Heat dissipation substrate, heat dissipation structure, preparation method of heat dissipation structure and electronic device packaging structure

Abstract

The invention relates to the field of semiconductors, in particular to a heat dissipation substrate, a heat dissipation structure, a preparation method of the heat dissipation structure and an electronic device packaging structure. The preparation method of the heat dissipation substrate provided by the invention comprises the following steps: a metal substrate treatment process: providing a metal substrate, and forming a plurality of mounting holes based on the surface of the metal substrate in the thickness direction; column implanting: providing a plurality of ceramic columns, implanting each ceramic column into the corresponding mounting hole and forming close fit with the hole wall to obtain an assembly; and a molding step of performing a first sintering process on the assembly to obtain the heat dissipation substrate. According to the preparation method, the thermal expansion coefficient of the heat dissipation substrate can be adjusted, so that the heat dissipation substrate can be directly bonded on the metalized ceramic substrate without deformation, the reduction of a thermal resistance layer and the influence on the heat dissipation effect are realized at the same time, and the production cost is remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging, and more particularly to a heat dissipation substrate, a heat dissipation structure, a method for preparing the same, and an electronic device packaging structure. Background Technology

[0002] In power electronic device packaging technology, the heat sink substrate, as a heat sink, can work with the metallized ceramic substrate to conduct away the heat of the chip, providing mechanical support, electrical interconnection and insulation and heat dissipation functions for the chip.

[0003] Taking the traditional IGBT packaging structure as an example (e.g.) Figure 1 As shown, the metallized ceramic substrate consists of a ceramic substrate and copper layers bonded to both sides of the ceramic substrate. The copper layers on both sides of the ceramic substrate are connected to the chip and the heat dissipation substrate respectively through solder layers. The metallized ceramic substrate and the heat dissipation substrate together form the heat dissipation structure of the chip. During operation, the heat generated by the chip is mainly dissipated vertically. The heat generated by the chip first passes through a solder layer, then through the metallized ceramic substrate, then through a solder layer, and finally to the heat dissipation substrate. Through active or passive heat dissipation, the heat is dissipated to the surrounding environment. The entire heat transfer path requires passing through at least 6 thermal resistance interface layers (i.e., heterogeneous material interfaces) to successfully reach the heat dissipation substrate. However, due to the large differences in the crystal structure of different materials, the thermal resistance interface layer also has a large number of defects. In addition, after the solidification of the liquid metal phase in the thermal resistance interface layer, there are a large number of voids, which also leads to compositional segregation. As a result, heat scattering occurs at the thermal resistance interface layer during the heat transfer process, hindering heat transfer. In particular, the solder layer is prone to forming brittle intermetallic compounds, which further hinders thermal conductivity, resulting in poor heat dissipation performance.

[0004] To improve heat dissipation performance, existing technologies attempt to directly sinter metallized ceramic substrates onto the surface of a heat dissipation substrate, thereby eliminating the solder layer between the metallized ceramic substrate and the heat dissipation substrate and reducing the thermal resistance interface layer. However, traditional heat dissipation substrates are mainly metal substrates such as copper and aluminum or aluminum / silicon carbide substrates. Metal substrates have a large and non-adjustable coefficient of thermal expansion, making it difficult to match the coefficient of thermal expansion of metallized ceramic substrates. During the heat dissipation structure fabrication process, the high sintering temperatures can easily cause deformation and cracking, making them unsuitable for practical applications. On the other hand, aluminum / silicon carbide substrates rely on composition to control the coefficient of thermal expansion; however, as the composition is adjusted, their thermal conductivity is severely affected, making it difficult to simultaneously reduce the thermal resistance layer without compromising heat dissipation performance.

[0005] In view of the above, this invention is proposed. Summary of the Invention

[0006] This application provides a heat dissipation substrate, a heat dissipation structure, a method for preparing the same, and an electronic device packaging structure, aiming to solve the above-mentioned problems or at least alleviate the defects existing in the prior art.

