Package electrode and manufacturing method thereof, and semiconductor package device

Abstract

The present disclosure relates to a packaging electrode and a manufacturing method thereof, and a semiconductor packaging device. The manufacturing method comprises: preparing a diamond composite metal base layer, and forming a first alloy layer and a second alloy layer on the upper and lower surfaces of the diamond composite metal base layer respectively, and forming a conductive flange on the side wall of the diamond composite metal base layer; wherein the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; the surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for direct contact with the chip; the flange welding surface of the conductive flange has no diamond component. The present disclosure is conducive to improving the molding quality and performance of large-size packaging electrodes, thereby effectively improving the packaging reliability of semiconductor packaging devices.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor packaging technology, and in particular to a packaging electrode and a manufacturing method thereof, and a semiconductor packaging device. Background Art

[0002] With the development of semiconductor technology, electronic devices are moving towards miniaturization, lightness, high performance and multi-function. Due to the rapid increase in chip integration, the heat generated per unit area of ​​integrated circuits is getting higher and higher. Therefore, how to improve the packaging reliability of semiconductor packaging devices has become one of the urgent problems to be solved. Summary of the invention

[0003] Based on this, the embodiments of the present disclosure provide a packaging electrode and a manufacturing method thereof, and a semiconductor packaging device, which are beneficial to improving the molding quality and performance of the packaging electrode, thereby effectively improving the packaging reliability of the semiconductor packaging device.

[0004] In order to achieve the above-mentioned purpose, in the first aspect, some embodiments of the present disclosure provide a method for manufacturing a packaged electrode. The method for manufacturing a packaged electrode comprises: preparing a diamond composite metal base layer, and forming a first alloy layer and a second alloy layer on the upper and lower surfaces of the diamond composite metal base layer respectively, and forming a conductive flange on the side wall of the diamond composite metal base layer; wherein the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; the surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for directly contacting the chip; and the flange welding surface of the conductive flange has no diamond component.

[0005] In some embodiments of the present disclosure, the steps of preparing a diamond composite metal base layer, forming a first alloy layer and a second alloy layer on the upper and lower surfaces of the diamond composite metal base layer, respectively, and forming a conductive flange on the side wall of the diamond composite metal base layer may include any of the following implementations.

[0006] Implementation method 1:

[0007] Diamond particles are provided and surface modification is performed on the diamond particles.

[0008] A first mold is provided, and the surface-modified diamond particles are vibrated and compacted based on the first mold to form a diamond preform.

[0009] A second mold is provided, wherein the second mold has an electrode region and a flange region arranged in a stepped manner with the electrode region.

[0010] The first alloy material, diamond preform, metal material and second alloy material are stacked in the electrode area of ​​the second mold, a conductive flange is placed in the flange area of ​​the second mold, and the obtained structure is pressure sintered to form an initial structure of the packaged electrode.

[0011] The upper and lower surfaces of the initial structure of the packaging electrode are subjected to a machining process to obtain the packaging electrode.

[0012] Implementation method 2:

[0013] Diamond particles are provided and surface modification is performed on the diamond particles.

[0014] A third mold is provided, a metal belt is pre-placed on the inner wall of the third mold, and the surface-modified diamond particles are vibrated and compacted based on the third mold to form a diamond preform with the metal belt.

[0015] A fourth mold is provided, wherein the fourth mold has an electrode region and a cavity region located around the electrode region.

[0016] The first alloy material, diamond preform, metal material and second alloy material are stacked in the electrode area of ​​the fourth mold, and the obtained structure is pressure sintered to form an initial structure of the packaged electrode; wherein the part of the metal material that flows into the cavity area after melting forms a conductive flange together with the metal belt.

[0017] The upper and lower surfaces of the initial structure of the package electrode are subjected to a machining process to obtain the package electrode.

[0018] Implementation method three:

[0019] Diamond particles are provided and surface modification is performed on the diamond particles.

[0020] A fifth mold is provided, wherein the fifth mold has an electrode region and a flange region arranged in a stepped manner with the electrode region.

[0021] The surface-modified diamond particles are vibrated and compacted based on the fifth mold to form a diamond preform.

[0022] A sixth mold is provided, and a first alloy material, a diamond preform, a metal material and a second alloy material are stacked in the sixth mold, and the obtained structure is pressure sintered to form an initial structure of the packaged electrode; wherein the portion of the initial structure of the packaged electrode located in the flange area constitutes the body of the conductive flange.

[0023] A metal plating layer is formed on at least one surface of the body to obtain a conductive flange.

[0024] The upper and lower surfaces of the initial structure of the packaging electrode after the conductive flange is formed are subjected to a machining process to obtain the packaging electrode.

[0025] In the second aspect, some embodiments of the present disclosure provide a packaging electrode, which can be prepared by the manufacturing method provided in any of the above embodiments. The packaging electrode includes: a diamond composite metal base layer, a first alloy layer and a second alloy layer located on the upper and lower surfaces of the diamond composite metal base layer, and a conductive flange located on the side wall of the diamond composite metal base layer; wherein the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; the surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for direct contact with the chip; the flange welding surface of the conductive flange has no diamond component.

[0026] In some embodiments of the present disclosure, the packaged electrode further includes: a flange welded to the flange welding surface; wherein the material of the flange welding surface is the same as the material of the flange.

[0027] In some embodiments of the present disclosure, the conductive flange comprises a metal flange, and the metal flange has the same metal component as that in the diamond composite metal base layer.

[0028] Optionally, the metal flange and the diamond composite metal base layer are integrally formed by infiltration or casting.

