Power module and power conversion device

Abstract

The utility model provides a power module and power conversion equipment, and relates to the technical field of electronics. The power module comprises a power device, an insulating substrate, a composite substrate and a radiator. The power device, the insulating substrate, the composite substrate and the radiator are sequentially arranged in the thickness direction of the insulating substrate. The radiator comprises a containing cavity and a mounting hole, and the composite substrate is at least partially contained in the mounting hole and seals the containing cavity. The composite substrate comprises a first connecting piece and a second connecting piece which are connected, in the thickness direction of the insulating substrate, the first connecting piece is connected with the insulating substrate, the side wall of the second connecting piece is connected with the hole wall of the mounting hole, and the material of the second connecting piece is the same as that of the radiator; the maximum size of the second connecting piece is larger than or equal to the maximum size of the first connecting piece in the direction perpendicular to the thickness direction of the insulating substrate. The power module is higher in heat dissipation efficiency, the power conversion equipment is better in structural stability and performance, and the power module is convenient to assemble and low in cost.

Description

TECHNICAL FIELD

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

[0002] In the prior art, a thermal interface material (TMS) is filled between an insulating substrate and a heat sink, and the heat of a power device is diffused to the heat sink through the insulating substrate and the thermal interface material, and then diffused to the outside from the heat sink, so as to achieve heat dissipation of the power device. However, the low thermal conductivity of the thermal interface material leads to low heat dissipation efficiency of the power device. CONTENT OF THE UTILITY MODEL

[0003] The present application provides a power module and a power conversion device, aiming to solve the problem of low heat dissipation efficiency of the power device.

[0004] In a first aspect, the present application provides a power module, which comprises a power device, an insulating substrate, a composite substrate and a heat sink. The power device, the insulating substrate, the composite substrate and the heat sink are sequentially arranged in the thickness direction of the insulating substrate. The heat sink comprises a receiving cavity and a mounting hole, the mounting hole is located on one side of the receiving cavity and communicates with the receiving cavity in the thickness direction of the insulating substrate, and the composite substrate is at least partially accommodated in the mounting hole and closes the receiving cavity. The composite substrate comprises a first connecting member and a second connecting member connected to each other, the first connecting member is connected to the insulating substrate in the thickness direction of the insulating substrate, the side wall of the second connecting member is connected to the hole wall of the mounting hole, and the material of the second connecting member is the same as that of the heat sink; in the direction perpendicular to the thickness direction of the insulating substrate, the maximum size of the second connecting member is greater than or equal to the maximum size of the first connecting member.

[0005] The power module provided by the present application is applied to a power conversion device. The receiving cavity contains cooling liquid. The composite substrate is at least partially accommodated in the mounting hole and closes the receiving cavity, so that the cooling liquid in the receiving cavity can contact the composite substrate, and the heat generated by the power device during operation can be transmitted to the cooling liquid through the composite substrate, and then transmitted to the external environment through the cooling liquid. The heat generated by the power device during operation can not pass through the heat sink, which is conducive to shortening the heat dissipation path of the power device, and the heat of the power device can be diffused to the cooling liquid more quickly, which is conducive to improving the heat dissipation efficiency of the power device.

[0006] In addition, the design that the material of the second connecting member is the same as that of the heat sink makes the second connecting member and the heat sink fixedly connected, which is conducive to improving the connection strength of the second connecting member and the heat sink, and is conducive to improving the structural stability and reliability; moreover, it is convenient for assembly, the processing efficiency is higher, and the cost is reduced.

[0007] In some embodiments, the first connecting member has a thermal conductivity greater than that of the second connecting member. The design that the first connecting member has a thermal conductivity greater than that of the second connecting member makes the first connecting member have better thermal conductivity, and the heat of the power device can be quickly spread to the cooling liquid through the first connecting member, thereby improving the heat dissipation efficiency of the power device.

[0008] In some embodiments, the first connecting member and the second connecting member jointly enclose a receiving groove, the opening of the receiving groove faces away from the receiving cavity in the thickness direction of the insulating substrate, and the insulating substrate is at least partially arranged in the receiving groove and fixedly stacked with the first connecting member. The design that the first connecting member and the second connecting member jointly enclose a receiving groove, the opening of the receiving groove faces away from the heat sink in the thickness direction of the insulating substrate, and the insulating substrate is at least partially arranged in the receiving groove and fixedly stacked with the first connecting member reduces the size of the power module in the thickness direction of the insulating substrate, and the structure is compact, which is conducive to miniaturization design.

[0009] In some embodiments, the second connecting member is fixedly stacked on the side of the first connecting member facing away from the receiving cavity, and the receiving groove penetrates the second connecting member in the thickness direction of the insulating substrate. The design that the second connecting member is fixedly stacked on the side of the first connecting member facing away from the receiving cavity, and the receiving groove penetrates the second connecting member in the thickness direction of the insulating substrate can realize the sealing of the receiving cavity through only the first connecting member, which is conducive to increasing the contact area of the first connecting member and the cooling liquid in the receiving cavity and improving the heat dissipation efficiency of the power device. Moreover, the structure is simple, which is convenient for processing, improves the processing efficiency, and further reduces the processing cost.

[0010] In some embodiments, the second connecting member surrounds and covers at least part of the side wall of the first connecting member. The design that the second connecting member surrounds and covers at least part of the side wall of the first connecting member makes the first connecting member more difficult to deform when subjected to the pressure of the cooling liquid in the receiving cavity, thereby avoiding damage to the insulating substrate and the power device caused by the deformation of the first connecting member and improving the service life of the power module.

[0011] In some embodiments, the size of the second connecting member in the thickness direction of the insulating substrate is greater than that of the first connecting member in the thickness direction of the insulating substrate. The design that the size of the second connecting member in the thickness direction of the insulating substrate is greater than that of the first connecting member in the thickness direction of the insulating substrate makes the first connecting member be better covered by the second connecting member, and the first connecting member is more difficult to deform when subjected to the pressure of the cooling liquid in the receiving cavity, thereby avoiding damage to the insulating substrate and the power device caused by the deformation of the first connecting member and further improving the service life of the power module. Moreover, it is conducive to increasing the connection area of the second connecting member and the hole wall of the mounting hole, improving the connection strength, and improving the structural stability of the power module.

[0012] In some embodiments, the power module further comprises a package, the package covering the insulating substrate and the power device. The package can protect the power device from damage, thereby prolonging the service life of the power module and the power conversion device.

[0013] In some embodiments, the first connecting member is provided with a barrier wall facing the surface of the insulating substrate, the barrier wall surrounds the insulating substrate, and the barrier wall is spaced apart from the second connecting member, and the package covers the barrier wall. The barrier wall is provided on the surface of the first connecting member facing the insulating substrate, and the package covers the barrier wall. The design improves the bonding force between the package and the composite substrate, and improves the stability of the connection between the package and the composite substrate.

[0014] In some embodiments, the barrier wall is provided with a first protrusion on one side along the thickness direction of the barrier wall, and the first protrusion faces the insulating substrate. The package is partially located between the first protrusion and the first connecting member. By providing the first protrusion, the first protrusion limits the package in the thickness direction of the insulating substrate, which helps to improve the stability of the connection between the package and the composite substrate.