[0007] The first aspect of this application provides a method for preparing a heat dissipation substrate, comprising the following steps: A metal substrate processing step involves providing a metal substrate and forming multiple mounting holes on the surface of the metal substrate along its thickness direction. The column planting process involves providing multiple ceramic columns, inserting each ceramic column into a corresponding mounting hole, and forming a tight fit with the hole wall to obtain an assembly. In the molding process, the assembly undergoes a first sintering treatment to obtain a heat dissipation substrate.

[0008] In some embodiments, the method further includes a surface treatment step of metallizing the surface of the heat dissipation substrate with exposed ceramic pillars to form a metal overlay covering the metal substrate and the ceramic pillars.

[0009] In some embodiments, the preparation method satisfies at least one of the following conditions: A. In the metal substrate processing process, the hole walls of the mounting holes are oxidized, or active metal solder is applied to the hole walls of the mounting holes. B. In the metal substrate processing step, the surface of the metal substrate is cleaned before and / or after the formation of multiple mounting holes; C. In the metal substrate processing step, multiple mounting holes are made based on at least one of the following processes: machining, laser processing, or chemical etching. D. The first sintering process adopts any one of the following: direct copper plating process, active metal brazing process, or direct aluminum plating process. E. In the molding process, the surface of the heat dissipation substrate with exposed ceramic pillars obtained from the first sintering process is flattened.

[0010] In some implementations, at least one of the following conditions is met: F. The material of the metal substrate includes a single metal or an alloy made of multiple metals. G. The material of the metal substrate is selected from copper, aluminum, copper alloy or aluminum alloy. H. Ceramic columns include any one of alumina ceramic columns, aluminum nitride ceramic columns, silicon nitride ceramic columns, zirconia-toughened alumina ceramic columns, or silicon carbide ceramic columns. I. The mounting holes are blind holes or through holes; J. Multiple mounting holes are arranged in an array on the metal substrate; K. Oxidation treatment includes either chemical oxidation treatment or thermal oxidation treatment; L. Active metal solders include any one of Ag-Cu-Ti solder, Ni-Ti-Cu solder, or Sn-Ti-Cu solder.

[0011] In some embodiments, when the first sintering process is a direct copper plating process, the first sintering process is performed in an inert atmosphere; or, when the first sintering process is an active metal brazing process or a direct aluminum plating process, the first sintering process is performed in a vacuum environment.

[0012] In some embodiments, during the column implantation process, before each ceramic column is implanted into the corresponding mounting hole, the ceramic column undergoes a first surface modification treatment to form an affinity layer containing a transition metal or non-metal, and the first surface modification treatment is performed when any of the following conditions are met: (1) When the metal substrate is made of copper or copper alloy, the ceramic pillar is an aluminum nitride ceramic pillar, and the first sintering process adopts a direct copper plating process; (2) When the metal substrate is made of copper, aluminum, copper alloy or aluminum alloy, the ceramic pillar is aluminum nitride ceramic pillar or silicon nitride ceramic pillar, and the first sintering process adopts active metal brazing process; (3) When the metal heat sink substrate is made of aluminum or aluminum alloy, the ceramic pillar is an aluminum nitride ceramic pillar, and the first sintering process adopts the direct aluminum coating process.

[0013] The second aspect of this application provides a heat dissipation substrate, which is manufactured by the preparation method described above, including a metal substrate and a plurality of ceramic pillars. The metal substrate has a plurality of mounting holes along its thickness direction. Each ceramic pillar is embedded in a corresponding mounting hole and fixedly connected to the metal substrate. The end face of the ceramic pillar is flush with the surface of the metal substrate or located inside the metal substrate.

[0014] A third aspect of this application provides a heat dissipation structure, which is made by attaching at least one metallized ceramic substrate along the thickness direction to a heat dissipation substrate as described above, and then performing a second sintering process; wherein the metallized ceramic substrate includes two metal layers spaced apart along the thickness direction and a ceramic layer bonded between the two metal layers, and at least one metal layer is bonded to the heat dissipation substrate along the thickness direction.

