Power modules and power conversion devices

Abstract

Power module and power conversion device. The power module includes a plastic package, a wafer, a cutting piece and an interconnection piece. The plastic package wraps the wafer, the cutting piece and the interconnection piece. The interconnection piece connects the wafer. At least a portion of the cutting piece is disposed on the side of the interconnection piece away from the wafer, and the cutting piece is used to cut off the interconnection piece when the current flowing through the wafer is greater than or equal to a threshold value. When the current flowing through the wafer is greater than or equal to the threshold value, the wafer fails and short-circuits. During the release of the wafer failure energy (i.e., when the wafer explodes), part of the plastic package covering the wafer cracks and explodes, and a force is applied to the interconnection piece toward the side away from the wafer, thereby pulling at least a portion of the interconnection piece toward the cutting piece, causing the cutting piece to cut off the pulled interconnection piece, thereby interrupting the current diversion of the interconnection piece, effectively reducing the possibility of short-circuiting the power circuit where the power module is located, and helping to improve the safety and reliability of the power module.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a power module and a power conversion device. Background Art

[0002] Power modules are increasingly being used, and their safety and reliability have a significant impact on the devices or equipment in which they are used. For example, when used in electric vehicles, power modules are affected by the operating environment of the vehicle, potentially leading to power module failure, or wafer failure. This can cause a short circuit in the power circuit where the power module resides, resulting in power loss for the entire vehicle and, in severe cases, fire. Summary of the Invention

[0003] The technical problem to be solved by the embodiments of the present application is to provide a power module and a power conversion device that are conducive to improving safety and reliability.

[0004] In a first aspect, embodiments of the present application provide a power module comprising a plastic encapsulation body, a wafer, a cutting element, and an interconnection element. The plastic encapsulation body encapsulates the wafer, the cutting element, and the interconnection element. The interconnection element connects the wafer. At least a portion of the cutting element is disposed on a side of the interconnection element facing away from the wafer, and the cutting element is configured to disconnect the interconnection element when the current flowing through the wafer is greater than or equal to a threshold value.

[0005] When the current flowing through the wafer is greater than or equal to the threshold, the wafer fails and short-circuits. During the release of wafer failure energy (i.e., when the wafer explodes), part of the plastic package covering the wafer cracks and explodes, and a force is applied to the interconnection component toward the side away from the wafer, thereby pulling at least part of the interconnection component toward the cutting component, so that the cutting component cuts off the pulled interconnection component, thereby interrupting the current conduction of the interconnection component, effectively reducing the possibility of short-circuit in the power circuit where the power module is located, for example, the possibility of a busbar short-circuit caused by a bridge arm straight-through in the inverter circuit, which is beneficial to improving the safety and reliability of the power module.

[0006] In combination with the first aspect, in one possible implementation, the interconnect includes a main body and a thinning portion, one end of the main body is stacked with the wafer, and the thickness of the thinning portion is less than the thickness of the main body; the cutting member is used to cut off the thinning portion when the current flowing through the wafer is greater than a threshold value.

[0007] In this possible implementation, by providing a thinning portion on the interconnect, since the thickness of the thinning portion is smaller, when a short circuit occurs in the wafer, the pulled interconnect can be more easily cut off by the cutting member, thereby shortening the time it takes for the cutting member to cut off the interconnect.

[0008] In combination with the first aspect, in one possible implementation, the cutting member includes a connected handle and a blade, at least a portion of the cutting member is disposed on a side of the thinning portion facing away from the wafer; and the thickness of the blade is smaller than that of the handle.

[0009] In this possible implementation, when the failure energy of the wafer causes the interconnect to move toward the blade, the blade with a smaller thickness can more easily cut off the interconnect from the thinned portion, further shortening the time to cut off the interconnect and improving the safety performance of the power module.

[0010] In combination with the first aspect, in one possible implementation, the blade includes a first edge and a second edge that are connected, the first edge and the second edge are both connected to the handle, and the first edge and / or the second edge are used to cut off the thinning portion when the current flowing through the wafer is greater than or equal to a threshold.