[0015] In some embodiments, the barrier wall is spaced apart from the groove side wall of the receiving groove, the barrier wall is provided with a flow hole, the flow hole penetrates the barrier wall along the thickness direction of the barrier wall, and the flow hole penetrates the barrier wall along the thickness direction of the insulating substrate. By providing the flow hole, it is beneficial to improve the flowability of the package in the receiving groove, so that the package can fill the entire receiving groove, prevent the occurrence of voids, improve the bonding force between the package and the composite substrate, and further improve the reliability.

[0016] In some embodiments, the groove side wall of the receiving groove is provided with a second protrusion facing the insulating substrate. The package is partially located between the second protrusion and the first connecting member. By providing the second protrusion, the second protrusion limits the package in the thickness direction of the insulating substrate, which further improves the stability of the connection between the package and the composite substrate.

[0017] In some embodiments, the first connecting member is fixedly stacked with the insulating substrate, and the second connecting member is fixedly stacked on the side of the first connecting member away from the insulating substrate. The first connecting member is fixedly stacked with the insulating substrate, and the second connecting member is fixedly stacked on the side of the first connecting member away from the insulating substrate. The design seals the receiving cavity with the second connecting member, and the second connecting member can resist the pressure of the cooling liquid in the receiving cavity. The pressure of the cooling liquid does not directly act on the first connecting member, preventing the first connecting member from deforming, avoiding damage to the insulating substrate and the power device on the first connecting member, which helps to improve the service life of the power module and the power conversion device.

[0018] In some embodiments, the surface of the second connecting piece away from the first connecting piece is provided with a through hole. By providing the through hole, the cooling liquid can flow into the through hole, the first connecting piece can directly contact the cooling liquid, the distance between the power device and the cooling liquid is shorter, the heat dissipation path is shorter, the heat of the power device can be more quickly spread to the cooling liquid, and the heat dissipation effect and efficiency of the power module are improved.

[0019] In some embodiments, the insulating substrate comprises, in the thickness direction of the insulating substrate, a heat-conducting layer, an insulating layer and an electrically-conductive layer arranged in sequence, the electrically-conductive layer faces the power device, the first connecting piece is fixed to the side of the heat-conducting layer away from the insulating layer, and the size of the first connecting piece in the thickness direction of the insulating substrate is greater than the size of the heat-conducting layer in the thickness direction of the insulating substrate. The design that the size of the first connecting piece in the thickness direction of the insulating substrate is greater than the size of the heat-conducting layer in the thickness direction of the insulating substrate is conducive to improving the strength of the first connecting piece, improving the reliability of the connection between the first connecting piece and the insulating substrate, and improving the structural stability and reliability of the power module.

[0020] In some embodiments, the number of insulating substrates and the number of power devices are both plural, at least one power device is arranged on the side of each insulating substrate away from the heat sink, and the plural insulating substrates are arranged in sequence and spaced apart in a direction perpendicular to the thickness direction of the insulating substrate. The power module further comprises a first electrically-conductive piece arranged between two adjacent insulating substrates, one end of the first electrically-conductive piece is connected to the electrically-conductive layer of one of the insulating substrates, and the other end is connected to the electrically-conductive layer of the other insulating substrate.

[0021] The design that the first electrically-conductive piece is arranged between two adjacent insulating substrates realizes current flow between the two adjacent insulating substrates, so that in the two adjacent insulating substrates, the power device arranged in one of the insulating substrates can flow current with the power device arranged in the other insulating substrate, which is conducive to reducing the stray inductance in the circuit, reducing the risk of oscillation and overvoltage in the circuit, improving the performance of the power module, and further improving the performance of the power conversion device.

[0022] In some embodiments, the surface of the first connecting piece facing the insulating substrate is provided with a first groove, and the first groove is close to the edge of the insulating substrate. By providing the first groove, the stress generated by the edge of the insulating substrate can be released in the first groove, avoiding the stress directly acting on the first connecting piece and avoiding the deformation of the first connecting piece damaging the insulating substrate and the power device, which is conducive to improving the service life of the power module and further improving the service life of the power conversion device.

[0023] In a second aspect, the embodiments of the present application also provide a power conversion device. The power conversion device comprises a circuit board and the power module of any one of the first aspect, and the power module is mounted on the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the drawings needed to be used in the embodiments of the present application or the background art will be described below.

[0025] Figure 1 is a structural block diagram of a power conversion device cooperating with a photovoltaic module and a power grid provided by the embodiments of the present application;

[0026] Figure 2 is a perspective structural schematic diagram of the power conversion device shown in Figure 1

[0027] Figure 3 is a perspective structural schematic diagram of a power module of the power conversion device shown in Figure 2

[0028] Figure 4 is a perspective structural exploded schematic diagram of the power module shown in Figure 3

[0029] Figure 5 is a sectional view of the power module shown in Figure 3

[0030] Figure 6 is an enlarged view of the power module at A shown in Figure 5

[0031] Figure 7 is an enlarged view of the power module at B shown in Figure 5

[0032] Figure 8 is an enlarged view of the power module at C shown in Figure 4

[0033] Figure 9 is a sectional view of the power module shown in Figure 3

[0034] Figure 10 is an enlarged view of the power module at D shown in Figure 9

[0035] Figure 11 is a sectional view of the power module shown in Figure 3

[0036] Figure 12 is a sectional view of the power module shown in Figure 3 DETAILED DESCRIPTION ​​​​​​​​​​​

[0037] The embodiment of the present application provides a power module and a power conversion device. The power module is applied to the power conversion device. In the present application, the material of feature A is the same as that of feature B means that the main component of feature A is the same as that of feature B; wherein the content of the main component of feature A can be equal to or different from that of feature B.

[0038] The embodiment of the present application is described below with reference to the drawings in the embodiment of the present application.

[0039] Please refer to Figure 1 and Figure 2 , Figure 1 is a structural block diagram of a power conversion device 1000 provided by the embodiment of the present application and a photovoltaic module 2000 and a power grid 3000. Figure 2 is Figure 1 a perspective structural schematic diagram of the power conversion device 1000.

[0040] Exemplarily, the power conversion device 1000 is a photovoltaic inverter. In other embodiments, the power conversion device 1000 can also be a rectifier, a transformer or other inverters and electronic devices for power conversion. The power conversion device 1000 is used to convert direct current output by the photovoltaic module 2000 into alternating current to supply the power grid 3000. In other embodiments, the power conversion device 1000 can also be used to convert direct current output by the photovoltaic module 2000 into alternating current to supply a load device. The load device can be electronic devices using alternating current, including but not limited to motors, fans or air conditioners. In other embodiments, the power conversion device 1000 can also be applied to an electric drive controller. The power conversion device 1000 can also be used to convert direct current output by a battery into alternating current to supply a motor.

[0041] In some embodiments, the power conversion device 1000 comprises a power module 100, a circuit board 200, an input terminal 300 and an output terminal 400. The power module 100, the input terminal 300 and the output terminal 400 are all mounted on the circuit board 200. Specifically, the power module 100 is mounted on one side of the circuit board 200, and the input terminal 300 and the output terminal 400 are mounted on the other side of the circuit board 200. In other embodiments, the power module 100, the input terminal 300 and the output terminal 400 can also be mounted on the same side of the circuit board 200.

[0042] The input terminal 300 is configured to receive the direct current output by the photovoltaic module 2000. The power module 100 is configured to receive the direct current from the input terminal 300 and convert the direct current into alternating current. The output terminal 400 is configured to receive the alternating current output by the power module 100 and transmit the alternating current to the power grid 3000. The power conversion device 1000 converts the direct current output by the photovoltaic module 2000 into alternating current through the power module 100.