[0015] In some implementations, at least one of the following conditions is met: a. Metallized ceramic substrates include any one of the following: direct copper-clad substrates, active metal brazing substrates, direct aluminum-clad substrates, direct electroplated copper substrates, thin-film metallized substrates, or thick-film printed substrates. b. The second sintering process adopts any one of the following processes: direct copper plating process, active metal brazing process, direct aluminum plating process, direct copper electroplating process, thin film metallization process, or thick film printing process. c. The metal layer is made of a single metal or an alloy of multiple metals; the metal layer material includes any one of copper, aluminum, copper alloy, or aluminum alloy; the metal layer is made of the same material as the metal substrate. d. The ceramic layer material is any one of alumina, aluminum nitride, zirconium oxide-toughened alumina, silicon nitride, or silicon carbide; e. Before the metallized ceramic substrate is bonded to the heat dissipation substrate along the thickness direction, a second surface modification treatment is performed on the mating surfaces of the metallized ceramic substrate and the heat dissipation substrate to form a transition layer.

[0016] The fourth aspect of this application provides an electronic device packaging structure, including a chip, a solder layer, and a heat dissipation structure as described above, wherein the solder layer is connected to the metal layer surfaces of the chip and the heat dissipation structure on both sides along the thickness direction.

[0017] Compared with the prior art, the heat dissipation substrate, heat dissipation structure, fabrication method, and electronic device provided in this application have at least the following advantages: In the fabrication of heat dissipation substrates, mounting holes are made in the metal substrate and ceramic pillars are implanted. The ceramic pillars have a lower coefficient of thermal expansion than the metal substrate, thus reducing the coefficient of thermal expansion of the heat dissipation substrate. Therefore, based on the coefficient of thermal expansion of the heat dissipation substrate to be bonded to the metallized ceramic substrate, the location, size, shape, and number of mounting holes in the metal substrate can be designed. After implanting the corresponding ceramic pillars, the coefficient of thermal expansion of the heat dissipation substrate can be made close to that of the metallized ceramic substrate. This avoids the deformation and cracking caused by excessive thermal stress due to the mismatch in coefficients of thermal expansion when the heat dissipation substrate and the metallized ceramic substrate are directly bonded without a solder layer, promoting the sintering and integration of the heat dissipation substrate and the metallized ceramic substrate. Furthermore, the elimination of the solder layer between the heat dissipation substrate and the metallized ceramic substrate reduces the thermal resistance interface layer, thereby improving the chip heat dissipation capacity of the electronic device packaging structure. This achieves a balance between reducing the thermal resistance layer and not affecting the heat dissipation effect.

[0018] Therefore, the preparation method of this application can adjust the thermal expansion coefficient of the heat dissipation substrate, reduce the thermal resistance interface of the power electronic device from at least 6 layers to at least 4 layers, significantly improve the heat dissipation performance, reduce the thermal resistance interface, and meet the requirements of no deformation and cracking when the metallized ceramic substrate is directly bonded to the heat dissipation substrate, thereby improving the reliability of the power electronic device. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the IGBT packaging structure in the prior art; Figure 2 This is a flowchart illustrating the fabrication process of the heat dissipation substrate and heat dissipation structure, provided as an example in the embodiments of this application. Figure 3 This is a schematic diagram of an electronic device packaging structure provided as an example in an embodiment of this application.

[0021] Figure label: 100. Heat dissipation substrate; 10. Metal substrate; 11. Mounting hole; 20. Ceramic pillar; 1. Heat dissipation structure; 200. Metallized ceramic substrate; 30. Ceramic layer; 40. Metal layer; 1000. Electronic device packaging structure; 50. Solder layer; 60. Chip. Detailed Implementation

[0022] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0023] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0024] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0025] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0026] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0027] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0028] In this application, the term "heat sink" refers to the heat dissipation substrate 100, which is mainly used to conduct heat from the heat source (such as electronic components, chips 60, etc.) to a larger heat dissipation area, thereby achieving heat dissipation.

