Electrode, method for manufacturing the same, and power semiconductor device including the same

Abstract

An electrode for a power semiconductor device, a manufacturing method thereof, and a power semiconductor device. The electrode includes an electrode body and a cover plate; the electrode body is provided with a plurality of blind holes spaced apart, the open ends of the blind holes are located on the upper surface of the electrode body, each blind hole is provided with a capillary microtube, and a cooling medium is accommodated in the blind hole; the cover plate is disposed on the upper surface of the electrode body to sealingly cover the blind holes. Through the electrode for a power semiconductor device, a manufacturing method thereof, and a power semiconductor device, the purpose of improving the heat transfer efficiency of the device electrode, reducing the device junction-to-case thermal resistance, enabling the chip junction temperature to be lower when the device operates, and enhancing the rated current-carrying capacity of the device is achieved.

Description

Technical Field

[0001] The present invention relates to the field of power semiconductor devices, and more particularly, to electrodes for power semiconductor devices, a method for manufacturing electrodes, and power semiconductor devices. Background Art

[0002] In the field of power electronics, power semiconductor devices, as key components, play a crucial role in the realization and improvement of system performance. As Figure 1 shown, the housing of existing packaged semiconductor devices consists of upper and lower copper electrodes and a ceramic ring on the side to form a closed cavity, and the chip is placed therein. There is a water-cooling plate on each of the upper and lower sides of the copper electrodes of the housing for dissipating heat from the device, and the entire device achieves effective electrical connection by applying pressure.

[0003] Chinese Patent Application with Publication No. CN114207817A discloses a power semiconductor device, including: a disc-shaped first electrode and a disc-shaped second electrode; a chip, with the chip sandwiched between the first electrode and the second electrode.

[0004] According to the prior art, a heat pipe is combined with fins to form an air-cooled radiator. By using the phase change of the cooling medium in the heat pipe, the heat of the heat-dissipating body is absorbed, and the heat is conducted to the fin position, and then the heat is dissipated into the environment by air cooling. The main problem with this solution is that the air-cooled radiator based on a heat pipe is not suitable for press-pack power semiconductor devices with high-power heat dissipation requirements. Under the application conditions of such devices, a water-cooled radiator is usually used. How to introduce the high-efficiency heat dissipation ability of the heat pipe while maintaining the existing water-cooling system to further improve the heat dissipation efficiency and the current-carrying capacity of the device has become a key problem to be solved.

[0005] Chinese Patent Application with Publication No. CN117080352A discloses a system-in-package structure on a wafer and a preparation method thereof, including: a first wafer substrate, a second wafer substrate, and a chip. The first wafer substrate includes a first substrate and a first interconnecting layer, and a first microchannel is provided on the second surface of the first substrate. The second wafer substrate is stacked with the first wafer substrate. The second wafer substrate includes a second substrate and a second interconnecting layer, and a second microchannel is provided on the second surface of the second substrate. The first microchannel and the second microchannel are interconnected to form a microchannel heat dissipation structure. Both the first microchannel and the second microchannel are filled with foam metal. The foam metal has a high thermal conductivity.

[0006] Chinese Patent Application with Publication No. CN104966704A discloses a press-pack power device package with low thermal resistance. Among them, the cavities inside the upper electrode are interconnected, and a heat-conducting fluid medium is filled in the cavities for conducting heat; or, the cavities are used to circulate a cooling liquid after the interface is connected to an external cooling device, and the cooling liquid takes away the heat, thereby realizing the cooling of the heat source.

[0007] Since the material of the copper electrode is oxygen-free copper and its thermal conductivity is close to 400 W / (m·K), which is already the second-highest thermal conductivity among conductive materials, second only to silver, it is difficult to further improve its own thermal conductivity. However, the phase change thermal conductivity of the cooling medium is usually greater than 1500 W / (m·K), much higher than that of copper. Therefore, it is possible to consider using the phase change of the cooling medium to improve the comprehensive heat conduction ability of the copper electrode, thereby increasing the equivalent thermal conductivity of the copper electrode and reducing the device junction-to-case thermal resistance. Summary of the Invention

[0008] The present invention discloses an electrode for a power semiconductor device, so as to achieve the purpose of improving the heat transfer efficiency of the device electrode, reducing the device junction-to-case thermal resistance, making the chip junction temperature lower when the device is working, and enhancing the rated current-carrying capacity of the device.