[0043] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , in combination with Figure 1 and Figure 2 , Figure 3 is a perspective structural schematic diagram of the power module 100 of the power conversion device 1000 shown in Figure 2 . Figure 4 is a perspective structural exploded schematic diagram of the power module 100 shown in Figure 3 . Figure 5 is a sectional view of the power module 100 along the line L1-L1 shown in Figure 3 . Figure 6 is an enlarged view of the power module 100 at A shown in Figure 5 . Figure 7 is an enlarged view of the power module 100 at B shown in Figure 5 . Figure 8 is an enlarged view of the power module 100 at C shown in Figure 4 .

[0044] As shown in Figure 3 , Figure 4 and Figure 5 , in some embodiments, the power module 100 comprises a functional assembly 10 and a heat sink 20, the functional assembly 10 comprising a terminal 11, a power device 12, an insulating substrate 13, a composite substrate 14 and a package 15. In this embodiment, the thickness direction of the insulating substrate 13 is defined as the first direction (i.e. the direction of the Z axis shown in the figure), the direction perpendicular to the thickness direction of the insulating substrate 13 is defined as the second direction (i.e. the direction of the X axis shown in the figure), and the direction perpendicular to the first direction and the second direction is defined as the third direction (i.e. the direction of the Y axis shown in the figure). In this embodiment, the second direction (i.e. the direction of the X axis shown in the figure) is the length direction of the insulating substrate 13, and the third direction (i.e. the direction of the Y axis shown in the figure) is the width direction of the insulating substrate 13. In other embodiments, the direction of the Y axis shown in the figure can also be the length direction of the insulating substrate 13, and the direction of the X axis shown in the figure can also be the width direction of the insulating substrate 13.

[0045] In the Z-axis direction, the power device 12, the insulating substrate 13, the composite substrate 14 and the heat sink 20 are sequentially arranged, the terminal 11 is arranged on the side of the insulating substrate 13 away from the heat sink 20 and is electrically connected with the power device 12, and the packaging member 15 covers the insulating substrate 13, the power device 12 and part of the terminal 11. The end of the terminal 11 away from the insulating substrate 13 is exposed outside the packaging member 15 and is mounted on the circuit board 200 (as shown in Figure 2 The direct current delivered from the input terminal 300 (as shown in Figure 1 is transmitted to the power device 12 through the terminal 11. The power device 12 is used to convert the direct current into alternating current. The alternating current output by the power device 12 is transmitted to the output terminal 400 (as shown in Figure 1 ) through the terminal 11. The output terminal 400 receives the alternating current output by the power device 12 and transmits the alternating current to the power grid 3000 (as shown in Figure 1 ) for supplying the power grid 3000. The heat sink 20 is used to dissipate heat of the power device 12 to ensure that the power module 100 can work normally. In some embodiments, the size of the composite substrate 14 in the Z-axis direction can be less than or equal to 15 mm. In other embodiments, the size of the composite substrate 14 in the Z-axis direction can also be greater than 15 mm.

[0046] As shown in Figure 4 and Figure 5 , in some embodiments, the heat sink 20 comprises a receiving cavity 21 and a mounting hole 22. In the Z-axis direction, the mounting hole 22 is located on one side of the receiving cavity 21 and communicates with the receiving cavity 21. The receiving cavity 21 is used to accommodate the cooling liquid, which can be water, ethanol or other cooling liquid. The mounting hole 22 is rectangular in shape. In other embodiments, the mounting hole 22 can also be circular, triangular or other special-shaped structures, etc. The four corners of the mounting hole 22 are provided with round corners. In other embodiments, the four corners of the mounting hole 22 can also be provided with bevels or right angles.

[0047] In some embodiments, the heat sink 20 further comprises a first through hole 23 and a second through hole 24. The first through hole 23 and the second through hole 24 both communicate with the receiving cavity 21 and are both arranged on both sides of the mounting hole 22 and spaced apart from the mounting hole 22. Specifically, in the X-axis direction, the first through hole 23 and the second through hole 24 are located on both sides of the receiving cavity 21 and on both sides of the mounting hole 22. In other embodiments, in the Y-axis direction, the first through hole 23 and the second through hole 24 can also be located on both sides of the receiving cavity 21 and on both sides of the mounting hole 22. In other embodiments, in the Z-axis direction, the first through hole 23 and the second through hole 24 can be located on one side or both sides of the receiving cavity 21; in the X-axis direction or the Y-axis direction, the first through hole 23 and the second through hole 24 are located on both sides of the mounting hole 22. The cooling liquid can flow into the receiving cavity 21 from the first through hole 23 and then flow out of the receiving cavity 21 from the second through hole 24.

[0048] As Figure 5 and Figure 6 shown, in some embodiments, the insulating substrate 13 includes a heat-conductive layer 132, an insulating layer 131 and a conductive layer 133 arranged in sequence in the Z-axis direction. Specifically, in the Z-axis direction, the heat-conductive layer 132, the insulating layer 131 and the conductive layer 133 are fixed and stacked in sequence. The heat-conductive layer 132 faces the composite substrate 14, and the conductive layer 133 faces the power device 12. Among them, the projection of the heat-conductive layer 132 along the Z-axis direction overlaps the projection of the conductive layer 133 along the Z-axis direction. For example, the insulating layer 131 is made of an insulating material including but not limited to ceramic or epoxy resin. The heat-conductive layer 132 and the conductive layer 133 are made of the same conductive material. Specifically, the heat-conductive layer 132 and the conductive layer 133 are both made of copper. It can be understood that the material of the heat-conductive layer 132 and the material of the conductive layer 133 are the same. The design that the material of the heat-conductive layer 132 and the material of the conductive layer 133 are the same is beneficial to reduce the material cost of the heat-conductive layer 132 and the conductive layer 133, beneficial to reduce the processing cost of the insulating substrate 13, and beneficial to reduce the processing cost of the power module 100. In other embodiments, the heat-conductive layer 132 and the conductive layer 133 can also be made of different conductive materials. That is, the material of the heat-conductive layer 132 and the material of the conductive layer 133 can also be different.

[0049] The power device 12 is an IGBT (Insulated Gate Bipolar Transistor) chip. In other embodiments, the power device 12 can also be an FRD (Fast Recovery Diode) chip, a Mosfet (Metal oxide semiconductor field-effect transistor) chip, or other electronic devices such as a triode. Through a method including but not limited to soldering, sintering or brazing, the power device 12 is arranged on the side of the conductive layer 133 of the insulating substrate 13 away from the insulating layer 131.

[0050] As Figure 4 , Figure 5 and Figure 6As shown, in some embodiments, the composite substrate 14 is at least partially accommodated in the mounting hole 22 and closes the accommodation cavity 21. The composite substrate 14 includes a first connecting member 141 and a second connecting member 142 connected together. In the Z-axis direction, the first connecting member 141 is connected to the insulating substrate 13, and the sidewall 1423 of the second connecting member 142 is connected to the hole wall of the mounting hole 22. The material of the first connecting member 141 is different from the material of the second connecting member 142. The material of the second connecting member 142 is the same as the material of the heat sink 20. In the direction perpendicular to the thickness direction of the insulating substrate 13, the maximum size of the second connecting member 142 is greater than or equal to the maximum size of the first connecting member 141. The direction perpendicular to the thickness direction of the insulating substrate 13 is the X-axis direction or the Y-axis direction. Among them, the thermal conductivity of the first connecting member 141 is greater than the thermal conductivity of the second connecting member 142. In this embodiment, the first connecting member 141 and the second connecting member 142 are both accommodated in the mounting hole 22, and the first connecting member 141 and the second connecting member 142 jointly close the accommodation cavity 21. The cooling liquid in the accommodation cavity 21 is in contact with the first connecting member 141 and the second connecting member 142.

