Power module and power conversion apparatus

Abstract

The present application provides a power module and a power conversion apparatus. The power module comprises a substrate, a first sintered layer, and a power device. The substrate comprises an insulating layer and a first conductive layer. In the thickness direction of the substrate, the first conductive layer is stacked on one side of the insulating layer, and the first sintered layer and the power device are sequentially stacked on the side of the first conductive layer facing away from the insulating layer. The power device comprises a power chip, a first fixing layer and a first connecting layer that are sequentially stacked in the thickness direction of the substrate, the first connecting layer being in contact with the first sintered layer. In the thickness direction of the substrate, the thickness of the first sintered layer is greater than the thickness of the first connecting layer and less than the thickness of the first conductive layer. The first sintered layer has a relatively low porosity, which is beneficial to improving the heat dissipation efficiency of the power device, thereby improving the bonding strength between the power device and the substrate by means of the first sintered layer, and improving the structural stability of the power module.

Description

Power module and power conversion device

[0001] The present application claims priority to the Chinese patent application No. 202411082647.3, filed on August 7, 2024, entitled "Power module and power conversion device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of electronic technology, and in particular, to a power module and a power conversion device. BACKGROUND

[0003] In the existing power module, the power device is bonded to the substrate, and the substrate is bonded to the heat sink through the solder. A large amount of heat generated by the power device working is diffused to the heat sink through the substrate and the solder, and then diffused to the outside from the heat sink, so as to realize rapid heat dissipation of the power device. However, due to the low thermal conductivity of the solder, there is a problem of large heat dissipation resistance of the power device, and the heat dissipation efficiency of the power device is low. SUMMARY

[0004] 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.

[0005] In a first aspect, the embodiments of the present application provide a power module. The power module comprises a substrate, a first sintered layer and a power device. The substrate comprises an insulating layer and a first conductive layer, and in the thickness direction of the substrate, the first conductive layer is arranged on one side of the insulating layer in a stacked manner, and the first sintered layer and the power device are arranged on the side of the first conductive layer away from the insulating layer in a stacked manner. The power device comprises a power chip, a first fixed layer and a first connecting layer, and in the thickness direction of the substrate, the power chip, the first fixed layer and the first connecting layer are arranged in a stacked manner, the first connecting layer is in contact with the first sintered layer, and in the thickness direction of the substrate, the thickness of the first sintered layer is greater than the thickness of the first connecting layer and less than the thickness of the first conductive layer. In the power module provided by the embodiments of the present application, a large amount of heat generated by the power chip working can be transmitted to the substrate through the first fixed layer, the first connecting layer and the first sintered layer, and then transmitted to the external environment from the substrate, so as to realize rapid heat dissipation of the power device.

[0006] Compared with the prior art, in the application, the power device and the substrate are bonded through the first sintering layer between the first connecting layer and the first conductive layer. The first sintering layer has a low porosity, which is beneficial to improve the efficiency of heat generated by the power chip during operation to be transferred to the substrate through the first connecting layer and the first sintering layer, and is beneficial to improve the heat dissipation efficiency of the power device. Moreover, in the thickness direction of the substrate, the thickness of the first sintering layer is greater than the thickness of the first connecting layer and less than the thickness of the first conductive layer, which ensures that the first connecting layer and the first sintering layer have a high bonding strength, is beneficial to improve the bonding strength of the power device and the substrate through the first sintering layer, and is beneficial to improve the structural stability of the power module.

[0007] In a possible implementation, the material of the first connecting layer is the same as the material of the first sintering layer.

[0008] The design that the material of the first connecting layer is the same as the material of the first sintering layer is beneficial to improve the bonding strength of the first connecting layer and the first sintering layer, is beneficial to improve the bonding strength of the power device and the substrate through the first sintering layer, and is beneficial to improve the structural stability of the power module.

[0009] In a possible implementation, the material of the first sintering layer is the same as the material of the first conductive layer, the material of the first connecting layer is copper, nickel, gold or silver, and the material of the first sintering layer is a composite material of aluminum, copper or nickel.

[0010] The design that the material of the first sintering layer is the same as the material of the first conductive layer is beneficial to improve the bonding strength of the first sintering layer and the first conductive layer, is beneficial to improve the bonding strength of the power device and the substrate through the first sintering layer, and is beneficial to improve the structural stability of the power module. The design that the material of the first connecting layer is copper or nickel and the material of the first sintering layer is copper, nickel or aluminum ensures that the first sintering layer has a low porosity, which is beneficial to improve the heat conduction capacity of the first sintering layer, is beneficial to improve the efficiency of heat generated by the power chip during operation to be transferred to the substrate through the first connecting layer and the first sintering layer, is beneficial to improve the heat dissipation efficiency of the power device, and is beneficial to improve the bonding strength of the power device and the substrate through the first sintering layer. Moreover, the structural stability of the power module is improved. In addition, the cost of copper, the cost of nickel and the cost of the composite material of aluminum are all low, which ensures that the material cost of bonding the substrate and the power device is low, and is beneficial to reduce the processing cost of the power module.

[0011] In a possible implementation, the substrate includes a heat-conducting layer, the heat-conducting layer is arranged on one side of the insulating layer in the thickness direction of the substrate and faces away from the first conductive layer, the power module includes a second sintered layer and a heat sink, the second sintered layer and the heat sink are sequentially arranged on the side of the heat-conducting layer away from the insulating layer in the thickness direction of the substrate, the material of the second sintered layer is the same as that of the first sintered layer, and the projection of the second sintered layer in the thickness direction of the substrate has a larger area than the projection of the first sintered layer in the thickness direction of the substrate.

[0012] The heat-conducting layer is bonded together with the heat sink through the second sintered layer. The heat generated by the power device during operation can be transmitted to the heat sink through the substrate and the second sintered layer, and then transmitted to the external environment from the heat sink. The design of the heat sink is conducive to improving the efficiency of heat generated by the power device during operation to be transmitted to the external environment, and conducive to improving the heat dissipation efficiency of the power device. The first sintered layer and the second sintered layer both need to be made by high-temperature and high-pressure. Since the material of the second sintered layer is the same as that of the first sintered layer, the first sintered layer and the second sintered layer can be made by one-time high-temperature and high-pressure, which is conducive to reducing the cost of making the first sintered layer and the second sintered layer, reducing the material cost, and reducing the processing cost of the power module. The design that the projection of the second sintered layer in the thickness direction of the substrate has a larger area than the projection of the first sintered layer in the thickness direction of the substrate is conducive to improving the strength of the bonding of the heat sink and the substrate through the second sintered layer, and conducive to improving the structural stability of the power module.

[0013] In a possible implementation, the thickness of the second sintered layer is greater than the thickness of the first sintered layer and less than the thickness of the first conductive layer in the thickness direction of the substrate.

[0014] The design that the thickness of the second sintered layer is greater than the thickness of the first sintered layer and less than the thickness of the first conductive layer in the thickness direction of the substrate is conducive to increasing the strength of the bonding of the heat sink and the substrate through the second sintered layer, and conducive to improving the structural stability of the power module.

[0015] In a possible implementation, the material of the heat-conducting layer, the material of the second sintered layer, and the material of the heat sink are the same.

[0016] The design that the material of the heat-conducting layer, the material of the second sintered layer, and the material of the heat sink are the same is conducive to improving the bonding strength of the heat-conducting layer and the second sintered layer, improving the bonding strength of the second sintered layer and the heat sink, improving the bonding strength of the substrate and the heat sink through the second sintered layer, and improving the structural stability of the power module.

[0017] In a possible implementation, the second sintered layer is provided with an exhaust groove, and the exhaust groove extends in the thickness direction of the substrate from one side of the second sintered layer in the thickness direction of the substrate.

[0018] The exhaust groove is designed to ensure that the exhaust gas generated during the process of bonding the substrate and the heat sink together through the second sintering layer can escape from the exhaust groove to the external environment, which is conducive to improving the bonding strength of the substrate and the heat sink through the second sintering layer and improving the structural stability of the power module.

[0019] In a possible implementation, a projection of the exhaust groove in the thickness direction of the substrate is spaced apart from a projection of the power device in the thickness direction of the substrate.

[0020] The projection of the exhaust groove in the thickness direction of the substrate is spaced apart from the projection of the power device in the thickness direction of the substrate, which avoids the existence of air in the heat dissipation path from the substrate to the heat sink through the second sintering layer along the thickness direction of the substrate due to the exhaust groove when the power device works, ensures that the heat generated when the power device works is transmitted from the substrate to the heat sink through the second sintering layer along the thickness direction of the substrate, and is conducive to improving the efficiency of heat transmission from the substrate to the heat sink along the thickness direction of the substrate when the power device works and improving the heat dissipation efficiency of the power device.

[0021] In a possible implementation, along the thickness direction of the substrate, the width of the exhaust groove is less than the thickness of the second sintering layer, and the length of the exhaust groove along the first direction is equal to the length of the second sintering layer, where the first direction is perpendicular to the thickness direction of the substrate.

[0022] Along the thickness direction of the substrate, the width of the exhaust groove is less than the thickness of the second sintering layer, and the length of the exhaust groove along the first direction is equal to the length of the second sintering layer, which ensures that the exhaust gas generated during the process of bonding the substrate and the heat sink together through the second sintering layer can escape from the exhaust groove to the external environment along the length direction of the exhaust groove. And avoid the exhaust groove penetrating through the second sintering layer along the thickness direction of the substrate, which is conducive to improving the bonding strength of the heat sink and the substrate through the second sintering layer and improving the structural stability of the power module.

[0023] In a possible implementation, along the second direction, the width of the slot opening of the exhaust groove is greater than the width of the groove bottom of the exhaust groove, where the second direction is perpendicular to the thickness direction of the substrate.

[0024] Along the second direction, the width of the slot opening of the exhaust groove is greater than the width of the groove bottom of the exhaust groove, which is conducive to improving the efficiency of the exhaust gas generated during the process of bonding the substrate and the heat sink together through the second sintering layer escaping from the exhaust groove to the external environment, improving the bonding strength of the substrate and the heat sink through the second sintering layer, and improving the structural stability of the power module.

[0025] In a possible implementation, the number of substrates, the number of first sintered layers, the number of power devices, and the number of second sintered layers are all plural, each substrate corresponds to at least one first sintered layer, at least one power device, and at least one second sintered layer, and the plurality of substrates are arranged in a spaced manner.

[0026] Each substrate is bonded together with the heat sink through the corresponding second sintered layer, and is bonded together with the corresponding power device through the corresponding first sintered layer. The heat generated by each power device during operation can be transmitted to the heat sink through the corresponding first sintered layer, the substrate, and the second sintered layer, and then transmitted to the external environment from the heat sink, thereby achieving rapid heat dissipation for each power device. One heat sink can be used to dissipate heat for multiple power devices, thereby achieving rapid heat dissipation for multiple power devices.

[0027] In a possible implementation, the power module includes a plurality of plastic packages, each plastic package corresponds to one substrate, and in the corresponding plastic package, substrate, power device, first sintered layer, and second sintered layer, the plastic package covers part of the substrate, the heat-conducting layer of the substrate is exposed outside the plastic package, the plastic package completely covers the first sintered layer and the power device, and the second sintered layer is located between the plastic package and the heat sink.

[0028] The design of the plastic package can protect the substrate and the power device, avoid damage to the substrate and the power device due to collision, and is beneficial to improve the use safety of the substrate and the power device, and is beneficial to prolong the service life of the substrate and the power device.

[0029] In a possible implementation, the power module includes a plastic package, the plastic package completely covers the substrate, the first sintered layer, and the power device, the plastic package covers part of the second sintered layer, and the side of the second sintered layer away from the substrate is exposed outside the plastic package.

[0030] The design of the plastic package can protect the substrate and the power device, avoid damage to the substrate and the power device due to collision, and is beneficial to improve the use safety of the substrate and the power device, and is beneficial to prolong the service life of the substrate and the power device.

[0031] In a possible implementation, the power device includes a second fixing layer and a second connecting layer, the second fixing layer and the second connecting layer are sequentially stacked on the side of the power chip away from the first fixing layer in the thickness direction of the substrate; the substrate includes a second conductive layer, the second conductive layer is stacked on the side of the insulating layer and faces the first conductive layer in the thickness direction of the substrate, the power module includes a mounting layer, a terminal, and a connecting terminal, the mounting layer is stacked on the side of the second connecting layer and away from the power chip in the thickness direction of the substrate, the terminal is arranged on the side of the second conductive layer and away from the insulating layer, and the connecting terminal is arranged between the mounting layer and the second conductive layer.

[0032] The power device is connected with the terminal through the mounting layer between the second connecting layer and the connecting terminal, so that the power device is electrically connected with the terminal through the connecting terminal. The design that the connecting terminal is arranged between the mounting layer and the second conductive layer can avoid occupying additional area of the first conductive layer by the connecting terminal, is beneficial to reducing the area of the first conductive layer, and is beneficial to miniaturization design of the substrate.

[0033] In a possible implementation, the second connecting layer is made of copper, nickel, silver or gold, and the mounting layer is made of an aluminum composite material, copper or nickel.

[0034] The second connecting layer is made of copper, nickel, silver or gold, and the mounting layer is made of an aluminum composite material, copper or nickel, so that the second connecting layer has high bonding strength with the mounting layer, which is beneficial to improving the bonding strength of the power device and the connecting terminal through the mounting layer, and is beneficial to improving the structural stability and reliability of the power module.

[0035] In a possible implementation, the mounting layer is made of the same material as the second connecting layer.

[0036] The mounting layer is made of the same material as the second connecting layer, which is beneficial to improving the bonding strength of the mounting layer and the second connecting layer, is beneficial to improving the bonding strength of the power device and the connecting terminal through the mounting layer, is beneficial to improving the stability of the power device and the terminal electrically connected through the connecting terminal, and is beneficial to improving the structural stability and reliability of the power module.

[0037] In a possible implementation, the connecting terminal includes a connecting portion, the connecting portion is arranged on one side of the mounting layer in the thickness direction of the substrate and faces away from the second connecting layer, and the connecting portion is made of the same material as the mounting layer.

[0038] The connecting portion is made of the same material as the mounting layer, which is beneficial to improving the bonding strength of the connecting terminal and the mounting layer, is beneficial to improving the bonding strength of the power device and the connecting terminal through the mounting layer, is beneficial to improving the stability of the power device and the terminal electrically connected through the connecting terminal, and is beneficial to improving the structural stability and reliability of the power module.

[0039] In a second aspect, the embodiments of the present application further provide a power conversion device. The power conversion device includes a circuit board and the power module of any one of the first aspect, and the power module is bonded to the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0040] 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.

[0041] Figure 1 is a structural block diagram of a power conversion device cooperating with a photovoltaic module and a power grid according to an embodiment of the present application;

[0042] Figure 2 is a structural diagram of a power module of the power conversion device shown in Figure 1 ;

[0043] Figure 3 is a structural diagram of the power module shown in Figure 2 omitting a heat sink, a second sintering layer and a plastic package;

[0044] Figure 3a is a structural diagram of the power module shown in Figure 2 according to another embodiment;

[0045] Figure 4 is a structural diagram of the power module shown in Figure 2 according to another embodiment;

[0046] Figure 5 is a structural diagram of the power module shown in Figure 2 according to another embodiment;

[0047] Figure 6 is an enlarged view of a VI part of the power module shown in Figure 5;

[0048] Figure 7 is a flow diagram of a processing method of a power module according to an embodiment of the present application;

[0049] Figure 8 is a structural diagram of a substrate according to the processing method according to an embodiment of the present application;

[0050] Figure 9 is a structural diagram of a power device according to the processing method according to an embodiment of the present application;

[0051] Figure 10 is a structural diagram of covering a first sintering material on a first conductive layer by a printing plate;

[0052] Figure 11 is a structural diagram of forming a first pre-sintering layer on the first conductive layer;

[0053] Figure 12 is a structural diagram of a printing plate required by the processing method according to an embodiment of the present application;

[0054] Figure 13 is a structural diagram of the printing plate shown in Figure 12 according to another embodiment;

[0055] Figure 14 is a structural diagram of the printing plate shown in Figure 13 according to another embodiment;

[0056] Figure 15 is a structural diagram of the printing plate shown in Figure 13 according to another embodiment;

[0057] Figure 16 is a structural diagram of a first pre-sintering layer located between a first conductive layer and a first connecting layer;

[0058] Figure 17 is a structural diagram of a heat sink according to the processing method according to an embodiment of the present application;

[0059] FIG. 18 is a structural schematic diagram of covering the second sintering material on the heat sink through the printing plate;

[0060] FIG. 19 is a structural schematic diagram of forming the second pre-sintering layer on the heat sink;

[0061] FIG. 20 is a structural schematic diagram of the second pre-sintering layer being located between the heat conduction layer and the heat sink;

[0062] FIGS. 21 to 22 are structural schematic diagrams of the process of pressure sintering the first pre-sintering layer and the second pre-sintering layer;

[0063] FIGS. 23 to 25 are structural schematic diagrams of part of the process of the processing method shown in FIG. 7 in another embodiment;

[0064] FIGS. 26 to 28 are structural schematic diagrams of part of the process of the processing method shown in FIG. 7 in another embodiment;

[0065] FIGS. 29 to 30 are structural schematic diagrams of part of the process of the processing method shown in FIG. 7 in another embodiment. DETAILED DESCRIPTION

[0066] The embodiments of the present application provide a power module and a power conversion device. The power module is applied to the power conversion device. "Copper" in the present application refers to pure copper or copper alloy. "Nickel" in the present application refers to pure nickel or nickel alloy. "Gold" in the present application refers to pure gold or gold alloy. "Silver" in the present application refers to pure silver or silver alloy. "Aluminum composite material" in the present application refers to a material composed of micron-sized aluminum and nanometer-sized nickel. In the present application, the material quality of feature A is the same as that of feature B refers to 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.

