Power module and power conversion device

Abstract

The utility model relates to the technical field of power electronic conversion, in particular to a power module and a power conversion device. The power module comprises a substrate, a plurality of electronic elements, a plurality of connecting terminals and a packaging body, wherein the plurality of electronic elements are electrically connected with the substrate to form a power conversion circuit; two opposite ends of each connecting terminal along the first direction are respectively a fixed end and a connecting end, the fixed end is fixed on the substrate and is connected with the power conversion circuit through the substrate, the connecting end is used for connecting an electric device, and the connecting terminal is an input end or an output end of the power conversion circuit; in the first direction, the connecting terminal comprises a default part located between the fixed end and the connecting end, and the cross sectional area of the connecting terminal at the default part is smaller than the cross sectional area of the connecting terminal at the fixed end and the cross sectional area of the connecting terminal at the connecting end. According to the power module, the influence of installation stress generated in the terminal connection process on the structure of the module can be reduced.

Description

Technical Field

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

[0002] Power modules play a vital role in power electronic devices and power conversion devices. Their ability to support high current and high voltage enables them to be widely used in various functional fields such as voltage transformation, power amplification, frequency conversion, rectification, and power control.

[0003] The power module connects to upstream and downstream devices through its own connection terminals. The force exerted on the connection terminals and other devices during the connection process is transmitted back to the module itself, which may cause the module's packaging structure to crack and fail, affecting the module's functionality. Utility Model Content

[0004] This application provides a power module and a power conversion device, which can reduce the impact of installation stress generated during terminal connection on the module's own structure.

[0005] In a first aspect, this application provides a power module, which includes a substrate, multiple electronic components, multiple connection terminals, and a package. The multiple electronic components are electrically connected to the substrate. Each connection terminal has a fixed end and a connection end at opposite ends along a first direction. The fixed end is fixed to the substrate, and the connection end is used to connect to an electrical device. Along the first direction, the connection terminal includes a default portion located between the fixed end and the connection end. The cross-sectional area of ​​the connection terminal in the default portion is smaller than the cross-sectional area of ​​the connection terminal in the fixed end and the cross-sectional area of ​​the connection terminal in the connection end.

[0006] In the aforementioned power module, the connection terminals have low rigidity but a certain degree of flexibility by default. When connected to other electrical components, the connection terminals themselves can deform as needed to meet connection requirements, reducing the installation stress transmitted from the connection terminals back to the power module, thereby ensuring the structural integrity and connection reliability of the power module.

[0007] In one embodiment, the default portion includes a hollow structure that penetrates the connecting terminal along a second direction parallel to the thickness direction of the substrate. The hollow structure reduces the cross-sectional area of ​​the connecting terminal in the default portion, lowers the rigidity of the connecting terminal at the default portion location, and improves the flexibility of the connecting terminal. When connecting electrical components, the connecting terminal is subjected to force, causing deformation in the default portion to meet connection requirements and reduce the adverse effects of installation stress on the module structure.

[0008] In one embodiment, the hollow structure includes a strip-shaped hole, the extension direction of which is angled to a first direction. Along the first direction, the strip-shaped hole includes opposing first and second inner walls, the distance between the first inner wall and the substrate being smaller than the distance between the second inner wall and the substrate. When connecting an electrical device, the deformation of the connection terminal in the default portion extends along the extension direction of the strip-shaped hole, and the strip-shaped hole provides guidance for the deformation of the connection terminal.

[0009] In one embodiment, both the first inner wall and the second inner wall are arc-shaped surfaces, and the first inner wall and the second inner wall share a common center. Given that the spacing between the arc-shaped holes and the package body along the first direction is equal, the arc-shaped holes have a larger distribution area along the first direction, enabling faster stress transmission blocking.

[0010] In one embodiment, the hollow structure includes a plurality of through holes arranged sequentially along a third direction, which is perpendicular to the first direction and the second direction; along the first direction, the spacing between each through hole and the package body is equal to ensure uniform stress transmission.

[0011] In one embodiment, the hollow structure includes two notches, which are opposite each other along a third direction and are respectively connected to two sides of the connecting terminal. The third direction is perpendicular to the first direction and the second direction. Along the first direction, the spacing between each notch and the package body is equal to ensure the uniformity of stress transmission.

[0012] In one embodiment, the default portion includes one or more strip grooves, each strip groove being formed on the surface of the connecting terminal perpendicular to a second direction, the second direction being parallel to the thickness direction of the substrate; the extension direction of each strip groove is set at an angle to a first direction, and both ends of each strip groove are connected to the two sides of the connecting terminal along a third direction. The portion of the strip groove along the second direction reduces the structure of the connecting terminal, reduces the rigidity of the connecting terminal at the location of the default portion, and improves the flexibility of the connecting terminal.

[0013] In one embodiment, the connecting terminal includes two surfaces opposite each other along a second direction, each surface including a slot; along a first direction, the distance between the slot on one surface and the substrate is not equal to the distance between the slot on the other surface and the substrate. The two slots can increase the deformation range of the connecting terminal along the first direction, thereby improving the flexibility of the connecting terminal.

[0014] Secondly, this application provides a power conversion device, which includes at least one copper busbar and any of the power modules provided in the first aspect. Each copper busbar is used to connect to a connection terminal. Along a first direction, the distance between the copper busbar and the substrate is greater than the distance between the default portion and the substrate. Deformation of the connection terminal in the default portion is not affected by the connection between the copper busbar and the connection terminal.

[0015] In one embodiment, the default portion includes a strip-shaped hole, the extension direction of which is angled to a first direction. The strip-shaped hole includes a first inner wall and a second inner wall opposite to each other along the first direction. Along the first direction, the distance between the copper busbar and the substrate is greater than the distance between the first inner wall and the package and less than the distance between the second inner wall and the package. Deformation of the connection terminal in the default portion is not affected by the connection between the copper busbar and the connection terminal.