[0051] For example, the material of the first connecting member 141 is copper, and the material of the heat sink 20 and the material of the second connecting member 142 are aluminum. In other embodiments, the material of the first connecting member 141 can be one of aluminum alloy, Al Si (aluminum silicon) alloy, magnesium alloy, steel, titanium alloy, Al Si C (aluminum silicon carbide), and zinc, and the material of the second connecting member 142 and the material of the heat sink 20 can be another one of aluminum alloy, Al Si alloy, magnesium alloy, steel, titanium alloy, Al Si C, and zinc. The thermal conductivity of the first connecting member 141 can also be less than or equal to the thermal conductivity of the second connecting member 142. It should be noted that in this application, the "thermal conductivity of component A" refers to the thermal conductivity of the material of component A.

[0052] In the embodiments of the present application, the composite substrate 14 is at least partially accommodated in the mounting hole 22 and closes the accommodation cavity 21, so that the cooling liquid in the accommodation cavity 21 can contact the composite substrate 14, and the heat generated by the power device 12 is transmitted to the cooling liquid through the composite substrate 14, and then transmitted to the external environment through the cooling liquid. The heat generated by the power device 12 can not pass through the heat sink 20, which is beneficial to shorten the heat dissipation path of the power device 12, so that the heat of the power device 12 can be more quickly spread to the cooling liquid, which is beneficial to improve the heat dissipation efficiency of the power device 12.

[0053] In addition, in the present application, the material of the second connecting piece 142 is the same as that of the heat sink 20, so that the second connecting piece 142 and the heat sink 20 can be fixedly connected by welding, which is conducive to improving the connection strength of the second connecting piece 142 and the heat sink 20, and is conducive to improving the structural stability and reliability; moreover, it is convenient to assemble, the processing efficiency is higher, and the cost is reduced.

[0054] In addition, the composite substrate 14 can be welded and fixed with the heat sink 20 first, and then the insulating substrate 13 and the power device 12 are mounted on the composite substrate 14 after the welding temperature of the composite substrate 14 and the heat sink 20 is reduced, so as to avoid the welding temperature of the composite substrate 14 and the heat sink 20 acting on the insulating substrate 13 and the power device 12, and avoid the deformation of the insulating substrate 13 and the power device 12 due to the excessive temperature, thereby improving the production yield.

[0055] The thermal conductivity of the first connecting piece 141 is greater than that of the second connecting piece 142, so that the heat dissipation performance of the first connecting piece 141 is better, and the heat of the power device 12 can be quickly spread to the cooling liquid through the first connecting piece 141, thereby improving the heat dissipation efficiency of the power device 12.

[0056] As shown in Figure 4 , Figure 5 and Figure 6 , in some embodiments, the first connecting piece 141 and the second connecting piece 142 form a receiving groove 143, and in the Z-axis direction, the opening 1430 of the receiving groove 143 faces away from the receiving cavity 21, and the insulating substrate 13 is at least partially arranged in the receiving groove 143 and is fixedly stacked with the first connecting piece 141. For example, the insulating substrate 13 and the power device 12 are received in the receiving groove 143. Among them, the first connecting piece 141 and the opening 1430 of the receiving groove 143 are oppositely arranged.

[0057] The second connecting piece 142 is fixedly stacked on the side of the first connecting piece 141 away from the receiving cavity 21 of the heat sink 20 by means of sintering, welding, rolling or gluing, etc. In the X-axis direction, the maximum size of the second connecting piece 142 is equal to the maximum size of the first connecting piece 141, and the maximum size of the second connecting piece 142 is equal to the maximum size of the mounting hole 22. In the Y-axis direction, the maximum size of the second connecting piece 142 is equal to the maximum size of the first connecting piece 141, and the maximum size of the second connecting piece 142 is equal to the maximum size of the mounting hole 22.

[0058] In this embodiment, the mounting hole 22 is a rectangular hole, the maximum dimension of the mounting hole 22 in the X-axis direction is the length of the mounting hole 22, and the maximum dimension of the mounting hole 22 in the Y-axis direction is the width of the mounting hole 22. The first connecting piece 141 is a rectangular plate, the maximum dimension of the first connecting piece 141 in the X-axis direction is the length of the first connecting piece 141, and the maximum dimension of the first connecting piece 141 in the Y-axis direction is the width of the first connecting piece 141. The second connecting piece 142 is a rectangular plate, the maximum dimension of the second connecting piece 142 in the X-axis direction is the length of the second connecting piece 142, and the maximum dimension of the second connecting piece 142 in the Y-axis direction is the width of the second connecting piece 142.

[0059] In other embodiments, the mounting hole 22 can also be a circular hole, the maximum dimension of the mounting hole 22 in the X-axis direction is the diameter of the mounting hole 22, and the maximum dimension of the mounting hole 22 in the Y-axis direction is the diameter of the mounting hole 22. The first connecting piece 141 can also be a circular plate, the maximum dimension of the first connecting piece 141 in the X-axis direction is the diameter of the first connecting piece 141, and the maximum dimension of the first connecting piece 141 in the Y-axis direction is the diameter of the first connecting piece 141. The second connecting piece 142 can also be a circular plate, the maximum dimension of the second connecting piece 142 in the X-axis direction is the diameter of the second connecting piece 142, and the maximum dimension of the second connecting piece 142 in the Y-axis direction is the diameter of the second connecting piece 142.

[0060] The accommodation groove 143 penetrates the second connecting piece 142 along the Z-axis direction, and the opening 1430 of the accommodation groove 143 is opposite to the first connecting piece 141 in the Z-axis direction. Specifically, the projection of the opening 1430 of the accommodation groove 143 along the Z-axis direction overlaps the projection of the first connecting piece 141 along the Z-axis direction.

[0061] The insulating substrate 13 is accommodated in the accommodation groove 143. The first connecting piece 141 is fixed to the side of the heat-conducting layer 132 of the insulating substrate 13 away from the insulating layer 131 by means including but not limited to soldering, sintering or brazing. Before the heat-conducting layer 132 is welded with the first connecting piece 141, an oxidation-resistant plating layer made of an organic material can be applied to the surface of the first connecting piece 141, which is beneficial to reduce the porosity of the welding between the first connecting piece 141 and the heat-conducting layer 132, and improve the welding effect and reliability of the first connecting piece 141 and the heat-conducting layer 132. In other embodiments, other plating layers can be used instead of the oxidation-resistant plating layer, such as a Ni plating layer, an Ag plating layer, an Au plating layer or a composite plating layer.