[0011] In this possible implementation, the connection between the first edge and the second edge can be opposite to the thinning portion and close to the thinning portion. When the failure energy of the wafer impacts the interconnection part and causes the interconnection part to move toward the cutting part, the connection between the first edge and the second edge is the tip of the blade, which can pierce the middle position of the thinning portion and cut off the thinning portion from both sides of the first edge and the second edge respectively.

[0012] In combination with the first aspect, in one possible implementation, along the first direction, at least part of the blade is located on one side of the thinning portion, and the first edge or the second edge is used to cut off the thinning portion when the current flowing through the wafer is greater than or equal to a threshold value, and the first direction is perpendicular to the thickness direction of the thinning portion.

[0013] In this possible implementation, the first edge or the second edge can be close to the thinning portion. When the wafer failure energy impacts the thinning portion, the first edge or the second edge can more easily cut off the pulled thinning portion, which is beneficial to improving the safety and reliability of the power module.

[0014] In combination with the first aspect, in a possible implementation, a recess is formed in the thinned portion, and at least a portion of the blade away from the end of the handle is located in the recess.

[0015] In this possible implementation, the thickness of the recess is smaller than the thickness of other positions of the thinning portion, and at least part of the end of the blade away from the handle is located in the recess. When the thinning portion is pulled, the two opposite side walls in the groove can be cut off by the first edge and the second edge respectively, wherein the recess can pass through the entire thinning portion and form a through hole in the thinning portion. The provision of the through hole makes the thinning portion easier to cut off, shortens the time it takes for the thinning portion to be cut off, and is beneficial to improving the safety and reliability of the power module.

[0016] In combination with the first aspect, in a possible implementation, along a stacking direction of the wafer and one end portion of the body, there is a distance between a projection of the thinned portion and a projection of the wafer.

[0017] In this possible implementation, the thinning portion and the wafer are staggered. When the failure energy generated by the wafer is released, it is easier to impact the interconnecting parts that are not fixedly connected to the wafer to move away from the wafer, which is conducive to cutting off the thinning portion.

[0018] In combination with the first aspect, in a possible implementation, the power module also includes a drive generator, which is arranged on the surface of the plastic package body close to the cutting piece, and the drive generator is used to drive the cutting piece to move toward the interconnecting piece when the current flowing through the wafer is greater than a threshold.

[0019] In this possible implementation, after the interconnect is impacted by wafer failure energy and moves away from the wafer, the driving generator drives the cutting element toward the interconnect when the wafer fails, making it easier for the cutting element to cut off the interconnect.

[0020] In combination with the first aspect, in a possible implementation, the drive generator includes an pyrotechnic device, which is configured to explode when the current flowing through the wafer is greater than a threshold value, and the impact force of the explosion drives the cutting member to move toward the interconnecting member.

[0021] In this possible implementation, the interconnection part will move toward the cutting piece under the failure energy of the wafer. At the same time, the cutting piece is driven to move toward the interconnection part under the explosive impact force of the pyrotechnics, making the interconnection part easier to be cut off by the cutting piece.

[0022] In a second aspect, the present application provides a power conversion device, which includes a circuit board and a power module provided in any implementation manner of the first aspect, wherein the power module is connected to the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0024] Figure 1 A schematic structural diagram of an electric vehicle provided in an embodiment of the present application;

[0025] Figure 2 A schematic structural diagram of a power conversion device provided in an embodiment of the present application;

[0026] Figure 3 A schematic structural diagram of a dual-tube packaged power module provided in this application;

[0027] Figure 4 A schematic structural diagram of a cutting member and a thinning portion provided in an embodiment of the present application;

[0028] Figure 5 A schematic structural diagram of another cutting member and thinning portion provided in one embodiment of the present application;

[0029] Figure 6 A schematic structural diagram of another cutting member and thinning portion provided in one embodiment of the present application;

[0030] Figure 7 A schematic structural diagram of another power module provided in one embodiment of the present application.