[0009] According to one aspect of the present invention, the present invention provides an electrode for a power semiconductor device, the electrode comprising an electrode body and a cover plate; the electrode body is provided with a plurality of blind holes spaced apart, the open ends of the blind holes are located on the upper surface of the electrode body, each blind hole is provided with a capillary microtube, and the blind holes accommodate a cooling medium; the cover plate is disposed on the upper surface of the electrode body to hermetically cover the blind holes.

[0010] Preferably, the bottom end of the blind hole is as close as possible to the bottom of the electrode body.

[0011] Preferably, the blind holes extend along the central axis direction of the electrode body.

[0012] Preferably, the outer diameter of the capillary microtube is not greater than the diameter of the blind hole.

[0013] Preferably, the blind holes and the capillary microtubes are coaxial.

[0014] Preferably, the length of the blind hole is the same as the length of the capillary microtube.

[0015] Preferably, the amount of the cooling medium in the blind hole does not exceed half of the volume of the blind hole.

[0016] Preferably, the electrode further comprises a shell flange, and the shell flange is connected to the side wall step of the electrode body.

[0017] According to another aspect of the present invention, the present invention provides a power semiconductor device including the above electrode, the electrode being used as the upper electrode, or the lower electrode, or the upper electrode and the lower electrode of the power semiconductor device; wherein, when the electrode is used as the lower electrode, the upper surface of the electrode body corresponds to the lower surface of the lower electrode body.

[0018] Preferably, the power semiconductor device includes an upper electrode, an upper electrode metal sheet, a chip, a lower electrode metal sheet, and a lower electrode housing base sequentially arranged from top to bottom in the vertical direction; wherein, the lower electrode housing base includes a lower electrode.

[0019] According to another aspect of the present invention, the present invention provides a manufacturing method for the electrode of the above-mentioned power semiconductor device, and the manufacturing method includes the following steps: processing the electrode body and the housing flange; performing a first welding on the electrode body and the housing flange; assembling the capillary microtube and the electrode body; performing a second welding on the electrode body and the cover plate.

[0020] Based on the above technical solutions, the present invention has at least one of the following beneficial effects compared with the prior art.

[0021] 1. The thermal resistance of the power semiconductor device is greatly reduced. After introducing the phase change heat dissipation of the cooling medium into the electrode of the power semiconductor, the thermal conductivity of copper is improved, breaking through the theoretical limit of the device junction-to-case thermal resistance, and greatly improving the current-carrying capacity of the device.

[0022] 2. On the basis of improving the thermal conductivity, the original functions of the electrode, such as conducting electricity and withstanding mechanical pressure, are retained.

[0023] 3. High compatibility. The device packaging structure can be well compatible with the existing valve string press-fitting structure, and does not change the existing housing sealing and welding process.

[0024] Other features and advantages of the present application will be described in the subsequent specification, and part of them will become obvious from the specification, or will be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the drawings. Description of the Drawings

[0025] The drawings are used to provide an understanding of the technical solutions of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0026] Figure 1 is a schematic diagram of an existing power semiconductor device;

[0027] Figure 2 is a schematic cross-sectional view of a semiconductor device according to an embodiment of the present invention;

[0028] Figure 3 is a schematic cross-sectional perspective view of a semiconductor device according to an embodiment of the present invention, mainly showing the upper electrode and the lower electrode, etc.;

[0029] Figure 4 is a schematic cross-sectional view of an electrode of a semiconductor device according to an embodiment of the present invention;

[0030] Figure 5 Flow chart of a method for manufacturing an electrode of a semiconductor device according to an embodiment of the present invention.