[0016] Thirdly, this application provides a power conversion device, which includes a power module, at least one copper busbar, and at least one bending adapter. The power module includes a substrate, multiple electronic components, multiple connection terminals, and a package. The multiple electronic components are electrically connected to the substrate. Each connection terminal has a fixed end and a connection end at opposite ends along a first direction. The fixed end is fixed to the substrate, and the connection end extends out of the package. The bending adapter includes two connection segments arranged at an included angle and a flexible segment connecting the two connection segments. The two connection segments are respectively used to connect a copper busbar to the connection end of a connection terminal. The deformation of the flexible segment can absorb installation stress, and the installation stress will not be transmitted to the power module through the connection terminal, affecting the structural stability of the module.

[0017] In one embodiment, the flexible segment includes at least one bend. At least one bend can enhance the flexibility of the bending adapter and reduce the impact of installation stress transmitted through the connection terminals to the power module on the module's structural stability.

[0018] In one embodiment, the thickness of the bending adapter is 0.8-2 times the thickness of the connecting terminal, which can ensure the reliability of the circuit connection and good flexibility.

[0019] In one embodiment, along a first direction, the connecting terminal includes a default portion located between a fixed end and a connecting end. The cross-sectional area of ​​the connecting terminal in the default portion is smaller than the cross-sectional area of ​​the connecting terminal in the fixed end and the cross-sectional area of ​​the connecting terminal in the connecting end. The distance between the bent adapter and the package is greater than the distance between the default portion and the package. The deformation of the flexible segment and the connecting terminal can absorb installation stress, and the installation stress will not be transmitted to the power module through the connecting terminal, affecting the structural stability of the module. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a power module provided in an embodiment of this application;

[0021] Figure 2 This application provides a schematic diagram of the structure of the connecting electrical components of a power module.

[0022] Figure 3a This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0023] Figure 3b This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0024] Figure 4a This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0025] Figure 4b This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0026] Figure 5a This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0027] Figure 5b This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0031] Figure 9a This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0032] Figure 9b This is a schematic diagram of the structure of a connection terminal of a power module provided in an embodiment of this application;

[0033] Figure 10a This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0034] Figure 10b This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0035] Figure 11 This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0036] Figure 12a This is a partial structural schematic diagram of a power conversion device provided in an embodiment of this application;

[0037] Figure 12b This is a partial structural schematic diagram of a power conversion device provided in an embodiment of this application;

[0038] Figure 12c This is a partial structural schematic diagram of a power conversion device provided in an embodiment of this application;

[0039] Figure 13a This is a schematic diagram of the structure of a power conversion device provided in an embodiment of this application;

[0040] Figure 13b This is a partial structural schematic diagram of a power conversion device provided in an embodiment of this application;

[0041] Figure 14 This is a partial structural schematic diagram of a power conversion device provided in an embodiment of this application;

[0042] Figure 15a A schematic diagram of the structure of a bent adapter for a power conversion device provided in an embodiment of this application;

[0043] Figure 15b A schematic diagram of the structure of a bent adapter for a power conversion device provided in an embodiment of this application;

[0044] Figure 16 This is a schematic diagram of a power conversion device provided in an embodiment of this application.

[0045] Figure label:

[0046] 10 - Power module; 20 - Electrical components; 201 - Copper busbar; 30 - Bending adapter; 301 - Connecting section; 302 - Flexible section;

[0047] 1-Substrate; 11-Base plate; 12-Metal layer; 2-Electronic component; 3-Connecting terminal; 31-Koiler structure; 311-Strip hole; 312-Through hole; 3111-First inner wall; 3112-Second inner wall; 313-Notch; 32-Strip groove; 4-Package body;

[0048] a1 - Fixed end; a2 - Connecting end; P0, P1, P2 - Cross-section; G - Fixed position; J - Intersection point. Detailed Implementation

[0049] With the rapid development of new energy vehicles, smart grids, and industrial automation, the power density requirements for power modules are becoming increasingly stringent. A power module is a packaged structure comprising semiconductor devices, also known as a power module assembly. These semiconductor devices include insulated-gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), and diodes. Power modules are widely used in electric vehicles, new energy, photovoltaics, and wind power, achieving complex specifications such as high voltage, high current, stable temperature, and low electromagnetic radiation. Power modules enable both power conversion and circuit control, and are widely used in power conversion equipment in consumer electronics, industrial control, network communication, power energy, automotive electronics, defense, and aerospace industries.

[0050] Specifically, the power module is electrically connected to other components via connection terminals to form a power conversion circuit. The structure of the connection terminals and the structures of other components themselves have manufacturing errors, and coupled with assembly tolerances during the connection process, the connection terminals are subjected to significant forces. Taking the electrical connection between the power module and the copper busbar via connection terminals as an example, the connection terminals and the copper busbar may have an interference fit or a clearance fit. An interference fit results in a force exerted between the connection terminals and the copper busbar, while a clearance fit forces the connection terminals and the copper busbar into contact during the connection process. Both types of fits subject the connection terminals to significant forces. The installation stress generated by the force on the connection terminals is transmitted to the power module itself, which may cause weaker components of the power module, such as the package, to crack or be damaged, resulting in impaired power module functionality.

[0051] Based on this, the present application provides a power module and a power conversion device. The connection terminals of the power module have great flexibility. During the connection of the power module with other devices, the installation stress is absorbed by deformation, thereby reducing the impact on the module's own structure.

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

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

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

[0055] Figure 1 This is a schematic diagram of the structure of a power module 10 provided in an embodiment of this application. The power module 10 can realize power conversion circuits such as AC to DC, DC to AC, and DC to DC. Figure 1 In one embodiment, the power module 10 includes a substrate 1, multiple electronic components 2, and multiple connection terminals 3. The substrate 1 includes a base plate 11 and a metal layer 12, the metal layer 12 being formed on the base plate 11 by etching, deposition, or other methods. The multiple electronic components 2 are electrically connected to the metal layer 12 of the substrate 1. One end of each connection terminal 3 is electrically connected to the metal layer 12 of the substrate 1. The multiple connection terminals 3 include at least one input terminal and at least one output terminal; the input terminal is used for current input, and the output terminal is used for current output.

