals. The copper-clad ceramic substrate is disposed on the first heat dissipation section. One end of each of the at least two busbar terminals is connected to the copper-clad ceramic substrate, and the other end extends upward toward the second heat dissipation section to form a connection portion for connecting an external capacitor. The connection portion is spaced at a specified distance from the second heat dissipation section so that when each busbar terminal is energized, the second heat dissipation section can generate an induced current in the opposite direction to the current in each busbar terminal, thereby reducing the parasitic inductance of each busbar terminal.

2. The power module with low inductance structure according to claim 1, characterized in that, The specified distance is less than 1 mm.

3. The power module with low inductance structure according to claim 1, characterized in that, The connection portion is formed by bending the other end of each busbar terminal toward the direction of the second heat dissipation section, and then extending horizontally above the second heat dissipation section.

4. The power module with low inductance structure according to claim 1, characterized in that, The side of the connecting portion facing the second heat dissipation section has a protrusion that sets it at a specified distance from the second heat dissipation section.

5. The power module with low inductance structure according to claim 1, characterized in that, The upper surface of the second heat dissipation section is formed with a stepped portion that is spaced a specified distance from the connecting portion.

6. The power module with low inductance structure according to claim 1, characterized in that, The length of the connecting portion along its extension direction is less than the length of the second heat dissipation section.

7. The power module with low inductance structure according to claim 1, characterized in that, The connection between the connecting part and the external capacitor is a laser connection.

8. The power module with low inductance structure according to claim 1, characterized in that, The heat dissipation substrate is a copper pin-type heat dissipation substrate or a copper flat-bottom heat dissipation substrate.

9. A package structure, characterized by, The power module with a low-inductance structure according to any one of claims 1-8, the packaging structure further includes: An external capacitor has a connection terminal at one end that is adapted to the connection portion.

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