[0029] In other embodiments of the present disclosure, the conductive flange includes: a body made of the same material as the diamond composite metal base and formed integrally, and a metal coating located on at least one side of the body. The surface of the metal coating facing away from the body is the flange welding surface.

[0030] In some embodiments of the present disclosure, the thickness of the metal coating ranges from 2 μm to 8 μm.

[0031] In some embodiments of the present disclosure, the surface flatness of the machined surface is less than or equal to 10 μm, and the surface roughness Ra is less than or equal to 0.5 μm.

[0032] In some embodiments of the present disclosure, the thickness of the first alloy layer and / or the second alloy layer ranges from 0.1 mm to 0.2 mm.

[0033] In some embodiments of the present disclosure, the diamond composite metal base layer includes: one or more layers of an aluminum diamond composite layer, a copper diamond composite layer, a molybdenum-copper alloy diamond composite layer, a tungsten-copper alloy diamond composite layer or a copper-graphene diamond composite layer.

[0034] In a third aspect, some embodiments of the present disclosure provide a semiconductor packaging device, including: a packaging electrode as described in any of the above embodiments; or a packaging electrode prepared by a manufacturing method as described in any of the above embodiments.

[0035] The embodiments of the present disclosure may or at least have the following advantages:

[0036] In the disclosed embodiment, the packaging electrode comprises: a diamond composite metal base layer, a first alloy layer and a second alloy layer located on the upper and lower surfaces of the diamond composite metal base layer, and a conductive flange located on the side wall of the diamond composite metal base layer; and the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; the surfaces of the first alloy layer and the second alloy layer away from the diamond composite metal base layer are machined surfaces for direct contact with the chip; and the flange welding surface of the conductive flange parallel to the machined surface has no diamond component. In this way, it is not only conducive to simplifying the packaging structure of the semiconductor packaging device to avoid chip failure due to large thermal stress, but also can take into account the performance requirements of high thermal conductivity and high electrical conductivity of the packaging electrode through the diamond composite metal base layer and the first alloy layer and the second alloy layer, so as to ensure that the packaging electrode has good heat resistance, corrosion resistance, chemical stability and thermal and electrical conductivity, and effectively weld the flange through the flange welding surface without diamond component of the conductive flange, improve the welding strength and welding reliability of the flange, thereby effectively improving the molding quality and performance of the packaging electrode, and further can effectively improve the packaging reliability of the semiconductor packaging device.

[0037] In addition, in the embodiments of the present disclosure, the packaged electrodes are also likely to have high compatibility so as to be well compatible with various valve string press-fit structures.

[0038] In the disclosed embodiments, the manufacturing method of the packaging electrode is mature and the process is simple, which can easily realize the mass-scale production control of packaging electrodes with large size, high thickness and high surface quality, and comprehensively considers the joint optimization of the electrical and thermal properties of the packaging electrodes, which can effectively improve the molding quality and performance of the packaging electrodes, thereby improving the packaging reliability of semiconductor packaging devices.

[0039] The details of one or more embodiments of the present disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the present disclosure will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 is a schematic structural diagram of a semiconductor packaging device provided in some embodiments;

[0042] Figure 2A schematic diagram of the structure of a packaged electrode provided in some embodiments;

[0043] Figure 3 is a schematic diagram of the structure of another packaged electrode provided in some embodiments;

[0044] Figure 4 is a schematic structural diagram of another packaged electrode provided in some embodiments;

[0045] Figure 5 for Figure 4 A schematic diagram of a cross-sectional structure of a packaged electrode provided in the illustrated embodiment;

[0046] Figure 6 A schematic flow chart of a method for manufacturing a packaged electrode provided in some embodiments;

[0047] Figure 7 for Figure 6 A schematic diagram of a preparation process of an initial structure of a packaged electrode provided in the illustrated embodiment;

[0048] Figure 8 A schematic flow chart of another method for manufacturing a packaged electrode provided in some embodiments;

[0049] Fig. 9 for Figure 8 A schematic diagram of a process for preparing a diamond preform provided in the illustrated embodiment;

[0050] Fig.10 A schematic flow chart of another method for manufacturing a packaged electrode provided in some embodiments;

[0051] Fig.11 for Fig.10 A schematic structural diagram of a diamond preform provided in the illustrated embodiment;

[0052] Fig.12 for Fig.10 A schematic structural diagram of a conductive flange provided in the illustrated embodiment.

[0053] Description of reference numerals:

[0054] 1-chip, 2-cathode electrode, 3-anode electrode, 4-tube shell, 10-packaged electrode, 10A-packaged electrode initial structure, 101-diamond composite metal base layer, 102-first alloy layer, 103-second alloy layer, 104-conductive flange, 105-flange, 51-diamond preform, 511-diamond particles, 512-metal strip, 61-body, 62-metal coating. DETAILED DESCRIPTION

[0055] In order to facilitate understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0057] It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below can be represented as a second element, component, region, layer or part.

[0058] It should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0059] It should be understood that the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0060] It is understood that the ideal requirements for the performance of packaging materials for semiconductor packaging devices, such as high-voltage and large-capacity press-fit power devices, may specifically include the following:

[0061] ① The coefficient of thermal expansion (CTE) of the packaging material should match or be close to that of the semiconductor material (such as silicon, gallium arsenide, gallium nitride, etc.) to reduce the thermal stress between it and the semiconductor material, thereby avoiding failure of the semiconductor packaging device due to thermal stress.

[0062] ② The packaging material should have high thermal conductivity so that the heat generated by the semiconductor material can be dissipated to the environment in a timely and uniform manner.

[0063] ③The packaging material should have sufficient strength and rigidity to provide better support and protection for semiconductor packaging devices.