[0056] In one specific example, power module 10 is used for power conversion. Multiple electronic components 2 included in power module 10 are electrically connected to the metal layer 12 of substrate 1 to form a power conversion circuit. Input terminals included in multiple connection terminals 3 are used for current input to the power conversion circuit, and output terminals included in multiple connection terminals 3 are used for current output to the power conversion circuit. The power conversion circuit can convert DC to AC, AC to DC, or DC to DC.

[0057] exist Figure 1 In the power module 10 shown, the input terminal and the output terminal are exemplary connected to both sides of the metal layer 12 of the substrate 1 along the first direction X. For ease of understanding, a three-dimensional coordinate system is established with reference to the structure of the power module 10. The thickness direction of the substrate 1 is the second direction Z, the length direction of the substrate 1 is the first direction X, and the width direction of the substrate 1 is the third direction Y. The first direction X, the second direction Z, and the third direction Y are all perpendicular to each other.

[0058] The substrate 1 can be a ceramic substrate, a metal substrate, a single-sided or double-sided copper-clad ceramic substrate (which can be a DBC board or a DCB board), an active metal bonding (AMB) ceramic board, an insulated metal substrate (IMS), a substrate, a printed circuit board (PCB), or other packaging substrates. DBC is short for direct bond copper, and DCB is short for direct copper bonding. Figure 1 An example of a double-sided copper-clad substrate 1 is provided. The substrate 1 includes a base plate 11 and metal layers 12 located on two opposite surfaces of the base plate 11. A plurality of electronic components 2 are disposed on one of the metal layers 12 to be electrically connected to the metal layer 12 to form a power conversion circuit. Each connection terminal 3 is connected to the metal layer 12 to connect to the power conversion circuit.

[0059] Electronic component 2 can be one or a combination of chips, power components, and passive components. For example, the chip can be an integrated circuit (IC) chip. The power component can be a diode, transistor, or other such component, wherein the transistor can be an insulated-gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or other such transistors. The passive component can be a capacitor, resistor, inductor, or other such component. Furthermore, electronic component 2 can also be a fan-in or fan-out structure chip or a complete pre-packaged structure derived from a chip, power component, or passive component. The packaging structure in this application can include materials such as silicone gel, epoxy molding compound, and epoxy potting compound.

[0060] In some embodiments, the power module 10 further includes a package 4, which can encapsulate and fix the substrate 1, multiple electronic components 2, and multiple connection terminals 3. Each connection terminal 3 has one end hidden inside the package 4 and the other end extending outside the package 4 for connecting other devices to achieve circuit connection. The connection terminal 3 has a cantilever beam structure. Figure 1 To illustrate the connection relationship between the connection terminal 3 and the substrate 1, the package 4 is shown with dashed lines.

[0061] In the power module 10 provided in this application embodiment, each connection terminal 3 is used to connect with other devices to realize the input and output of the power conversion circuit. In one embodiment, such as Figure 2As shown, at least one of the two surfaces of each connection terminal 3 along the second direction Z is used for connection with other devices in a surface contact manner. Each connection terminal 3 has a fixed end a1 and a connecting end a2 at opposite ends along the first direction X. The fixed end a1 is fixed to the substrate 1 to connect to the aforementioned power conversion circuit, while the connecting end a2 is used to connect to other electrical devices 20. In one embodiment, the electrical device 20 is a copper busbar.

[0062] When connecting terminal 3 to other electrical components 20, in some scenarios, terminal 3 needs to deform to connect to the electrical components 20. For example, if there is a gap between the connecting end a2 of terminal 3 and the electrical component 20, terminal 3 needs to deform to get closer to the electrical component 20 to achieve connection. The fixed end a1 of terminal 3 is fixed to the substrate 1 of power module 10, and the package 4 partially wraps around terminal 3. The installation stress generated by the force on terminal 3 will be transmitted back to power module 10, requiring power module 10 to release the installation stress. The structure of power module 10 may crack or be damaged under the action of installation stress, such as cracking of package 4 or cracking at the connection between terminal 3 and substrate 1, which may seriously lead to module failure or safety issues.

[0063] To address the aforementioned issues, in the power module 10 provided in this application embodiment, the structure between the fixed end a1 and the connecting end a2 of each connecting terminal 3 is configured with a default portion. This results in the connecting terminal 3 having a default portion, where the cross-sectional area is smaller than that at the fixed end a1 and the connecting end a2. Consequently, the rigidity of the default portion of the connecting terminal 3 is reduced, giving it a degree of flexibility. When connected to other electrical components 20, the connecting terminal 3 can deform as needed to meet connection requirements, reducing the installation stress transmitted back to the power module 10 and ensuring the structural integrity and connection reliability of the power module 10.

[0064] like Figure 3a The connecting terminal 3 shown includes a default portion, which is a hollow structure 31. For example... Figure 3a As shown, the hollow structure penetrates the connecting terminal 3 along the second direction Z. The hollow structure 31 is a specific implementation of a default portion. The fixed end a1, the connecting end a2, and the default portion 31 of the connecting terminal 3 are cut by three sections perpendicular to the first direction X. The cross-sectional area obtained by section P0 cutting the default portion is smaller than the cross-sectional area of ​​section P1 cutting the fixed end a1 and the cross-sectional area of ​​section P2 cutting the connecting end a2. For the overall structure of the connecting terminal 3, the location of the default portion is the weak part of the connecting terminal 3. Due to the presence of the default portion, the rigidity of the connecting terminal 3 is lower at this location, thus improving the flexibility of the connecting terminal 3.

[0065] Specifically, such as Figure 3b As shown, the dashed line represents the unstressed state of connection end a2 of connection terminal 3. When connection end a2 of connection terminal 3 is connected to other devices, it is subjected to a force F, the direction of which is approximately parallel to the second direction Z. The installation stress generated by the force on connection end a2 is transmitted to the hollow structure 31. Connection terminal 3 can deform at the hollow structure 31, allowing connection end a2 to change position relative to fixed end a1 to meet connection requirements. Since the deformation of connection terminal 3 at the hollow structure 31 can absorb installation stress, and the default portion of the hollow structure 31 can also block stress transmission, the stress on connection end a2 transmitted to the power module 10 itself through fixed end a1 can be reduced, thus protecting the integrity of the power module 10 structure and the reliability of the connections of each component.