[0029] In this application, the term "Direct Bonded Copper (DBC)" refers to a process in which oxygen is introduced between copper and ceramic during sintering to form a copper-oxygen eutectic liquid. Simultaneously, the liquid reacts with the ceramic to generate composite oxides such as CuAlO2 or CuAl2O4 as solder, which wets the interface between copper and ceramic, thereby bonding the ceramic and copper. This process can be carried out in an inert atmosphere with an oxygen content of 10-100ppm. Applicable ceramics are alumina (Al2O3) ceramics and aluminum nitride (AlN) ceramics with pre-oxidized surfaces.

[0030] The term "Active Metal Brazing (AMB) process" in this application refers to the process of adding active metals such as titanium and nickel as solder to wet and react the interface between ceramics and metals, thereby improving the wettability of ceramics and thus bonding ceramics and metals. This process is usually carried out in a high vacuum to prevent the active metal (such as Ti) from oxidizing and failing before the reaction, and is especially suitable for aluminum nitride (AlN) ceramics and silicon nitride (Si3N4) ceramics.

[0031] In this application, the term "Direct Bonded Aluminum (DBA) process" refers to bringing the ceramic surface into contact with liquid aluminum, where the aluminum can quickly wet the ceramic surface. That is, aluminum and ceramic have good wettability, thereby bonding the ceramic and aluminum. Typically, the aluminum is heated to above its melting point in a vacuum or protective atmosphere, causing it to undergo a eutectic reaction with the ceramic to achieve bonding.

[0032] In this application, the term "Direct Plated Copper (DPC) process" refers to the process of sputtering copper onto ceramic using semiconductor manufacturing technology, thereby bonding the ceramic and copper. In other words, a layer of metallic copper is first sputtered onto the ceramic, and then a circuit pattern is formed through processes such as photolithography, electroplating thickening, and etching.

[0033] In this application, the term "thick film printing process" refers to the process of using screen printing technology to print a paste made of metal powder (such as Au, Ag, Ag-Pd, Cu), glass powder and organic carrier onto ceramics, followed by high-temperature sintering, in which the organic carrier is burned off, and the glass powder melts to bond the metal particles together and adhere them to the ceramics.

[0034] The term "Thin Film Metallization" in this application refers to the process of depositing a thin metal layer 40 (such as Ti / Ni / Cu, Cr / Cu / Au) on ceramic using semiconductor technologies (such as sputtering, electron beam evaporation, electroplating / chemical plating), and then forming a fine circuit pattern through photolithography and etching techniques.

[0035] As mentioned above, in the prior art, the metal substrate 10 of the electronic device packaging structure 1000 is relatively thick, and its coefficient of thermal expansion is significantly higher than that of the metallized ceramic substrate 200. This causes deformation and cracking when the metal substrate 10 is directly bonded to the metallized ceramic substrate 200. Since the thickness of the metal substrate 10 is based on packaging requirements and cannot usually be adjusted, directly changing the composition of the metal substrate 10 to control the coefficient of thermal expansion would affect the heat dissipation effect. Therefore, the general concept of the embodiments of this application is to design a heat dissipation substrate 100 and its preparation method. By forming multiple mounting holes 11 on the metal substrate 10, ceramic pillars 20 are implanted into the mounting holes 11. The coefficient of thermal expansion of the ceramic pillars 20 is lower than that of the metal substrate 10, and the composite with the metal substrate 10 is used to form a heat dissipation substrate. After 100, the coefficient of thermal expansion can be reduced. By changing the position, size, shape and number of implanted ceramic pillars 20, the coefficient of thermal expansion of the heat dissipation substrate 100 can be flexibly designed between the metal substrate 10 and the metallized ceramic substrate 200. This makes the coefficient of thermal expansion of the heat dissipation substrate 100 more compatible with the metallized ceramic substrate 200, thereby reducing the deformation and cracking caused by the high temperature of sintering during the direct bonding of the heat dissipation substrate 100 to the metallized ceramic substrate 200. After the heat dissipation substrate 100 and the metallized ceramic substrate 200 are made into an integrated heat dissipation structure 1, no brazing layer 50 is required between the heat dissipation substrate 100 and the metallized ceramic substrate 200, so as to achieve the reduction of thermal resistance layer and without affecting the heat dissipation effect, thereby improving the reliability of power electronic devices.