[0064] ④ The packaging material should have high airtightness to withstand harmful environments such as high temperature, high humidity, corrosion or alternating conditions, thereby building a highly reliable working space for semiconductor packaging devices.

[0065] ⑤ The packaging material should have high formability and surface control capabilities, such as easy processing or near-final forming, to meet surface quality control requirements (such as surface roughness, surface flatness, etc.).

[0066] ⑥ Other special requirements, such as: certain functional characteristics requirements (electromagnetic / radio frequency / radiation shielding, conductivity / insulation, etc.), cost control and competitiveness requirements (high yield, suitable for mass production, low price, etc.).

[0067] However, in the related technology, taking the semiconductor packaging device as a press-fit power device as an example, there are: the problem that the thickness and diameter of each component layer cannot be changed due to the application standard requirements, the problem of whether the conductivity and uniformity of the packaging electrode meet the high voltage and high current application scenarios, the problem of whether the packaging electrode will cause the electrical performance of the semiconductor packaging device to deteriorate, the problem that the packaging electrode cannot achieve large size, large thickness and high surface quality control, the problem that the contact thermal resistance between the packaging electrode and the chip is greater than the body thermal resistance of the packaging electrode itself, thereby limiting the current carrying capacity of the device, and so on.

[0068] Based on this, the embodiments of the present disclosure provide a packaging electrode and a manufacturing method thereof, and a semiconductor packaging device, which are beneficial to improving the molding quality and performance of the packaging electrode, especially the molding quality and performance of large-size (for example, a diameter greater than 135 mm) and high-thickness (for example, a thickness greater than 20 mm) packaging electrodes, thereby effectively improving the packaging reliability of the semiconductor packaging device.

[0069] See also Figure 1 The embodiment of the present disclosure provides a semiconductor package device, comprising: a chip 1, a cathode electrode 2 and an anode electrode 3. The cathode electrode 2 is arranged on a first side of the chip 1; the anode electrode 3 is arranged on a second side of the chip 1, and the second side is opposite to the first side.

[0070] For example, the cathode electrode 2 and the anode electrode 3 are both tube shell electrodes, which are packaging electrodes of a semiconductor packaging device.

[0071] For example, the semiconductor packaging structure further includes a tube shell 4 sleeved around the chip 1 and the cathode electrode 2 and the anode electrode 3. The cathode electrode 2 can be used as a tube shell base, and the anode electrode 3 can be used as a tube shell cover. The cathode electrode 2 and the anode electrode 3 can be welded and interconnected with the tube shell 4 through corresponding flanges, thereby achieving tube shell sealing of the chip 1.

[0072] For example, the tube shell 4 includes but is not limited to an insulating ceramic ring, which can be used for high-voltage insulation, for example, to ensure that the creepage distance and electrical clearance meet the high-voltage requirements of 8.5 kV and above.

[0073] Please combine Figure 1 and Figure 2 It is understood that some embodiments of the present disclosure further provide a packaging electrode 10 that can be used as the cathode electrode 2 and / or the anode electrode 3 in the above-mentioned semiconductor packaging device, but is not limited thereto.

[0074] For example, see Figure 2 The package electrode 10 includes: a diamond composite metal base layer 101, a first alloy layer 102 and a second alloy layer 103 located on the upper and lower surfaces of the diamond composite metal base layer 101, and a conductive flange 104 located on the side wall of the diamond composite metal base layer 101; wherein the diamond composite metal base layer 101, the first alloy layer 102, the second alloy layer 103 and the conductive flange 104 are an integrated structure; the surfaces of the first alloy layer 102 and the second alloy layer 103 facing away from the diamond composite metal base layer 101 are machined surfaces for directly contacting the chip 1. The flange welding surface of the conductive flange 104 does not contain diamond components.

[0075] Illustratively, the flange welding surface of the conductive flange 104 is parallel to the machined surface of the first alloy layer 102 and / or the second alloy layer 103 .

[0076] Illustratively, the machined surface is a finely ground surface.

[0077] For example, the surface flatness of the machined surface is less than or equal to 10 μm, and the surface roughness Ra is less than or equal to 0.5 μm.

[0078] The package electrode 10 provided in the above embodiment of the present disclosure is not only conducive to simplifying the package structure of the semiconductor package device to avoid failure of the chip 1 due to large thermal stress, but also can take into account the performance requirements of the package electrode 10 in terms of high thermal conductivity and high electrical conductivity through the diamond composite metal base layer 101 and the first alloy layer 102 and the second alloy layer 103 in the package electrode 10, so as to ensure that the package electrode 10 has good heat resistance, corrosion resistance, chemical stability and thermal and electrical conductivity, and effectively weld the flange through the flange welding surface of the conductive flange 104 without diamond components, thereby improving the welding strength and welding reliability of the flange, thereby effectively improving the molding quality and performance of the package electrode 10, and then effectively improving the packaging reliability of the semiconductor package device. In addition, in the embodiment of the present disclosure, the package electrode 10 is also easy to have high compatibility, so as to be well compatible with various valve string press-fit structures.

[0079] In some examples, the surface flatness of the machined surfaces of the first alloy layer 102 and the second alloy layer 103 ranges from 3 μm to 8 μm, and the surface roughness is 0.1 μm.

[0080] In some examples, the thickness of the first alloy layer 102 and / or the second alloy layer 103 ranges from 0.1 mm to 0.2 mm, for example, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm or 0.2 mm.