[0031] Description of reference numerals:

[0032] 10-power module, 11-plastic package, 12-power tube, 12a-bridge arm upper tube, 12b-bridge arm lower tube, 121-wafer, 122-source, 123-drain, 13-interconnection, 131-body, 132-thinning part, 1321-recess, 1322-first side, 1323-second side, 14-cutting piece, 141-handle, 142-blade, 1421-first edge, 1422-second edge, 1423-third edge, 15-drive generator, 20-circuit board, 100-power conversion device, 200-wheel, 300-motor, 400-battery assembly, 1000-electric vehicle. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0034] See also Figure 1 , Figure 1 A schematic structural diagram of an electric vehicle 1000 provided in an embodiment of the present application. The electric vehicle 1000 includes a power conversion device 100, a wheel 200, a motor 300 and a battery assembly 400. The power conversion device 100 connects the motor 300 and the battery assembly 400. For example, the power conversion device 100 connects the motor 300 and the battery assembly 400 via a high-voltage bus. The power conversion device 100 can be applied to the motor controller (Motor Control Unit, MCU) of the electric vehicle 1000. The power conversion device 100 can be an inverter or a rectifier. Among them, the inverter is used to convert the direct current generated by the battery assembly 400 into alternating current and supply power to the motor 300, and the motor 300 drives the wheel 200 to rotate.

[0035] Electric vehicle 1000 is a vehicle powered by electricity. It can be a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), or a plug-in hybrid electric vehicle (PHEV).

[0036] Specifically, the battery assembly 400 is electrically connected to the motor 300 via an inverter, and the battery assembly 400 provides electrical energy to the motor 300. The motor 300 converts the electrical energy into mechanical energy, thereby providing kinetic energy for the electric vehicle 1000 and driving the wheels 200 to rotate.

[0037] Please combine Figure 2 , Figure 2 The present invention provides a schematic structural diagram of a power conversion device 100. The power conversion device 100 includes a circuit board 20 and a power module 10. The signal pins on the power module 10 are connected to the circuit board 20.

[0038] Power modules are increasingly being used in the automotive industry. Their safety and reliability have a significant impact on the devices or equipment in which they are used. For example, when used in electric vehicles, power modules are affected by the overall operating environment and may fail. This can cause a short circuit in the power circuit where the module resides, leading to power loss for the entire vehicle and, in severe cases, fire, threatening the safety of the vehicle and its passengers.

[0039] Please combine Figure 2 The present application provides a power module 10, which can effectively reduce the possibility of short circuit in the power circuit where the power module 10 is located, thereby improving safety and reliability.

[0040] The power module 10 includes a plastic package 11, a power transistor 12, an interconnect 13, and a cutting element 14. The plastic package 11 encapsulates the power transistor 12, the interconnect 13, and the cutting element 14. The interconnect 13 is connected to the power transistor 12. At least a portion of the cutting element 14 is disposed on a side of the interconnect 13 facing away from the power transistor 12. The cutting element 14 is configured to disconnect the interconnect 13 when the current flowing through the power transistor 12 is greater than or equal to a threshold.

[0041] When the current flowing through the power tube 12 is greater than or equal to the threshold value, the power tube 12 fails and short-circuits. During the release of the failure energy of the power tube 12 (i.e., the power tube 12 explodes), part of the plastic package 11 covering the power tube 12 cracks and explodes, and exerts a force on the interconnection member 13 toward the side away from the power tube 12, thereby pulling at least part of the interconnection member 13 toward the cutting member 14, so that the cutting member 14 cuts off the pulled interconnection member 13, thereby interrupting the current diversion of the interconnection member 13, effectively reducing the possibility of short circuit in the power circuit where the power module 10 is located, for example, the possibility of a busbar short circuit caused by a bridge arm straight-through in the inverter circuit, which is beneficial to improving the safety and reliability of the power module 10.

[0042] The plastic encapsulation body 11 can be made of silicone or epoxy resin. The plastic encapsulation body 11 is filled around the assembled power tube 12, interconnection member 13 and cutting member 14 to protect the power tube 12 and the internal connection of the power module 10 from external influences and also plays an insulating role.

[0043] The power module 10 may be packaged as a single-tube package, in which case the interconnection member 13 is used to connect the power tubes 12 between the power modules 10. The power module 10 may also be packaged as a dual-tube package, in which case the interconnection member 13 is used to connect the two power tubes 12 within the power module 10. This application takes the dual-tube package of the power module 10 as an example to illustrate the technical solution of this application.

[0044] Please combine Figure 3 , Figure 3 This is a schematic diagram of the structure of a dual-tube packaged power module 10 provided in this application. The dual tubes of power module 10 can be an upper tube 12a and a lower tube 12b in an MCU inverter circuit. Upper tube 12a and lower tube 12b are connected via an interconnect 13.