[0067] The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0068] Please refer to FIG. 1 and FIG. 2. FIG. 1 is a structural block diagram of a power conversion device 1000 cooperating with a photovoltaic assembly 2000 and a power grid 3000 according to an embodiment of the present application. FIG. 2 is a structural schematic diagram of a power module 300 of the power conversion device 1000 shown in FIG. 1.

[0069] The power conversion device 1000 is exemplarily a photovoltaic inverter. In other embodiments, the power conversion device 1000 can also be a rectifier, a transformer, or other electronic device for power conversion. The power conversion device 1000 is used to convert the direct current output by the photovoltaic module 2000 into alternating current for supplying the power grid 3000. In other embodiments, the power conversion device 1000 can also be used to convert the direct current output by the photovoltaic module 2000 into alternating current for supplying a load device. The load device can be an electronic device using alternating current, including but not limited to a motor, a fan, or an air conditioner. In other embodiments, the power conversion device 1000 can also be applied to an electric drive controller or a motor control unit (MCU) system. The power conversion device 1000 is used to convert the direct current output by a battery into alternating current for supplying a motor.

[0070] In some embodiments, the power conversion device 1000 includes a circuit board 100, an input terminal 200, a power module 300, and an output terminal 400. The input terminal 200, the power module 300, and the output terminal 400 are all coupled to the circuit board 100. Specifically, the input terminal 200, the power module 300, and the output terminal 400 are all coupled to one side of the circuit board 100. In other embodiments, the input terminal 200, the power module 300, and the output terminal 400 can also be coupled to opposite sides of the circuit board 100, respectively.

[0071] The input terminal 200 is used to receive the direct current output by the photovoltaic module 2000. The power module 300 is used to receive the direct current delivered from the input terminal 200 and convert the direct current into alternating current. The output terminal 400 is used to receive the alternating current output by the power module 300 and deliver 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 300.

[0072] In some embodiments, the power module 300 includes a substrate 10, a power device 20, a heat sink 30, a thermal device 40, a terminal 50, a connecting terminal 60, and a plastic package 70. The power device 20, the thermal device 40, and the terminal 50 are disposed on one side of the substrate 10. The terminal 50 is electrically connected to the power device 20 and the thermal device 40 through the connecting terminal 60. The heat sink 30 is disposed on the side of the substrate 10 opposite to the power device 20. The plastic package 70 covers the entire substrate 10, the entire power device 20, the entire thermal device 40, part of the terminal 50, and the entire connecting terminal 60. Part of the terminal 50 is located outside the plastic package 70.

[0073] The terminal 50 is joined to the circuit board 100 by means including but not limited to soldering or plugging. The direct current delivered from the input terminal 200 is delivered to the power device 20 through the terminal 50. The power device 20 is used to convert the direct current into alternating current. The alternating current output by the power device 20 is delivered to the output terminal 400 through the terminal 50.

[0074] Referring to FIG. 3, in combination with FIGS. 1 and 2, FIG. 3 is a structural schematic diagram of the power module 300 shown in FIG. 2, omitting the heat sink 30, the second sintering layer 30a and the plastic package 70.

[0075] As shown in FIG. 3, the substrate 10 is a DBC (Direct Bonded Copper) substrate in an example. In other embodiments, the substrate 10 can also be an AMB (Active Metal Brazed) substrate or other ceramic substrate. The substrate 10 can also be an IMS (Insulated Material Substrate) substrate or other organic insulating substrate or aluminum substrate with an insulating layer. The substrate 10 is a rectangular substrate. In other embodiments, the substrate 10 can also be a circular substrate, a triangular substrate or other irregularly-shaped substrate. In the present embodiment, the length direction of the substrate 10 is defined as the first direction (i.e. the Y-axis direction shown in the figure), the width direction of the substrate 10 is defined as the second direction (i.e. the X-axis direction shown in the figure), and the thickness direction of the substrate 10 is defined as the third direction (i.e. the Z-axis direction shown in the figure). The first direction, the second direction and the third direction (i.e. the thickness direction of the substrate 10) are perpendicular to each other. In other embodiments, the length direction of the substrate 10 can also be the X-axis direction shown in the figure, and the width direction of the substrate 10 can also be the Y-axis direction shown in the figure.

[0076] In some embodiments, the substrate 10 includes an insulating layer 11, a first conductive layer 12, a second conductive layer 13 and a heat-conductive layer 14. The insulating layer 11 is made of insulating material including but not limited to ceramic or epoxy resin in an example. The first conductive layer 12 is arranged in a stack on one side of the insulating layer 11 in the Z-axis direction (i.e. the thickness direction of the substrate 10). Specifically, the first conductive layer 12 is in contact with and fixed in a stack on one side of the insulating layer 11 in the Z-axis direction. The first conductive layer 12 is made of copper in an example. In other embodiments, the first conductive layer 12 can also be made of other conductive material such as nickel or aluminum.

[0077] In the Z-axis direction (i.e., the thickness direction of the substrate 10), the second conductive layer 13 is laminated on one side of the insulating layer 11 and faces the first conductive layer 12. Specifically, in the Z-axis direction, the second conductive layer 13 is in contact with and fixedly laminated on one side of the insulating layer 11 facing the first conductive layer 12. The second conductive layer 13 is arranged in a spaced manner from the first conductive layer 12. For example, the second conductive layer 13 is made of the same material as the first conductive layer 12, and is made of copper. In other embodiments, the second conductive layer 13 can also be made of other conductive materials such as nickel or aluminum. The material of the second conductive layer 13 can also be different from that of the first conductive layer 12.

[0078] The second conductive layer 13 includes a first sub-conductive layer 131 and a second sub-conductive layer 132. In the Z-axis direction, the first sub-conductive layer 131 and the second sub-conductive layer 132 are in contact with and fixedly laminated on one side of the insulating layer 11 facing the first conductive layer 12. In the X-axis direction, the first sub-conductive layer 131 and the second sub-conductive layer 132 are located on both sides of the first conductive layer 12 and are arranged in a spaced manner from the first conductive layer 12.

[0079] In the Z-axis direction (i.e., the thickness direction of the substrate 10), the heat-conductive layer 14 is laminated on one side of the insulating layer 11 and faces away from the first conductive layer 12. Specifically, in the Z-axis direction, the heat-conductive layer 14 is in contact with and fixedly laminated on one side of the insulating layer 11 facing away from the first conductive layer 12. For example, the heat-conductive layer 14 is made of the same material as the first conductive layer 12, and is made of copper. In other embodiments, the heat-conductive layer 14 can also be made of other conductive materials such as nickel or aluminum. The material of the heat-conductive layer 14 can also be different from that of the first conductive layer 12. The design that the material of the heat-conductive layer 14 is the same as that of the first conductive layer 12 is beneficial to reducing the material cost of the substrate 10, reducing the processing cost of the substrate 10, and reducing the processing cost of the power module 300.

[0080] In some embodiments, the substrate 10 is provided with a first sintering layer 10a. In other words, the power module 300 includes the first sintering layer 10a. In the Z-axis direction, the first sintering layer 10a is laminated on one side of the first conductive layer 12 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the first sintering layer 10a is in contact with and fixedly laminated on one side of the first conductive layer 12 facing away from the insulating layer 11. In the Z-axis direction, the thickness of the first sintering layer 10a is less than the thickness of the first conductive layer 12.

[0081] In some embodiments, the substrate 10 is provided with a first sintered layer 10a. In the Z-axis direction, the first sintered layer 10a is laminated on one side of the first conductive layer 12 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the first sintered layer 10a is in contact with and fixedly laminated on one side of the first conductive layer 12 that faces away from the insulating layer 11. In the X-axis direction, the first sintered layer 10a is spaced apart from the first sintered layer 10a. In the Z-axis direction, the thickness of the first sintered layer 10a is less than the thickness of the first conductive layer 12. For example, the first sintered layer 10a is made of the same material as the first conductive layer 12, and the first sintered layer 10a is made of copper. In other embodiments, the first sintered layer 10a can also be made of an aluminum composite material or nickel. It can be understood that the first sintered layer 10a is made of an aluminum composite material, copper, or nickel. The material of the first sintered layer 10a can also be different from the material of the first conductive layer 12. For example, the porosity of the first sintered layer 10a is less than 10%. In other embodiments, the porosity of the first sintered layer 10a can also be greater than or equal to 10%. The porosity refers to the percentage of the volume of the pores in the bulk material to the total volume of the material in the non-porous state. The first sintered layer 10a made of an aluminum composite material, copper, or nickel has a low porosity, so the first sintered layer 10a made of the material has a strong heat conduction capacity.

[0082] In some embodiments, the substrate 10 is provided with a first sintered layer 10a. In the Z-axis direction, the first sintered layer 10a is laminated on one side of the first conductive layer 12 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the first sintered layer 10a is in contact with and fixedly laminated on one side of the first conductive layer 12 that faces away from the insulating layer 11. In the X-axis direction, the first sintered layer 10a is spaced apart from the first sintered layer 10a. In the Z-axis direction, the thickness of the first sintered layer 10a is less than the thickness of the first conductive layer 12. For example, the first sintered layer 10a is made of the same material as the first conductive layer 12, and the first sintered layer 10a is made of copper. In other embodiments, the first sintered layer 10a can also be made of an aluminum composite material or nickel. It can be understood that the first sintered layer 10a is made of an aluminum composite material, copper, or nickel. The material of the first sintered layer 10a can also be different from the material of the first conductive layer 12. For example, the porosity of the first sintered layer 10a is less than 10%. In other embodiments, the porosity of the first sintered layer 10a can also be greater than or equal to 10%. The porosity refers to the percentage of the volume of the pores in the bulk material to the total volume of the material in the non-porous state. The first sintered layer 10a made of an aluminum composite material, copper, or nickel has a low porosity, so the first sintered layer 10a made of the material has a strong heat conduction capacity.

[0083] In some embodiments, the substrate 10 is provided with a first sintered layer 10a. In the Z-axis direction, the first sintered layer 10a is laminated on one side of the first conductive layer 12 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the first sintered layer 10a is in contact with and fixedly laminated on one side of the first conductive layer 12 that faces away from the insulating layer 11. In the X-axis direction, the first sintered layer 10a is spaced apart from the first sintered layer 10a. In the Z-axis direction, the thickness of the first sintered layer 10a is less than the thickness of the first conductive layer 12. For example, the first sintered layer 10a is made of the same material as the first conductive layer 12, and the first sintered layer 10a is made of copper. In other embodiments, the first sintered layer 10a can also be made of an aluminum composite material or nickel. It can be understood that the first sintered layer 10a is made of an aluminum composite material, copper, or nickel. The material of the first sintered layer 10a can also be different from the material of the first conductive layer 12. For example, the porosity of the first sintered layer 10a is less than 10%. In other embodiments, the porosity of the first sintered layer 10a can also be greater than or equal to 10%. The porosity refers to the percentage of the volume of the pores in the bulk material to the total volume of the material in the non-porous state. The first sintered layer 10a made of an aluminum composite material, copper, or nickel has a low porosity, so the first sintered layer 10a made of the material has a strong heat conduction capacity.

[0084] In some embodiments, the substrate 10 is provided with a third matching connection layer 10d. In the Z-axis direction, the third matching connection layer 10d is laminated on one side of the second sub-conductive layer 132 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the third matching connection layer 10d is in contact with and fixedly laminated on one side of the second sub-conductive layer 132 which faces away from the insulating layer 11. In the Z-axis direction, the thickness of the third matching connection layer 10d is less than the thickness of the first conductive layer 12. For example, the third matching connection layer 10d is made of the same material as the second sub-conductive layer 132, and is made of copper. In other embodiments, the third matching connection layer 10d can also be made of nickel. The material of the third matching connection layer 10d can also be different from that of the second sub-conductive layer 132.

[0085] In some embodiments, the substrate 10 is provided with a fourth matching connection layer 10e. In the Z-axis direction, the fourth matching connection layer 10e is laminated on one side of the second sub-conductive layer 132 and faces away from the insulating layer 11. Specifically, in the Z-axis direction, the fourth matching connection layer 10e is in contact with and fixedly laminated on one side of the second sub-conductive layer 132 which faces away from the insulating layer 11. In the X-axis direction, the fourth matching connection layer 10e is located on one side of the third matching connection layer 10d close to the first sintered layer 10a, and the fourth matching connection layer 10e is spaced apart from the third matching connection layer 10d. In the Z-axis direction, the thickness of the fourth matching connection layer 10e is less than the thickness of the first conductive layer 12. For example, the fourth matching connection layer 10e is made of the same material as the second sub-conductive layer 132, and is made of copper. In other embodiments, the fourth matching connection layer 10e can also be made of nickel. The material of the fourth matching connection layer 10e can also be different from that of the second sub-conductive layer 132.

[0086] In some embodiments, in the Z-axis direction, the power device 20 is laminated on one side of the first sintered layer 10a and faces away from the first conductive layer 12. Specifically, in the Z-axis direction, the power device 20 is in contact with and fixedly laminated on one side of the first sintered layer 10a which faces away from the first conductive layer 12. It can be understood that, in the Z-axis direction (i.e., the thickness direction of the substrate 10), the first sintered layer 10a and the power device 20 are sequentially laminated on one side of the first conductive layer 12 which faces away from the insulating layer 11.

[0087] In some embodiments, the power device 20 comprises a power chip 21, a first fixing layer 22, a first barrier layer 23, a first connecting layer 24, a second fixing layer 25, a second barrier layer 26 and a second connecting layer 27. In the Z-axis direction, the first fixing layer 22, the first barrier layer 23 and the first connecting layer 24 are sequentially stacked on one side of the power chip 21, and the second fixing layer 25, the second barrier layer 26 and the second connecting layer 27 are sequentially stacked on the other side of the power chip 21. That is, in the Z-axis direction (i.e. the thickness direction of the substrate 10), the power chip 21, the first fixing layer 22 and the first connecting layer 24 are sequentially stacked, and the first barrier layer 23 is stacked between the first fixing layer 22 and the first connecting layer 24. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the second fixing layer 25 and the second connecting layer 27 are sequentially stacked on the side of the power chip 21 away from the first fixing layer 22, and the second barrier layer 26 is stacked between the second fixing layer 25 and the second connecting layer 27. In other embodiments, the first barrier layer 23 and the second barrier layer 26 can also be omitted.

[0088] For example, the power chip 21 can be an insulated gate bipolar transistor (IGBT) or a fast recovery diode (FRD) or other device for power conversion. The power chip 21 is made of silicon carbide. Silicon carbide can increase the working frequency of the power device 20, and in the case of meeting the same working frequency, it is beneficial to reduce the volume of the power device 20, arrange more power devices 20 in the power module 300, and improve the power density of the power module 300. In other embodiments, the power chip 21 can also be made of gallium nitride or silicon. For example, the first fixing layer 22 is made of titanium. In the Z-axis direction, the first fixing layer 22 contacts and fixes the side of the power chip 21.

[0089] The first barrier layer 23 is made of nickel or nickel vanadium (NiV). In the Z-axis direction, the first barrier layer 23 contacts and fixes the side of the first fixing layer 22 away from the power chip 21. The thickness of the first barrier layer 23 (i.e. the size of the first barrier layer 23 in the Z-axis direction) is greater than the thickness of the first fixing layer 22 (i.e. the thickness of the first fixing layer 22 in the Z-axis direction).

[0090] In an example, the first connecting layer 24 is made of copper. In other embodiments, the first connecting layer 24 can also be made of nickel, silver or gold. It is appreciated that the first connecting layer 24 is made of copper, nickel, silver or gold. The first connecting layer 24 can also be made of a material different from that of the first sintering layer 10a. In the Z-axis direction, the first connecting layer 24 contacts and fixes the side of the first barrier layer 23 stacked away from the first fixing layer 22. The power chip 21 is fixed by the first fixing layer 22 and the first barrier layer 23, so that the power chip 21 is fixed by the first connecting layer 24. It is appreciated that the power chip 21 is fixed by the first fixing layer 22 and the first connecting layer 24. The first fixing layer 22 is designed to improve the structural stability of the power device 20. In this case, the thickness of the first connecting layer 24 (i.e. the size of the first connecting layer 24 in the Z-axis direction) is greater than the thickness of the first fixing layer 22 (i.e. the size of the first fixing layer 22 in the Z-axis direction).