[0062] It can be understood that in the Z-axis direction, the power device 12, the conductive layer 133, the insulating layer 131 and the heat-conducting layer 132 are sequentially arranged, and the first connecting piece 141 is fixed to the side of the heat-conducting layer 132 away from the insulating layer 131. The material of the first connecting piece 141 is the same as that of the heat-conducting layer 132. The design that the material of the first connecting piece 141 is the same as that of the heat-conducting layer 132 is conducive to improving the connection strength of the first connecting piece 141 and the heat-conducting layer 132, improving the structural stability, and making the heat-conducting layer 132 also have good heat-conducting performance. The heat of the power device 12 can be better transmitted to the first connecting piece 141, and the first connecting piece 141 transmits the heat to the cooling liquid in the accommodation cavity 21, which is conducive to improving the heat dissipation effect and efficiency of the power module 100.

[0063] The first connecting piece 141 and the second connecting piece 142 jointly form the accommodation groove 143, and in the Z-axis direction, the opening 1430 of the accommodation groove 143 is away from the heat sink 20. The design that the insulating substrate 13 is at least partially arranged in the accommodation groove 143 and fixedly stacked with the first connecting piece 141 reduces the size of the power module 100 in the Z-axis direction, is compact in structure, and is conducive to miniaturization design. The second connecting piece 142 is fixedly stacked on the side of the accommodation cavity 21 of the first connecting piece 141 away from the heat sink 20, and the accommodation groove 143 penetrates the second connecting piece 142 in the Z-axis direction. The design that the sealing of the accommodation cavity 21 is realized only by the first connecting piece 141 is conducive to increasing the contact area of the first connecting piece 141 and the cooling liquid in the accommodation cavity 21, and improving the heat dissipation efficiency of the power device 12. Moreover, the structure is simple, easy to process, improves the processing efficiency, and further reduces the processing cost.

[0064] The first connecting piece 141 and the opening 1430 of the accommodation groove 143 are oppositely arranged, and the design that the insulating substrate 13 is fixedly stacked with the first connecting piece 141 makes the first connecting piece 141 directly contact with the cooling liquid in the accommodation cavity 21. The heat generated by the power device 12 can be transmitted to the cooling liquid through the insulating substrate 13 and the first connecting piece 141, which is conducive to shortening the heat dissipation path of the power device 12 and improving the heat dissipation efficiency of the power device 12.

[0065] In some embodiments, the size of the first connecting piece 141 in the Z-axis direction is greater than the size of the heat-conducting layer 132 in the Z-axis direction. The design that the size of the first connecting piece 141 in the Z-axis direction is greater than the size of the heat-conducting layer 132 in the Z-axis direction is conducive to improving the strength of the first connecting piece 141, improving the reliability of the connection between the first connecting piece 141 and the insulating substrate 13, and improving the structural stability and reliability of the power module 100.

[0066] As Figure 5 and Figure 6As shown, in some embodiments, the terminal 11 is disposed on the side of the conductive layer 133 of the insulating substrate 13 facing away from the insulating layer 131 and is connected with the conductive layer 133. The electrical connection between the terminal 11 and the power device 12 is achieved through the conductive layer 133. In this embodiment, the terminal 11 is disposed along the Z-axis direction. In an example, the number of the terminal 11 is two. The two terminals 11 are respectively a first terminal 11a and a second terminal 11b. In other embodiments, the number of the terminal 11 can also be three, four or more.

[0067] In some embodiments, the encapsulant 15 is made of a plastic encapsulation material including but not limited to epoxy resin or polyimide. In other embodiments, the encapsulant 15 can also be made of other encapsulation materials such as potting adhesive. The encapsulant 15 is disposed on the side of the first connecting member 141 facing the insulating substrate 13, specifically, the encapsulant 15 is disposed in the accommodating groove 143. The encapsulant 15 covers the entire insulating substrate 13, the entire power device 12, part of the first terminal 11a and part of the second terminal 11b. In this embodiment, the end of the first terminal 11a facing away from the insulating substrate 13 is exposed outside the encapsulant 15 and is mounted on the circuit board 200 (as shown in Figure 2 As shown, the end of the second terminal 11b facing away from the insulating substrate 13 is exposed outside the encapsulant 15 and is mounted on the circuit board 200. The direct current transmitted from the input terminal 300 (as shown in Figure 1 The direct current transmitted from the input terminal 300 (as shown in Figure 1 The output terminal 400 receives the alternating current output by the power device 12 and transmits the alternating current to the power grid 3000 (as shown in Figure 1 The output terminal 400 receives the alternating current output by the power device 12 and transmits the alternating current to the power grid 3000 (as shown in

[0068] In some embodiments, the functional assembly 10 further includes a cover plate 19 disposed on the side of the power device 12 facing away from the insulating substrate 13 and sleeved outside the terminal 11. Specifically, in the Z-axis direction, the cover plate 19 is spaced apart from the power device 12 and is sleeved outside the first terminal 11a and the second terminal 11b. The encapsulant 15 covers part of the cover plate 19, and the surface of the cover plate 19 facing away from the power device 12 is exposed outside the encapsulant 15. In this embodiment, by disposing the cover plate 19, the overflow of the encapsulant 15 is prevented, the structural integrity of the encapsulant 15 is ensured, and the first terminal 11a and the second terminal 11b can be exposed outside the encapsulant 15.

[0069] As shown in Figure 4 and Figure 5As shown, in some embodiments, the side surface 1416 of the first connector 141 is flush with the surface 1422 of the second connector 142 facing away from the receiving groove 143. Specifically, the four corners of the first connector 141 and the four corners of the second connector 142 are all rounded, and the rounded radii of the four corners of the first connector 141 and the four corners of the second connector 142 are equal, and both the rounded radii of the four corners of the first connector 141 and the four corners of the second connector 142 are greater than 5mm. In this embodiment, the four corners of the mounting hole 22, the four corners of the first connector 141, and the four corners of the second connector 142 are all rounded, which facilitates the welding of the side wall 1423 of the second connector 142 to the hole wall of the mounting hole 22, resulting in better welding performance, better structural strength, and thus improved reliability. In other embodiments, the four corners of the first connector 141 and the four corners of the second connector 142 can also be set as bevels or right angles.

[0070] like Figure 4 , Figure 5 and Figure 7 As shown, in some embodiments, the surface of the first connector 141 facing the insulating substrate 13 is provided with a baffle 1411, which contacts the first connector 141 and is located within the receiving groove 143. The baffle 1411 surrounds the insulating substrate 13 and the power device 12 and is spaced apart from them. The encapsulation member 15 covers the baffle 1411. Exemplarily, the baffle 1411 is rectangular ring-shaped. In other embodiments, the baffle 1411 may also be ring-shaped or other irregularly shaped. The four corners of the baffle 1411 are rounded. In other embodiments, the four corners of the baffle 1411 may also be beveled or right-angled. The baffle 1411 is spaced apart from the groove sidewall of the receiving groove 143, which is the sidewall of the second connector 142 facing the insulating substrate 13; in other words, the baffle 1411 is spaced apart from the second connector 142. In particular, in the thickness direction of the retaining wall 1411, the ratio of the minimum distance D between the retaining wall 1411 and the side wall of the receiving groove 143 to the groove depth H of the receiving groove 143 is greater than 0.25.