[0045] The power tube 12 includes a wafer 121, a source 122 and a drain 123. The wafer 121 is connected to the source 122 and the drain 123. For example, the wafer 121 is arranged on the source 122. The wafer 121 in this application refers to a bare chip (die) with independent functions and not packaged that is cut from a wafer, which contains a complete circuit. Among them, the wafer 121 can be a single crystal silicon wafer. If the power tube 12 fails, the wafer 121 fails, and short-circuit energy will be accumulated when the wafer 121 fails. Specifically, the cutting piece 14 is arranged on the side of the interconnection piece 13 away from the wafer 121. In this application, the failure energy of the wafer 121 is used to cause the interconnection piece 13 to be pulled to the cutting piece 14, thereby interrupting the conduction of the interconnection piece 13, which is beneficial to improving the safety and reliability of the power module 10, thereby effectively ensuring that the inverter circuit will not have a bridge arm directly connected, causing the high-voltage bus to short-circuit and the entire vehicle to lose power.

[0046] The wafer 121 of the upper tube 12 a of the bridge arm is connected to the drain 123 of the lower tube 12 b of the bridge arm through the interconnection member 13 , thereby realizing internal interconnection of the power module 10 .

[0047] The interconnection member 13 is used to implement a current loop inside the power module 10 (or between power modules 10). The interconnection member 13 can be a structure that implements a current loop, such as an interconnection copper bus or a directed bonding copper (DBC).

[0048] For example, one end of the interconnection member 13 is stacked on the side of the wafer 121 facing away from the source 122 and fixedly connected, and the other end of the interconnection member 13 is stacked on the drain 123 of another power tube 12. The interconnection member 13 is located between the wafer 121 of one power tube 12 and the drain 123 of another power tube 12, and is surrounded by a plastic package 11. The portion of the interconnection member 13 is arranged opposite to the cutting member 14. When the wafer 121 fails, short-circuit energy is accumulated, and during the release of the short-circuit energy of the wafer 121, it is easier for the portion of the interconnection member 13 to move toward the cutting member 14, so that the interconnection member 13 is cut off by the cutting member 14.

[0049] The interconnect 13 includes a main body 131 and a thinned portion 132. The main body 131 is connected to the thinned portion 132, and one end of the main body 131 is stacked and fixedly connected to the wafer 121. The thinned portion 132 is thinner than the main body 131. Because the thinned portion 132 is thinner, the cutting element 14 can more easily sever the thinned portion 132 when the current flowing through the wafer 121 is greater than or equal to a threshold. This shortens the time it takes for the cutting element 14 to sever the interconnect 13, thereby increasing the probability of severing the interconnect 13.

[0050] For example, the thickness of the thinned portion 132 can be 20% of the thickness of the main body 131, effectively ensuring that the cutting member 14 cuts off the thinned portion 132 when the power tube 12 fails, thereby blocking the flow of the interconnection member 13. The thinned portion 132 includes, but is not limited to, being thinner or smaller than the main body 131.

[0051] The body 131 and the thinned portion 132 are integrally formed. Opposite ends of the thinned portion 132 are connected to the body 131. The body 131 on one side of the thinned portion 132 is stacked and fixedly connected to the wafer 121 of one power transistor 12. The body 131 on the other side of the thinned portion 132 is stacked and fixedly connected to the drain 123 of another power transistor 12.

[0052] Please combine Figure 4 , Figure 4The following is a schematic diagram of the structure of a cutting element 14 and a thinning portion 132 provided in an embodiment of the present application. In one embodiment, the thinning portion 132 may be provided with a recess 1321, wherein the recess 1321 may be located in the middle of the thinning portion 132. The thickness of the recess 1321 is smaller than the thickness of other positions of the thinning portion 132. The cutting element 14 is correspondingly provided at the recess 1321. For example, at least a portion of the cutting element 14 is located within the recess 1321. In this way, when the interconnect 13 is impacted by the energy of the wafer 121 failure, the cutting element 14 can be aligned with the recess 1321, and the cutting element 14 further pierces the recess 1321 and severs the thinning portion 132. The provision of the recess 1321 makes it easier to cut the thinning portion 132.