[0036] refer to Figure 2 and Figure 3 As shown, based on the above concept, this application provides a method for preparing a heat dissipation substrate 100, including the following steps: The metal substrate 10 processing step includes providing a metal substrate 10 and forming a plurality of mounting holes 11 on the surface of the metal substrate 10 in the thickness direction. In the column planting process, multiple ceramic columns 20 are provided, and each ceramic column 20 is inserted into the corresponding mounting hole 11 and forms a tight fit with the hole wall to obtain an assembly. In the molding process, the assembly undergoes a first sintering treatment to obtain a heat dissipation substrate 100.

[0037] It is understood that in this embodiment, multiple mounting holes 11 are formed on the surface of the metal substrate 10 in the thickness direction. The mounting holes 11 are mainly used for mounting ceramic pillars 20. Therefore, the size and shape of the mounting holes 11 should be adapted to the height of the ceramic pillars 20 to be implanted. For example, the diameter tolerance between the mounting holes 11 and the ceramic pillars 20 is 0~0.2mm to ensure that each ceramic pillar 20 is implanted into the corresponding mounting hole 11 and forms a tight fit with the hole wall, so as to form metallurgical bonding through the first sintering process. By flexibly designing the position, size, shape and number of mounting holes 11, the thermal expansion coefficient of the heat dissipation substrate 100 can be adjusted after the ceramic pillars 20 are implanted in the mounting holes 11 and the heat dissipation substrate 100 is made. Since the thermal expansion coefficient of the ceramic pillars 20 is lower than that of the metal substrate 10, that is, the more or larger the ceramic pillars 20 are implanted, the more significant the reduction in the thermal expansion coefficient of the heat dissipation substrate 100 is, so as to achieve flexible design of the thermal expansion coefficient between the traditional metal substrate 10 and the metallized ceramic substrate 200. Furthermore, depending on the location of the implantation column, the coefficient of thermal expansion of the heat dissipation substrate 100 can be adjusted locally or as a whole. For example, if the interface edge of the heat dissipation substrate 100 bonded to the metallized ceramic substrate 200 is subjected to greater thermal stress during the integrated sintering process, more or larger mounting holes 11 can be opened at the interface edge to reduce the thermal stress during firing at that location.

[0038] Since the metal in the heat dissipation substrate 100 is a continuous body and is not interrupted by the ceramic pillars 20, the presence of the ceramic pillars 20 has little impact on the thermal conductivity of the metal substrate 10 itself, thus achieving a change in the thermal expansion coefficient of the heat dissipation substrate 100 while maintaining heat dissipation performance. During the metallurgical bonding process of directly sintering the heat dissipation substrate 100 and the metallized ceramic substrate 200, the heat dissipation substrate 100 can match the thermal expansion coefficient of the metallized ceramic substrate 200, preventing deformation and cracking during integrated sintering. In the resulting heat dissipation structure 1, there is no brazing layer 50 between the heat dissipation substrate 100 and the metallized ceramic substrate 200. This eliminates the thermal resistance interface layers formed by the heterogeneous interface on the upper and lower surfaces of the original brazing layer 50, reducing the original at least 6 thermal resistance interface layers to at least 4 layers, significantly improving the heat dissipation performance of the chip 60. Since there is no brazing layer 50 between the heat dissipation substrate 100 and the metallized ceramic substrate 200, the use of brazing layer 50 material can be further saved, reducing production costs.