[0091] In an example, the second fixing layer 25 is made of titanium. In the Z-axis direction, the second fixing layer 25 contacts and fixes the side of the power chip 21 stacked away from the first fixing layer 22. The second barrier layer 26 is made of nickel or nickel vanadium. In the Z-axis direction, the second barrier layer 26 contacts and fixes the side of the second fixing layer 25 stacked away from the power chip 21. In this case, the thickness of the second barrier layer 26 (i.e. the size of the second barrier layer 26 in the Z-axis direction) is greater than the thickness of the second fixing layer 25 (i.e. the size of the second fixing layer 25 in the Z-axis direction).

[0092] In an example, the second connecting layer 27 is made of copper. In other embodiments, the second connecting layer 27 can also be made of nickel, silver or gold. It is appreciated that the second connecting layer 27 is made of copper, nickel, silver or gold. In the Z-axis direction, the second connecting layer 27 contacts and fixes the side of the second barrier layer 26 stacked away from the second fixing layer 25. The power chip 21 is fixed by the second fixing layer 25 and the second barrier layer 26, so that the power chip 21 is fixed by the second connecting layer 27. It is appreciated that the power chip 21 is fixed by the second fixing layer 25 and the second connecting layer 27. The second fixing layer 25 is designed to improve the structural stability of the power device 20. In this case, the thickness of the second connecting layer 27 (i.e. the size of the second connecting layer 27 in the Z-axis direction) is greater than the thickness of the second fixing layer 25 (i.e. the size of the second fixing layer 25 in the Z-axis direction).

[0093] In some embodiments, the power device 20 is provided with a mounting layer 20a. In other words, the power module 300 comprises the mounting layer 20a. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the mounting layer 20a is laminated on one side of the second connecting layer 27 and faces away from the power chip 21. Specifically, in the Z-axis direction, the mounting layer 20a is in contact with and fixedly laminated on one side of the second connecting layer 27 which faces away from the power chip 21. For example, the mounting layer 20a is made of the same material as the second connecting layer 27. The mounting layer 20a is made of copper. In other embodiments, the mounting layer 20a can also be made of an aluminum composite material or nickel. It can be understood that the mounting layer 20a is made of an aluminum composite material, copper or nickel. The mounting layer 20a can also be made of a material different from the material of the second connecting layer 27.

[0094] In some embodiments, the first connecting layer 24 is in contact with the first sintered layer 10a. Specifically, the first connecting layer 24 is in contact with and fixedly laminated on the first sintered layer 10a. In the Z-axis direction, the first connecting layer 24 is laminated on one side of the first sintered layer 10a and faces away from the first conductive layer 12, the first blocking layer 23, the first fixing layer 22, the power chip 21, the second fixing layer 25, the second blocking layer 26, the second connecting layer 27 and the mounting layer 20a all face away from the first sintered layer 10a. For example, the bonding strength between the substrate 10 and the power device 20 is greater than 30 MPa (mega pascal). In the Z-axis direction, the thickness of the first connecting layer 24 is less than the thickness of the first sintered layer 10a. It can be understood that, in the Z-axis direction (i.e. the thickness direction of the substrate 10), the thickness of the first sintered layer 10a is greater than the thickness of the first connecting layer 24 and less than the thickness of the first conductive layer 12.

[0095] It should be noted that, in the present embodiment, the sintering material for forming the first sintered layer 10a is first laminated on one side of the first conductive layer 12 and faces away from the insulating layer 11. The power device 20 is then laminated opposite to the first conductive layer 12, so that the sintering material for forming the first sintered layer 10a is located between the first connecting layer 24 of the power device 20 and the first conductive layer 12. By preheating the sintering material for forming the first sintered layer 10a and pressurizing the substrate 10 or the power device 20, the first sintered layer 10a is formed, so that the first connecting layer 24 and the first sintered layer 10a are bonded together, the first connecting layer 24 and the first sintered layer 10a are laminated, and the first sintered layer 10a is laminated between the first connecting layer 24 and the first conductive layer 12. Thus, the power device 20 is bonded together with the substrate 10 through the first sintered layer 10a.

[0096] In some other embodiments, the sintering material for forming the first sintering layer 10a can be first stacked on one side of the first connecting layer 24 and away from the power chip 21. The power device 20 is then stacked opposite to the first conductive layer 12, such that the sintering material for forming the first sintering layer 10a is located between the first connecting layer 24 and the first conductive layer 12. The sintering material for forming the first sintering layer 10a is preheated, and the substrate 10 or the power device 20 is pressed, so as to form the first sintering layer 10a, and the first conductive layer 12 is bonded to the first sintering layer 10a, and the first sintering layer 10a is stacked between the first connecting layer 24 and the first conductive layer 12. Thus, the power device 20 is also bonded to the substrate 10 through the first sintering layer 10a.

[0097] In the power module 300 provided by the embodiments of the present application, a large amount of heat generated by the power chip 21 during operation can be transferred to the substrate 10 through the first fixing layer 22, the first barrier layer 23, the first connecting layer 24 and the first sintering layer 10a, and then transferred to the external environment from the substrate 10, so as to achieve rapid heat dissipation of the power device 20.

[0098] Compared with the prior art, in the present application, the power device 20 and the substrate 10 are bonded through the first sintering layer 10a between the first connecting layer 24 and the first conductive layer 12, the first sintering layer 10a has a lower porosity, which is conducive to improving the efficiency of heat generated by the power chip 21 during operation being transferred to the substrate 10 through the first connecting layer 24 and the first sintering layer 10a, and is conducive to improving the heat dissipation efficiency of the power device 20. Moreover, in the Z-axis direction (i.e. the thickness direction of the substrate 10), the thickness of the first sintering layer 10a is greater than the thickness of the first connecting layer 24 and less than the thickness of the first conductive layer 12, which ensures that the first connecting layer 24 and the first sintering layer 10a have a higher bonding strength, is conducive to improving the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and is conducive to improving the structural stability of the power module 300.

[0099] The material of the first connecting layer 24 is copper, nickel, silver or gold, and the material of the first sintering layer 10a is a composite material of aluminum, copper or nickel. The first sintering layer 10a has a low porosity, which is beneficial to improve the heat conduction capacity of the first sintering layer 10a, improve the efficiency of heat generated by the power chip 21 during operation being transferred to the substrate 10 through the first connecting layer 24 and the first sintering layer 10a, and improve the heat dissipation efficiency of the power device 20. Moreover, the first connecting layer 24 and the first sintering layer 10a have a high bonding strength, which is beneficial to improve the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improve the structural stability of the power module 300. In addition, the cost of copper, nickel and the composite material of aluminum is low, which ensures that the material cost of bonding the substrate 10 and the power device 20 is low, and is beneficial to reduce the processing cost of the power module 300.

[0100] The material of the first connecting layer 24 is the same as that of the first sintering layer 10a, which is beneficial to improve the bonding strength of the first connecting layer 24 and the first sintering layer 10a, improve the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improve the structural stability of the power module 300. The material of the first sintering layer 10a is the same as that of the first conductive layer 12, which is beneficial to improve the bonding strength of the first sintering layer 10a and the first conductive layer 12, improve the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improve the structural stability of the power module 300.

[0101] The thickness (the size of the first connecting layer 24 in the Z-axis direction) of the first connecting layer 24 is greater than the thickness (i.e. the size of the first fixed layer 22 in the Z-axis direction) of the first fixed layer 22, which ensures that the first connecting layer 24 and the first sintering layer 10a have a high bonding force, which is beneficial to improve the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improve the structural stability of the power module 300.

[0102] During the bonding process of the first connecting layer 24 and the first conductive layer 12 of the substrate 10 through the first sintering layer 10a, the first barrier layer 23 can prevent the first connecting layer 24 from reacting with the first fixed layer 22, so as to avoid the first fixed layer 22 from being separated from the power chip 21, which is beneficial to improve the structural stability of the power device 20 and the structural stability of the power module 300.

[0103] The thickness of the first barrier layer 23 (i.e., the size of the first barrier layer 23 in the Z-axis direction) is greater than the thickness of the first fixed layer 22 (i.e., the thickness of the first fixed layer 22 in the Z-axis direction), which is designed to improve the blocking effect of the first barrier layer 23 on the first connecting layer 24 and the first fixed layer 22, thereby avoiding the first fixed layer 22 from being separated from the power chip 21, improving the structural stability of the power device 20, and improving the structural stability of the power module 300.

[0104] As shown in FIGS. 2 and 3, in the Z-axis direction, the heat sink 30 is located on one side of the heat-conductive layer 14 and faces away from the insulating layer 11. For example, the material of the heat sink 30 is the same as that of the heat-conductive layer 14. The heat sink 30 is made of copper. In other embodiments, the heat sink 30 can also be made of nickel or aluminum or other heat-conductive materials. The material of the heat sink 30 can also be different from that of the heat-conductive layer 14. The heat sink 30 includes a first mounting portion 31 and a second mounting portion 32. In the Z-axis direction, the second mounting portion 32 is disposed on one side of the first mounting portion 31 and faces away from the substrate 10. Specifically, in the Z-axis direction, the second mounting portion 32 is fixedly stacked on one side of the first mounting portion 31 and faces away from the substrate 10.

[0105] The first mounting portion 31 includes a first mounting surface 311 and a second mounting surface 312. In the Z-axis direction, the first mounting surface 311 and the second mounting surface 312 are disposed opposite to each other, the first mounting surface 311 faces the substrate 10, and the second mounting surface 312 faces away from the substrate 10. The second mounting portion 32 is fixedly stacked on one side of the second mounting surface 312 and faces away from the first mounting surface 311 by means including but not limited to welding or gluing. The second mounting portion 32 and the first mounting portion 31 jointly form a receiving cavity 33. The receiving cavity 33 is used to accommodate a cooling working medium. The cooling working medium can be a fluid including but not limited to water, methanol, or ethylene glycol.

[0106] The material of the first mounting portion 31 and the material of the second mounting portion 32 are the same as that of the heat-conductive layer 14. The first mounting portion 31 and the second mounting portion 32 are both made of copper. In other embodiments, the first mounting portion 31 and the second mounting portion 32 can also be made of nickel or aluminum or other heat-conductive materials. The material of the first mounting portion 31 can also be different from that of the heat-conductive layer 14. The material of the second mounting portion 32 can also be different from that of the heat-conductive layer 14. The material of the first mounting portion 31 can also be different from that of the second mounting portion 32.

[0107] In some embodiments, the heat sink 30 is provided with heat dissipation fins 34. Specifically, the side of the heat sink 30 facing away from the substrate 10 in the Z-axis direction is provided with the heat dissipation fins 34, which are fixed and stacked on the side of the second mounting surface 312 facing away from the first mounting surface 311. The heat dissipation fins 34 are accommodated in the accommodation cavity 33. For example, the number of the heat dissipation fins 34 is plural. In the X-axis direction, the plural heat dissipation fins 34 are arranged at intervals. In other embodiments, the number of the heat dissipation fins 34 can also be one.

[0108] In some embodiments, the heat sink 30 is provided with an inlet 35 and an outlet 36. Specifically, the second mounting portion 32 is provided with the inlet 35 and the outlet 36. In the X-axis direction, the inlet 35 and the outlet 36 are located on both sides of the accommodation cavity 33. The inlet 35 penetrates the second mounting portion 32 in the X-axis direction and communicates with the accommodation cavity 33, and the outlet 36 penetrates the second mounting portion 32 in the X-axis direction and communicates with the accommodation cavity 33. In other embodiments, the inlet 35 and the outlet 36 can also be arranged on the first mounting portion 31. The inlet 35 penetrates the first mounting portion 31 in the Z-axis direction and communicates with the accommodation cavity 33. The outlet 36 penetrates the first mounting portion 31 in the Z-axis direction and communicates with the accommodation cavity 33. The cooling working medium can flow into the accommodation cavity 33 from the inlet 35 and flow out of the accommodation cavity 33 from the outlet 36 through the heat dissipation fins 34. The cooling working medium can carry away the heat emitted by the heat dissipation fins 34 from the accommodation cavity 33, thereby achieving heat dissipation of the heat dissipation fins 34.

[0109] In some embodiments, in the Z-axis direction, the heat sink 30 and the substrate 10 are provided with a second sintering layer 30a, that is, the power module 300 comprises the second sintering layer 30a. The second sintering layer 30a is arranged and stacked between the heat sink 30 and the substrate 10. Specifically, the second sintering layer 30a is arranged and stacked between the first mounting portion 31 and the heat conduction layer 14, and the second sintering layer 30a is in contact with and fixedly stacked between the first mounting surface 311 and the heat conduction layer 14. That is, in the Z-axis direction (i.e., the thickness direction of the substrate 10), the second sintering layer 30a and the heat sink 30 are sequentially arranged and stacked on the side of the heat conduction layer 14 facing away from the insulating layer 11. The area of the projection of the second sintering layer 30a in the Z-axis direction (i.e., the thickness direction of the substrate 10) is greater than the area of the projection of the first sintering layer 10a in the Z-axis direction (i.e., the thickness direction of the substrate 10). In the Z-axis direction (i.e., the thickness direction of the substrate 10), the thickness of the second sintering layer 30a is greater than the thickness of the first sintering layer 10a and less than the thickness of the first conductive layer 12.

[0110] The material of the second sintered layer 30a is exemplarily the same as the material of the heat conducting layer 14 and the material of the heat spreader 30. That is, the material of the heat conducting layer 14, the material of the second sintered layer 30a and the material of the heat spreader 30 are the same. Specifically, the material of the second sintered layer 30a is the same as the material of the heat conducting layer 14 and the material of the first mounting portion 31. The material of the second sintered layer 30a is copper. In other embodiments, the material of the second sintered layer 30a can also be an aluminum composite material or nickel. It can be understood that the material of the second sintered layer 30a is an aluminum composite material, copper or nickel. The material of the second sintered layer 30a can also be different from the material of the heat conducting layer 14, and the material of the second sintered layer 30a can also be different from the material of the heat spreader 30. Exemplarily, the porosity of the second sintered layer 30a is less than 15%. The second sintered layer 30a made of an aluminum composite material, copper or nickel has a low porosity, and the second sintered layer 30a made of an aluminum composite material, copper or nickel has a high heat conduction capacity.

[0111] It should be noted that in the present embodiment, the sintered material for forming the second sintered layer 30a is first stacked on one side of the first mounting surface 311 of the first mounting portion 31 and faces away from the second mounting surface 312. The first mounting portion 31 of the heat spreader 30 is then stacked opposite the heat conducting layer 14, so that the sintered material for forming the second sintered layer 30a is located between the first mounting portion 31 and the heat conducting layer 14. By preheating the sintered material for forming the second sintered layer 30a and pressurizing the substrate 10 or the heat spreader 30, the second sintered layer 30a is formed, so that the heat conducting layer 14 and the second sintered layer 30a are bonded together, the heat conducting layer 14 and the second sintered layer 30a are stacked, and the second sintered layer 30a is stacked between the first mounting portion 31 (i.e. the heat spreader 30) and the heat conducting layer 14. Thus, the heat spreader 30 is bonded to the substrate 10 through the second sintered layer 30a. The bonding strength between the heat spreader 30 and the substrate 10 is greater than 30 MPa. Exemplarily, the bonding strength between the heat spreader 30 and the substrate 10 is greater than 35.36 MPa. In other embodiments, the bonding strength between the heat spreader 30 and the substrate 10 is greater than 42.4 MPa. In other embodiments, the bonding strength between the heat spreader 30 and the substrate 10 can also be equal to or less than 30 MPa. For example, the bonding strength between the heat spreader 30 and the substrate 10 can also be 27.8 MPa.

[0112] In some other embodiments, the sintering material for forming the second sintering layer 30a can be first stacked on one side of the heat conduction layer 14 and away from the insulating layer 11. The first mounting portion 31 of the heat sink 30 is then stacked opposite to the heat conduction layer 14, such that the sintering material for forming the second sintering layer 30a is located between the first mounting portion 31 and the heat conduction layer 14. The sintering material for forming the second sintering layer 30a is preheated, and the substrate 10 or the heat sink 30 is pressed, so as to form the second sintering layer 30a, and the first mounting portion 31 (i.e. the heat sink 30) is bonded to the second sintering layer 30a, and the second sintering layer 30a is stacked between the first mounting portion 31 (i.e. the heat sink 30) and the heat conduction layer 14. Thus, the heat sink 30 is also bonded to the substrate 10 through the second sintering layer 30a.