[0053] In particular, along the stacking direction of the wafer 121 and one end of the body 131, the recess 1321 penetrates the thinned portion 132 to form a through hole. The provision of the through hole further reduces the volume of the thinned portion 132, making it easier to cut the thinned portion 132 and shortening the time it takes to cut the thinned portion 132, thereby improving the safety and reliability of the power module 10. In other embodiments, the recess 1321 can be provided at the edge of the thinned portion 132, for example, the recess 1321 can be provided at the edges of both opposite sides of the thinned portion 132.

[0054] For example, in the stacking direction of wafer 121 and one end of body 131, a distance exists between the projection of thinned portion 132 and the projection of wafer 121. That is, thinned portion 132 is provided in the portion of interconnect 13 not connected to wafer 121, and is staggered relative to wafer 121. When failure energy generated by wafer 121 is released, it is more likely to cause the interconnect 13 not fixedly connected to wafer 121 (i.e., thinned portion 132) to move away from wafer 121, facilitating severing of thinned portion 132.

[0055] Cutting element 14 includes a connected handle 141 and a blade 142. Both handle 141 and blade 142 are enclosed and secured by plastic package 11. Blade 142 is thinner than handle 141 and is used to cut interconnect 13 when the current flowing through wafer 121 is greater than or equal to a threshold. The thickness of cutting element 14 is oriented in a direction different from the direction in which one end of body 131 and wafer 121 are stacked.

[0056] At least a portion of the cutting element 14 is located on the side of the thinning portion 132 facing away from the wafer 121. For example, along the stacking direction of one end of the body 131 and the wafer 121, at least a portion of the blade 142 and the entire handle 141 are located on the side of the thinning portion 132 facing away from the wafer 121, with the blade 142 being closer to the thinning portion 132 than the handle 141. When wafer 121 fails, the energy released from the failure of wafer 121 causes the interconnect 13 to move toward the cutting element 14. Because the cutting element 14 is entirely fixed by the plastic package 11, the thinning portion 132 can be directly impacted by the blade 142 after being impacted. Furthermore, when the energy from the failure of wafer 121 causes the interconnect 13 to move toward the blade 142, the thinner blade 142 can more easily sever the interconnect 13 from the thinning portion 132, further shortening the time required to sever the interconnect 13 and improving the safety performance of the power module 10.

[0057] In one embodiment, the blade portion 142 includes a first edge 1421 and a second edge 1422. The first edge 1421 and the second edge 1422 are both connected to the handle 141, with an end of the first edge 1421 away from the handle 141 connected to an end of the second edge 1422 away from the handle 141. The first edge 1421 and / or the second edge 1422 are configured to cut off the interconnect 13 when the current flowing through the wafer 121 is greater than or equal to a threshold value.

[0058] For example, along the first direction, at least a portion of the blade portion 142 is located on one side of the thinning portion 132, and the first edge 1421 or the second edge 1422 is used to cut off the thinning portion 132 when the current flowing through the wafer 121 is greater than or equal to a threshold value, and the first direction is perpendicular to the thickness direction of the thinning portion 132.

[0059] For example, the first edge 1421 is used to sever the interconnect 13 when the current flowing through the wafer 121 is greater than or equal to a threshold value. The first direction is the width of the interconnect 13, and the direction where the thinned portion 132 connects to the body 131 is the length of the interconnect 13. Along the stacking direction of one end of the body 131 and the wafer 121, the first edge 1421 and the second edge 1422 are both located on the side of the thinned portion 132 facing away from the wafer 121. The first edge 1421 may be closer to the thinned portion 132 than the second edge 1422, and the first edge 1421 extends to opposite sides of the thinned portion 132 along the first direction. In this way, when the interconnect 13 moves toward the cutting element 14 under the impact of the failure energy of the wafer 121, the thinned portion 132 is severed by the first edge 1421, thereby severing the connection of the interconnect 13.

[0060] For another example, the first edge 1421 and the second edge 1422 are respectively located on the first side 1322 and the second side 1323 opposite to the thinned portion 132. The direction from the first side 1322 to the second side 1323 is the first direction and is the width direction of the interconnection member 13.