[0031] List of reference numerals:

[0032] 1. Chip; 2. Upper electrode metal sheet; 3. Lower electrode metal sheet; 4. Upper electrode; 41. Upper electrode body; 42. Blind hole; 43. Capillary microtube; 44. Cover plate; 45. Upper electrode shell flange; 5. Lower electrode shell base; 51. Lower electrode; 52. Lower flange of lower electrode; 53. Gate lead-out ring; 54. Ceramic ring; 55. Upper flange of lower electrode; 10. Electrode; 11. Electrode body; 12. Shell flange. Detailed implementation manners

[0033] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the following further describes the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0034] To make the objectives, technical solutions and advantages of the present disclosure more clear and understandable, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the implementation manners can be implemented in multiple different forms. Those of ordinary skill in the art can easily understand the fact that the manners and contents can be transformed into various forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be construed as being limited only to the contents described in the following implementation manners. Without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other arbitrarily.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0036] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include at least one of such features.

[0037] In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0038] In the present application, unless otherwise clearly specified and defined, terms such as "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0039] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0040] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example" or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. To achieve the above object according to the embodiments of the present invention, the present invention adopts the following technical solutions.

[0041] As Figure 4 shown, the electrode 10 for a power semiconductor device according to the present invention includes an electrode body 11 and a cover plate 44.

[0042] The material of the electrode body 11 is oxygen-free copper. Preferably, in the embodiment of the present invention, the diameter of the electrode body 11 is 100 - 150 mm, the thickness is 10 - 35 mm, the flatness of the upper and lower sides is less than 10 μm, and the roughness is less than 0.8 μm. In the embodiment of the present invention, taking the electrode 10 as the upper electrode 4 or the anode electrode as an example, the side surface of the electrode body 11 is processed into a stepped shaft shape, and the step width is 1 - 3 mm. The functions of the electrode body 11 include: a) Conducting electricity, the current flows up and down along the axis, and the current-carrying capacity is 1 - 5 kA; b) Withstanding mechanical pressure, the pressure range is 5 - 20 MPa; c) Providing the outer pipe wall of the blind hole 42.

[0043] The electrode body 11 is provided with a plurality of blind holes 42 which are spaced apart, preferably spaced apart in parallel. The open ends of the blind holes 42 are located on the upper surface of the electrode body 11. Preferably, the blind holes 42 extend along the central axis direction of the electrode body 11. In a top view, the arrangement of the plurality of blind holes 42 in the electrode body 11 is regular or irregular. The blind holes 42 are distributed throughout the electrode body 11 for better heat dissipation. Preferably, the radius of the blind holes 42 is greater than 1 and less than or equal to 5 mm, and the bottom thickness of the blind holes 42 (i.e., the distance between the bottom end of the blind hole 42 and the bottom of the electrode body 11) is 1 - 3 mm. According to the embodiment of the present invention, the bottom end of the blind hole 42 can be set as close as possible to the bottom of the electrode body 11.

[0044] Each blind hole 42 is provided with a capillary microtube 43. The capillary microtube 43 is in a cylindrical shape and is open at both the upper and lower ends. Preferably, the blind hole 42 and the capillary microtube 43 are coaxially arranged. The material of the capillary microtube 43 is a foam metal, particularly copper or molybdenum or tungsten, and the melting point is required to be not lower than the melting point of copper, generally greater than 1200 °C. Preferably, the capillary microtube 43 is made by a metal 3D printing process, and the porosity is not less than 60%. The outer diameter of the capillary microtube 43 is not greater than the diameter of the blind hole 42 in the electrode body 11. Preferably, the inner diameter is not less than 2 mm. The length of the capillary microtube 43 is the same as the length of the blind hole 42 in the electrode body 11. The functions of the capillary microtube 43 include: a) By means of capillary action, the liquid cooling medium can be transferred from one side to the other side; b) Resisting the high temperature during the welding process and maintaining the original mechanical structure. Foam metal is a metal material with a special structure, its shape is similar to a sponge, and it has a highly open pore structure. It is formed by solid-state foaming of a metal, and the pore structure is formed by adding gas or foaming agent to the metal and the diffusion and solidification of the bubbles generated during the chemical combination and solidification process at high temperature.