[0113] It can be understood that the heat conduction layer 14 is bonded to the heat sink 30 through the second sintering layer 30a. When the power device 20 is working, the heat generated by the power device 20 can be transferred to the cooling medium in the receiving cavity 33 through the first conductive layer 12, the insulating layer 11, the heat conduction layer 14, the second sintering layer 30a, the first mounting portion 31 and the heat dissipation fins 34, and the heat generated by the power device 20 is taken out of the receiving cavity 33 through the cooling medium, so as to achieve rapid heat dissipation of the power device 20. That is, the heat generated by the power device 20 when working can be transferred to the heat sink 30 through the substrate 10 and the second sintering layer 30a, and then transferred to the external environment from the heat sink 30. The design of the heat sink 30 is conducive to improving the efficiency of transferring the heat generated by the power device 20 to the external environment, and is conducive to improving the heat dissipation efficiency of the power device 20.

[0114] The thickness of the second sintering layer 30a is greater than the thickness of the first sintering layer 10a and less than the thickness of the first conductive layer 12 along the Z-axis direction (i.e. the thickness direction of the substrate 10), which is conducive to increasing the bonding strength of the heat sink 30 and the substrate 10 through the second sintering layer 30a, and is conducive to improving the structural stability of the power module 300.

[0115] The material of the heat conduction layer 14, the material of the second sintering layer 30a and the material of the heat sink 30 are the same, which is conducive to improving the bonding strength of the heat conduction layer 14 and the second sintering layer 30a, the bonding strength of the second sintering layer 30a and the heat sink 30, the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and the structural stability of the power module 300.

[0116] It can be understood that the material of the second sintering layer 30a is the same as that of the first sintering layer 10a. The first sintering layer 10a and the second sintering layer 30a are both made by high-temperature and high-pressure. Since the material of the second sintering layer 30a is the same as that of the first sintering layer 10a, the first sintering layer 10a and the second sintering layer 30a can be made by one-time high-temperature and high-pressure, which is conducive to reducing the cost of making the first sintering layer 10a and the second sintering layer 30a, reducing the material cost, and reducing the processing cost of the power module 300.

[0117] The design that the area of the projection of the second sintering layer 30a on the Z-axis direction (i.e., the thickness direction of the substrate 10) is greater than the area of the projection of the first sintering layer 10a on the Z-axis direction (i.e., the thickness direction of the substrate 10) is conducive to improving the strength of the heat sink 30 and the substrate 10 bonded by the second sintering layer 30a, and improving the structural stability of the power module 300.

[0118] In some embodiments, the second sintering layer 30a is provided with an exhaust groove 301 extending along the Z-axis direction (i.e., the thickness direction of the substrate 10) from one side of the second sintering layer 30a in the Z-axis direction (i.e., the thickness direction of the substrate 10). For example, the exhaust groove 301 extends along the Z-axis direction from the surface of the second sintering layer 30a toward the heat conduction layer 14. Among them, along the Z-axis direction, the width of the exhaust groove 301 is less than the thickness of the second sintering layer 30a. That is, the exhaust groove 301 does not penetrate the heat conduction layer 14 along the Z-axis direction. In other embodiments, the exhaust groove 301 can also penetrate the heat conduction layer 14 along the Z-axis direction.

[0119] The exhaust groove 301 penetrates the second sintering layer 30a along the Y-axis direction. That is, along the Y-axis direction, the length of the exhaust groove 301 is equal to the length of the second sintering layer 30a. It can be understood that along the Z-axis direction (i.e., the thickness direction of the substrate 10), the width of the exhaust groove 301 is less than the thickness of the second sintering layer 30a, and along the Y-axis direction (i.e., the first direction), the length of the exhaust groove 301 is equal to the length of the second sintering layer 30a. For example, the number of exhaust grooves 301 is multiple. Specifically, the number of exhaust grooves 301 is 10. In other embodiments, the number of exhaust grooves 301 can also be 1, 2 or more. The multiple exhaust grooves 301 are arranged at intervals along the X-axis direction. In other embodiments, the exhaust groove 301 can also penetrate the second sintering layer 30a along the X-axis direction. The multiple exhaust grooves 301 are arranged at intervals along the Y-axis direction.

[0120] The exhaust gas generated in the process of bonding the second sintering layer 30a and the heat conduction layer 14 together can escape from each exhaust groove 301 to the external environment, which is conducive to improving the bonding strength of the second sintering layer 30a and the heat conduction layer 14, avoiding delamination between the second sintering layer 30a and the heat conduction layer 14, avoiding delamination between the second sintering layer 30a and the heat sink 30, and improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, thereby improving the structural stability of the power module 300.

[0121] It can be understood that the design of the exhaust groove 301 ensures that the exhaust gas generated in the process of bonding the substrate 10 and the heat sink 30 together through the second sintering layer 30a can escape from the exhaust groove 301 to the external environment, which is conducive to improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and improving the structural stability of the power module 300.

[0122] In the Z-axis direction (i.e., the thickness direction of the substrate 10), the width of the exhaust groove 301 is less than the thickness of the second sintering layer 30a, and the length of the exhaust groove 301 in the Y-axis direction (i.e., the first direction) is equal to the length of the second sintering layer 30a. The design ensures that the exhaust gas generated in the process of bonding the substrate 10 and the heat sink 30 together through the second sintering layer 30a can escape from the exhaust groove 301 to the external environment along the length direction of the exhaust groove 301 (i.e., the Y-axis direction). And avoid the exhaust groove 301 penetrating through the second sintering layer 30a in the Z-axis direction (i.e., the thickness direction of the substrate 10), which is conducive to improving the bonding strength of the heat sink 30 and the substrate 10 through the second sintering layer 30a, and improving the structural stability of the power module 300.

[0123] The design of multiple exhaust grooves 301 is conducive to increasing the efficiency of the exhaust gas generated in the process of bonding the substrate 10 and the heat sink 30 together through the second sintering layer 30a escaping from the exhaust grooves 301 to the external environment, which is conducive to improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and improving the structural stability of the power module 300.

[0124] In other embodiments, the exhaust groove 301 can also extend in the Z-axis direction from the second sintering layer 30a towards the surface of the heat sink 30. The exhaust groove 301 penetrates through the second sintering layer 30a in the Y-axis direction, or the exhaust groove 301 penetrates through the second sintering layer 30a in the X-axis direction. The design of the exhaust groove 301 ensures that the exhaust gas generated in the process of bonding the second sintering layer 30a and the first mounting portion 31 of the heat sink 30 together can escape from the exhaust groove 301 to the external environment, which is conducive to improving the bonding strength of the second sintering layer 30a and the first mounting portion 31 (i.e., the heat sink 30), and also conducive to improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, thereby improving the structural stability of the power module 300.

[0125] The projection of each exhaust groove in the Z-axis direction is spaced apart from the projection of the power device 20 in the Z-axis direction. That is, the projection of the exhaust groove 301 in the Z-axis direction (i.e., the thickness direction of the substrate 10) is spaced apart from the projection of the power device 20 in the Z-axis direction (i.e., the thickness direction of the substrate 10). The design that the projection of the exhaust groove 301 in the Z-axis direction (i.e., the thickness direction of the substrate 10) is spaced apart from the projection of the power device 20 in the Z-axis direction (i.e., the thickness direction of the substrate 10) avoids the existence of air in the heat dissipation path along the Z-axis direction (i.e., the thickness direction of the substrate 10) from the substrate 10 to the heat sink 30 via the second sintered layer 30a due to the exhaust groove 301 when the power device 20 is working, ensures that the heat generated by the power device 20 when working is completely transmitted from the substrate 10 to the heat sink 30 along the Z-axis direction (i.e., the thickness direction of the substrate 10) via the second sintered layer 30a, and is conducive to improving the efficiency of heat transmission from the substrate 10 to the heat sink 30 along the Z-axis direction (i.e., the thickness direction of the substrate 10) when the power device 20 is working, and is conducive to improving the heat dissipation efficiency of the power device 20.

[0126] For example, the thermal sensitive device 40 is a thermal resistor. In the Z-axis direction, the thermal sensitive device 40 is stacked on one side of the first matching connection layer 10b and faces away from the first conductive layer 12. Specifically, in the Z-axis direction, the thermal sensitive device 40 is in contact with and fixedly stacked on one side of the first matching connection layer 10b which faces away from the first conductive layer 12. The thermal sensitive device 40 is electrically connected with the power device 20. The thermal sensitive device 40 is used to monitor the temperature of the power device 20. The first matching connection layer 10b can be a sintered layer made by a sintering process, or can be a welding layer made by a welding process.

[0127] In some embodiments, in the Z-axis direction (i.e., the thickness direction of the substrate 10), the terminal 50 is arranged on one side of the second conductive layer 13 and faces away from the insulating layer 11. The terminal 50 includes a first terminal 51 and a second terminal 52. In the Z-axis direction, the first terminal 51 is stacked on one side of the second matching connection layer 10c and faces away from the first sub-conductive layer 131. Specifically, the first terminal 51 is in contact with and fixedly stacked on one side of the second matching connection layer 10c which faces away from the first sub-conductive layer 131. Through the second matching connection layer 10c, the first terminal 51 is arranged on one side of the first sub-conductive layer 131 and faces away from the insulating layer 11. For example, the material of the first terminal 51 is the same as that of the second matching connection layer 10c. The material of the first terminal 51 is copper. In other embodiments, the first terminal 51 can also be made of nickel, aluminum, iron or other conductive materials. The material of the first terminal 51 can also be different from that of the second matching connection layer 10c. The second matching connection layer 10c can be a sintered layer made by a sintering process, or can be a welding layer made by a welding process.

[0128] It can be understood that the material of the first terminal 51, the material of the second matching connection layer 10c and the material of the first sub-conductive layer 131 are the same. Such design is conducive to improving the bonding strength of the second matching connection layer 10c and the first terminal 51, improving the bonding strength of the second matching connection layer 10c and the first sub-conductive layer 131, improving the bonding strength of the substrate 10 and the first terminal 51 through the second matching connection layer 10c, and improving the structural stability of the power module 300.

[0129] In the Z-axis direction, the second terminal 52 is stacked on one side of the third matching connection layer 10d and faces away from the second sub-conductive layer 132. Specifically, the second terminal 52 contacts and fixes the side of the third matching connection layer 10d facing away from the second sub-conductive layer 132. Through the second matching connection layer 10c, the second terminal 52 is arranged on one side of the second sub-conductive layer 132 and faces away from the insulating layer 11. For details, please refer to the related description of the first terminal 51, which will not be repeated here. In the X-axis direction, the second terminal 52 is arranged opposite and spaced apart from the first terminal 51. The number of first terminals 51 and the number of second terminals 52 can also be multiple, and multiple first terminals 51 are arranged spaced apart along the Y-axis direction, and multiple second terminals 52 are arranged spaced apart along the Y-axis direction. Among them, the third matching connection layer 10d can be a sintering layer made by a sintering process, or a welding layer made by a welding process.

[0130] As shown in FIG. 1 and FIG. 3, in some embodiments, the connecting terminal 60 is arranged between the mounting layer 20a and the second conductive layer 13. Specifically, the connecting terminal 60 includes a first connecting terminal 60a and a second connecting terminal 60b. The first connecting terminal 60a is arranged between the mounting layer 20a and the first sub-conductive layer 131. The second connecting terminal 60b is arranged between the mounting layer 20a and the fourth matching connection layer 10e. Through the fourth matching connection layer 10e, the second connecting terminal 60b is arranged between the mounting layer 20a and the second sub-conductive layer 132.

[0131] Each connection terminal 60 includes a connecting portion 61 and a mating portion 62. The connecting portion 61 is fixedly connected with the mating portion 62. For example, the connecting portion 61 of the first connection terminal 60a is in a plate shape. The mating portion 62 of the first connection terminal 60a is a metal wire. In the Z-axis direction, the connecting portion 61 of the first connection terminal 60a is laminated on one side of the mounting layer 20a and faces away from the second connection layer 27. Specifically, in the Z-axis direction, the connecting portion 61 of the first connection terminal 60a is in contact with and fixedly laminated on one side of the mounting layer 20a that faces away from the second connection layer 27. The mating portion 62 of the first connection terminal 60a is disposed on one side of the first sub-conductive layer 131 and faces away from the insulating layer 11 by means including but not limited to welding or crimping. The mating portion 62 of the first connection terminal 60a is fixedly connected on one side of the first sub-conductive layer 131 and faces away from the insulating layer 11. The first terminal 51 is electrically connected with the power device 20 through the first sub-conductive layer 131, the first connection terminal 60a and the mounting layer 20a.

[0132] The connecting portion 61 of the second connection terminal 60b is in a plate shape. The mating portion 62 of the second connection terminal 60b includes a first sub-mating portion 621 and a second sub-mating portion 622. In the X-axis direction, the connecting portion 61 of the second connection terminal 60b is disposed opposite to and spaced apart from the second sub-mating portion 622 of the second connection terminal 60b. The first sub-mating portion 621 of the second connection terminal 60b is fixedly laminated between the connecting portion 61 of the second connection terminal 60b and the second sub-mating portion 622 of the second connection terminal 60b.

[0133] In the Z-axis direction, the connecting portion 61 of the second connection terminal 60b is laminated on one side of the mounting layer 20a and faces away from the second connection layer 27. Specifically, in the Z-axis direction, the connecting portion 61 of the second connection terminal 60b is in contact with and fixedly laminated on one side of the mounting layer 20a that faces away from the second connection layer 27. In the X-axis direction, the connecting portion 61 of the second connection terminal 60b is located on one side of the connecting portion 61 of the first connection terminal 60a and is close to the second terminal 52. In the Z-axis direction, the second sub-mating portion 622 of the second connection terminal 60b is laminated on one side of the fourth mating connection layer 10e and faces away from the second sub-conductive layer 132. Specifically, in the Z-axis direction, the second sub-mating portion 622 of the second connection terminal 60b is in contact with and fixedly laminated on one side of the fourth mating connection layer 10e that faces away from the second sub-conductive layer 132. The second terminal 52 is electrically connected with the power device 20 through the second sub-conductive layer 132, the second connection terminal 60b and the mounting layer 20a. The fourth mating connection layer 10e can be a sintered layer made by a sintering process or a welded layer made by a welding process.

[0134] The first terminal 51 and the second terminal 52 are mounted on the circuit board 100 by means including but not limited to welding or plugging. The direct current delivered from the input terminal 200 is delivered to the power device 20 through the first terminal 51. The power device 20 is used to convert the direct current into alternating current. The alternating current output by the power device 20 is delivered to the output terminal 400 through the second terminal 52.

[0135] It can be understood that in the Z-axis direction, the connecting portion 61 of each connecting terminal 60 is stacked on one side of the mounting layer 20a and faces away from the second connecting layer 27. That is, in the Z-axis direction (i.e., the thickness direction of the substrate 10), the connecting portion 61 is stacked on one side of the mounting layer 20a and faces away from the second connecting layer 27. The connecting portion 61 of the first connecting terminal 60a is engaged with the second connecting layer 27 of the power device 20 through the mounting layer 20a. The first connecting terminal 60a is engaged with the power device 20 through the mounting layer 20a. The connecting portion 61 of the second connecting terminal 60b is engaged with the second connecting layer 27 of the power device 20 through the mounting layer 20a. The second connecting terminal 60b is engaged with the power device 20 through the mounting layer 20a.

[0136] That is, the power device 20 is engaged with the connecting terminal 60 through the mounting layer 20a between the second connecting layer 27 and the connecting terminal 60, so that the power device 20 is electrically connected with the terminal 50 through the connecting terminal 60. The design that the connecting terminal 60 is arranged between the mounting layer 20a and the second conductive layer 13 can avoid occupying additional area of the first conductive layer 12 by the connecting terminal 60, which is conducive to reducing the area of the first conductive layer 12 and facilitating the miniaturization design of the substrate 10.

[0137] The material of the second connecting layer 27 is copper, nickel, silver or gold, and the material of the mounting layer 20a is a composite material of aluminum, copper or nickel, which not only ensures a high engagement strength between the second connecting layer 27 and the mounting layer 20a, but also facilitates to improve the engagement strength of the power device 20 and the connecting terminal 60 through the mounting layer 20a, and facilitates to improve the structural stability and reliability of the power module 300.

[0138] The material of the mounting layer 20a is the same as that of the second connecting layer 27, which facilitates to improve the engagement strength of the mounting layer 20a and the second connecting layer 27, facilitates to improve the engagement strength of the power device 20 and the connecting terminal 60 through the mounting layer 20a, facilitates to improve the stability of the electrical connection between the power device 20 and the first terminal 51 through the first connecting terminal 60a, facilitates to improve the stability of the electrical connection between the power device 20 and the second terminal 52 through the second connecting terminal 60b, facilitates to improve the stability of the electrical connection between the power device 20 and the terminal 50 through the connecting terminal 60, and facilitates to improve the structural stability and reliability of the power module 300.

[0139] In the process that the second connecting layer 27 is joined with the connecting terminal 60 through the mounting layer 20a, the second barrier layer 26 can prevent the second connecting layer 27 from reacting with the second fixing layer 25, avoid the second fixing layer 25 from being separated from the power chip 21, and be beneficial to improving the structural stability of the power device 20 and the structural stability of the power module 300.