[0071] In this embodiment, the first connector 141 has a baffle 1411 on the surface facing the insulating substrate 13. The design of the encapsulation 15 covering the baffle 1411 improves the bonding force between the encapsulation 15 and the composite substrate 14, and enhances the stability of the connection between the encapsulation 15 and the composite substrate 14. The design that the ratio of the minimum distance D between the baffle 1411 and the second connector 142 to the groove depth H of the receiving groove 143 is greater than 0.25 provides a larger space between the baffle 1411 and the groove sidewall of the receiving groove 143 (e.g., the second connector 142 shown in the figure). This facilitates the encapsulation 15 filling the space between the baffle 1411 and the groove sidewall of the receiving groove 143, which helps to improve the bonding force between the encapsulation 15 and the composite substrate 14, thereby improving reliability.

[0072] like Figure 4 , Figure 7 and Figure 8 As shown, in some embodiments, the baffle 1411 has a first protrusion 1414 and a flow hole 1415. The first protrusion 1414 is disposed on one side of the baffle 1411 in the thickness direction (i.e., the direction perpendicular to the Z-axis). The cross-section of the baffle 1411 is L-shaped, and the cross-section of the baffle 1411 is perpendicular to the length direction of the baffle 1411. In the Z-axis direction, the first protrusion 1414 is spaced apart from the first connector 141. The first protrusion 1414 is disposed facing the insulating substrate 13. In other embodiments, the first protrusion 1414 may also be disposed on the side of the baffle 1411 facing the second connector 142. Alternatively, the baffle 1411 has first protrusions 1414 on both sides in the thickness direction, so that the cross-section of the baffle 1411 is T-shaped.

[0073] The flow hole 1415 penetrates the retaining wall 1411 along its thickness direction and also penetrates the retaining wall 1411 along the Z-axis direction. The dimension of the flow hole 1415 along the length direction of the retaining wall 1411 is larger than the dimension of the retaining wall 1411 along the Z-axis direction. In this embodiment, there are multiple flow holes 1415, which are evenly spaced along the length direction of the retaining wall 1411. In other embodiments, the multiple flow holes 1415 may also be unevenly spaced along the length direction of the retaining wall 1411, and the number of flow holes 1415 may be one.

[0074] In this embodiment, during the process of filling the receiving groove 143 with the package 15, the package 15 flows from inside the baffle 1411 through the flow hole 1415 to the space between the baffle 1411 and the second connector 142, or flows from the space between the baffle 1411 and the second connector 142 through the flow hole 1415 back into the baffle 1411. The design of the flow hole 1415 helps to improve the fluidity of the package 15 in the receiving groove 143, allowing the package 15 to fill the entire receiving groove 143, preventing voids, and improving the bonding force between the package 15 and the composite substrate 14, thereby improving reliability. Specifically, the design of the flow hole 1415 having a larger dimension along the length of the baffle 1411 than the dimension of the baffle 1411 along the Z-axis results in a larger flow hole 1415, further enhancing the fluidity of the package 15.

[0075] Additionally, the package 15 flows into the space between the first protrusion 1414 and the first connector 141, with the package 15 partially located between the first protrusion 1414 and the first connector 141. The first protrusion 1414 limits the package 15 in the Z-axis direction, further improving the stability of the connection between the package 15 and the composite substrate 14. In some other embodiments, the baffle 1411 may be omitted.

[0076] like Figure 4 , Figure 5 and Figure 6 As shown, in some embodiments, the first connector 141 has a first groove 1413 on its surface facing the insulating substrate 13. The first groove 1413 is located within the baffle 1411. In the Z-axis direction, the first groove 1413 is opposite to the thermally conductive layer 132 of the insulating substrate 13, and the first groove 1413 is close to the edge of the thermally conductive layer 132 of the insulating substrate 13. For example, there may be multiple first grooves 1413 arranged in a rectangular pattern. In the Z-axis direction, the multiple first grooves 1413 are opposite to the thermally conductive layer 132 of the insulating substrate 13, and the multiple first grooves 1413 are close to the edge of the thermally conductive layer 132 of the insulating substrate 13. In other embodiments, there may be only one first groove 1413.

[0077] In this embodiment, by providing a first groove 1413, and the first groove 1413 being close to the edge of the insulating substrate 13, the stress generated at the edge of the insulating substrate 13 can be released in the first groove 1413, avoiding the stress directly acting on the first connector 141, and preventing the first connector 141 from deforming and damaging the insulating substrate 13 and the power device 12. This is beneficial to improving the service life of the power module 100, and thus improving the service life of the power conversion device 1000.

[0078] In some embodiments, the surface of the first connector 141 facing away from the insulating substrate 13 is provided with a second groove 1412. The second groove 1412 is opposite to and communicates with the receiving cavity 21, and the coolant in the receiving cavity 21 flows into the second groove 1412. Exemplarily, there are multiple second grooves 1412, which are arranged sequentially at intervals in a direction perpendicular to the Z-axis. In this embodiment, the multiple second grooves 1412 are arranged sequentially at intervals in the X-axis direction. In other embodiments, there may be only one second groove 1412.

[0079] In this embodiment, by providing a second groove 1412 on the surface of the first connector 141 facing away from the insulating substrate 13, when the first connector 141 is received in the mounting hole 22, the second groove 1412 is opposite to and communicates with the receiving cavity 21. The second groove 1412 increases the contact area between the first connector 141 and the coolant in the receiving cavity 21, which is beneficial to improving the heat dissipation efficiency of the power device 12. Moreover, the coolant in the receiving cavity 21 flows into the second groove 1412, bringing the coolant closer to the power device 12, shortening the heat dissipation path, and further improving the heat dissipation effect. In some other embodiments, fins can also be provided on the surface of the first connector 141 facing away from the insulating substrate 13. The fins can increase the contact area between the first connector 141 and the coolant in the receiving cavity 21, which is beneficial to improving the heat dissipation efficiency of the power device 12. In some other embodiments, the second groove 1412 and fins can also be provided simultaneously on the surface of the first connector 141 facing away from the insulating substrate 13. In other words, the surface of the first connector 141 facing away from the insulating substrate 13 is provided with a second groove 1412 and / or fins.

[0080] like Figure 7 and Figure 8 As shown, in some embodiments, the sidewall of the receiving groove 143 is provided with a second protrusion 1431, which faces the insulating substrate 13. Specifically, the second protrusion 1431 is disposed on the side of the second connector 142 facing the insulating substrate 13. In the Z-axis direction, the second protrusion 1431 is spaced apart from the first connector 141. During the process of filling the receiving groove 143 with the package 15, the package 15 will flow into the space between the second protrusion 1431 and the first connector 141, with part of the package 15 located between the second protrusion 1431 and the first connector 141. The second protrusion 1431 limits the package 15 in the Z-axis direction, further improving the stability of the connection between the package 15 and the composite substrate 14.

[0081] Please refer to Figure 9 and Figure 10 and combined Figure 3 , Figure 9 yes Figure 3 The power module 100 shown is a cross-sectional view taken along line L1-L1 in another embodiment.Figure 10 yes Figure 9 The enlarged view of the power module 100 at point D is shown.

[0082] like Figure 9 and Figure 10 As shown, in some embodiments, both the number of insulating substrates 13 and the number of power devices 12 are multiple. Multiple insulating substrates 13 are arranged sequentially at intervals in a direction perpendicular to the Z-axis. Specifically, multiple insulating substrates 13 are arranged sequentially at intervals in the X-axis direction. Each insulating substrate 13 has at least one power device 12 disposed on the side facing away from the heat sink 20. Exemplarily, each insulating substrate 13 has multiple power devices 12 disposed on the side facing away from the heat sink 20, and the multiple power devices 12 disposed on the insulating substrate 13 are spaced apart from each other.