[0066] Combination Figure 3a and Figure 3b As shown, the deformation of the connecting terminal 3 at the hollow structure 31 is related to the shape of the hollow structure 31.

[0067] In one embodiment, such as Figure 4a As shown, observing the connecting terminal 3 along the second direction Z, the hollow structure 31 is exemplified as a strip-shaped hole 311, the extension direction of which is set at an angle to the first direction X. When the connecting end a2 of the connecting terminal 3 is subjected to force, the installation stress generated by the force on the connecting end a2 can deform the connecting terminal 3 at the strip-shaped hole 311. The extension direction of the strip-shaped hole 311 can guide the deformation of the connecting terminal 3. The deformation of the connecting terminal 3 occurs in the extension direction of the strip-shaped hole 311, such as... Figure 4a The discontinuous lines in the diagram are shown.

[0068] Specifically, the strip-shaped hole 311 includes a first inner wall 3111 and a second inner wall 3112 opposite to each other along the first direction X. Referring to the structure of the connecting terminal 3, along the first direction X, the distance between the first inner wall 3111 and the fixed end a1 is smaller than the distance between the second inner wall 3112 and the fixed end a1. Referring to the structure of the power module 10, along the first direction X, the distance between the first inner wall 3111 and the substrate 1 is smaller than the distance between the second inner wall 3112 and the substrate 1.

[0069] like Figure 4a As shown, when the extension direction of the strip hole 311 is set at an angle of less than 90° with the first direction X, the connecting terminal 3 is deformed along the extension direction of the strip hole 311. The structural change of the connecting end a2 of the connecting terminal 3 relative to the fixed end a1 is uneven along the third direction Y, and the deformed connecting end a2 may be tilted.

[0070] In one embodiment, such as Figure 4bAs shown, the extension direction of the strip hole 311 is perpendicular to the first direction X. When the connecting end a2 of the connecting terminal 3 is subjected to force, the deformation area of ​​the connecting terminal 3 at the strip hole 311 is perpendicular to the first direction X. The deformation of the connecting terminal 3 on both sides along the third direction Y remains balanced. After the structural change of the connecting end a2 relative to the fixed end a1, it is easier to maintain balance.

[0071] Combination Figure 4a and Figure 4b As shown, in the power module 10 provided in this application embodiment, the hollow structure 31 of the connection terminal 3 is symmetrically distributed relative to the first direction X. This allows the structural change of the connection end a2 relative to the fixed end a1 to remain balanced after the connection terminal 3 is deformed at the hollow structure 31, without affecting the connection reliability of the connection end a2 to other devices.

[0072] like Figure 5a The diagram shows a connection terminal 3, whose hollow structure 31 includes an arc-shaped strip hole 311. The first inner wall 3111 and the second inner wall 3112 of the strip hole 311 are both arc-shaped surfaces, and the first inner wall 3111 and the second inner wall 3112 share a common center. The arc-shaped strip hole 311 is axially symmetrically distributed along the first direction X. When the connection end a2 of the connection terminal 3 is subjected to force, the deformation area of ​​the connection terminal 3 at the strip hole 311 extends along the arc of the strip hole 311. The structural change of the connection end a2 relative to the fixed end a1 can remain balanced, without affecting the connection reliability of the connection end a2 with other devices. Compared to a straight strip hole, the arc-shaped strip hole 311 has a larger distribution range along the first direction X. Under the premise that the distance between the arc-shaped strip hole and the package body 4 is the same along the first direction X, the arc-shaped strip hole 311 can more quickly prevent the stress from being transmitted back to the power module 10 after the connection end a2 is subjected to force.

[0073] like Figure 5b The diagram shows a connection terminal 3, whose hollow structure 31 includes a bridge-shaped slot 311. The first inner wall 3111 and the second inner wall 3112 of the slot 311 have similar shapes. The slot 311 is axially symmetrically distributed along the first direction X. When the connection end a2 of the connection terminal 3 is subjected to force, the deformation area of ​​the connection terminal 3 at the slot 311 extends along the arc of the slot 311. The structural change of the connection end a2 relative to the fixed end a1 can also remain balanced, without affecting the connection reliability of the connection end a2 with other devices. Compared with a straight slot, the bridge-shaped slot 311 has a larger distribution range along the first direction X. Under the premise that the distance between the connection end a2 and the package body 4 is the same along the first direction X, the bridge-shaped slot 311 can more quickly prevent the stress from being transmitted back to the power module 10 after the connection end a2 is subjected to force.

[0074] Combination Figure 5a and Figure 5bAs shown, the shape of the strip hole 311 may have various deformations. The strip hole 311 is axially symmetrical about the first direction X, which can make the structural change of the connecting end a2 relative to the fixed end a1 remain balanced after the connecting terminal 3 is deformed at the hollow structure 31, and will not affect the connection reliability of the connecting end a2 with other devices.

[0075] Figure 6 A connection terminal 3 is provided for an embodiment of this application. For example... Figure 6 As shown, the hollow structure 31 of the connecting terminal 3 includes multiple through holes 312 arranged sequentially along the third direction Y. The multiple through holes 312 can reduce the rigidity of the connecting terminal 3 at this location. The force exerted on the connecting end a2 is transmitted to the multiple through holes 312, allowing the connecting terminal 3 to deform at these holes, thus enabling the connecting end a2 to change position relative to the fixed end a1 to meet connection requirements. Because the deformation of the connecting terminal 3 at the multiple through holes 312 can absorb installation stress, it can reduce the force exerted on the connecting end a2 from being transmitted to the substrate 1 through the fixed end a1, thereby protecting the structural integrity of the substrate 1 and the reliability of the connection between the substrate 1 and the connecting terminal 3.