[0039] Furthermore, in traditional high-power LED packaging structures, the spacing between the two electrodes of chip 60 is generally less than 200 micrometers. Conventional DBC, DBA, and AMB processes struggle to meet the minimum line spacing of 200 micrometers. Therefore, only by using DPC technology to increase the copper layer thickness on the metallized ceramic substrate 200 to approximately 100 micrometers can a 200-micrometer line spacing be guaranteed. However, a 100-micrometer thick copper layer has poor thermal conductivity. The heat dissipation substrate 100 provided in this application, which handles the main heat dissipation, replaces the traditional solder layer 50 combined with an independent heat sink structure. This allows for a copper layer thickness of less than 50 μm on the metallized ceramic substrate 200 obtained through DPC technology to achieve a 200 μm line spacing while maintaining heat dissipation efficiency and preventing high-temperature deformation.

[0040] In specific applications, on the heat dissipation substrate 100 of this application embodiment, the two end faces of the ceramic pillar 20 along the axial direction can be exposed on the two sides of the metal substrate 10 along the thickness direction, or one end face of the ceramic pillar 20 along the axial direction can be exposed on one side of the metal substrate 10 along the thickness direction and the other end is located inside the metal substrate 10, or both end faces of the ceramic pillar 20 along the axial direction can be located inside the metal substrate 10. All of these can effectively adjust the thermal expansion coefficient of the heat dissipation substrate 100.

[0041] In some embodiments, the mounting hole 11 is a blind hole or a through hole. When the mounting hole 11 is a blind hole, one end face of the ceramic pillar 20 along the axial direction can be exposed on one side of the metal substrate 10 along the thickness direction, while the other end is located inside the metal substrate 10. This helps to maintain the integrity and flatness of one side of the metal substrate 10, providing space for other mounting or wiring needs, while also controlling costs to a certain extent and ensuring the mechanical strength of the substrate. When the mounting hole 11 is a through hole, the processing is simple, the ceramic pillar 20 penetrates the substrate, and the coefficient of thermal expansion is reduced more significantly.

[0042] In some embodiments, multiple mounting holes 11 are arranged in an array on the metal substrate 10. The array arrangement is beneficial to the uniformity of heat flux density distribution, helps to suppress thermal stress concentration during sintering, and ensures the continuity of the metal material of the metal substrate 10, thereby achieving more efficient and uniform heat dissipation.

[0043] In some embodiments, the method further includes a surface treatment step of metallizing the surface of the heat dissipation substrate 100 where the ceramic pillars 20 are exposed to form a metal overlay layer covering the metal substrate 10 and the ceramic pillars 20.

[0044] It is understandable that the metal capping layer can encapsulate the ceramic pillar 20 within the metal substrate 10, thereby providing a continuous, flat, and bondable surface. This supports the subsequent sintering of the upper metallized ceramic substrate 200 onto the heat dissipation substrate 100, ensuring the robustness of the interface bonding. Furthermore, the metal capping layer simultaneously covers both the ceramic pillar 20 and the metal substrate 10, which have different thermal conductivity, forming a continuous component with the metal substrate 10. This effectively allows heat to be rapidly diffused laterally from the top of the ceramic pillar 20 to the entire surface of the metal substrate 10, eliminating local hot spots and significantly improving overall heat uniformity and heat dissipation efficiency.

[0045] It should be noted that when the mounting hole 11 is a blind hole, only the side of the heat dissipation substrate 100 exposing the ceramic pillar 20 can be metallized. When the mounting hole 11 is a through hole, both sides of the heat dissipation substrate 100 exposing the ceramic pillar 20 can be metallized. For example, when the metal substrate 10 is made of copper, the mounting hole 11 penetrates the metal substrate 10 along the thickness direction, and both ends of the ceramic pillar 20 are exposed on the end face of the metal substrate 10. In this case, a copper layer can be laminated onto both end faces of the metal substrate 10. The laminated copper layer is integrated with the metal substrate 10, completely encapsulating the ceramic pillar 20 within the metal substrate 10.

[0046] In some embodiments, the metal substrate 10 is made of a single metal or an alloy of multiple metals. A single metal, such as pure copper or pure aluminum, can achieve good thermal conductivity or cost advantages. Alternatively, an alloy of multiple metals (such as chromium zirconium copper or 6061 aluminum alloy) can be used to achieve higher strength, hardness, or softening temperature, thereby meeting the comprehensive requirements for heat dissipation, mechanical properties, and reliability in different application scenarios.