[0083] The functional component 10 also includes a first conductive element 16, a second conductive element 17, and a heat-conducting element 18. The first conductive element 16 is disposed between two adjacent insulating substrates 13. One end of the first conductive element 16 is connected to the conductive layer 133 of one of the insulating substrates 13, and the other end is connected to the conductive layer 133 of the other insulating substrate 13.

[0084] Specifically, the first conductive element 16 is a metal clip, such as a copper clip. The first conductive element 16 includes a first fixing part 161, a first intermediate part 162, and a second fixing part 163 that are fixedly connected in sequence. In the X-axis direction, the first fixing part 161, the first intermediate part 162, and the second fixing part 163 are fixedly connected in sequence. In the Z-axis direction, both the first fixing part 161 and the second fixing part 163 are perpendicular to the Z-axis direction, and the first intermediate part 162 is arc-shaped. By means including but not limited to soldering, sintering, or brazing, the first fixing part 161 is fixedly stacked on the side of the conductive layer 133 of one of the insulating substrates 13 facing away from the insulating layer 131, and the second fixing part 163 is fixedly stacked on the side of the conductive layer 133 of the other insulating substrate 13 facing away from the insulating layer 131. This achieves electrical connection between the conductive layers 133 of two adjacent insulating substrates 13, and further achieves electrical connection between the power devices 12 on the two adjacent insulating substrates 13. In some other embodiments, the first conductive element 16 can also be configured as a wire. The wire has a smaller volume, which is beneficial for reducing the volume of the power module 100 and for miniaturization design.

[0085] The second conductive element 17 is disposed on the side of the power device 12 facing away from the insulating substrate 13. One end of the second conductive element 17 is connected to one power device 12, and the other end is connected to another power device 12. Specifically, one end of the second conductive element 17 is fixedly connected to the side of one power device 12 facing away from the insulating substrate 13, and the other end is fixedly connected to the side of another power device 12 facing away from the insulating substrate 13. Electrical connection between different power devices 12 can be achieved through the second conductive element 17. The structure of the second conductive element 17 can be referred to the relevant description of the first conductive element 16, and will not be repeated here. The heat-conducting element 18 is disposed on the side of the power device 12 facing away from the insulating substrate 13. The heat-conducting element 18 can be in contact with the power device 12. The heat-conducting element 18 can also be disposed on the side of the second conductive element 17 facing away from the insulating substrate 13.

[0086] The first terminal 11a is disposed on the side of the conductive layer 133 of one of the insulating substrates 13 facing away from the insulating layer 131 and is connected to the conductive layer 133. The second terminal 11b is disposed on the side of the conductive layer 133 of the other insulating substrate 13 facing away from the insulating layer 131 and is connected to the conductive layer 133. (e.g., from the input terminal 300...) Figure 1 The direct current (DC) supplied (as shown) is delivered to multiple power devices 12 via the first terminal 11a. The multiple power devices 12 are used to convert the DC to AC. The AC output from the multiple power devices 12 is delivered to the output terminal 400 (as shown) via the second terminal 11. Figure 1 (As shown). Output terminal 400 receives AC power from multiple power devices 12 and transmits the AC power to the power grid 3000 (e.g., Figure 1 (As shown), to supply 3000 to the power grid.

[0087] In this embodiment, by setting multiple insulating substrates 13 and multiple power devices 12, the performance of the power module 100 is enhanced. The design of the first conductive element 16 being disposed between two adjacent insulating substrates 13 enables current flow between the two adjacent insulating substrates 13. This allows a power device 12 disposed on one insulating substrate 13 to flow with a power device 12 disposed on the other insulating substrate 13, which helps reduce stray inductance in the circuit, thereby reducing the risk of oscillation and overvoltage, improving the performance of the power module 100, and consequently improving the performance of the power conversion device 1000. The design of the heat-conducting element 18 being disposed on the side of the power device 12 facing away from the insulating substrate 13 allows heat from the power device 12 to be transferred to the heat-conducting element 18, which then transfers the heat to the outside, improving the heat dissipation effect of the power device 12.

[0088] Please refer to Figure 11 and combined Figure 5 , Figure 11 yes Figure 3The power module 100 shown is a cross-sectional view taken along line L1-L1 in another embodiment.

[0089] like Figure 5 and Figure 11 As shown, Figure 11 The power module 100 shown is Figure 5 The power module 100 shown is similar, but the difference lies in the way the first connector 141 and the second connector 142 form the receiving groove 143. Specifically, in Figure 11 In the illustrated embodiment, the second connector 142 surrounds and encloses at least a portion of the sidewalls of the first connector 141. Exemplarily, the second connector 142 surrounds and encloses the entire sidewalls of the first connector 141. In the X-axis direction, the maximum size of the second connector 142 is greater than the maximum size of the first connector 141, and the maximum size of the second connector 142 is equal to the maximum size of the mounting hole 22. In the Y-axis direction, the maximum size of the second connector 142 is greater than the maximum size of the first connector 141, and the maximum size of the second connector 142 is equal to the maximum size of the mounting hole 22. Furthermore, the size of the second connector 142 in the Z-axis direction is greater than the size of the first connector 141 in the Z-axis direction. The surface of the first connector 141 facing the receiving cavity 21 is flush with the surface of the second connector 142 facing the receiving cavity 21. In some other embodiments, they may not be flush.

[0090] In this embodiment, the design of the second connector 142 surrounding and wrapping at least part of the sidewall of the first connector 141 makes it more difficult for the first connector 141 to deform when it is subjected to the pressure of the coolant in the receiving cavity 21. This avoids damage to the insulating substrate 13 and the power device 12 due to the deformation of the first connector 141, which is beneficial to improving the life of the power module 100 and thus improving the service life of the power conversion device 1000.

[0091] The design of the second connector 142 having a larger Z-axis dimension than the first connector 141 allows the second connector 142 to better enclose the first connector 141. When the first connector 141 is subjected to the pressure of the coolant in the receiving cavity 21, it is less likely to deform, thus preventing damage to the insulating substrate 13 and power device 12 due to deformation, further improving the lifespan of the power module 100. Furthermore, it increases the connection area between the second connector 142 and the wall of the mounting hole 22, improving connection strength and structural stability of the power module 100.

[0092] Understandable. Figure 11In the illustrated embodiment, the second connector 142 surrounds and encloses at least a portion of the sidewall of the first connector 141. The design that the dimension of the second connector 142 in the Z-axis direction is larger than the dimension of the first connector 141 in the Z-axis direction can be applied to... Figures 1-10 In any of the embodiments shown.

[0093] Please refer to Figure 12 and combined Figure 5 , Figure 12 yes Figure 3 The power module 100 shown is a cross-sectional view taken along line L1-L1 in another embodiment.