[0076] like Figure 6 As shown, along the first direction X, each through hole 312 has the same size. Referring to the structure of the connecting terminal 3, along the first direction X, the distance between each through hole 312 and the fixed end a1 is equal, and the distance between each through hole 312 and the connecting end a2 is equal. Referring to the structure of the power module 10, along the first direction X, the distance between each through hole 312 and the substrate 1 is equal. When the connecting end a2 of the connecting terminal 3 is subjected to force, the deformation area of ​​the connecting terminal 3 at the strip hole 311 extends along the third direction Y. The structural change of the connecting end a2 relative to the fixed end a1 can remain balanced, and will not affect the connection reliability of the connecting end a2 with other devices.

[0077] In one embodiment, the plurality of through holes 312 are spaced equally along the third direction Y to both sides of the connection terminal 3, and the plurality of through holes 312 are axially symmetrically distributed about the first direction X, which can further balance the structural changes of the connection end a2 relative to the fixed end a1, and is beneficial to improving the connection reliability of the connection end a2 with other devices.

[0078] Figure 7 A connection terminal 3 is provided for an embodiment of this application. For example... Figure 7 As shown, the hollow structure 31 of the connecting terminal 3 includes two notches 313, which are spaced apart along the third direction Y and respectively connected to the two sides of the connecting terminal 3. Figure 7As shown, two notches 313 are formed on two opposite sides of the connecting terminal 3 along the third direction Y. These two notches 313 can reduce the rigidity of the connecting terminal 3 at this location. The force exerted on the connecting end a2 is transmitted to these two notches 313, and the connecting terminal 3 can deform at these two notches 313, allowing the connecting end a2 to change position relative to the fixed end a1 to meet connection requirements. Since the deformation of the connecting terminal 3 at these two notches 313 can absorb installation stress, it can reduce the force exerted on the connecting end a2 transmitted to the substrate 1 through the fixed end a1, thus protecting the structural integrity of the substrate 1 and the reliability of the connection between the substrate 1 and the connecting terminal 3.

[0079] like Figure 7 As shown, along the first direction X, each notch 313 has the same size. Referring to the structure of the connecting terminal 3, along the first direction X, the distance between each notch 313 and the fixed end a1 is equal, and the distance between each notch 313 and the connecting end a2 is equal. Referring to the structure of the power module 10, along the first direction X, the distance between each notch 313 and the substrate 1 is equal. When the connecting end a2 of the connecting terminal 3 is subjected to force, the deformation area of ​​the connecting terminal 3 at the strip hole 311 extends along the third direction Y. The structural change of the connecting end a2 relative to the fixed end a1 can remain balanced, and will not affect the connection reliability of the connecting end a2 with other devices.

[0080] In one embodiment, the two notches 313 have the same shape and are symmetrically distributed about the first direction X, which can further balance the structural changes of the connection end a2 relative to the fixed end a1, and help improve the connection reliability of the connection end a2 with other devices.

[0081] Figure 8 A connection terminal 3 is provided for an embodiment of this application. For example... Figure 8 As shown, the connecting terminal 3 includes one or more strip grooves 32, which, as a default part, can reduce the rigidity of the connecting terminal 3 at this location.

[0082] Figure 8 An example is provided, comprising a strip groove 32, each strip groove 32 formed on one of two surfaces of the connecting terminal 3 along a second direction Z, the extension direction of each strip groove 32 being angled to a first direction X. Taking a connecting terminal 3 including one strip groove 32 as an example, this strip groove 32 connects two opposite sides of the connecting terminal 3 along a third direction Y. For the overall structure of the connecting terminal 3, the location of the strip groove 32 is a weak point of the connecting terminal 3; due to the presence of the weak point, the rigidity of the connecting terminal 3 is low at this location. When the connecting end a2 of the connecting terminal 3 is subjected to force, the force on the connecting end a2 can cause the connecting terminal 3 to deform at the strip groove 32. The extension direction of the strip groove 32 can guide the deformation of the connecting terminal 3, and the deformation of the connecting terminal 3 occurs in the extension direction of the strip groove 32.

[0083] In one embodiment, the extension direction of the strip groove 32 is perpendicular to the first direction X. When the connecting end a2 of the connecting terminal 3 is subjected to force, the deformation area of ​​the connecting terminal 3 at the strip groove 32 is perpendicular to the first direction X, and the deformation of the connecting terminal 3 on both sides along the third direction Y remains balanced. After the structural change of the connecting end a2 relative to the fixed end a1, it is easier to maintain balance.

[0084] Figure 9a A cross-sectional structural diagram of a connecting terminal 3 is shown. For example... Figure 9a As shown, in one embodiment, the connecting terminal 3 includes two surfaces opposite each other along a second direction Z, each surface including a strip groove 32. The two strip grooves 32 correspond to each other along the second direction Z. The connecting terminal 3 has low rigidity at the location of the two strip grooves 32, which are the structural weak points of the connecting terminal 3. The deformation range of the connecting terminal 3 at the location of the two strip grooves 32 is approximately the dimensional range of the two strip grooves 32 along the first direction X.

[0085] Figure 9b A cross-sectional structural diagram of a connecting terminal 3 is shown. For example... Figure 9b As shown, in one embodiment, the connecting terminal 3 includes two surfaces opposite each other along a second direction Z, each surface including a strip groove 32. Along a first direction X, the distance between the strip groove 32 of one surface and the substrate 1 is not equal to the distance between the strip groove 32 of the other surface and the substrate 1.

[0086] Along the second direction Z, the two strip grooves 32 correspond to each other. The connection terminal 3 has low rigidity at the locations of the two strip grooves 32, which are the weakest points in the structure of the connection terminal 3. Specifically, along the first direction X, the two strip grooves 32 are arranged at intervals. Taking the structure of the connection terminal 3 as a reference, along the first direction X, the distance between one strip groove 32 and the fixed end a1 is not equal to the distance between the other strip groove 32 and the fixed end a1. When the connection end a2 of the connection terminal 3 is subjected to force, the connection terminal 3 can deform at the locations of the two strip grooves 32. The connection terminal 3 has a larger deformation range along the first direction X, which is beneficial to enhancing the flexibility of the connection terminal 3.