[0081] In some examples, the first alloy layer 102 and / or the second alloy layer 103 includes at least one of a molybdenum-copper alloy layer or a tungsten-copper alloy layer. Among them, the thermal expansion coefficient of molybdenum-copper / tungsten-copper is close to that of copper diamond, which is conducive to reducing thermal stress. Secondly, molybdenum-copper / tungsten-copper is easier to process and grind than diamond, so it is easy to process and obtain a machined surface for direct contact with the chip, so as to keep the surface roughness and surface flatness of the package electrode to meet the design standards, and ensure that the uniformity of the pressure distribution of the package electrode can also meet the design requirements. In addition, it is also easy to process the required positioning holes on the outer shape of the package electrode.

[0082] In some embodiments of the present disclosure, the diamond composite metal base layer 101 includes: one or more layers of an aluminum diamond composite layer, a copper diamond composite layer, a molybdenum-copper alloy diamond composite layer, a tungsten-copper alloy diamond composite layer or a copper-graphene diamond composite layer.

[0083] In some examples, the diamond composite metal-based layer 101 is a copper diamond composite layer.

[0084] For example, the copper-diamond composite layer comprises: a plurality of surface-modified diamond particles and a copper matrix that is infiltrated to fill the gaps between the diamond particles.

[0085] In some examples, the diameter of the diamond particles ranges from, but is not limited to, 50 μm to 200 μm.

[0086] Optionally, the particle size of the diamond particles may be 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm or 200 μm, etc.

[0087] In some examples, the surface modification of the diamond particles can be achieved by, for example, coating a modified coating on the surface of the diamond particles using a chemical plating method, a magnetron sputtering method, or a sol-gel method.

[0088] Optionally, the material of the modified coating coated on the surface of the diamond particles includes at least one of titanium (Ti), chromium (Cr), molybdenum (Mo), tungsten (W), zirconium (Zr) or boron (B).

[0089] Optionally, the coating thickness of the modified coating layer ranges from, but is not limited to, 100 nm to 2000 nm.

[0090] Further optionally, the plating thickness of the modified plating layer can be 100 nm, 200 nm, 500 nm, 800 nm, 1000 nm, 1200 nm, 1500 nm, 1800 nm or 2000 nm, etc.

[0091] In the disclosed embodiment, the diamond particles have extremely high thermal conductivity and low thermal expansion coefficient, therefore, after the surface of the diamond particles is modified and then infiltrated with metal material, the surface bonding state between the metal material and the diamond particles can be improved, so as to facilitate the combination of the two to obtain a diamond composite metal base layer 101 with good heat dissipation performance. In this way, the performance of the packaged electrode can be effectively improved through the characteristics of high thermal conductivity and high electrical conductivity of the diamond composite metal base layer 101.

[0092] In some embodiments, by adjusting the filling ratio of diamond in the diamond composite metal base layer 101 (i.e., the volume ratio of metal to diamond), the combination and balance of thermal conductivity, thermal expansion and electrical conductivity of the packaged electrode can be achieved. The following is an example in which the diamond composite metal base layer 101 is a copper diamond composite layer.

[0093] For example, when the filling ratio of diamond particles in the copper-diamond composite layer is 30%, the electrical conductivity of the copper-diamond composite layer is 25% IACS, the thermal conductivity is 553 W / (m·K), and the average linear expansion coefficient thereof at 25°C to 125°C is 5.77 ppm / °C.

[0094] For example, when the filling ratio of diamond particles in the copper-diamond composite layer is 35%, the electrical conductivity of the copper-diamond composite layer is 22% IACS, the thermal conductivity is 584 W / (m·K), and the average linear expansion coefficient thereof at 25°C to 125°C is 5.62 ppm / °C.

[0095] For example, when the filling ratio of diamond particles in the copper diamond composite layer is 40%, the electrical conductivity of the copper diamond composite layer is 20% IACS, the thermal conductivity is 628 W / (m·K), and its average linear expansion coefficient at 25°C to 125°C is 5.55 ppm / °C.

[0096] In some embodiments of the present disclosure, please continue to refer to Figure 2 The conductive flange 104 includes a metal flange having the same metal component as that in the diamond composite metal base layer 101 .

[0097] Optionally, the metal flange and the diamond composite metal base layer 101 are integrally formed by infiltration or casting.

[0098] Illustratively, the conductive flange 104 is a pure copper flange or a copper alloy flange.

[0099] For example, the diamond composite metal base layer 101 is a copper diamond composite layer. The pure copper flange or the copper alloy flange can be prepared and formed in the same infiltration process or the same casting process as the diamond composite metal base layer 101.

[0100] In other embodiments of the present disclosure, please combine Fig.12 It is understood that the conductive flange 104 includes: a body 61 made of the same material as the diamond composite metal base layer 101 and formed integrally, and a metal coating 62 located on at least one side of the body 61. The surface of the metal coating 62 facing away from the body 61 is a flange welding surface.

[0101] For example, the thickness of the metal plating layer 62 ranges from 2 μm to 8 μm; for example, it may be 2 μm, 3 μm, 5 μm, 6 μm, or 8 μm.

[0102] By way of example, the metal plating layer 62 includes, but is not limited to, a metal nickel layer.

[0103] For example, the metal coating layer 62 may also cover the sidewalls of the diamond composite metal-based layer 101 .

[0104] In some embodiments of the present disclosure, please refer to Figure 3 , Figure 4 and Figure 5 The package electrode 10 further includes: a flange 105 welded to the flange welding surface of the conductive flange 104 .

[0105] Here, the flange 105 can be selected and set to match the packaging requirements of the semiconductor packaging device, and the embodiments of the present disclosure are not limited to this.

[0106] For example, the flange 105 can be a conductive flange or an insulating flange.

[0107] Illustratively, the material of the flange welding surface of the conductive flange 104 is the same as the material of the flange 105 .