[0094] like Figure 5 and Figure 12 As shown, Figure 12 The power module 100 shown is Figure 5 The power module 100 shown is similar to the one shown, except that the first connector 141 and the second connector 142 are connected in different ways. Figure 12 In the illustrated embodiment, the first connector 141 is fixedly stacked with the insulating substrate 13 by means including but not limited to welding or adhesive bonding, and the second connector 142 is fixedly stacked on the side of the first connector 141 facing away from the insulating substrate 13. In the X-axis direction, the maximum size of the second connector 142 is greater than the maximum size of the first connector 141, and the maximum size of the second connector 142 is equal to the maximum size of the mounting hole 22. In the Y-axis direction, the maximum size of the second connector 142 is greater than the maximum size of the first connector 141, and the maximum size of the second connector 142 is equal to the maximum size of the mounting hole 22. Both the first connector 141 and the second connector 142 are received in the mounting hole 22, with the first connector 141 spaced apart from the hole wall of the mounting hole 22, and the second connector 142 welded and fixed to the hole wall of the mounting hole 22. In the Z-axis direction, the second connector 142 is opposite to the receiving cavity 21. The design of the sidewall of the first connector 141 being spaced apart from the wall of the mounting hole 22 facilitates the insertion of a welding torch into the mounting hole 22 to weld the sidewall of the second connector 142 and the wall of the mounting hole 22. In some other embodiments, the first connector 141 may also be located outside the mounting hole 22.

[0095] The second connector 142 is fixedly stacked on the side of the first connector 141 facing away from the insulating substrate 13. The second connector 142 seals the receiving cavity 21 and can resist the pressure of the coolant in the receiving cavity 21. The pressure of the coolant will not directly act on the first connector 141, avoiding damage to the insulating substrate 13 and power device 12 due to deformation of the first connector 141. This helps to improve the life of the power module 100 and thus improve the service life of the power conversion device 1000.

[0096] existFigure 12 In the illustrated embodiment, the surface of the second connector 142 facing away from the first connector 141 is provided with a through hole 1421, which penetrates the second connector 142 along the Z-axis direction. Exemplarily, there are multiple through holes 1421, arranged sequentially at intervals in a direction perpendicular to the Z-axis. Specifically, in the X-axis direction, multiple through holes 1421 are arranged sequentially at intervals. In some other embodiments, the through hole 1421 may not penetrate the second connector 142. In these embodiments, the through hole 1421 is opposite to and communicates with the receiving cavity 21, allowing coolant from the receiving cavity 21 to flow into the through hole 1421, thus enabling the coolant to contact the first connector 141.

[0097] By providing a through hole 1421 in the second connector 142, coolant can flow into the through hole 1421, and the first connector 141 can directly contact the coolant. The distance between the power device 12 and the coolant is shorter, the heat dissipation path is shorter, and the heat of the power device 12 can be diffused to the coolant more quickly, thus improving the heat dissipation effect of the power module 100.

[0098] Understandable. Figure 12 The design of the first connector 141 being fixedly stacked with the insulating substrate 13, and the second connector 142 being fixedly stacked on the side of the first connector 141 facing away from the insulating substrate 13, and the design of the second connector 142 having a through hole 1421 on the surface of the second connector 142 facing away from the first connector 141, can be applied to Figures 1-11 In any of the embodiments shown.

[0099] The above are merely some embodiments and implementation methods of this application. 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 by The power module comprises a power device, an insulating substrate, a composite substrate and a heat sink; The power device, the insulating substrate, the composite substrate and the heat sink are sequentially arranged in the thickness direction of the insulating substrate; the heat sink comprises a receiving cavity and a mounting hole, the mounting hole is located on one side of the receiving cavity and communicates with the receiving cavity in the thickness direction of the insulating substrate, and the composite substrate is at least partially received in the mounting hole and closes the receiving cavity; The composite substrate comprises a first connecting member and a second connecting member, the first connecting member is connected with the insulating substrate in the thickness direction of the insulating substrate, the side wall of the second connecting member is connected with the hole wall of the mounting hole, and the material of the second connecting member is the same as that of the heat sink; in the direction perpendicular to the thickness direction of the insulating substrate, the maximum size of the second connecting member is greater than or equal to the maximum size of the first connecting member.

2. The power module of claim 1, wherein, The thermal conductivity of the first connecting member is greater than that of the second connecting member.

3. The power module of claim 1, wherein, The first connecting member and the second connecting member form a receiving groove, the opening of the receiving groove faces away from the receiving cavity in the thickness direction of the insulating substrate, and the insulating substrate is at least partially arranged in the receiving groove and fixedly stacked with the first connecting member.

4. The power module of claim 3, wherein, The second connecting member is fixedly stacked on the side of the first connecting member facing away from the receiving cavity, and the receiving groove penetrates the second connecting member in the thickness direction of the insulating substrate.

5. The power module of claim 3, wherein, The second connecting member surrounds and covers at least part of the side wall of the first connecting member.

6. The power module of claim 5, wherein, The size of the second connecting member in the thickness direction of the insulating substrate is greater than that of the first connecting member in the thickness direction of the insulating substrate.

7. The power module of any one of claims 3 to 6, characterized in that The power module further comprises a packaging member covering the insulating substrate and the power device.

8. The power module of claim 7, wherein, The surface of the first connecting member facing the insulating substrate is provided with a retaining wall surrounding the insulating substrate, and the retaining wall is arranged in a spaced manner with the second connecting member, and the packaging member covers the retaining wall.

9. The power module of claim 8, wherein, One side of the retaining wall in the thickness direction of the retaining wall is provided with a first protrusion facing the insulating substrate; and the packaging member is partially located between the first protrusion and the first connecting member.

10. The power module according to claim 8 or 9, characterized in that The retaining wall is arranged in a spaced manner with the groove side wall of the receiving groove, the retaining wall is provided with a flow-through hole penetrating the retaining wall in the thickness direction of the retaining wall and penetrating the retaining wall in the thickness direction of the insulating substrate.

11. The power module according to any one of claims 7 to 10, characterized in that The groove side wall of the receiving groove is provided with a second protrusion facing the insulating substrate; and the packaging member is partially located between the second protrusion and the first connecting member.

12. The power module of claim 1, wherein, The first connecting member is fixedly stacked with the insulating substrate, and the second connecting member is fixedly stacked on the side of the first connecting member facing away from the insulating substrate.

13. The power module of claim 12, wherein, The surface of the second connecting member facing away from the first connecting member is provided with a through hole.

14. The power module of any one of claims 1 to 13, characterized in that The insulating substrate comprises a heat-conducting layer, an insulating layer and an electrically-conductive layer arranged in sequence in the thickness direction of the insulating substrate, the electrically-conductive layer faces the power device, the first connecting member is fixed to the side of the heat-conducting layer away from the insulating layer, and the size of the first connecting member in the thickness direction of the insulating substrate is greater than the size of the heat-conducting layer in the thickness direction of the insulating substrate.

15. The power module of claim 14, wherein, The number of the insulating substrates and the number of the power devices are both plural, at least one power device is arranged on the side of each insulating substrate away from the heat sink, and the plural insulating substrates are arranged in sequence and spaced apart in the direction perpendicular to the thickness direction of the insulating substrate. The power module further comprises a first electrically-conductive member arranged between two adjacent insulating substrates, one end of the first electrically-conductive member is connected to the electrically-conductive layer of one of the insulating substrates, and the other end is connected to the electrically-conductive layer of the other insulating substrate.

16. The power module of any one of claims 1 to 15, characterized in that The first connecting member is provided with a first groove on the surface facing the insulating substrate, and the first groove is close to the edge of the insulating substrate.

17. A power conversion device, characterized by The power conversion device comprises a circuit board and the power module according to any one of claims 1 to 16, and the power module is arranged on the circuit board.

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