[0140] For example, the material of the connecting part 61 is the same as that of the mounting layer 20a. Specifically, the material of the connecting part 61 of the first connecting terminal 60a and the material of the connecting part 61 of the second connecting terminal 60b are the same as that of the mounting layer 20a. The material of the connecting part 61 is copper. In other embodiments, the material of the connecting part 61 can also be nickel, aluminum or other conductive materials. The material of the connecting part 61 can also be different from that of the mounting layer 20a. The design that the material of the connecting part 61 is the same as that of the mounting layer 20a is beneficial to improving the joint strength of the connecting terminal 60 and the mounting layer 20a, improving the joint strength of the power device 20 and the connecting terminal 60 through the mounting layer 20a, improving the stability of the electrical connection between the power device 20 and the terminal 50 through the connecting terminal 60, and improving the structural stability and reliability of the power module 300.

[0141] As shown in FIG. 2, the plastic package 70 completely covers the substrate 10, the first sintering layer 10a, the first matching connecting layer 10b, the second matching connecting layer 10c, the third matching connecting layer 10d, the fourth matching connecting layer 10e, the power device 20, the mounting layer 20a, the thermal device 40, the first connecting terminal 60a and the second connecting terminal 60b. The plastic package 70 covers part of the first terminal 51, part of the second terminal 52 and part of the second sintering layer 30a. In the Z-axis direction, one end of the first terminal 51 away from the substrate 10 is exposed outside the plastic package 70, one end of the second terminal 52 away from the substrate 10 is exposed outside the plastic package 70, and one side of the second sintering layer 30a away from the substrate 10 is exposed outside the plastic package 70. That is to say, the plastic package 70 completely covers the substrate 10, the first sintering layer 10a and the power device 20. The plastic package 70 covers part of the second sintering layer 30a, and one side of the second sintering layer 30a away from the substrate 10 is exposed outside the plastic package 70.

[0142] The plastic sealing member 70 is made of a plastic sealing material such as epoxy resin, polyester resin, organic silicone, or the like. The plastic sealing member 70 encapsulates the substrate 10, the power device 20, the thermal sensitive device 40, the first terminal 51, the second terminal 52, the first connecting terminal 60a, and the second connecting terminal 60b. The plastic sealing member 70 protects the substrate 10 and the power device 20 from damage caused by impact, thereby improving the safety of the substrate 10 and the power device 20 and prolonging the service life of the substrate 10 and the power device 20.

[0143] Referring to FIG. 3a and FIG. 2, FIG. 3a is a structural schematic diagram of the power module 300 in another embodiment.

[0144] In some other embodiments, the width L1 of the slot opening of the exhaust slot 301 is greater than the width of the slot bottom L2 of the exhaust slot 301 in the X-axis direction (i.e., the second direction). In the Z-axis direction, the dimension of the exhaust slot 301 in the X-axis direction gradually decreases from the slot opening of the exhaust slot 301. The design that the width L1 of the slot opening of the exhaust slot 301 is greater than the width of the slot bottom L2 of the exhaust slot 301 in the X-axis direction (i.e., the second direction) improves the efficiency of the exhaust gas generated during the bonding of the substrate 10 and the heat sink 30 through the second sintering layer 30a escaping from the exhaust slot 301 to the external environment, improves the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and improves the structural stability of the power module 300.

[0145] Referring to FIG. 4 and FIG. 1 and FIG. 2, FIG. 4 is a structural schematic diagram of the power module 300 in another embodiment.

[0146] In some other embodiments, the substrate 10 includes an insulating layer 11, a first conductive layer 12, a second conductive layer 13, and a heat-conductive layer 14. The second conductive layer 13 includes a first sub-conductive layer 131 and a second sub-conductive layer 132. The above-mentioned features cooperate and have the structures as described with reference to FIG. 2. In the X-axis direction, the first conductive layer 12 is located between and spaced apart from the first sub-conductive layer 131 and the second sub-conductive layer 132. In this embodiment, the number of the first conductive layer 12 is plural. For example, the number of the first conductive layer 12 is two. In the X-axis direction, the plural first conductive layers 12 are spaced apart. Between any two adjacent first conductive layers 12, a cooperating member 80 is arranged, and the cooperating member 80 is fixedly connected with the two first conductive layers 12 adjacent thereto. The two first conductive layers 12 adjacent to the cooperating member 80 are electrically connected through the cooperating member 80.

[0147] In the Z-axis direction, each first conductive layer 12 is provided with a first sintering layer 10a on the side opposite to the insulating layer 11. In other words, the number of first sintering layers 10a is plural, and the plural first sintering layers 10a are correspondingly stacked on one side of the plural first conductive layers 12 and opposite to the insulating layer 11. The number of power devices 20 is plural. For example, the number of power devices 20 is 2. The plural power devices 20 are correspondingly stacked on one side of the plural first sintering layers 10a and opposite to the first conductive layer 12. In the Z-axis direction, each power device 20 is provided with a mounting layer 20a on the side opposite to the substrate 10. The above-mentioned matching relationship and structure can refer to the related description of the embodiment shown in FIG. 2. In other embodiments, the number of first conductive layers 12 and the number of power devices 20 can also be 3, 4 or more. Through two first conductive layers 12 and the matching piece 80, two power devices 20 are electrically connected.

[0148] It can be understood that each power device 20 is combined with one first conductive layer 12 through one first sintering layer 10a. In other embodiments, each power device 20 can also be combined with one first conductive layer 12 through a plurality of first sintering layers 10a. That is, each power device 20 corresponds to a plurality of first sintering layers 10a.

[0149] In the Z-axis direction, the heat sink 30 is located on one side of the heat-conductive layer 14 of the substrate 10 and opposite to the insulating layer 11. The second sintering layer 30a is provided between the heat sink 30 and the heat-conductive layer 14. The above-mentioned matching relationship and structure can refer to the related description of the embodiment shown in FIG. 2. In this embodiment, the number of second sintering layers 30a is plural. For example, the number of second sintering layers 30a is 3. In other embodiments, the number of second sintering layers 30a can also be 2, 4 or more. In the X-axis direction, the plural second sintering layers 30a are spaced apart.

[0150] It can be understood that the substrate 10 corresponds to at least one first sintering layer 10a, at least one power device 20 and at least one second sintering layer 30a. The substrate 10 is combined with one heat sink 30 through at least one second sintering layer 30a. The substrate 10 is combined with at least one power device 20 through at least one first sintering layer 10a. The heat generated by each power device 20 during operation can be transmitted to the heat sink 30 through the corresponding first sintering layer 10a, the substrate 10 and the second sintering layer 30a, and then transmitted to the external environment from the heat sink 30, thereby achieving rapid heat dissipation for each power device 20. Through one heat sink 30, the plural power devices 20 can be cooled, thereby achieving rapid heat dissipation for the plural power devices 20.

[0151] In the Z-axis direction, the thermal device 40 is stacked on one side of one of the first conductive layers 12 and faces away from the insulating layer 11, the first terminal 51 is stacked on one side of the first sub-conductive layer 131 and faces away from the insulating layer 11, and the second terminal 52 is stacked on one side of the second sub-conductive layer 132 and faces away from the insulating layer 11. The first connecting terminal 60a is fixedly connected with the mounting layer 20a and the first sub-conductive layer 131 of one of the power devices 20. The second connecting terminal 60b is fixedly connected with the mounting layer 20a and the second sub-conductive layer 132 of the other power device 20. For details, please refer to the related description of the embodiment shown in FIG. 2.

[0152] The first terminal 51 is electrically connected with one of the power devices 20 through the first connecting terminal 60a. The second terminal 52 is electrically connected with the other power device 20 through the second connecting terminal 60b. In addition, the two power devices 20 are electrically connected through the two first conductive layers 12 and the cooperating member 80. The direct current output by the photovoltaic module 2000 is transmitted to the plurality of power devices 20 through the input terminal 200 and the first terminal 51, and the plurality of power devices 20 cooperatively convert the direct current into alternating current. The alternating current is output to the power grid 3000 through the output terminal 400 and the second terminal 52. The power module 300 can also convert the direct current output by the photovoltaic module 2000 into alternating current to supply the power grid 3000. The thermal device 40 is used to monitor the temperature of the plurality of power devices 20. The plastic package 70 can refer to the related description of the embodiment shown in FIG. 2, which will not be described here.

[0153] Please refer to FIG. 5 and FIG. 6, and combine FIG. 2 and FIG. 4. FIG. 5 is a structural schematic diagram of the power module 300 shown in FIG. 2 in another embodiment. FIG. 6 is an enlarged view of the VI part of the power module 300 shown in FIG. 5.

[0154] As shown in FIG. 2, FIG. 5 and FIG. 6, in some other embodiments, the power module 300 includes the power assembly 300a, the heat sink 30 and the second sintering layer 30a. The heat sink 30 is arranged on one side of the power assembly 300a. In other words, the power assembly 300a is arranged on one side of the heat sink 30. The second sintering layer 30a is arranged between the power assembly 300a and the heat sink 30. The power assembly 300a and the heat sink 30 are bonded together through the second sintering layer 30a.

[0155] The power component 300a comprises the substrate 10, the first sintering layer 10a, the power device 20, the mounting layer 20a, the thermal device 40, the first terminal 51, the second terminal 52, the first connecting terminal 60a, the second connecting terminal 60b, and the plastic package 70. The structures and the matching relationship of the substrate 10, the first sintering layer 10a, the power device 20, the mounting layer 20a, the thermal device 40, the first terminal 51, the second terminal 52, the first connecting terminal 60a, and the second connecting terminal 60b can refer to the related descriptions of the embodiment shown in FIG. 2, and will not be repeated here.

[0156] The plastic package 70 covers part of the substrate 10, part of the first terminal 51, and part of the second terminal 52. The plastic package 70 completely covers the first sintering layer 10a, the power device 20, the mounting layer 20a, the thermal device 40, the first connecting terminal 60a, and the second connecting terminal 60b. In the Z-axis direction, the side of the heat-conducting layer 14 of the substrate 10 facing away from the insulating layer 11 is exposed to the outside of the plastic package 70, one end of the first terminal 51 facing away from the substrate 10 is exposed to the outside of the plastic package 70, and one end of the second terminal 52 facing away from the substrate 10 is exposed to the outside of the plastic package 70.

[0157] In the Z-axis direction, the second sintering layer 30a and the heat sink 30 are sequentially stacked on one side of the heat-conducting layer 14 of the substrate 10 and face away from the insulating layer 11. In the Z-axis direction, the second sintering layer 30a is located between the plastic package 70 and the heat sink 30, and the second sintering layer 30a is stacked with the heat sink 30 and the plastic package 70. Specifically, in the Z-axis direction, the second sintering layer 30a is in contact with and fixedly stacked between the heat sink 30 and the plastic package 70.

[0158] That is to say, in the Z-axis direction, the power component 300a is stacked on one side of the second sintering layer 30a and faces away from the heat sink 30. For example, the number of the power components 300a is multiple. Specifically, the number of the power components 300a is three. In some other embodiments, the number of the power components 300a can also be one, two, or more. In the X-axis direction, the multiple power components 300a are arranged at intervals. In some other embodiments, the multiple power components 300a can also be arranged at intervals along the Y-axis direction. The number of the second sintering layers 30a is multiple. The multiple second sintering layers 30a are correspondingly stacked between the multiple power components 300a and the heat sink 30.

[0159] It can be understood that the number of substrates 10, the number of first sintered layers 10a, the number of power devices 20 and the number of plastic encapsulants 70 are all plural. The plurality of substrates 10, the plurality of first sintered layers 10a, the plurality of power devices 20 and the plurality of plastic encapsulants 70 are one-to-one corresponding. In the X-axis direction, the plurality of substrates 10 are sequentially and spacedly arranged, and the plurality of plastic encapsulants 70 are spacedly arranged. In other embodiments, the plurality of substrates 10 can also be spacedly arranged along the Y-axis direction, and the plurality of plastic encapsulants 70 can also be spacedly arranged along the Y-axis direction.

[0160] In the embodiment, each substrate 10 corresponds to one first sintered layer 10a, one power device 20 and one second sintered layer 30a. Each plastic encapsulant 70 corresponds to one substrate 10. In other embodiments, each substrate 10 can also correspond to a plurality of first sintered layers 10a, a plurality of power devices 20 and a plurality of second sintered layers 30a, which can be specifically referred to the related description of the embodiment shown in FIG. 4. That is, each substrate 10 corresponds to at least one first sintered layer 10a, at least one power device 20 and at least one second sintered layer 30a.

[0161] It can be understood that, in the corresponding plastic encapsulant 70, substrate 10, power device 20, first sintered layer 10a and second sintered layer 30a, the plastic encapsulant 70 covers part of the substrate 10, and the heat-conducting layer 14 of the substrate 10 is exposed outside the plastic encapsulant 70. The plastic encapsulant 70 completely covers the first sintered layer 10a and the power device 20. The second sintered layer 30a is located between the plastic encapsulant 70 and the heat sink 30. The design of the plastic encapsulant 70 can protect the substrate 10, the first sintered layer 10a and the power device 20, so as to avoid damage of the substrate 10 and the power device 20 due to collision, which is beneficial to improve the use safety of the substrate 10 and the power device 20 and prolong the working life of the substrate 10 and the power device 20.

[0162] The substrate 10 of each power assembly 300a is joined together with the heat sink 30 through the corresponding second sintered layer 30a, and is joined together with the corresponding power device 20 through the corresponding first sintered layer 10a. The heat generated by each power device 20 during operation can be transmitted to the heat sink 30 through the corresponding first sintered layer 10a, the substrate 10 and the second sintered layer 30a, and then transmitted to the external environment from the heat sink 30, so as to achieve rapid heat dissipation of each power device 20. One heat sink 30 can be used to dissipate heat of the plurality of power devices 20, so as to achieve rapid heat dissipation of the plurality of power devices 20.

[0163] Please refer to Fig. 2, Fig. 4 and Fig. 5 again, the embodiment of the application provides a power module 300. The power module 300 comprises a substrate 10, a first sintering layer 10a and a power device 20. The substrate 10 comprises an insulating layer 11 and a first conductive layer 12. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the first conductive layer 12 is arranged on one side of the insulating layer 11 in a stacked manner, and the first sintering layer 10a and the power device 20 are arranged on the side of the first conductive layer 12 away from the insulating layer 11 in a stacked manner. The power device 20 comprises a power chip 21, a first fixing layer 22 and a first connecting layer 24. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the power chip 21, the first fixing layer 22 and the first connecting layer 24 are arranged in a stacked manner, and the first connecting layer 24 is in contact with the first sintering layer 10a. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the thickness of the first sintering layer 10a is greater than the thickness of the first connecting layer 24 and less than the thickness of the first conductive layer 12.

[0164] In the power module 300 provided by the embodiment of the application, a large amount of heat generated by the power chip 21 during operation can be transmitted to the substrate 10 through the first fixing layer 22, the first connecting layer 24 and the first sintering layer 10a, and then transmitted to the external environment from the substrate 10, thereby achieving rapid heat dissipation of the power chip 21 and rapid heat dissipation of the power device 20.

[0165] Compared with the prior art, in the application, the power device 20 and the substrate 10 are connected through the first sintering layer 10a between the first connecting layer 24 and the first conductive layer 12, the first sintering layer 10a has a low porosity, which is conducive to improving the efficiency of heat generated by the power chip 21 during operation being transmitted to the substrate 10 through the first connecting layer 24 and the first sintering layer 10a, and is conducive to improving the heat dissipation efficiency of the power device 20. Moreover, in the Z-axis direction (i.e. the thickness direction of the substrate 10), the thickness of the first sintering layer 10a is greater than the thickness of the first connecting layer 24 and less than the thickness of the first conductive layer 12, which ensures that the first connecting layer 24 and the first sintering layer 10a have a high bonding strength, is conducive to improving the strength of the connection between the power device 20 and the substrate 10 through the first sintering layer 10a, and is conducive to improving the structural stability of the power module 300.

[0166] In some embodiments, the first connecting layer 24 is made of copper, nickel, silver or gold, and the first sintering layer 10a is made of an aluminum composite material, copper or nickel. The first connecting layer 24 is made of copper, nickel, silver or gold, and the first sintering layer 10a is made of an aluminum composite material, copper or nickel. The first sintering layer 10a has a low porosity, which is conducive to improving the heat conduction capacity of the first sintering layer 10a, improving the efficiency of heat generated by the power chip 21 during operation being transferred to the substrate 10 through the first connecting layer 24 and the first sintering layer 10a, and improving the heat dissipation efficiency of the power device 20. Moreover, the first connecting layer 24 and the first sintering layer 10a have a high bonding strength, which is conducive to improving the strength of the power device 20 and the substrate 10 being bonded through the first sintering layer 10a, and improving the structural stability of the power module 300. In addition, the cost of copper, nickel and aluminum composite material is low, which ensures that the substrate 10 and the power device 20 have a low material cost when being bonded, and reduces the processing cost of the power module 300.