[0045] The blind hole 42 is filled with a cooling medium. Preferably, the filling amount of the liquid cooling medium does not exceed half of the volume of the blind hole 42. The phase change temperature range of the cooling medium is 60 to 70 °C. On the side close to the chip 1, the cooling medium changes from liquid to gas due to the temperature exceeding the phase change temperature, absorbing a large amount of heat. The gaseous cooling medium transfers from the side close to the chip 1 to the side close to the water-cooled radiator. Due to the temperature decrease, the cooling medium changes from gas to liquid, releasing a large amount of heat. With the capillary action of the capillary microtube 43 and / or under the action of gravity, the liquid cooling medium transfers from the side close to the water-cooled radiator to the side close to the chip 1 to complete the cycle.

[0046] A cover plate 44 is disposed on the upper surface of the electrode body 11 to hermetically cover the blind hole 42. The material of the cover plate 44 is oxygen-free copper. According to an embodiment of the present invention, the thickness of the cover plate 44 is 1 to 3 mm. The cover plate 44 is hermetically connected to the electrode body 11 by vacuum welding. Specifically, before vacuum welding, the capillary microtube 43 should be placed inside each blind hole 42 to keep the interior of the pores in a vacuum state.

[0047] Preferably, as Figure 4 shown, the electrode 10 for a power semiconductor device according to the present invention further includes a shell flange 12. The shell flange 12 is connected to the side wall step of the electrode body 11, preferably by welding. The material of the shell flange 12 is oxygen-free copper. According to an embodiment of the present invention, the thickness of the shell flange 12 is 0.5 to 0.8 mm. The functions of the shell flange 12 are: a) it is prone to plastic deformation, and the cold pressure welding process can be used to seal the flanges of the upper electrode and the lower electrode; b) its welding reliability with the electrode body 11 is high, meeting the sealing requirements.

[0048] As Figure 2 and Figure 3 shown, the power semiconductor device according to the present invention includes the electrode 10. The electrode 10 can be used as the upper electrode 4, or the lower electrode 51, or both the upper electrode 4 and the lower electrode 51 of the power semiconductor device packaging structure. Specifically, the power semiconductor device includes an upper electrode 4, an upper electrode metal sheet 2, a chip 1, a lower electrode metal sheet 3, and a lower electrode shell base 5 arranged in sequence from top to bottom in the vertical direction.

[0049] The chip 1 is a whole-wafer silicon-based chip, which can be one of a thyristor, GTO, GCT, or diode. Preferably, the size of the chip 1 is 2 inches, 3 inches, 4 inches, 6 inches, 8 inches, etc., and the thickness is 0.2 mm to 2 mm. The chip 1 includes an active region in the central region and a terminal region in the edge region. Among them, the active region is the main current-carrying region and the heat-generating region, and the terminal region is the main insulating region. The upper electrode metal sheet 2 and the lower electrode metal sheet 3 can both be made of pure molybdenum, with a thickness of 0.5 mm to 5 mm, and have extremely high flatness, ensuring that the pressure acting on the chip 1 when pressed is very uniform. Since molybdenum metal has the closest coefficient of thermal expansion to the silicon chip 1 among all conductive materials, it can buffer the thermal stress between the electrode and the silicon chip 1 during temperature cycling, improving the reliability of the chip 1.

[0050] As Figure 3 shown, the upper electrode 4 is made of oxygen-free copper and includes an upper electrode main body in the central region and an upper electrode shell flange 45 in the edge region. The upper electrode main body and the upper electrode shell flange 45 are connected to each other by high-temperature welding. According to an embodiment of the present invention, the upper electrode 4 is an anode. The electrode 10 according to the present invention can be used as the upper electrode 4. In this case, the electrode main body 11 corresponds to the upper electrode main body; in addition, the upper electrode 4 further includes a cover plate 44. In addition, the shell flange 12 of the electrode 10 corresponds to the upper electrode shell flange 45, see Figure 2 . Therefore, according to an embodiment of the present invention, the upper electrode 4 includes the electrode main body 11, the cover plate 44, etc. The related structure will not be elaborated.