[0047] In some embodiments, the metal substrate 10 is made of any one of copper, aluminum, copper alloys or aluminum alloys; copper and its alloys have excellent thermal conductivity, which is more conducive to high-performance heat dissipation; aluminum and its alloys have the advantages of low cost and light weight.

[0048] In some embodiments, the ceramic column 20 includes any one of alumina (Al2O3) ceramic column 20, aluminum nitride (AlN) ceramic column 20, silicon nitride (Si3N4) ceramic column 20, zirconia-toughened alumina (ZTA) ceramic column 20 or silicon carbide (SiC) ceramic column 20.

[0049] In some embodiments, during the metal substrate 10 processing steps, the hole walls of the mounting holes 11 are oxidized or active metal solder is applied to the hole walls of the mounting holes 11 to ensure that the ceramic pillars 20 form metallurgical bonds with the hole walls during the subsequent sintering process.

[0050] For example, when the first sintering process uses the DBC process, and the metal substrate 10 is made of copper or a copper alloy, and the ceramic pillar 20 is an Al2O3 ceramic pillar 20, a ZTA ceramic pillar 20, or an AlN ceramic pillar 20, an oxidation treatment can be performed on the hole wall of the mounting hole 11 to form a cuprous oxide layer on the hole wall, which reacts with the surface of the ceramic pillar 20 to form a bond, achieving a stable connection between the hole wall and the ceramic pillar 20. Alternatively, if the ceramic pillar 20 is a Si3N4 ceramic pillar 20 or a SiC ceramic pillar 20, when using a non-DBC process for the first sintering process, an active metal solder containing transition metal elements such as titanium and nickel can be applied to the hole wall of the mounting hole 11 to improve the wettability between the ceramic pillar 20 and the hole wall, thereby forming a strong, dense, and low thermal resistance metallurgical bonding interface after sintering.

[0051] In some embodiments, the oxidation treatment includes either chemical oxidation or thermal oxidation; chemical oxidation is wet oxidation, which introduces oxygen into the surface of the metal substrate 10 (such as a copper metal substrate 10) using chemical reagents; thermal oxidation is dry oxidation, which forms a copper oxide layer by oxidizing the copper surface in a weak oxygen environment.

[0052] In some embodiments, the active metal solder includes any one of Ag-Cu-Ti solder, Ni-Ti-Cu solder, or Sn-Ti-Cu solder. Ag-Cu-Ti exhibits stable performance and excellent wettability and bonding strength, while Ni-Ti-Cu and Sn-Ti-Cu can provide different melting points, costs, and mechanical properties to accommodate different sintering temperature windows in the first sintering process and subsequent process requirements, increasing process flexibility.

[0053] In some embodiments, during the metal substrate 10 processing steps, the surface of the metal substrate 10 is cleaned before and / or after the formation of the plurality of mounting holes 11. The cleaning process can remove defects such as burrs and flash after processing, as well as remove oil stains, oxide layers and processing residues from the surface, so as to improve the sintering yield, the quality and reliability of the bonding interface.

[0054] In some embodiments, during the metal substrate 10 processing steps, the plurality of mounting holes 11 are formed based on at least one of machining, laser processing, or chemical etching. Machining removes material from the metal substrate 10 to form holes by physical cutting (such as drill bits or milling cutters); laser processing melts / vaporizes metal with a high-energy laser beam to form holes; chemical etching refers to the selective etching of metal by acid / alkali solutions to form holes.

[0055] In some embodiments, the first sintering process employs any one of the following: direct copper cladding (DBC), active metal brazing (AMB), or direct aluminum cladding (DBA). Based on the materials of the metal substrate 10 and the ceramic pillar 20, the first sintering process can select a suitable bonding process from the DBC, AMB, or DBA processes to achieve metallurgical bonding between the ceramic pillar 20 and the metal substrate 10.