[0167] Please refer to FIG. 7, FIG. 8 and FIG. 9, and combine FIG. 2 and FIG. 4. FIG. 7 is a flow diagram of a processing method 500 of a power module 300 provided by an embodiment of the present application. FIG. 8 is a structural diagram of a substrate 10 provided by the processing method 500. FIG. 9 is a structural diagram of a power device 20 provided by the processing method 500.

[0168] As shown in FIG. 2, FIG. 4 and FIG. 7, the processing method 500 of the power module 300 provided by an embodiment of the present application includes the following steps.

[0169] S501, providing a substrate 10 and a power device 20. The substrate 10 includes an insulating layer 11 and a first conductive layer 12. In the thickness direction of the substrate 10, the first conductive layer 12 is arranged on one side of the insulating layer 11. The power device 20 includes a power chip 21, a first fixed layer 22 and a first connecting layer 24. In the thickness direction of the substrate 10, the power chip 21, the first fixed layer 22 and the first connecting layer 24 are arranged in sequence.

[0170] S502, forming a first pre-sintering layer 101 on the side of the first conductive layer 12 away from the insulating layer 11, or forming a first pre-sintering layer 101 on the side of the first connecting layer 24 away from the power chip 21;

[0171] S503, arranging the substrate 10 and the power device 20 in layers so that the first pre-sintering layer 101 is located between the first conductive layer 12 and the first connecting layer 24;

[0172] S504, pressure sintering the first pre-sintering layer 101 in a reducing gas, an inert gas or a vacuum environment to form a first sintering layer 10a, so that the first sintering layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24; wherein the first connecting layer 24 is made of copper, nickel, silver or gold, and the first sintering layer 10a is made of an aluminum composite material, copper or nickel.

[0173] In the power module 300 manufactured by the processing method provided in the embodiments of the present application, a large amount of heat generated by the power chip 21 during operation can be transferred to the substrate 10 through the first fixing layer 22, the first connecting layer 24 and the first sintering layer 10a, and then transferred to the external environment from the substrate 10, thereby achieving rapid heat dissipation of the power device 20.

[0174] Compared with the prior art, in the present application, the power device 20 and the substrate 10 are bonded by the first sintering layer 10a between the first connecting layer 24 and the first conductive layer, the first connecting layer 24 is made of copper, nickel, silver or gold, the first sintering layer 10a is made of an aluminum composite material, copper or nickel, the first sintering layer 10a has a low porosity, which is conducive to improving the heat conduction capacity of the first sintering layer 10a, improving the efficiency of heat generated by the power chip 21 during operation being transferred to the substrate 10 through the first connecting layer 24 and the first sintering layer 10a, and improving the heat dissipation efficiency of the power device 20. Moreover, the first connecting layer 24 and the first sintering layer 10a have a high bonding strength, which is conducive to improving the strength of the bonding of the power device 20 and the substrate 10 through the first sintering layer 10a, and improving the structural stability of the power module 300. In addition, the cost of copper, the cost of nickel and the cost of the aluminum composite material are all low, which ensures that the material cost of the bonding of the substrate 10 and the power device 20 is low, and is conducive to reducing the processing cost of the power module 300.

[0175] Moreover, in the reducing gas or the vacuum environment, the design of the first sintering layer 10a manufactured by the pressure sintering process can avoid oxidation reaction during the manufacturing of the first sintering layer 10a, which is conducive to improving the strength of the bonding of the first connecting layer 24 and the first conductive layer through the first sintering layer 10a, improving the bonding strength of the substrate 10 and the power device 20, and improving the structural stability of the power module 300.

[0176] As shown in FIG. 7, FIG. 8 and FIG. 9, in some embodiments, the substrate 10 provided in step S501 further comprises a second conductive layer 13 and a heat conductive layer 14. That is, the substrate 10 comprises the insulating layer 11, the first conductive layer 12, the second conductive layer 13 and the heat conductive layer 14. In the Z-axis direction (i.e. the thickness direction of the substrate 10), the first conductive layer 12 is arranged on one side of the insulating layer 11. For example, the number of the first conductive layer 12 is plural. In the X-axis direction, the plural first conductive layers 12 are arranged at intervals. The second conductive layer 13 is arranged on one side of the insulating layer 11 and faces the first conductive layer 12. The second conductive layer 13 comprises a first sub-conductive layer 131 and a second sub-conductive layer 132. In the X-axis direction, the first sub-conductive layer 131 is arranged on one side of the plural first conductive layers 12 and at intervals with the plural first conductive layers 12, and the second sub-conductive layer 132 is arranged on the other side of the plural first conductive layers 12 and at intervals with the plural first conductive layers 12. In the Z-axis direction, the heat conductive layer 14 is arranged on one side of the insulating layer 11 and faces away from the first conductive layer 12. For details, please refer to the related description of the embodiment shown in FIG. 2. In some embodiments, the material of the first conductive layer 12, the second conductive layer 13 and the heat conductive layer 14 is copper. In other embodiments, the material of the first conductive layer 12, the second conductive layer 13 and the heat conductive layer 14 is respectively a composite material of aluminum, nickel or other heat conductive material.

[0177] In some embodiments, the power device 20 provided in step S501 further comprises a first barrier layer 23, a second fixing layer 25, a second barrier layer 26 and a second connecting layer 27. That is, the power device 20 comprises the power chip 21, the first fixing layer 22, the first barrier layer 23, the first connecting layer 24, the second fixing layer 25, the second barrier layer 26 and the second connecting layer 27. In the Z-axis direction, the first fixing layer 22, the first barrier layer 23 and the first connecting layer 24 are sequentially arranged on one side of the power chip 21, and the second fixing layer 25, the second barrier layer 26 and the second connecting layer 27 are sequentially arranged on the other side of the power chip 21. For details, please refer to the related description of the embodiment shown in FIG. 2. In some embodiments, the material of the first connecting layer 24 is copper, and the material of the second connecting layer 27 is copper. In other embodiments, the material of the first connecting layer 24 is nickel, and the material of the second connecting layer 27 is nickel. For example, the number of the power device 20 is plural. Specifically, the number of the power device 20 is two. In other embodiments, the number of the power device 20 can be 1, 3 or more.

[0178] Referring to FIG. 10, FIG. 11, FIG. 12, FIG. 13, FIG. 14 and FIG. 15, and in combination with FIG. 7 and FIG. 9, FIG. 10 is a schematic structural diagram of covering the first sintering material 101a on the first conductive layer 12 by the printing plate 90. FIG. 11 is a schematic structural diagram of forming the first pre-sintering layer 101 on the first conductive layer 12. FIG. 12 is a schematic structural diagram of one printing plate 90 required by the processing method 500 provided by the embodiment of the present application. FIG. 13 is a schematic structural diagram of the printing plate 90 shown in FIG. 12 from another angle. FIG. 14 is a schematic structural diagram of the printing plate 90 shown in FIG. 13 in another embodiment. FIG. 15 is a schematic structural diagram of the printing plate 90 shown in FIG. 13 in another embodiment.

[0179] As shown in FIG. 7, FIG. 10 and FIG. 11, in some embodiments, the step S502 of forming the first pre-sintering layer 101 on the side of the first conductive layer 12 away from the insulating layer 11 specifically includes:

[0180] covering the first sintering material 101a on the side of the first conductive layer 12 away from the insulating layer 11 by the printing plate 90;

[0181] removing the printing plate 90 and drying the first sintering material 101a to form the first pre-sintering layer 101. Thus, the first pre-sintering layer 101 is formed on the side of the first conductive layer 12 away from the insulating layer 11. It can be understood that the first pre-sintering layer 101 is formed by the printing plate 90. For example, the first sintering material 101a is copper, and the material of the first pre-sintering layer 101 is copper. In other embodiments, the first sintering material 101a can also be an aluminum composite material or nickel.

[0182] As shown in FIG. 12 and FIG. 13, in the embodiment, the printing plate 90 includes a first printing plate 90a. The first printing plate 90a (i.e. the printing plate 90) includes a first fitting surface 91 and a second fitting surface 92. In the Z-axis direction, the first fitting surface 91 is opposite to and spaced apart from the second fitting surface 92. The first printing plate 90a (i.e. the printing plate 90) is provided with a filling hole 93. The filling hole 93 penetrates through the first printing plate 90a (i.e. the printing plate 90) in the Z-axis direction (i.e. the thickness direction of the substrate 10). For example, the number of the filling holes 93 of the first printing plate 90a is multiple. Specifically, the number of the filling holes 93 of the first printing plate 90a is two. In other embodiments, the number of the filling holes 93 can also be three, four or more. In the X-axis direction, the multiple filling holes 93 are sequentially and spaced apart.

[0183] The first printed plate 90a (i.e., the printed plate 90) is provided with a matching hole 94. The matching hole 94 extends from one side of the printed plate 90 in the Z-axis direction (i.e., the thickness direction of the substrate 10) along the Z-axis direction (i.e., the thickness direction of the substrate 10). Specifically, the matching hole 94 extends from the first matching surface 91 along the Z-axis direction. Exemplarily, the number of the matching holes 94 is plural. The plural matching holes 94 correspond to the plural filling holes 93 one-to-one. Each matching hole 94 surrounds and communicates with the corresponding filling hole 93. That is, the matching hole 94 surrounds and communicates with the filling hole 93. The size of the matching hole 94 in the Z-axis direction is smaller than the size of the filling hole 93 in the Z-axis direction.

[0184] As shown in FIG. 14, in some other embodiments, the number of the filling holes 93 and the number of the matching holes 94 of the first printed plate 90a (i.e., the printed plate 90) can also be one. As shown in FIG. 15, in some other embodiments, the plural filling holes 93 of the first printed plate 90a (i.e., the printed plate 90) can also be arranged in a matrix. For example, the number of the filling holes 93 of the first printed plate 90a (i.e., the printed plate 90) can be four. Two filling holes 93 are sequentially and spaced apart along the X-axis direction and form one row of filling holes 93, and two rows of filling holes 93 are spaced apart along the Y-axis direction.

[0185] As shown in FIGS. 10, 11 and 12, in the present embodiment, the first printed plate 90a is stacked on the side of the first conductive layer 12 away from the insulating layer 11, so that the first matching surface 91 of the first printed plate 90a is away from the first conductive layer 12 (i.e., the substrate 10), the second matching surface 92 of the first printed plate 90a contacts and is stacked on the surface of the first conductive layer 12 away from the insulating layer 11, and the second matching surface 92 of the first printed plate 90a contacts and is stacked on the surface of the first sub-conductive layer 131 away from the insulating layer 11 and the surface of the second sub-conductive layer 132 away from the insulating layer 11.

[0186] By means of the doctor blade, the first sintering material 101a is filled in each filling hole 93 and each matching hole 94 of the first printed plate 90a, so that the surface of each first sintering material 101a away from the first conductive layer 12 is flush with the first matching surface 91. Thus, the first sintering material 101a covers the side of each first conductive layer 12 away from the insulating layer 11.

[0187] The first printed plate 90a (i.e. the printed plate 90) is removed, and each first sintering material 101a is dried to form a first pre-sintering layer 101, thereby forming the first pre-sintering layer 101 on the side of each first conductive layer 12 opposite to the insulating layer 11. It can be understood that, in the process of removing the first printed plate 90a, the first sintering material 101a in the fitting hole 94 is removed together with the first printed plate 90a, and the remaining first sintering material 101a is dried to form the first pre-sintering layer 101. In this case, the size of the first pre-sintering layer 101 in the Z-axis direction (i.e. the thickness direction of the substrate 10) is constant along the length direction of the first pre-sintering layer 101 (i.e. the X-axis direction in the figure). In some other embodiments, the length direction of the first pre-sintering layer 101 can also be parallel to the Y-axis direction in the figure.

[0188] Referring to FIG. 16, in combination with FIG. 7 and FIG. 11, FIG. 16 is a structural schematic view of the first pre-sintering layer 101 between the first conductive layer 12 and the first connecting layer 24.

[0189] As shown in FIG. 7, FIG. 11 and FIG. 16, in some embodiments, the step S503 of stacking the substrate 10 and the power device 20 so that the first pre-sintering layer 101 is between the first conductive layer 12 and the first connecting layer 24 specifically comprises:

[0190] heating treatment is performed on each first pre-sintering layer 101;

[0191] heating treatment is performed on each first pre-sintering layer 101;

[0192] cooling treatment is performed on the first pre-sintering layer 101.

[0193] In some other embodiments, the step S502 can also be forming the first pre-sintering layer 101 on the side of the first connecting layer 24 opposite to the power chip 21. That is, the first pre-sintering layer 101 is formed on the side of the first connecting layer 24 of each power device 20 opposite to the power chip 21. For details, reference can be made to the related description of forming the first pre-sintering layer 101 on the side of the first conductive layer 12 opposite to the insulating layer 11.

[0194] The step S503 can further include: heating each first pre-sintering layer 101; stacking the substrate 10 and each power device 20 such that each first conductive layer 12 of the substrate 10 is in pressure contact with the first pre-sintering layer 101 formed on one first connecting layer 24, each first pre-sintering layer 101 being located between one first conductive layer 12 and one first connecting layer 24, i.e. the first conductive layer 12 of the substrate 10 is in pressure contact with the first pre-sintering layer 101 formed on the first connecting layer 24, such that the first pre-sintering layer 101 is located between the first conductive layer 12 and the first connecting layer 24; and cooling the first pre-sintering layer 101. Thus, the first pre-sintering layer 101 can also be located between the first conductive layer 12 and the first connecting layer 24.

[0195] Referring to FIGS. 17, 18, 19 and 20, and in combination with FIGS. 2, 7 and 12, FIG. 17 is a structural schematic diagram of a heat sink 30 provided by the processing method 500. FIG. 18 is a structural schematic diagram of covering the second pre-sintering layer 102a on the heat sink 30 by the printing plate 90. FIG. 19 is a structural schematic diagram of forming the second pre-sintering layer 102 on the heat sink 30. FIG. 20 is a structural schematic diagram of the second pre-sintering layer 102 being located between the heat conductive layer 14 and the heat sink 30.

[0196] As shown in FIGS. 2, 7 and 17, in some embodiments, between the step S503 and the step S504, i.e. before the first sintering layer 10a is made, the processing method 500 further includes: S601, providing the heat sink 30. The structure of the heat sink 30 can be explained in the embodiment shown in FIG. 2. The heat sink 30 includes the first mounting portion 31 and the second mounting portion 32, and the first mounting portion 31 includes the first mounting surface 311. The heat sink 30 is made of copper. In other embodiments, the heat sink 30 can also be made of other heat conductive materials such as aluminum.

[0197] As shown in FIGS. 18, 19 and 20, S602, forming the second pre-sintering layer 102 on the heat sink 30.

[0198] Specifically, the second sintering material 102a is covered on the side of the first mounting surface 311 away from the second mounting portion 32 by the printing plate 90; the printing plate 90 is removed and the second sintering material 102a is dried to form the second pre-sintering layer 102. Thus, the second pre-sintering layer 102 is formed on the heat sink 30. It can be understood that the second pre-sintering layer 102 is formed by the printing plate 90. For example, the second sintering material 102a is copper and the material of the second pre-sintering layer 102 is copper. In other embodiments, the second sintering material 102a can also be a composite material of aluminum or nickel, and the material of the second pre-sintering layer 102 can also be a composite material of aluminum or nickel.

[0199] In this embodiment, the printing plate 90 includes a second printing plate 90b. The structure of the second printing plate 90b can refer to the related description of the first printing plate 90a (as shown in FIG. 12). That is, the second printing plate 90b includes a first mating surface 91 and a second mating surface 92, and the second printing plate 90b is provided with a plurality of filling holes 93 and a plurality of matching holes 94. The second printing plate 90b is arranged in a stacked manner on the side of the first mounting surface 311 away from the second mounting portion 32, so that the first mating surface 91 of the second printing plate 90b faces away from the heat sink 30, and the second mating surface 92 of the second printing plate 90b is in contact with and stacked on the first mounting surface 311.

[0200] By means of the scraper, the second sintering material 102a is filled in each filling hole 93 and each matching hole 94 of the second printing plate 90b, so that the surface of each second sintering material 102a away from the heat sink 30 is flush with the first mating surface 91. Thus, a plurality of second sintering materials 102a are covered on the side of the first mounting surface 311 away from the second mounting portion 32.

[0201] After removing the second printing plate 90b (i.e., the printing plate 90), each second sintering material 102a is dried to form a second pre-sintering layer 102, thereby forming a second pre-sintering layer 102 on the heat sink 30. The size of the second pre-sintering layer 102 in the Z-axis direction (i.e., the thickness direction of the substrate 10) is constant along the length direction of the second pre-sintering layer 102 (i.e., the X-axis direction shown in the figure). In some other embodiments, the length direction of the second pre-sintering layer 102 can also be parallel to the Y-axis direction shown in the figure. For example, the number of second pre-sintering layers 102 is a plurality. In the X-axis direction, the plurality of second pre-sintering layers 102 are arranged in sequence with intervals. In some other embodiments, the number of second pre-sintering layers 102 can also be one.