[0087] In summary, in the power module 10 provided in this application embodiment, the default portion of the connection terminal 3 can be in the form of a hollow structure 31 or a groove. Both are achieved by removing part of the structure of the connection terminal 3, thus reducing the rigidity of the connection terminal 3 at the default location. When the connection end a2 is subjected to force, the connection terminal 3 deforms at the default portion, allowing the connection end a2 to deform relative to the fixed end a1 to meet the connection requirements of the connection terminal 3. Since the deformation of the connection terminal 3 at the default portion can absorb installation stress, it can reduce the force on the connection end a2 from being transmitted to the substrate 1 through the fixed end a1, protecting the structural integrity of the substrate 1 and the reliability of the connection between the substrate 1 and the connection terminal 3. The default portion of the connection terminal 3 can be axially symmetrical about the first direction X, ensuring that the structural change of the connection end a2 relative to the fixed end a1 remains balanced after the connection terminal 3 deforms at the default portion, without affecting the reliability of the connection between the connection end a2 and other devices.

[0088] It should be understood that in the above embodiments, the connection terminal 3 is used in the power module 10. In some possible application scenarios, the connection terminal 3 may also be used in other connections for electrical components.

[0089] Based on the above structural diagram of the power module 10, as follows: Figure 10a The power conversion device shown includes at least one electrical component 20 and any of the aforementioned power modules 10. The electrical component 20 includes one or more copper busbars 201, each copper busbar 201 being connected to a connection terminal a2 of a connection terminal 3 of the power module 10. Figure 10a This example illustrates a structure in which a copper busbar 201 is connected to a connection terminal a2 of a connection terminal 3.

[0090] like Figure 10a As shown, the fixed end a1 of the connection terminal 3 is electrically connected to the substrate 1 of the power module 10. The connection terminal 3 can serve as the input or output terminal of the power conversion circuit formed by connecting the substrate 1 and the electronic component 2. The package 4 of the power module 10 encapsulates the substrate 1, the electronic component 2, and the fixed end a1 of the connection terminal 3. The connection end a2 of the power module 10 extends outside the package 4. The connection terminal 3 includes a default portion located between the connection end a2 and the fixed end a1. The default portion is shown in the diagram with a cutout structure 31 and is also located outside the package 4.

[0091] In one embodiment, such as Figure 10aAs shown, along the first direction X, the distance between the copper busbar 201 and the package 4 of the power module 10 is greater than the distance between the hollow structure 31 and the package 4. The connecting end a2 is connected to the copper busbar 201 along the second direction Z. When connecting to the copper busbar 201, the connecting end a2 is subjected to a force along the second direction Z, which can cause the connecting terminal 3 to deform in the hollow structure 31. The structural change of the connecting end a2 relative to the fixed end a1 meets the connection requirements between the connecting end a2 and the copper busbar 201. The deformation of the connecting terminal 3 in the hollow structure 31 can absorb installation stress, reducing the force on the connecting end a2 transmitted to the substrate 1 through the fixed end a1, thus protecting the structural integrity of the substrate 1 and the reliability of the connection between the substrate 1 and the connecting terminal 3. Figure 10a In the structure shown, along the second direction Z, the hollow structure 31 and the copper busbar 201 do not overlap.

[0092] In one embodiment, such as Figure 10a As shown, the copper busbar 201 is completely fixed, and the installation stress generated by the connection between the copper busbar 201 and the connecting terminal 3 needs to be dissipated and absorbed by the connecting terminal 3 through the deformation of the hollow structure 31.

[0093] In another embodiment, combined Figure 10b As shown, the copper busbar 201 is a cantilever beam structure. Part of the installation stress generated by the connection between the copper busbar 201 and the connecting terminal 3 can be absorbed by the connecting terminal 3 through the deformation of the hollow structure 31, and another part can be absorbed by the deformation of the cantilever structure of the copper busbar 201. Within a reasonable size range, the cantilever beam form of the copper busbar 201 can further reduce the magnitude of the installation stress generated by the connection between the copper busbar 201 and the connecting terminal 3. Specifically, along the first direction X, the ratio of the length h2 of the connecting terminal 3 exposed above the encapsulation body 4 to the length h1 of the copper busbar 201 extending beyond the fixed surface has a certain correlation with the installation stress generated by the connecting terminal 3. As the ratio of h1 / h2 gradually increases, the installation stress generated by the connecting terminal 3 tends to decrease.

[0094] In some embodiments, such as Figure 11 As shown, along the first direction X, the distance between the copper busbar 201 and the package 4 of the power module 10 is greater than the distance between the hollow structure 31 and the package 4, and the copper busbar 201 and the hollow structure 31 partially overlap. Specifically, along the first direction X, the distance between the copper busbar 201 and the package 4 is less than the distance between the end of the hollow structure 31 facing away from the copper busbar 201 and the package 4, and greater than the distance between the end of the hollow structure 31 facing the copper busbar 201 and the package 4. When the connecting end a2 connects to the copper busbar 201, the connecting end a2 is subjected to a force along the second direction Z, and the deformation of the connecting terminal 3 in the hollow structure 31 is not affected by the connection between the copper busbar 201 and the connecting terminal 3.

[0095] Figures 12a to 12cThis is a schematic diagram of the connection between the copper busbar 201 and the connecting terminal 3. The connecting terminal 3 includes the default portion of the example of the strip hole 311. The shape of the end of the copper busbar 201 facing the power module 10 is similar to the shape of the strip hole 311. At least a portion of the end of the copper busbar 201 facing the power module 10 is located within the area of ​​the strip hole 311.

[0096] Refer to together Figures 12a to 12c As shown, the hollow structure 31 of the connecting terminal 3 is a strip-shaped hole 311, and the extension direction of the strip-shaped hole 311 is set at an angle to the first direction X. Exemplarily, the extension direction of the strip-shaped hole 311 is perpendicular to the first direction X. The strip-shaped hole 311 includes a first inner wall 3111 and a second inner wall 3112 opposite to each other along the first direction X. Referring to the structure of the connecting terminal 3, along the first direction X, the distance between the copper busbar 201 and the fixed end a1 is greater than the distance between the first inner wall 3111 and the fixed end a1, and less than the distance between the second inner wall 3112 and the fixed end a1. Referring to the structure of the power module 10, along the first direction X, the distance between the copper busbar 201 and the package 4 is greater than the distance between the first inner wall 3111 and the package 4, and less than the distance between the second inner wall 3112 and the package 4.