[0108] It should be added that in the related art, the flange 105 in the packaged electrode is usually welded by a cold pressure welding process, so as to use a material with better ductility, so that it can produce plastic deformation under pressure and realize interconnection at the metal atomic level. However, when the packaged electrode adopts a diamond composite metal base layer 101, a large number of diamond particles will be exposed and dispersed on the surface of the diamond composite metal base layer 101, resulting in the solder being unable to spread evenly on the interface to be welded during the accumulation and melting process. The material difference between the flange 105 and the diamond composite metal base layer 101 can easily cause the two to be unable to be tightly combined, resulting in welding failure. Therefore, the embodiment of the present disclosure integrally sets a conductive flange 104 on the side wall of the diamond composite metal base layer 101 (the relevant implementation of the integral structure can refer to the relevant content of the manufacturing method in the following text), and a high-reliability connection can be achieved through the flange welding surface of the conductive flange 104 and the flange 105.

[0109] Some embodiments of the present disclosure also provide a method for manufacturing a packaged electrode, which is used to manufacture the packaged electrodes in some of the above embodiments. The manufacturing method also has the technical advantages of the above packaged electrodes, which will not be described in detail here.

[0110] By way of example, a method for manufacturing a packaged electrode includes: preparing a diamond composite metal base layer, and forming a first alloy layer and a second alloy layer on the upper and lower surfaces of the diamond composite metal base layer, respectively, and forming a conductive flange on the side wall of the diamond composite metal base layer; wherein the diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integral structure; the surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for directly contacting the chip; and the flange welding surface of the conductive flange has no diamond component.

[0111] During specific implementation, the method for manufacturing the packaged electrode may adopt any of the following implementations.

[0112] Implementation method 1:

[0113] See also Figure 6 The manufacturing method of the packaged electrode may include the following steps S100 to S500.

[0114] Step S100, providing diamond particles and performing surface modification on the diamond particles.

[0115] For example, the diameter of the diamond particles may range from, but is not limited to, 50 μm to 200 μm.

[0116] Optionally, the particle size of the diamond particles may be 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm or 200 μm, etc.

[0117] For example, the surface modification of diamond particles can be achieved by coating a modified coating on the surface of the diamond particles using a chemical plating method, a magnetron sputtering method, or a sol-gel method.

[0118] For example, the material of the modified coating includes at least one of titanium (Ti), chromium (Cr), molybdenum (Mo), tungsten (W), zirconium (Zr) or boron (B).

[0119] Optionally, the coating thickness of the modified coating layer ranges from, but is not limited to, 100 nm to 2000 nm.

[0120] Further optionally, the plating thickness of the modified plating layer can be 100 nm, 200 nm, 500 nm, 800 nm, 1000 nm, 1200 nm, 1500 nm, 1800 nm or 2000 nm, etc.

[0121] Step S200, providing a first mold, and vibrating and compacting the surface-modified diamond particles based on the first mold to form a diamond preform.

[0122] For example, when vibrating and compacting the surface-modified diamond particles, the surface-modified diamond particles can be first loaded into a first mold (i.e., a molding mold), and then the first mold is placed in an ultrasonic vibration device of a target frequency and vibrated for a preset time, and a graphite indenter is used to apply a certain pressure for compaction, so that, for example, Figure 7 The diamond preform 51 is shown in FIG.

[0123] Optionally, the ultrasonic vibration device includes an ultrasonic vibration plate.

[0124] Optionally, the target frequency includes but is not limited to 30 kHz, for example, 35 kHz or 40 kHz which is greater than 30 kHz.

[0125] Optionally, the preset vibration time includes but is not limited to 20 minutes, for example, it can be 25 minutes or 30 minutes, which is greater than 20 minutes.

[0126] Step S300, providing a second mold, wherein the second mold has an electrode region and a flange region arranged in a step manner with the electrode region.

[0127] For example, the flange area is located in the middle area around the electrode area, or close to the top of the electrode area, or close to the bottom of the electrode area, as long as a step is formed between the flange area and the electrode area.

[0128] Step S400, stacking the first alloy material, diamond preform, metal material and second alloy material in the electrode area of ​​the second mold, placing a conductive flange in the flange area of ​​the second mold, and pressure sintering the obtained structure to form an initial structure of the packaged electrode.

[0129] For example, see Figure 7 The conductive flange 104 may be, for example, an oxygen-free copper ring.

[0130] For example, the first alloy material and the second alloy material may be provided as molybdenum-copper alloy sheets or tungsten-copper alloy sheets. Also, optionally, the thickness of the first alloy material and / or the second alloy material may range from 0.1 mm to 0.3 mm.

[0131] Optionally, the first alloy material and the second alloy material have different thicknesses; for example, the thickness of the first alloy material is less than the thickness of the second alloy material.

[0132] For example, the metal material includes, but is not limited to, pure copper or a copper alloy block with a copper volume fraction of 60% to 70%.

[0133] Furthermore, when the obtained structure is pressure sintered, the second mold after being filled with the first alloy material, the diamond preform, the metal material, the second alloy material, and the conductive flange can be placed in a gas-assisted infiltration furnace, and heated and pressurized so that the metal material infiltrates into the gaps between the diamond particles of the diamond preform after melting to form a diamond composite metal base layer, and the conductive flange and the side wall of the diamond composite metal base layer are infiltrated to obtain, for example Figure 7 The package electrode initial structure 10A is shown in FIG.