[0061] Please combine Figure 5 , Figure 5 This is a schematic diagram of the structure of another cutting element 14 and thinned portion 132 according to one embodiment of the present application. The angle between the extension direction of the second edge 1422 and the direction from the blade 142 to the handle 141 is an acute angle. Along the direction from the blade 142 to the handle 141, the orthographic projection of the second edge 1422 extends from the first side 1322 to the second side 1323. Among them, the handle 141 is arranged on the side of the thinning portion 132 along the stacking direction of one end of the interconnecting member 13 and the wafer 121, away from the wafer 121; a part of the blade 142 is located on the side of the thinning portion 132 along the stacking direction of one end of the main body 131 and the wafer 121, away from the wafer 121; another part of the blade 142 is located on the side of the thinning portion 132 along the stacking direction of one end of the main body 131 and the wafer 121, facing the wafer 121; at least a part of the second edge 1422 is arranged on the first side 1322 of the thinning portion 132 and is close to the side of the thinning portion 132 on the first side 1322. With such an arrangement, when the failure energy of the wafer 121 impacts the interconnecting member 13 and causes the interconnecting member 13 to face the cutting member 14, the second edge 1422 of the blade 142 is more likely to cut off the pulled thinning portion 132, which is beneficial to reducing the possibility of a bridge arm straight-through in the inverter circuit causing a bus short circuit.

[0062] like Figure 5 As shown, the extension direction of the first edge 1421 is parallel to the direction from the blade 142 to the handle 141. In other words, the blade 142 is shaped like a right triangle, the hypotenuse of the right triangle is the second edge 1422, and the right angle of the right triangle is the first edge 1421.

[0063] For example, the included angle between the extension direction of the second edge 1422 and the direction from the blade 142 to the handle 141 includes an acute angle, that is, the blade 142 is in the shape of an acute triangle.

[0064] Furthermore, when the blade portion 142 is shaped like an acute triangle, both the first edge 1421 and the second edge 1422 are used to sever the interconnect 13 when the current flowing through the wafer 121 is greater than or equal to a threshold. Specifically, the junction of the first edge 1421 and the second edge 1422 may directly face and be close to the thinned portion 132, wherein the junction of the first edge 1421 and the second edge 1422 constitutes the tip of the blade portion 142. When the failure energy of the wafer 121 impacts the interconnect 13 and causes the interconnect 13 to move toward the cutting element 14, the thinned portion 132 may be pierced and severed from both sides of the first edge 1421 and the second edge 1422.

[0065] Please combine Figure 6 , Figure 6 A schematic diagram of the structure of another cutting element 14 and thinning portion 132 provided in one embodiment of the present application. In another embodiment, the blade portion 142 includes a first edge 1421, a second edge 1422, and a third edge 1423. The first edge 1421 and the second edge 1422 are located on the first side 1322 and the second side 1323 of the thinning portion 132, respectively. The third edge 1423 is located on the side of the blade portion 142 facing away from the handle 141 and connects the first edge 1421 and the second edge 1422. The first edge 1421, the second edge 1422, and the third edge 1423 can all be used to cut the interconnect 13 when the current flowing through the wafer 121 is greater than or equal to a threshold value.

[0066] Specifically, at least a portion of the cutting element 14 is located on a side of the thinned portion 132 that faces away from the wafer 121 along the stacking direction of the wafer 121 and one end of the interconnecting element 13. The third edge 1423 extends in the same direction as the direction from the first side 1322 to the second side 1323. Thus, when the energy from the failure of the power tube 12 causes the thinned portion 132 to fly away from the power tube 12, the thinned portion 132 moves toward the cutting element 14 and acts on the third edge 1423. Because the cutting element 14 is entirely enclosed by the plastic package 11, the third edge 1423 is less impacted. As a result, the thinned portion 132 can be severed by the third edge 1423 of the blade 142, or pierced by the third edge 1423 and then severed by the first edge 1421 and the second edge 1422, thereby interrupting the flow diversion of the interconnecting element 13.

[0067] In addition, when a recess 1321 is formed on the thinning portion 132, at least a portion of the connection between the first edge 1421 and the second edge 1422 or at least a portion of the third edge 1423 is penetrated by the recess 1321. When the thinning portion 132 is pulled, the side walls on both sides of the recess 1321 can be cut off by the first edge 1421 and the second edge 1422.