[0202] S603, forming an exhaust groove 301 on the side of the second pre-sintering layer 102 away from the heat sink 30. For example, the exhaust groove 301 is formed on the side of each second pre-sintering layer 102 away from the heat sink 30. The exhaust groove 301 extends in the Z-axis direction. The exhaust groove 301 penetrates the second pre-sintering layer 102 in the Y-axis direction. In some other embodiments, the exhaust groove 301 can also penetrate the second pre-sintering layer 102 in the X-axis direction.

[0203] S604, arranging the substrate 10 and the heat sink 30 in a stacked manner, so that the second pre-sintering layer 102 is located between the heat-conducting layer 14 and the heat sink 30.

[0204] Specifically, each second pre-sintering layer 102 is subjected to a heating treatment;

[0205] The substrate 10 and the heat sink 30 are stacked so that the heat-conductive layer 14 of the substrate 10 is in pressure contact with each second pre-sintered layer 102 formed on the heat sink 30, each second pre-sintered layer 102 being located between the heat sink 30 and the heat-conductive layer 14, i.e. the heat-conductive layer 14 of the substrate 10 is in pressure contact with the second pre-sintered layer 102 formed on the heat sink 30, the second pre-sintered layer 102 being located between the heat-conductive layer 14 and the first connecting layer 24;

[0206] The second pre-sintered layer 102 is subjected to cooling treatment. The exhaust groove 301 is spaced apart from the projection of the power device 20 in the Z-axis direction.

[0207] In other embodiments, the step S602 can also be forming the second pre-sintered layer 102 on the side of the heat-conductive layer 14 away from the insulating layer 11. For details, refer to the related description of forming the second pre-sintered layer 102 on the heat sink 30. The step S603 can also be providing the exhaust groove 301 on the side of the second pre-sintered layer 102 away from the heat-conductive layer 14. The exhaust groove 301 extends in the Z-axis direction. The exhaust groove 301 penetrates the second pre-sintered layer 102 in the Y-axis direction. In other embodiments, the exhaust groove 301 can also penetrate the second pre-sintered layer 102 in the X-axis direction.

[0208] The step S604 can also specifically include: subjecting each second pre-sintered layer 102 to heating treatment; stacking the substrate 10 and the heat sink 30 so that the first mounting portion 31 of the heat sink 30 is in pressure contact with each second pre-sintered layer 102 formed on the heat-conductive layer 14, each second pre-sintered layer 102 being located between the heat-conductive layer 14 and the first mounting portion 31 (i.e. the heat sink 30), i.e. the heat sink 30 is in pressure contact with the second pre-sintered layer 102 formed on the heat-conductive layer 14, the second pre-sintered layer 102 being located between the heat-conductive layer 14 and the heat sink 30; and subjecting the second pre-sintered layer 102 to cooling treatment. Thus, the second pre-sintered layer 102 can also be located between the heat-conductive layer 14 and the heat sink 30.

[0209] Please refer to FIGS. 21 and 22, and combine FIGS. 4, 7, 10 and 18, which are process structure schematic diagrams of pressure sintering of the first pre-sintered layer 101 and the second pre-sintered layer 102.

[0210] As shown in FIGS. 7, 21 and 22, in some embodiments, the step S504 of making the first pre-sintered layer 101 into the first sintered layer 10a in a reducing gas, an inert gas or a vacuum environment so that the first sintered layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24 specifically includes:

[0211] The first pre-sintered layer 101 and the second pre-sintered layer 102 are subjected to pressure sintering in a reducing gas, an inert gas or a vacuum environment, so that the first pre-sintered layer 101 is made into the first sintered layer 10a, and the first sintered layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24, and the second pre-sintered layer 102 is made into the second sintered layer 30a, and the second sintered layer 30a is stacked with the heat conductive layer 14 and the heat sink 30.

[0212] It should be noted that the pressure sintering refers to applying pressure to the bonded body at high temperature, so as to increase the density of the sintered body, promote the atomic diffusion between the sintered material particles and the interface between the sintered material and the bonded body, and enhance the bonding strength and bonding reliability.

[0213] Exemplarily, the reducing gas can be a mixed gas of N2 (nitrogen) and H2 (hydrogen), a mixed gas of N2 and formic acid, H2 or other reducing gases. The inert gas can be N2 or He (helium) or other inert gases. The sintering conditions for pressure sintering are that the sintering temperature is controlled at 150-280°C, and the applied pressure is controlled at 3-20 MPa.

[0214] In the embodiment, a removable mask 1 is arranged on the side of the substrate 10 away from the heat sink 30. The mask 1 is sleeved on the outside of each power device 20. The mask 1 is stacked on the side of each first conductive layer 12 away from the insulating layer 11, the mask 1 is stacked on the side of the first sub-conductive layer 131 away from the insulating layer 11, and the mask 1 is stacked on the side of the second sub-conductive layer 132 away from the insulating layer 11. The design of the mask 1 can avoid damaging the patterns on the first conductive layer 12, the patterns on the first sub-conductive layer 131 and the patterns on the second sub-conductive layer 132 during pressure sintering.

[0215] A removable stress buffer film 2 is arranged on the side of the power device 20 away from the substrate 10. The stress buffer film 2 is stacked on the side of the power device 20 away from the substrate 10. The stress buffer film 2 is stacked on the side of the mask 1 away from the substrate 10. Exemplarily, the stress buffer film 2 can adopt, but is not limited to, a Teflon film or other organic films.

[0216] The stress buffer film 2 is used to apply pressure to each power device 20 along the Z-axis direction towards the substrate 10, so that the first pre-sintered layer 101 and the second pre-sintered layer 102 are synchronously sintered under pressure, the first pre-sintered layer 101 is made into the first sintered layer 10a, the first sintered layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24, and the power device 20 and the substrate 10 are bonded together through the first sintered layer 10a; the second pre-sintered layer 102 is made into the second sintered layer 30a, the second sintered layer 30a is stacked with the heat-conductive layer 14 and the heat sink 30, and the substrate 10 and the heat sink 30 are bonded together through the second sintered layer 30a. The design of the stress buffer film 2 can avoid direct contact of the power device 20 during the sintering under pressure, avoid stress concentration on the power device 20 during the sintering under pressure, ensure uniform distribution of the stress during the sintering under pressure, and avoid damage to the power device 20.

[0217] It can be understood that the heat sink 30 and the substrate 10 are bonded together through the second sintered layer 30a. The design of the second pre-sintered layer 102 being sintered into the second sintered layer 30a in a reducing gas, an inert gas or a vacuum environment can avoid oxidation of the second pre-sintered layer 102 during the sintering under pressure, improve the bonding strength of the heat-conductive layer 14 and the heat sink 30 through the second sintered layer 30a, improve the bonding strength of the substrate 10 and the heat sink 30, and improve the structural stability of the power module 300 (as shown in FIG. 4). Moreover, the first sintered layer 10a and the second sintered layer 30a can be made by one-time sintering under pressure in a reducing gas, an inert gas or a vacuum environment, which can save processing procedures, improve processing efficiency, and reduce the processing cost of the power module 300.

[0218] As shown in FIGS. 10, 21 and 22, the design of the matching hole 94 of the printing plate 90 ensures that the surface of the first pre-sintered layer 101 formed by the first printing plate 90a (i.e., the printing plate 90) is flat and the edge is not raised, avoids the edge of the first pre-sintered layer 101 being raised, avoids stress concentration caused by the edge of the first sintered layer 10a being raised, and avoids damage to the power device 20 during the bonding of the power device 20 and the substrate 10. Moreover, the sintered surface of the first pre-sintered layer 101 is uniformly stressed, which improves the bonding strength of the power device 20 and the substrate 10 through the first sintered layer 10a, and improves the structural stability of the power module 300.

[0219] It can be understood that, since the size of the first pre-sintering layer 101 in the thickness direction of the substrate 10 (i.e. the direction of the Z axis shown in the figure) does not change along the length direction of the first pre-sintering layer 101 (i.e. the direction of the X axis shown in the figure), the surface of the first pre-sintering layer 101 is flat and the edge is not raised, and the surface of the first sintering layer 10a made by pressure sintering the first pre-sintering layer 101 is flat and the edge is not raised. In this way, stress concentration caused by the edge of the first pre-sintering layer 101 being raised can be avoided, and damage to the power device 20 during the process of bonding the power device 20 and the substrate 10 can be avoided. Moreover, uniform stress on the sintering surface of the first pre-sintering layer 101 is ensured, which is conducive to improving the strength of the bonding of the power device 20 and the substrate 10 through the first sintering layer 10a, and is conducive to improving the structural stability of the power module 300.

[0220] As shown in FIGS. 18, 21 and 22, the design of the matching hole 94 of the printed board 90 ensures that the surface of the second pre-sintering layer 102 formed by the second printed board 90b (i.e. the printed board 90) is flat and the edge is not raised, avoiding the edge of the second pre-sintering layer 102 being raised, avoiding stress concentration caused by the edge of the second sintering layer 30a being raised, and avoiding damage to the substrate 10 during the process of bonding the heat sink 30 and the substrate 10. Moreover, uniform stress on the sintering surface of the second pre-sintering layer 102 is ensured, which is conducive to improving the strength of the bonding of the heat sink 30 and the substrate 10 through the second sintering layer 30a, and is conducive to improving the structural stability of the power module 300.

[0221] It can be understood that, since the size of the second pre-sintering layer 102 in the thickness direction of the substrate 10 (i.e. the direction of the Z axis shown in the figure) does not change along the length direction of the second pre-sintering layer 102 (i.e. the direction of the X axis shown in the figure), the surface of the second pre-sintering layer 102 is flat and the edge is not raised, and the surface of the second sintering layer 30a made by pressure sintering the second pre-sintering layer 102 is flat and the edge is not raised. In this way, stress concentration caused by the edge of the second pre-sintering layer 102 being raised can be avoided, and damage to the substrate 10 during the process of bonding the heat sink 30 and the substrate 10 can be avoided. Moreover, uniform stress on the sintering surface of the second pre-sintering layer 102 is ensured, which is conducive to improving the strength of the bonding of the heat sink 30 and the substrate 10 through the second sintering layer 30a, and is conducive to improving the structural stability of the power module 300.

[0222] As shown in FIG. 21 and FIG. 22, it can be understood that the material of the first pre-sintering layer 101 is copper, and the material of the first sintering layer 10a is copper. In some other embodiments, the material of the first sintering layer 10a can also be a composite material of aluminum or nickel. The material of the first sintering layer 10a is the same as the material of the first connecting layer 24 and the material of the first conductive layer 12. The design that the material of the first connecting layer 24 is the same as the material of the first sintering layer 10a is conducive to improving the bonding strength of the first connecting layer 24 and the first sintering layer 10a, improving the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improving the structural stability of the power module 300 (as shown in FIG. 4). The design that the material of the first sintering layer 10a is the same as the material of the first conductive layer 12 is conducive to improving the bonding strength of the first sintering layer 10a and the first conductive layer 12, improving the bonding strength of the power device 20 and the substrate 10 through the first sintering layer 10a, and improving the structural stability of the power module 300.

[0223] It can be understood that the material of the second pre-sintering layer 102 is copper, and the material of the second sintering layer 30a is copper. In some other embodiments, the material of the second sintering layer 30a can also be a composite material of aluminum or nickel. The material of the second sintering layer 30a is the same as the material of the first sintering layer 10a, the material of the heat sink 30, and the material of the heat conduction layer 14. Since the material of the second sintering layer 30a is the same as the material of the first sintering layer 10a, the first sintering layer 10a and the second sintering layer 30a can be made by one-time high-temperature and high-pressure, which is conducive to reducing the cost of making the first sintering layer 10a and the second sintering layer 30a, reducing the material cost, and reducing the processing cost of the power module 300 (as shown in FIG. 4).

[0224] The design that the material of the heat conduction layer 14, the material of the second sintering layer 30a, and the material of the heat sink 30 are the same is conducive to improving the bonding strength of the heat conduction layer 14 and the second sintering layer 30a, improving the bonding strength of the second sintering layer 30a and the heat sink 30, improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and improving the structural stability of the power module 300 (as shown in FIG. 4).

[0225] The design of the exhaust groove 301 ensures that the exhaust gas generated during the process of bonding the substrate 10 and the heat sink 30 together through the second sintering layer 30a can escape from the exhaust groove 301 to the external environment, which is conducive to improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a, and improving the structural stability of the power module 300 (as shown in FIG. 4).

[0226] As shown in FIG. 4 and FIG. 22, after step S504, the processing method 500 further comprises S505, disposing the thermal sensitive device 40 on one of the first conductive layers 12 by means of sintering or welding, and the thermal sensitive device 40 faces away from the insulating layer 11.

[0227] S506, disposing the first terminal 51 on the first sub-conductive layer 131 by means of sintering or welding, and disposing the second terminal 52 on the second sub-conductive layer 132 by means of sintering or welding, and the first terminal 51 and the second terminal 52 face away from the insulating layer 11.

[0228] S507, disposing the first connecting terminal 60a between the first sub-conductive layer 131 and one of the power devices 20 by means of sintering or welding, disposing the second connecting terminal 60b between the second sub-conductive layer 132 and the other power device 20 by means of sintering or welding, and disposing the matching part 80 between the two first conductive layers 12.

[0229] S508, covering the heat sink 30 with the plastic sealing material on the side of the heat sink 30 facing the substrate 10 to form the plastic sealing part 70, and the plastic sealing part 70 completely covers the substrate 10, the first sintering layer 10a, the power device 20, the thermal sensitive device 40, the first connecting terminal 60a and the second connecting terminal 60b, and the plastic sealing part 70 covers part of the first terminal 51, part of the second terminal 52 and part of the second sintering layer 30a. In the Z-axis direction, one end of the first terminal 51 facing away from the substrate 10 is exposed outside the plastic sealing part 70, one end of the second terminal 52 facing away from the substrate 10 is exposed outside the plastic sealing part 70, and the side of the second sintering layer 30a facing away from the substrate 10 is exposed outside the plastic sealing part 70.

[0230] For example, the plastic sealing material can be epoxy resin, polyester resin or silicone, etc. That is, the plastic sealing part 70 is made of plastic sealing material including but not limited to epoxy resin, polyester resin or silicone, etc. The plastic sealing part 70 realizes the packaging of the substrate 10, the power device 20, the thermal sensitive device 40, the first terminal 51, the second terminal 52, the first connecting terminal 60a and the second connecting terminal 60b. The design of the plastic sealing part 70 can protect the substrate 10 and the power device 20, avoid the damage of the substrate 10 and the power device 20 due to collision, and is beneficial to improve the use safety of the substrate 10 and the power device 20, and is beneficial to prolong the working life of the substrate 10 and the power device 20.

[0231] Please refer to FIG. 23, FIG. 24 and FIG. 25, and combine FIG. 4, FIG. 21 and FIG. 22, FIG. 23 to FIG. 25 are structure schematic diagrams of part of the flow of another embodiment of the processing method 500 shown in FIG. 7.

[0232] As shown in FIG. 23 and FIG. 24, in some other embodiments, the heat sink 30 is provided before forming the first pre-sintering layer 101.

[0233] A second pre-sintering layer 102 is formed on the side of the heat-conducting layer 14 opposite the insulating layer 11, or a second pre-sintering layer 102 is formed on the heat sink 30. Details can be found in the description of the embodiment shown in Fig. 21.

[0234] The substrate 10 and the heat sink 30 are stacked so that the second pre-sintering layer 102 is between the heat-conducting layer 14 and the heat sink 30. Details can be found in the description of the embodiment shown in Fig. 21.

[0235] The second pre-sintering layer 102 is pressure-sintered in a reducing gas, an inert gas or a vacuum environment to form a second sintering layer 30a, so that the second sintering layer 30a is stacked with the heat-conducting layer 14 and the heat sink 30. The pressure-sintering of the second pre-sintering layer 102 is achieved by applying pressure to the substrate 10 on the side of the substrate 10 opposite the heat sink 30. Details can be found in the description of the embodiment shown in Fig. 21.

[0236] Exemplarily, the reducing gas can be a mixture of N2 and H2, a mixture of N2 and formic acid, H2 or other reducing gases. The inert gas can be N2 or He or other inert gases. The sintering conditions for pressure-sintering are that the sintering temperature is controlled at 150-280°C and the applied pressure is controlled at 3-20 MPa. The sintering conditions for the two pressure-sintering can be the same or different.

[0237] As shown in Figs. 22, 24 and 25, after the second sintering layer 30a is formed, a first pre-sintering layer 101 is formed on the side of the first conductive layer 12 opposite the insulating layer 11, or a first pre-sintering layer 101 is formed on the side of the first connecting layer 24 opposite the power chip 21;

[0238] The substrate 10 and the power device 20 are stacked so that the first pre-sintering layer 101 is between the first conductive layer 12 and the first connecting layer 24.