[0134] For example, after the second mold filled with the first alloy material, the diamond preform, the metal material and the second alloy material, and the conductive flange is placed in a gas-assisted infiltration furnace, the furnace can be evacuated to provide a vacuum environment, and then an inert gas at a target pressure is introduced into the gas-assisted infiltration furnace. At the same time, the gas-assisted infiltration furnace is heated at a preset heating rate until the furnace body temperature is higher than the melting point of the metal material, and then the temperature and pressure are maintained for a preset time, so that the metal material infiltrates into the gaps between the diamond particles of the diamond preform after melting to form a diamond composite metal base layer, and the conductive flange and the side walls of the diamond composite metal base layer are infiltrated and formed.

[0135] Optionally, the vacuum degree of the vacuum environment in the furnace includes but is not limited to a range of 0.05Pa~0.1Pa.

[0136] Optionally, the value range of the target pressure of the inert gas includes but is not limited to 5 MPa~10 MPa.

[0137] Optionally, the heating rate of the gas-assisted infiltration furnace may range from, but is not limited to, 5°C / min to 10°C / min.

[0138] Optionally, after the furnace body temperature of the gas-assisted infiltration furnace is higher than the melting point of the metal material, the preset time length for heat preservation and pressure preservation includes, but is not limited to, 30 minutes to 1 hour.

[0139] Optionally, the gas-assisted infiltration furnace is cooled, and the second mold is demolded after cooling to obtain the initial structure of the packaged electrode. For example, after the diamond composite metal base layer is formed, the heating of the gas-assisted infiltration furnace is stopped, and the external cooling circulating water system can be started to cool the furnace body, and the second mold is demolded after cooling.

[0140] In the disclosed embodiment, the diamond composite metal base layer can take into account the performance advantages of high thermal conductivity and low thermal expansion coefficient of diamond particles, as well as the performance advantages of high electrical conductivity of metal materials, so that it is easy to greatly reduce the body thermal resistance of the device and eliminate part of the contact thermal resistance without affecting the electrical conductivity of the semiconductor package device, thereby greatly improving the flow capacity of the semiconductor package device. In addition, the conductive flange can be composed only of metal materials without diamond components, which can effectively avoid the problem of poor welding between the diamond composite metal base layer and the dissimilar metals (such as flanges) of single-phase metal materials, and can improve the connection strength between the flange and the tube shell and the sealing reliability of the tube shell.

[0141] Step S500 , performing machining process on the upper and lower surfaces of the initial structure of the package electrode to obtain the package electrode.

[0142] For example, a machining process is performed on the upper and lower surfaces of the initial structure of the packaged electrode, such as precision machining, to finely grind the upper and lower surfaces of the initial structure of the packaged electrode to remove excess first alloy material and second alloy material, thereby correspondingly forming a first alloy layer and a second alloy layer.

[0143] For example, the surface flatness of the machined surfaces of the first alloy layer and the second alloy layer is less than or equal to 10 μm, and the surface roughness Ra is less than or equal to 0.5 μm.

[0144] In some examples, the surface flatness of the machined surfaces of the first alloy layer and the second alloy layer ranges from 3 μm to 8 μm, and the surface roughness is 0.1 μm.

[0145] In some examples, the thickness of the first alloy layer and / or the second alloy layer ranges from 0.1 mm to 0.2 mm, for example, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm or 0.2 mm.

[0146] The process steps in the following embodiment 2 or embodiment 3 that are the same or similar to embodiment 1 can be performed with reference to the specific implementation of the corresponding steps in embodiment 1. In the following examples of the present disclosure, only the process steps in embodiment 2 or embodiment 3 that are significantly different from embodiment 1 are described in detail.

[0147] Implementation method 2:

[0148] See also Figure 8 The method for manufacturing the packaged electrode may include the following steps S100' to S500'.

[0149] Step S100 ′: providing diamond particles and performing surface modification on the diamond particles.

[0150] Step S200', providing a third mold, pre-setting a metal strip on the inner wall of the third mold, and treating the surface-modified diamond particles (e.g. Fig. 9 The diamond particles 511 shown in FIG. 5 are vibrated and compacted to form a diamond preform having a metal band (e.g. Fig. 9 The diamond preform 51 shown in FIG.

[0151] For example, see Fig. 9 , the thickness of the metal strip 512 is less than 0.3 mm.

[0152] For example, the material of the metal strip 512 includes, but is not limited to, pure copper or a copper alloy block with a copper volume fraction of 60% to 70%.

[0153] Step S300 ′, providing a fourth mold, wherein the fourth mold has an electrode region and a cavity region located around the electrode region.

[0154] Step S400', stacking the first alloy material, diamond preform, metal material and second alloy material in the electrode area of ​​the fourth mold, and pressure sintering the obtained structure to form an initial structure of the packaged electrode; wherein the part of the metal material that flows into the cavity area after melting forms a conductive flange together with the metal belt.

[0155] Here, the metal material flows into the gaps between the diamond particles of the diamond preform after melting, and can form a diamond composite metal base layer in the same step as the conductive flange, while ensuring that the material of the conductive flange has the same metal component as that of the diamond composite metal base layer 101 .

[0156] Furthermore, the metal belt pre-placed when forming the metal preform can not only prevent the diamond particles of the diamond preform from entering the cavity area (i.e., the flange area) of the fourth mold during the aforementioned pressure sintering process, but also simultaneously realize the integral connection and molding of the diamond composite metal base layer 101 and the metal molten material in the cavity area.

[0157] Step S500 ′, performing machining process on the upper and lower surfaces of the initial structure of the package electrode to obtain the package electrode.

[0158] Implementation method three:

[0159] See also Fig.10 The manufacturing method of the packaged electrode may include the following steps S100'' to S600''.