[0051] As Figure 2 shown, the material of the lower electrode shell base 5 includes oxygen-free copper and alumina ceramic. The lower electrode shell base 5 includes a lower electrode 51, a lower electrode lower flange 52, a gate lead-out ring 53, a ceramic ring 54, and an upper electrode upper flange 55. The above components are connected into one body by high-temperature welding. The ceramic ring 54 mainly plays a role in high-voltage insulation, and the creepage distance and electrical clearance meet the high-voltage requirements of 8.5 kV and above. The lower electrode 51 has the functions of conducting current and dissipating heat. The lower electrode lower flange 52 and the upper electrode upper flange 55 mainly play the roles of connection and sealing. According to an embodiment of the present invention, the lower electrode 51 is a cathode. The electrode 10 according to the present invention can be used as the lower electrode 51. In this case, the lower electrode 51 further includes a cover plate 44. In addition, the shell flange 12 of the electrode 10 corresponds to the lower electrode lower flange 52 and the upper electrode upper flange 55. Therefore, according to an embodiment of the present invention, the lower electrode 51 includes the electrode main body 11, the cover plate 44, etc. The related structure will not be elaborated. It should be noted that when the electrode 10 is used as the lower electrode 51, the upper surface of the electrode main body 11 refers to the lower surface of the lower electrode main body.

[0052] The upper electrode 4 and the lower electrode shell base 5 are connected to each other through a cold pressure welding process to achieve device shell sealing, providing a sealed protection space for the chip 1. After evacuating the inside and filling it with nitrogen, the influence of the external environment on the chip 1 is isolated. Specifically, the upper electrode shell flange 45 and the lower electrode upper flange 55 are plastically deformed under pressure, enabling the two flanges to be connected to each other at the metal atom level, thus completing the cold pressure welding process. This step is carried out in a vacuum mold.

[0053] According to an embodiment of the present invention, the heat dissipation process of the electrode 10 is described as follows:

[0054] Since the chip 1 is a heat source and the heat sink is a cold source, that is, the heat source is always located inside the power semiconductor device and the cold source is always located on the device shell, it is necessary to conduct a detailed analysis according to different installation forms of the power semiconductor device. According to the installation forms of the power semiconductor device under actual application conditions, it can be roughly divided into three types: flat placement, vertical placement, and inverted placement.

[0055] In the flat placement state, one side of the bottom end of the blind hole 42 is the heat source, and the side of the open end is the cold source. The liquid cooling medium mainly exists in the lower part of the blind hole 42 and inside the capillary microtube 43 under the action of gravity and capillary action. When the liquid cooling medium undergoes a phase change due to heat, it becomes a gaseous cooling medium, absorbs a large amount of heat, and moves to the side of the open end. When the gaseous cooling medium moves to the opening, it encounters the cold source, dissipates heat and cools down, and then returns to the bottom end of the blind hole 42 under the action of gravity to complete the cycle. Typically, this working state corresponds to the working state when the electrode 10 is used as the upper electrode 4.

[0056] In the vertical placement state, the left side (bottom end side) of the blind hole 42 is the heat source, and the right side (open end side) is the cold source. According to an embodiment of the present invention, the filling amount of the liquid cooling medium reaches half of the volume of the blind hole 42 (the lower side of the central axis of the blind hole 42), ensuring that the other half of the volume has no cooling medium (the upper side of the central axis of the blind hole 42) to provide space for the flow of the gaseous cooling medium. When the liquid cooling medium undergoes a phase change due to heat, it becomes a gaseous cooling medium and moves to the space on the upper side of the central axis of the blind hole 42, dissipates heat and cools down, and then returns to the lower side of the central axis of the blind hole 42 under the action of gravity.

[0057] In the inverted placement state, the upper side (bottom end side) of the blind hole 42 is the heat source, and the lower side (open end side) is the cold source. The liquid cooling medium mainly relies on capillary action to be on the upper side, close to the heat source. When the liquid cooling medium undergoes a phase change due to heat, it becomes a gaseous cooling medium and reaches the lower side (open end side) of the blind hole 42, dissipates heat and cools down, and then returns to the upper side (bottom end side) of the blind hole 42 under the action of capillary action. Typically, this working state corresponds to the working state when the electrode 10 is used as the lower electrode 51.

[0058] See Figure 5 , the manufacturing method of the electrode 10 of the present invention will be described below.

[0059] Machine process the electrode body 11 and the shell flange 12. The electrode body 11 is processed by machining, and the flatness and roughness of the upper and lower sides are ensured to meet the requirements through grinding, so as to achieve uniform pressure distribution of the large-size electrode 10; the shell flange 12 is processed by die stamping, and burrs are removed after stamping.