[0097] Combination Figures 12a to 12c As shown, in some embodiments, along the third direction Y, the size of the copper busbar 201 is larger than the size of the slot 311, and the intersection point J of the two ends of the copper busbar 201 and the two ends of the slot 311 meets certain conditions, enabling the copper busbar 201 to achieve a more stable and flexible connection with the connecting terminal 3. The parting surface M of the package 4 of the power module 10 is exemplified by a discontinuous line. Along the first direction X, the distance d between the intersection point J of the two ends of the copper busbar 201 and the two ends of the slot 311 and the parting surface M is greater than 20% of the length of the connecting terminal 3.

[0098] Figure 13a Another power conversion device is provided for embodiments of this application. The power conversion device includes a copper busbar 201, a power module 10, and a bending adapter 30. The copper busbar 201 and the connection terminal 3 of the power module 10 are arranged at an angle, and the two ends of the bending adapter 30 are used to connect the copper busbar 201 and the connection terminal 3 of the power module 10, respectively.

[0099] In one specific embodiment, the portion of the copper busbar 201 used to connect the connecting terminal 3 is parallel to the second direction Z. For example... Figure 13a In the middle, the copper busbar 201 is a straight plate parallel to the second direction Z, and one end of the copper busbar 201 along the second direction Z is fixed to the fixed position G.

[0100] Please refer to the reference. Figure 13bThe bending adapter 30 shown includes two connecting segments 301 arranged at an included angle and a flexible segment 302 connecting the two connecting segments 301. The two connecting segments 301 can be used to connect the copper busbar 201 and the connecting terminal 3, respectively. One connecting segment 301 is parallel to the connecting terminal 3 and is in contact with the surface of the connecting terminal 3 along the second direction Z. The other connecting segment 301 is parallel to the copper busbar 201 and is in contact with the copper busbar 201 along the first direction X.

[0101] based on Figure 13b The connection structure shown allows for the connection of the copper busbar 201 to the connecting terminal 3 via the bending adapter 30. The copper busbar 201 connects to one of the connecting segments 301, generating a force between them. Similarly, the connecting terminal 3 connects to the other connecting segment 301, also generating a force. The installation stress generated by the forces on the two connecting segments 301 is transmitted to the flexible segment 302, causing it to deform. This ensures that the two connecting segments 301 can make good contact with the connecting terminal 3 and the copper busbar 201, respectively. The deformation of the flexible segment 302 absorbs the installation stress, preventing the force from being transmitted to the power module 10 via the connecting terminal 3 and affecting the module's structural stability.

[0102] To maintain good flexibility, the bending adapter 30 needs to meet the characteristics of low yield strength and high elongation. In one embodiment, the bending adapter 30 is made of annealed copper, which has a yield strength of less than 30 MPa and an elongation of more than 15%. When connecting the copper busbar 201 and the connecting terminal 3, it can achieve a large range of deformation allowance, meeting the connection requirements of more scenarios.

[0103] When the bending adapter 30 is connected to the connection terminal 3, it is positioned as close as possible to the package 4 of the power module 10 along the first direction X to reduce parasitic inductance. Furthermore, the circuit connecting the copper busbar 201 and the connection terminal 3 via the bending adapter 30 is designed to be as short as possible to minimize parasitic inductance.

[0104] In one embodiment, the copper busbar 201 is a bent component, and the copper busbar 201 is used to connect a portion of the connecting terminal 3 parallel to the second direction Z. For example... Figure 14 As shown, the copper busbar 201 includes a portion parallel to the second direction Z and a portion parallel to the first direction X. The portion parallel to the second direction Z is used to connect the connecting terminal 3, and the portion parallel to the first direction X is fixed to the fixing position G.

[0105] Figure 15a and Figure 15b Two structures for the bending adapter 30 are illustrated. For example... Figure 15aAs shown, the flexible section 302 of the bending adapter 30 is straight, and the flexible section 302 is inclinedly connected between the two connecting sections 301. Figure 15b As shown, the flexible segment 302 of the bending adapter 30 includes at least one bend, and the flexible segment 302 connected between the two connecting segments 301 can provide greater flexibility.

[0106] In one specific embodiment, the bending adapter 30 is in the form of a sheet metal, with a thickness of 0.8-2 times that of the connecting terminal 3, which can ensure the reliability of the circuit connection and good flexibility.

[0107] In some embodiments, such as Figure 16 As shown, the connecting terminal 3 includes a default portion in the form of a hollow structure 31, which is located between the fixed end a1 and the connecting end a2 along the first direction X. When the connecting terminal 3 is connected to the copper busbar 201 via the bending adapter 30, the distance between the bending adapter 30 and the encapsulation body 4 along the first direction X is greater than the distance between the hollow structure 31 and the encapsulation body 4. When the copper busbar 201 is connected to the connecting terminal 3 via the bending adapter 30, the copper busbar 201 is connected to one of the connecting segments 301 and a force is generated between them, and the connecting terminal 3 is connected to the other connecting segment 301 and a force is generated between them. The installation stress generated by the force on the two connecting segments 301 is transmitted to the flexible segment 302, causing the flexible segment 302 to deform. At the same time, the installation stress generated by the force on the connecting terminal 3 can cause the connecting terminal 3 to deform at the hollow structure 31, so that the two connecting segments 301 can make good contact and connection with the connecting terminal 3 and the copper busbar 201 respectively. The deformation of the flexible section 302 and the connecting terminal 3 can absorb the installation stress, and the installation stress will not be transmitted to the power module 10 through the connecting terminal 3, thus affecting the structural stability of the module.

[0108] The power module 10 provided in this application embodiment can be applied to consumer electronics, power energy, automotive electronics, and other fields.