[0160] Step S100'', providing diamond particles, and performing surface modification on the diamond particles.

[0161] Step S200 ″: providing a fifth mold, wherein the fifth mold has an electrode region and a flange region arranged in a stepped manner with the electrode region.

[0162] Step S300'', vibrating and compacting the surface-modified diamond particles based on the fifth mold to form a diamond preform, for example Fig.11 as shown in .

[0163] Here, see Fig.11 The diamond preform 51 has both an electrode region and a flange region located around the electrode region.

[0164] Step S400'', providing a sixth mold, and stacking the first alloy material, diamond preform, metal material and second alloy material in the sixth mold, and pressure sintering the obtained structure to form an initial structure of the packaged electrode; wherein the portion of the initial structure of the packaged electrode located in the flange area constitutes the body of the conductive flange.

[0165] Here, please combine Fig.11 and Fig.12 It is understood that the portion of the initial structure of the packaged electrode located in the flange area constitutes the body of the conductive flange, that is, the body 61 of the conductive flange is made of the same material as the diamond composite metal base layer 101 and is integrally formed.

[0166] Step S500'': forming a metal plating layer on at least one surface of the body to obtain a conductive flange.

[0167] For example, see Fig.12A metal coating 62 is formed on one side of the body 61 to obtain a conductive flange 104; wherein the surface of the metal coating 62 away from the body 61 is a flange welding surface. The metal coating 62 can cover the exposed diamond particles on the surface of the body 61, so as to effectively solve the problem that the diamond composite metal base layer and the single metal material cannot be welded.

[0168] For example, the metal coating 62 can be formed by plating using at least one process such as roughening, sensitization or activation, so as to achieve complete coverage of the metal coating 62 on the diamond particles by increasing the surface roughness of the diamond, while ensuring that the surface of the metal coating 62 is uniform, dense and free of holes, thereby effectively improving the bonding strength between the metal coating 62 and the body 61.

[0169] For example, the thickness of the metal plating layer 62 ranges from 2 μm to 8 μm; for example, it may be 2 μm, 3 μm, 5 μm, 6 μm, or 8 μm.

[0170] By way of example, the metal plating layer 62 includes, but is not limited to, a metal nickel layer.

[0171] By way of example, the metal coating layer 62 may also be formed on the sidewalls of the diamond composite metal-based layer 101 .

[0172] Step S600 ″, performing machining process on the upper and lower surfaces of the initial structure of the package electrode after the conductive flange is formed, to obtain the package electrode.

[0173] It is worth mentioning that, based on the above-mentioned embodiments, the manufacturing method of the packaged electrode further includes: welding a flange on the flange welding surface of the conductive flange.

[0174] For example, the flange is an oxygen-free copper flange, which can be directly welded at high temperature to the conductive flange prepared in the first or second embodiment; or welded at high temperature to the metal coating of the conductive flange prepared in the third embodiment.

[0175] For example, a vacuum brazing furnace can be used to heat silver-copper (AgCu) solder in a hydrogen protective gas atmosphere. The heating time can be 1 hour, and the heating target can be a maximum temperature of 800°C to 900°C, for example, heating to 840°C, then keeping the temperature for 10 minutes, and then slowly cooling to room temperature, so as to complete the welding of the flange. The room temperature is, for example, 20°C to 25°C.

[0176] For example, after the flange welding is completed, the package electrode is tested for air tightness, and its air tightness is less than 1×10 - 9 Pa•m 3 / s can meet the usage requirements.

[0177] In the disclosed embodiment, the flange is welded to the conductive flange on the side wall of the diamond composite metal base layer, which has high feasibility and easy operability, and can effectively improve the connection strength and reliability between the flange and the diamond composite metal base layer, thereby facilitating improving the reliability of the packaged electrode.

[0178] In summary, in the embodiments of the present disclosure, by infiltrating metal materials on the surface of the diamond preform and pressure sintering alloy materials, the surface of the first alloy material and the second alloy material can be machined after the diamond composite metal base layer is integrated with the first alloy material and the second alloy material, thereby effectively controlling the surface quality of both sides of the package electrode to ensure that the machined surface of the package electrode can directly contact the chip and has a better surface quality, for example, it can avoid the warping problem of large-sized and high-thickness package electrodes due to stress concentration. In addition, the package electrode manufactured by the embodiments of the present disclosure can also significantly reduce its own body thermal resistance without increasing the contact thermal resistance, so as to easily improve the flow capacity of the semiconductor package device.

[0179] The manufacturing method of the packaged electrode provided in the embodiment of the present disclosure has a mature scheme and a simple process, and is easy to realize large-scale production control of packaged electrodes with large size, high thickness and high surface quality. It also comprehensively considers the joint optimization of the electrical and thermal properties of the packaged electrodes, as well as the connection problem between the diamond composite metal base layer and the single-phase metal in the packaged electrode, and can effectively improve the molding quality and performance of the packaged electrode, while eliminating or reducing the risk of welding failure of dissimilar materials, thereby improving the packaging reliability of semiconductor packaging devices.

[0180] In addition, the packaged electrode manufactured by the embodiment of the present disclosure has high compatibility and is easily compatible with various valve string press-fit structures.

[0181] It should be understood that although Figure 6 , Figure 8 and Fig.10 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 6 , Figure 8 and Fig.10 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0182] Some embodiments of the present disclosure also provide a semiconductor packaging device, including: a packaging electrode as described in any of the above embodiments; or a packaging electrode prepared by a manufacturing method as described in any of the above embodiments. The semiconductor packaging device also has the technical advantages of the above packaging electrode, which will not be elaborated here.