[0060] Perform a first welding on the electrode body 11 and the shell flange 12. Adopt the silver-copper brazing process to complete the high-temperature welding of the electrode body 11 and the shell flange 12. Preferably, the welding temperature is 840 °C, and the solder is the Ag72Cu28 eutectic alloy without any flux. Through welding, the following is achieved: the weld is smooth and there are no visible holes to the naked eye. The solder is not allowed to overflow onto the surface of the electrode 10 and within a region, such as 3 mm, from the flange edge. These two regions are both working surfaces. Among them, the surface of the electrode 10 is the pressure-receiving surface, and if there is overflow material, it will affect the uniform pressure distribution. The region within 3 mm, for example, from the flange edge is the working surface for cold pressure welding, and if there is overflow material, it will affect the cold pressure welding seal quality.

[0061] Assemble the capillary microtube 43 and the electrode body 11. Load a capillary microtube 43 into each blind hole 42 on the electrode body 11 respectively, and adopt the manual assembly method to ensure that the outer wall of the capillary microtube 43 is closely attached to the inner wall of the blind hole 42 of the electrode 10.

[0062] Perform a second welding on the electrode body 11 and the cover plate 44. In a vacuum environment, fill the cooling medium into the blind hole 42, cover the cover plate 44, and complete the welding at the connection using a low-temperature welding process. The welding temperature needs to be lower than the temperature of the first welding, such as 840 °C, and preferably the temperature is controlled below 500 °C to avoid the influence of the second welding on the first welding. After welding, the entire surface of the electrode 10 is nickel-plated, and thus the preparation of the high-thermal conductivity electrode 10 packaging structure of the power semiconductor device can be completed.

[0063] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An electrode (10) for a power semiconductor device, characterized in that: The electrode (10) comprises an electrode body (11) and a cover plate (44); The electrode body (11) is provided with a plurality of blind holes (42) spaced apart from each other, the opening ends of the blind holes (42) are located on the upper surface of the electrode body (11), a capillary microtube (43) is provided in each blind hole (42), and a cooling medium is contained in the blind hole (42); A cover plate (44) is disposed on the upper surface of the electrode body (11) to cover the blind hole (42) in a sealing manner; The electrode (10) further comprises a tube shell flange (12), and the tube shell flange (12) is connected to the side wall step of the electrode body (11); The manufacturing method of the electrode (10) for a power semiconductor device comprises the following steps: Processing the electrode body (11) and the tube shell flange (12); Performing a first welding operation on the electrode body (11) and the shell flange (12); Assembling the capillary microtube (43) and the electrode body (11); The electrode body (11) and the cover plate (44) are welded for a second time, and the welding temperature of the second welding is lower than the temperature of the first welding.

2. The electrode (10) according to claim 1, characterized in that The blind hole (42) extends along the central axis direction of the electrode body (11).

3. The electrode (10) according to claim 1, characterized in that The outer diameter of the capillary microtube (43) is not greater than the diameter of the blind hole (42).

4. The electrode (10) according to claim 1, characterized in that The blind hole (42) and the capillary microtube (43) are coaxial.

5. The electrode (10) according to claim 1, characterized in that The length of the blind hole (42) is the same as the length of the capillary microtube (43).

6. The electrode (10) according to claim 1, characterized in that The amount of cooling medium in the blind hole (42) does not exceed half of the volume of the blind hole (42).

7. A power semiconductor device comprising the electrode (10) according to any one of claims 1 to 6, characterized in that: The electrode (10) is used as an upper electrode (4), or a lower electrode (51), or an upper electrode (4) and a lower electrode (51) of a power semiconductor device; When the electrode (10) is used as a lower electrode (51), the upper surface of the electrode body (11) corresponds to the lower surface of the lower electrode body.

8. The power semiconductor device according to claim 7, characterized in that: The power semiconductor device comprises an upper electrode (4), an upper electrode metal sheet (2), a chip (1), a lower electrode metal sheet (3), and a lower electrode tube shell base (5) which are arranged in sequence from top to bottom in a vertical direction; Wherein, the lower electrode tube shell base (5) comprises a lower electrode (51).

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