[0239] The first pre-sintering layer 101 is pressure-sintered in a reducing gas, an inert gas or a vacuum environment to form a first sintering layer 10a, so that the first sintering layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24. The pressure-sintering of the first pre-sintering layer 101 is achieved by applying pressure to the power device 20 on the side of the power device 20 opposite the substrate 10. Details can be found in the description of the embodiment shown in Fig. 21.

[0240] The reducing gas can be a mixture of N2and H2, a mixture of N2and formic acid, H2, or other reducing gas. The inert gas can be N2or He, or other inert gas. The sintering conditions for pressure sintering are as follows: the sintering temperature is controlled at 150-280°C, and the applied pressure is controlled at 3-20 MPa. The sintering conditions for the two pressure sintering processes can be the same or different.

[0241] In this way, the substrate 10 is also bonded to the power device 20 through the first sintering layer 10a, and the heat sink 30 is bonded to the substrate 10 through the second sintering layer 30a. The design of the second sintering layer 30a formed by the pressure sintering process in a reducing gas, an inert gas, or a vacuum environment can also avoid oxidation reaction during the formation of the second sintering layer 30a, which is conducive to improving the bonding strength between the heat conduction layer 14 and the heat sink 30 through the second sintering layer 30a, improving the bonding strength between the substrate 10 and the heat sink 30, and improving the structural stability of the power module 300 (as shown in FIG. 4).

[0242] In this embodiment, the second sintering layer 30a is first formed by one pressure sintering process, and the heat conduction layer 14 is bonded to the heat sink 30 through the second sintering layer 30a. Then, the first sintering layer 10a is formed by another pressure sintering process, and the first conductive layer 12 is bonded to the first connecting layer 24 of the power device 20 through the first sintering layer 10a. The sintering temperature and the applied pressure of the two pressure sintering processes can be adjusted respectively, which is conducive to reducing the processing difficulty and reducing the processing cost of the power module 300 (as shown in FIG. 4).

[0243] In this embodiment, the first conductive layer 12 can be oxidized during the sintering process of forming the second sintering layer 30a. Between the formation of the second sintering layer 30a and the formation of the first pre-sintering layer 101, the first conductive layer 12 of the substrate 10 can be reduced by a reducing gas (such as formic acid or hydrogen), which is conducive to improving the bonding strength between the first conductive layer 12 and the first sintering layer 10a, and improving the bonding strength between the substrate 10 and the power device 20 through the first sintering layer 10a.

[0244] Please refer to FIGS. 26, 27, and 28, and also refer to FIGS. 4, 21, and 22. FIGS. 26-28 are structural schematic diagrams of part of the flow of the processing method 500 in another embodiment.

[0245] As shown in FIG. 26 and FIG. 27, in some other embodiments, the first pre-sintering layer 101 is sintered into the first sintering layer 10a in a reducing gas, an inert gas or a vacuum environment, so that the first sintering layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24. The pressure sintering of the first pre-sintering layer 101 is achieved by pressing the power device 20 on the side opposite to the substrate 10, which can be referred to the related description of the embodiment shown in FIG. 21. Exemplarily, the reducing gas can be a mixture of N2 and H2, a mixture of N2 and formic acid, H2 or other reducing gas. The inert gas can be N2 or He or other inert gas. The sintering condition for the pressure sintering is that the sintering temperature is controlled at 150-280°C and the applied pressure is controlled at 3-20 MPa.

[0246] As shown in FIG. 22, FIG. 27 and FIG. 28, after the first sintering layer 10a is prepared, the heat sink 30 is provided.

[0247] The second pre-sintering layer 102 is formed on the side of the heat conductive layer 14 opposite to the insulating layer 11, or on the heat sink 30. The related description can be referred to the embodiment shown in FIG. 21.

[0248] The substrate 10 and the heat sink 30 are stacked so that the second pre-sintering layer 102 is located between the heat conductive layer 14 and the heat sink 30. The related description can be referred to the embodiment shown in FIG. 21.

[0249] The second pre-sintering layer 102 is pressure sintered in a reducing gas, an inert gas or a vacuum environment to form the second sintering layer 30a, so that the second sintering layer 30a is stacked with the heat conductive layer 14 and the heat sink 30. The pressure sintering of the second pre-sintering layer 102 is achieved by pressing the power device 20 on the side opposite to the substrate 10, which can be referred to the related description of the embodiment shown in FIG. 21.

[0250] Exemplarily, the reducing gas can be a mixture of N2 and H2, a mixture of N2 and formic acid, H2 or other reducing gas. The inert gas can be N2 or He or other inert gas. The sintering condition for the pressure sintering is that the sintering temperature is controlled at 150-280°C and the applied pressure is controlled at 3-20 MPa. The sintering conditions for the two times of pressure sintering can be the same or different.

[0251] In this way, the substrate 10 and the power device 20 are bonded together by the first sintering layer 10a, and the heat sink 30 and the substrate 10 are bonded together by the second sintering layer 30a. The design of the second sintering layer 30a made by the pressure sintering process in a reducing gas, an inert gas or a vacuum environment can also avoid oxidation reaction in the process of making the second sintering layer 30a, which is conducive to improving the bonding strength of the heat conduction layer 14 and the heat sink 30 through the second sintering layer 30a, improving the bonding strength of the substrate 10 and the heat sink 30, and improving the structural stability of the power module 300 (as shown in FIG. 4).

[0252] In this embodiment, the first sintering layer 10a is first made by one-time pressure sintering, and the first conductive layer 12 and the first connecting layer 24 of the power device 20 are bonded together by the first sintering layer 10a. Then, the second sintering layer 30a is made by another time of pressure sintering, and the heat conduction layer 14 and the heat sink 30 are bonded together by the second sintering layer 30a. The sintering temperature and the applied pressure of the two times of pressure sintering can be adjusted respectively, which is conducive to reducing the processing difficulty and reducing the processing cost of the power module 300 (as shown in FIG. 4).

[0253] In this embodiment, the heat conduction layer 14 may be oxidized during the sintering process of making the first sintering layer 10a. Between the first sintering layer 10a and the heat sink 30, the heat conduction layer 14 of the substrate 10 can be reduced by a reducing gas (such as formic acid or hydrogen), which is conducive to improving the bonding strength of the heat conduction layer 14 and the second sintering layer 30a, and improving the bonding strength of the substrate 10 and the heat sink 30 through the second sintering layer 30a.

[0254] Please refer to FIGS. 29 and 30, and combine FIGS. 5, 10, 19, 20 and 26, FIGS. 29 and 30 are structural schematic diagrams of part of the flow of another embodiment of the processing method 500 shown in FIG. 7.

[0255] In other embodiments, the processing method 500 includes:

[0256] As shown in FIGS. 26, 29 and 30, S701, a plurality of power components 300a are provided.

[0257] The providing process of each power component 300a specifically includes: providing a substrate 10 and a power device 20. The structures of the substrate 10 and the power device 20 can refer to the related descriptions of the embodiment shown in FIG. 5. The substrate 10 includes an insulating layer 11, a first conductive layer 12, a first sub-conductive layer 131, a second sub-conductive layer 132 and a heat conduction layer 14, and the power device 20 includes a first connecting layer 24.

[0258] The first pre-sintering layer 101 is formed on the side of the first conductive layer 12 opposite to the insulating layer 11, or the first pre-sintering layer 101 is formed on the side of the first connecting layer 24 opposite to the power chip 21.

[0259] The substrate 10 and the power device 20 are stacked so that the first pre-sintering layer 101 is between the first conductive layer 12 and the first connecting layer 24.

[0260] The first pre-sintering layer 101 is pressure-sintered in a reducing gas, an inert gas or a vacuum environment to form the first sintering layer 10a, so that the first sintering layer 10a is stacked with the first conductive layer 12 and the first connecting layer 24. The above can be combined with the related description of the embodiments shown in FIG. 10 and the embodiments shown in FIG. 26.

[0261] The thermosensitive device 40 is arranged on the side of the first conductive layer 12 opposite to the insulating layer 11 by sintering or welding.

[0262] The first terminal 51 is arranged on the side of the first sub-conductive layer 131 opposite to the insulating layer 11 by sintering or welding, and the second terminal 52 is arranged on the side of the second sub-conductive layer 132 opposite to the insulating layer 11.

[0263] The first connecting terminal 60a is arranged between the first sub-conductive layer 131 and the power device 20 by welding or sintering, and the second connecting terminal 60b is arranged between the second sub-conductive layer 132 and the power device 20.

[0264] The plastic package 70 is formed by covering the outside of the substrate 10 with a plastic material to completely cover the first sintering layer 10a, the power device 20, the thermosensitive device 40, the first connecting terminal 60a and the second connecting terminal 60b, and the plastic package 70 covers part of the substrate 10, part of the first terminal 51 and part of the second terminal 52 to form the power assembly 300a. In the Z-axis direction, one end of the first terminal 51 opposite to the substrate 10 is exposed outside the plastic package 70, one end of the second terminal 52 opposite to the substrate 10 is exposed outside the plastic package 70, and the side of the heat-conducting layer 14 opposite to the insulating layer 11 is exposed outside the plastic package 70.

[0265] The plastic sealing material can be epoxy resin, polyester resin, silicone or the like. The plastic sealing member 70 is made of plastic sealing material including but not limited to epoxy resin, polyester resin, silicone or the like. The plastic sealing member 70 encapsulates the substrate 10, the power device 20, the thermal sensitive device 40, the first terminal 51, the second terminal 52, the first connecting terminal 60a and the second connecting terminal 60b. The design of the plastic sealing member 70 protects the substrate 10 and the power device 20 from damage due to impact, thereby improving the safety of the substrate 10 and the power device 20 and prolonging the service life of the substrate 10 and the power device 20.

[0266] As shown in FIGS. 5, 29 and 30, S702, a heat sink 30 is provided. In each power assembly 300a, a second pre-sintering layer 102 is formed on the side of the heat conductive layer 14 away from the insulating layer 11, or a plurality of second pre-sintering layers 102 are formed on the heat sink 30. Each second pre-sintering layer 102 corresponds to one heat conductive layer 14. For details, refer to the related description of the embodiment shown in FIG. 19.

[0267] S703, each power assembly 300a is stacked with the heat sink 30, so that each second pre-sintering layer 102 is located between one heat conductive layer 14 and the heat sink 30. For details, refer to the related description of the embodiment shown in FIG. 20.

[0268] S704, pressure sintering is performed on the plurality of second pre-sintering layers 102 in a reducing gas, an inert gas or a vacuum environment, so that the plurality of second pre-sintering layers 102 are correspondingly made into a plurality of second sintering layers 30a. The plurality of second sintering layers 30a correspond to the plurality of heat conductive layers 14 one by one, and each second sintering layer 30a is stacked with one heat conductive layer 14 and the heat sink 30. The reducing gas can be a mixture of N2 and H2, a mixture of N2 and formic acid, H2 or other reducing gas. The inert gas can be N2 or He or other inert gas. The sintering condition for pressure sintering is that the sintering temperature is controlled at 150-280°C and the applied pressure is controlled at 3-20 MPa.

[0269] Specifically, in each power assembly 300a, a removable stress buffer film 2 is arranged on the side of the plastic sealing member 70 away from the heat sink 30. The stress buffer film 2 is stacked on the side of the plastic sealing member 70 away from the heat sink 30. The stress buffer film 2 is sleeved on the outside of the first terminal 51, and the stress buffer film 2 is sleeved on the outside of the second terminal 52. The stress buffer film 2 can be Teflon film or other organic film.

[0270] By applying pressure along the Z-axis towards the heat sink 30 to each power component 300a through the stress buffer film 2, each second pre-sintered layer 102 can be pressure-sintered. Multiple second pre-sintered layers 102 are then formed into multiple second sintered layers 30a, such that each second sintered layer 30a is stacked with a thermally conductive layer 14 and the heat sink 30. The substrate 10 of the power component 300a and the heat sink 30 are bonded together through the second sintered layer 30a, achieving large-area sintering of multiple power components 300a and the heat sink 30. The design of the stress buffer film 2 avoids stress concentration and helps improve the bonding strength between the power components 300a and the heat sink 30 through the second sintered layer 30a.

[0271] In this way, the substrate 10 and the power device 20 are bonded together through the first sintered layer 10a, and the heat sink 30 is bonded to the substrate 10 through the second sintered layer 30a. The design of the second sintered layer 30a, manufactured by pressure sintering in a reducing gas, inert gas, or vacuum environment, also avoids oxidation reactions during its fabrication. This improves the bonding strength between the thermally conductive layer 14 and the heat sink 30 through the second sintered layer 30a, enhances the bonding strength between the substrate 10 and the heat sink 30, and improves the structural stability of the power module 300. Furthermore, a single heat sink 30 can dissipate heat from the power devices 20 of multiple power components 300a, achieving rapid heat dissipation from multiple power devices 20.

Claims

A power module characterized by The power module comprises a substrate, a first sintering layer and a power device; the substrate comprises an insulating layer and a first conductive layer, the first conductive layer is arranged on one side of the insulating layer in the thickness direction of the substrate, and the first sintering layer and the power device are sequentially arranged on the side of the first conductive layer away from the insulating layer. The power device comprises a power chip, a first fixing layer and a first connecting layer, the power chip, the first fixing layer and the first connecting layer are sequentially arranged in the thickness direction of the substrate, the first connecting layer is in contact with the first sintering layer, and the thickness of the first sintering layer is greater than the thickness of the first connecting layer and less than the thickness of the first conductive layer in the thickness direction of the substrate. The power module of claim 1, wherein The material of the first connecting layer is the same as that of the first sintering layer. The power module of claim 1, wherein The material of the first sintering layer is the same as that of the first conductive layer, the material of the first connecting layer is copper, nickel, silver or gold, and the material of the first sintering layer is a composite material of aluminum, copper or nickel. The power module of claim 1, wherein The substrate comprises a heat-conducting layer, the heat-conducting layer is arranged on one side of the insulating layer away from the first conductive layer in the thickness direction of the substrate, the power module comprises a second sintering layer and a heat sink, the second sintering layer and the heat sink are sequentially arranged on the side of the heat-conducting layer away from the insulating layer in the thickness direction of the substrate, the material of the second sintering layer is the same as that of the first sintering layer, and the area of the projection of the second sintering layer in the thickness direction of the substrate is greater than the area of the projection of the first sintering layer in the thickness direction of the substrate. The power module according to claim 4, characterized in that The thickness of the second sintering layer is greater than the thickness of the first sintering layer and less than the thickness of the first conductive layer in the thickness direction of the substrate. The power module according to claim 4, characterized in that The material of the heat-conducting layer, the material of the second sintering layer and the material of the heat sink are the same. The power module according to claim 4, characterized in that The second sintering layer is provided with an exhaust groove, and the exhaust groove extends in the thickness direction of the substrate from one side of the second sintering layer in the thickness direction of the substrate. The power module according to claim 7, characterized in that The projection of the exhaust groove in the thickness direction of the substrate is arranged in interval with the projection of the power device in the thickness direction of the substrate. The power module according to claim 7, characterized in that In the thickness direction of the substrate, the width of the exhaust groove is less than the thickness of the second sintering layer, and the length of the exhaust groove in the first direction is equal to the length of the second sintering layer, wherein the first direction is perpendicular to the thickness direction of the substrate. The power module according to claim 7, characterized in that In the second direction, the width of the groove opening of the exhaust groove is greater than the width of the groove bottom of the exhaust groove, wherein the second direction is perpendicular to the thickness direction of the substrate. The power module according to any one of claims 4 to 10, characterized in that The number of the substrate, the number of the first sintering layer, the number of the power device and the number of the second sintering layer are all multiple, each substrate corresponds to at least one first sintering layer, at least one power device and at least one second sintering layer, and multiple substrates are arranged in interval. The power module of claim 11, wherein The power module comprises a plurality of plastic packages, each of which corresponds to one of the substrates, in the corresponding plastic package, substrate, power device, first sintered layer and second sintered layer, the plastic package covers part of the substrate, the heat conduction layer of the substrate is exposed outside the plastic package, the plastic package completely covers the first sintered layer and the power device, and the second sintered layer is located between the plastic package and the heat sink. The power module according to any one of claims 4 to 10, characterized in that The power module comprises a plastic package, which completely covers the substrate, the first sintered layer and the power device, and covers part of the second sintered layer, and the side of the second sintered layer away from the substrate is exposed outside the plastic package. The power module according to any one of claims 1 to 10, characterized in that The power device comprises a second fixing layer and a second connecting layer, which are sequentially stacked on the side of the power chip away from the first fixing layer in the thickness direction of the substrate. The substrate comprises a second conductive layer, which is stacked on one side of the insulating layer and faces the first conductive layer in the thickness direction of the substrate, the power module comprises a mounting layer, a terminal and a connecting terminal, the mounting layer is stacked on one side of the second connecting layer and away from the power chip in the thickness direction of the substrate, the terminal is arranged on one side of the second conductive layer and away from the insulating layer, and the connecting terminal is arranged between the mounting layer and the second conductive layer. A power conversion device characterized by comprising: The power conversion device comprises a circuit board and the power module according to any one of claims 1 to 14, and the power module is combined with the circuit board.

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