[0068] Please combine Figure 7 , Figure 7 A schematic structural diagram of another power module 10 provided in one embodiment of the present application. In other embodiments, the power module 10 may further include a drive generator 15. The drive generator 15 is provided on the surface of the plastic package 11 close to the cutting member 14. The drive generator 15 is used to drive the cutting member 14 toward the interconnecting member 13 when the current flowing through the wafer 121 is greater than or equal to a threshold value. For example, along the stacking direction of one end of the interconnecting member 13 and the wafer 121, the drive generator 15 is located on the side of the cutting member 14 facing away from the wafer 121, and is fixedly connected to the surface of the plastic package 11.

[0069] Among them, the driving generator 15 can be an pyrotechnic device, which explodes when the current flowing through the wafer 121 is greater than or equal to a threshold value. The impact force of the explosion blows the plastic package 11 away and drives the cutting piece 14 in the plastic package 11 to move toward the interconnecting piece 13. At the same time, the impact force of the failure energy of the wafer 121 on the interconnecting piece 13 moves toward the cutting piece 14, making it easier for the interconnecting piece 13 to be cut off by the cutting piece 14.

[0070] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixed", etc. should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined.

[0071] Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances. The first, second and various numerical numbers involved in this article are only for the convenience of description and are not intended to limit the scope of this application.

[0072] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0073] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power module, characterized in that: The invention comprises a plastic package, a wafer, a cutting piece and an interconnection piece, wherein the plastic package wraps the wafer, the cutting piece and the interconnection piece, the interconnection piece connects the wafer, at least a portion of the cutting piece is arranged on a side of the interconnection piece away from the wafer, and the cutting piece is used to cut off the interconnection piece when the current flowing through the wafer is greater than or equal to a threshold value, wherein when the current flowing through the wafer is greater than or equal to the threshold value, the wafer fails, and the short-circuit energy accumulated by the wafer failure is used to apply a force to the interconnection piece toward the side away from the wafer, so as to pull at least a portion of the interconnection piece toward the cutting piece, so that the cutting piece cuts off the pulled interconnection piece.

2. The power module according to claim 1, wherein: The interconnection component includes a main body and a thinning portion, one end of the main body is stacked with the wafer, and the thickness of the thinning portion is smaller than the thickness of the main body; the cutting component is used to cut off the thinning portion when the current flowing through the wafer is greater than a threshold.

3. The power module according to claim 2, characterized in that: The cutting piece includes a connected handle and a blade. At least a portion of the cutting piece is provided on a side of the thinning portion away from the wafer. The thickness of the blade is smaller than that of the handle.

4. The power module according to claim 3, characterized in that: The blade portion includes a first edge and a second edge connected to each other, wherein the first edge and the second edge are both connected to the handle portion, and the first edge and / or the second edge are used to cut off the thinned portion when the current flowing through the wafer is greater than or equal to a threshold value.

5. The power module according to claim 4, characterized in that: At least part of the blade is located on one side of the thinning portion along a first direction, and the first edge or the second edge is used to cut off the thinning portion when the current flowing through the wafer is greater than or equal to a threshold value. The first direction is perpendicular to the thickness direction of the thinning portion.

6. The power module according to claim 3, characterized in that: The thinned portion is formed with a recess, and at least a portion of an end of the blade away from the handle is located in the recess.

7. The power module according to claim 2, characterized in that: Along a stacking direction of the wafer and one end portion of the body, a distance exists between a projection of the thinned portion and a projection of the wafer.

8. The power module according to claim 1, wherein: The power module further includes a drive generator, which is disposed on a surface of the plastic package body close to the cutting piece. The drive generator is configured to drive the cutting piece to move toward the interconnecting piece when a current flowing through the wafer is greater than a threshold.

9. The power module according to claim 8, characterized in that: The driving generator includes an initiating explosive device, which is configured to explode when the current flowing through the wafer is greater than a threshold value, and the impact force of the explosion drives the cutting member to move toward the interconnecting member.

10. A power conversion device, characterized in that: It comprises a circuit board and a power module as described in any one of claims 1 to 9, wherein the power module is connected to the circuit board.

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