[0183] For example, the semiconductor package device is a power device, including a thyristor; the thyristor includes at least an integrated gate-commutated thyristor (IGCT), an insulated gate bipolar transistor (IGBT) or a gate turn-off thyristor (GTO); wherein the thyristor includes a semiconductor package structure as described in any of the above embodiments. It is understood that the thyristor may also be an ordinary transistor (Thyristor).

[0184] Some embodiments of the present disclosure also provide an electronic device, comprising the power device as described in any of the above embodiments.

[0185] For example, in an electronic device, a power device may be used as a control element and / or a switching element. The electronic device may be, for example, a converter valve.

[0186] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0187] The above-described embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the attached claims.

Claims

1. A method for manufacturing a packaged electrode, characterized in that: Prepare a diamond composite metal base layer, and form a first alloy layer and a second alloy layer on upper and lower surfaces of the diamond composite metal base layer respectively, and form a conductive flange on the side wall of the diamond composite metal base layer; The diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; the surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for directly contacting the chip; and the flange welding surface of the conductive flange has no diamond component.

2. The method for manufacturing a packaged electrode according to claim 1, wherein: The method of preparing a diamond composite metal base layer, forming a first alloy layer and a second alloy layer on the upper and lower surfaces of the diamond composite metal base layer, and forming a conductive flange on the side wall of the diamond composite metal base layer includes any one of the following embodiments: Implementation method 1: Providing diamond particles, and performing surface modification on the diamond particles; Providing a first mold, and vibrating and compacting the surface-modified diamond particles based on the first mold to form a diamond preform; Providing a second mold, wherein the second mold has an electrode area and a flange area arranged in a step with the electrode area; Laying the first alloy material, the diamond preform, the metal material and the second alloy material in layers in the electrode region of the second mold, placing a conductive flange in the flange region of the second mold, and pressure sintering the obtained structure to form an initial structure of the packaged electrode; Performing machining process on upper and lower surfaces of the initial structure of the package electrode to obtain the package electrode; Implementation method 2: Providing diamond particles, and performing surface modification on the diamond particles; Providing a third mold, pre-setting a metal belt on the inner wall of the third mold, and vibrating and compacting the surface-modified diamond particles based on the third mold to form a diamond preform having the metal belt; Providing a fourth mold, wherein the fourth mold has an electrode region and a cavity region located around the electrode region; The first alloy material, the diamond preform, the metal material and the second alloy material are stacked in the electrode region of the fourth mold, and the obtained structure is pressure-sintered to form an initial structure of the packaged electrode; wherein the portion of the metal material that flows into the cavity region after melting forms the conductive flange together with the metal band; Performing machining process on upper and lower surfaces of the initial structure of the package electrode to obtain the package electrode; Implementation method three: Providing diamond particles, and performing surface modification on the diamond particles; Providing a fifth mold, the fifth mold having an electrode area and a flange area arranged in a step with the electrode area; Vibrating and compacting the surface-modified diamond particles based on the fifth mold to form a diamond preform; Providing a sixth mold, and stacking the first alloy material, the diamond preform, the metal material, and the second alloy material in the sixth mold, and performing pressure sintering on the obtained structure to form an initial structure of the packaged electrode; wherein the portion of the initial structure of the packaged electrode located in the flange area constitutes the body of the conductive flange; Forming a metal plating layer on at least one side surface of the body to obtain the conductive flange; The upper and lower surfaces of the initial structure of the packaging electrode after the conductive flange is formed are subjected to a machining process to obtain the packaging electrode.

3. A packaged electrode, characterized in that: include: A diamond composite metal base layer, a first alloy layer and a second alloy layer located on the upper and lower surfaces of the diamond composite metal base layer, and a conductive flange located on the side wall of the diamond composite metal base layer; wherein, The diamond composite metal base layer, the first alloy layer, the second alloy layer and the conductive flange are an integrated structure; The surfaces of the first alloy layer and the second alloy layer facing away from the diamond composite metal base layer are machined surfaces for directly contacting the chip; the flange welding surface of the conductive flange has no diamond component.

4. The packaged electrode according to claim 3, characterized in that: Also includes: A flange welded to the flange welding surface; Wherein, the material of the flange welding surface is the same as the material of the flange.

5. The packaged electrode according to claim 3 or 4, characterized in that: The conductive flange comprises a metal flange; the metal flange has the same metal component as that in the diamond composite metal base layer.

6. The packaged electrode according to claim 5, characterized in that: The metal flange and the diamond composite metal base layer are integrally formed by melt infiltration or integrally cast.

7. The packaged electrode according to claim 3 or 4, characterized in that: The conductive flange comprises: a body which is made of the same material as the diamond composite metal base material and is integrally formed, and a metal coating located on at least one side of the body; the surface of the metal coating away from the body is the flange welding surface.

8. The packaged electrode according to claim 7, characterized in that: The thickness of the metal coating ranges from 2 μm to 8 μm.

9. The packaged electrode according to claim 3, characterized in that: Include at least one of the following characteristics: The surface flatness of the machined surface is less than or equal to 10 μm, and the surface roughness Ra is less than or equal to 0.5 μm; The thickness of the first alloy layer and / or the second alloy layer ranges from 0.1 mm to 0.2 mm; The diamond composite metal base layer includes: one or more layers of an aluminum diamond composite layer, a copper diamond composite layer, a molybdenum-copper alloy diamond composite layer, a tungsten-copper alloy diamond composite layer or a copper-graphene diamond composite layer.

10. A semiconductor packaging device, characterized in that: include: The encapsulated electrode prepared by the manufacturing method according to claim 1 or 2; Or, a packaged electrode as described in any one of claims 3 to 9.

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