[0109] In the consumer electronics field, power modules are primarily used in power conversion devices such as power adapters, inverters, and frequency converters. Power adapters are power conversion devices for small portable electronic devices and appliances. Power modules are used for power conversion and amplification, converting AC to DC to provide a stable and reliable power supply for these devices, ensuring their normal operation. Inverters are power electronic devices composed of semiconductor switching devices. Power modules can convert DC to AC, achieving efficient power conversion within the inverter to provide power support for homes, offices, and other locations.

[0110] In the field of power energy, power modules are mainly used in power conversion devices such as solar inverters and wind power converters. Solar inverters convert direct current (DC) generated by solar panels into alternating current (AC) and feed it into the power grid. Power modules are responsible for achieving efficient power conversion and reliable grid connection, providing power support for homes, businesses, and other applications. Wind power converters are devices used in wind power systems to control generator speed, regulate output power, and ensure stable grid operation. Power modules can adjust the generator speed and output power according to wind speed and load changes, playing a role in power conversion and control, ensuring the safe and stable operation of the wind power system.

[0111] In the automotive electronics field, power modules are primarily used in power conversion devices such as electric vehicle drive motors, battery management systems, and electric power steering. The electric vehicle drive motor converts electrical energy into mechanical energy to drive the vehicle; the power module amplifies and controls the power, precisely controlling the motor's current and voltage to achieve efficient and smooth driving performance. The battery management system controls and protects the electric vehicle's battery by charging and discharging; the power module converts and protects the battery, monitoring its status and taking appropriate protective measures to ensure battery safety and longevity. Electric power steering is a device that upgrades a traditional mechanical steering system to an electronic steering system; the power module amplifies and controls the power, providing appropriate assistance based on the driver's steering intentions, improving driving comfort and safety.

[0112] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power module, characterized in that, The power module includes a substrate, multiple electronic components, multiple connection terminals, and a package, wherein the multiple electronic components are electrically connected to the substrate. Each of the connection terminals has a fixed end and a connection end at opposite ends along the first direction, the fixed end being fixed to the substrate, and the connection end being used to connect electrical components; Along the first direction, the connecting terminal includes a default portion located between the fixed end and the connecting end, wherein the cross-sectional area of ​​the connecting terminal in the default portion is smaller than the cross-sectional area of ​​the connecting terminal in the fixed end and the cross-sectional area of ​​the connecting terminal in the connecting end.

2. The power module of claim 1, wherein, The default portion includes a cutout structure that penetrates the connection terminal along a second direction, which is parallel to the thickness direction of the substrate.

3. The power module of claim 2, wherein, The hollow structure includes a strip-shaped hole, and the extension direction of the strip-shaped hole is set at an angle to the first direction; Along the first direction, the strip hole includes opposing first inner walls and second inner walls, the distance between the first inner wall and the substrate being less than the distance between the second inner wall and the substrate.

4. The power module of claim 3, wherein, Both the first inner wall and the second inner wall are arc-shaped surfaces, and the first inner wall and the second inner wall share the same center.

5. The power module of claim 2, wherein, The hollow structure includes a plurality of through holes arranged sequentially along a third direction, which is perpendicular to the first direction and the second direction; Along the first direction, the spacing between each of the through holes and the package body is equal.

6. The power module of claim 2, wherein, The hollow structure includes two notches, which are opposite each other along a third direction and are respectively connected to the two sides of the connecting terminal. The third direction is perpendicular to the first direction and the second direction. Along the first direction, the spacing between each of the notches and the package is equal.

7. The power module of claim 1, wherein, The default portion includes one or more strip grooves, each of the strip grooves being formed on the surface of the connection terminal perpendicular to a second direction, the second direction being parallel to the thickness direction of the substrate; The extension direction of each of the strip grooves is set at an angle to the first direction, and the two ends of each strip groove are connected to the two sides of the connecting terminal along the third direction, which is perpendicular to the first direction and the second direction.

8. The power module of claim 7, wherein, The connection terminal includes two surfaces opposite each other along a second direction, each surface including one of the strip grooves; Along the first direction, the distance between the groove on one of the surfaces and the substrate is not equal to the distance between the groove on the other surface and the substrate.

9. The power module of any one of claims 1-8, wherein, The default part is arranged symmetrically about the first direction.

10. A power conversion device, characterized in that, The power conversion device includes at least one copper busbar and a power module as described in any one of claims 1-9, each of the copper busbars being used to connect to the connection end of one of the connection terminals; Along the first direction, the distance between the copper busbar and the package body is greater than the distance between the default portion and the package body.

11. The power conversion device of claim 10, wherein, The default part includes a strip-shaped hole, and the extension direction of the strip-shaped hole is set at an angle to the first direction; The strip-shaped hole includes a first inner wall and a second inner wall opposite to each other along the first direction. Along the first direction, the distance between the copper busbar and the substrate is greater than the distance between the first inner wall and the package and less than the distance between the second inner wall and the package.

12. A power conversion device, characterized by, The power conversion device includes a power module, at least one copper busbar, and at least one bent adapter. The power module includes a substrate, multiple electronic components, multiple connection terminals, and a package. The multiple electronic components are electrically connected to the substrate. Each connection terminal has a fixed end and a connection end at opposite ends along a first direction. The fixed end is connected to the substrate, and the connection end extends out of the package. The bending adapter includes two connecting segments arranged at an angle and a flexible segment connecting the two connecting segments. The two connecting segments are respectively used to connect one of the copper busbars and the connecting end of one of the connecting terminals.

13. The power conversion device of claim 12, wherein, The flexible segment includes at least one bend.

14. The power conversion device of claim 12, wherein, The thickness of the bending adapter is 0.8-2 times the thickness of the connecting terminal.

15. The power conversion device of any of claims 12-14, wherein, Along the first direction, the connecting terminal includes a default portion located between the fixed end and the connecting end, the cross-sectional area of ​​the connecting terminal in the default portion is smaller than the cross-sectional area of ​​the connecting terminal in the fixed end and the cross-sectional area of ​​the connecting terminal in the connecting end, and the distance between the bending adapter and the package body is greater than the distance between the default portion and the package body.

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