[0056] In some embodiments, during the molding process, the surface of the heat dissipation substrate 100 obtained from the first sintering treatment, where the ceramic pillars 20 are exposed, is flattened. After the first sintering treatment, the ceramic pillars 20 may not be flush with the surface of the metal substrate 10. By grinding and polishing by mechanical processing or by mechanical-chemical polishing, the end face of the metal substrate 10 and the end face of the ceramic pillars can be kept on the same plane, which is beneficial for subsequent bonding of the metallized ceramic substrate 200.

[0057] In some embodiments, when the first sintering process is a direct copper plating process, the first sintering process is performed in an inert atmosphere; or, when the first sintering process is an active metal brazing process or a direct aluminum plating process, the first sintering process is performed in a vacuum environment.

[0058] When the first sintering process uses the DBC process, its principle relies on the eutectic reaction between copper and a precisely controlled trace amount of oxygen. A small amount of oxygen can be incorporated into the inert gas (such as high-purity nitrogen) protective atmosphere to provide the oxygen required for the reaction while preventing excessive oxidation and failure of the copper, thus achieving a high-quality DBC bond. When the first sintering process uses the AMB or DBA process, the presence of active metals (such as Ti) or easily oxidized aluminum can cause instantaneous oxidation in air, forming an inert layer and leading to complete process failure. Therefore, a high-vacuum environment completely eliminates oxygen and moisture, protecting the pure chemical reaction between the active metal and the ceramic, as well as ensuring good wetting of the aluminum, thereby obtaining a reliable metallurgical bonding interface.

[0059] In some embodiments, during the pillar implantation process, before each ceramic pillar 20 is implanted into the corresponding mounting hole 11, the ceramic pillar 20 undergoes a first surface modification treatment to form an affinity layer containing a transition metal (such as nickel, chromium, etc.) or a non-metal (such as silicon dioxide, aluminum oxide, etc.), and the first surface modification treatment is performed when any of the following conditions are met: (1) when the metal substrate 10 is made of copper or a copper alloy, the ceramic pillar 20 is an aluminum nitride ceramic pillar 20, and the first sintering treatment uses a direct copper plating process; (2) when the metal substrate 10 is made of copper, aluminum, a copper alloy, or an aluminum alloy, the ceramic pillar 20 is an aluminum nitride ceramic pillar 20 or a silicon nitride ceramic pillar 20, and the first sintering treatment uses an active metal brazing process; (3) when the metal heat dissipation substrate 100 is made of aluminum or an aluminum alloy, the ceramic pillar 20 is an aluminum nitride ceramic pillar 20, and the first sintering treatment uses a direct aluminum plating process.

[0060] In this embodiment, if a copper or copper alloy substrate is used in conjunction with Al2O3 ceramic pillars 20 or ZTA ceramic pillars 20 and the DBC process, then the Al2O3 or ZTA ceramic pillars 20 do not need to undergo a first surface modification treatment. In the subsequent first sintering process, the Al2O3 or ZTA ceramic pillars 20 and the hole walls can achieve a tight bond. However, when the metal substrate 10 is made of copper or a copper alloy, the ceramic pillars 20 are AlN ceramic pillars 20, and the first sintering process uses the DBC process, the AlN ceramic itself does not react with the Cu-O eutectic liquid due to its chemical inertness. Through surface modification, an Al2O3 transition layer is generated on its surface. Only this Al2O3 layer can react with the Cu-O liquid, thereby achieving a strong bond. When the metal substrate 10 is made of copper, aluminum, copper alloy, or aluminum alloy, the ceramic pillar 20 is an AlN ceramic pillar 20 or a Si3N4 ceramic pillar 20, and the first sintering process uses the AMB process, AlN and Si3N4 have low surface energy. Although they can react with active metals, the effect is not good. By modifying the surface (such as coating with a Ti-containing paste or sputtering a Ti layer), highly active reactive elements are pre-enriched on the ceramic surface, which can greatly promote and enhance the chemical reaction with the solder in the subsequent AMB process sintering, resulting in a denser, stronger, and lower thermal resistance interface layer, significantly improving the thermal conductivity reliability and lifespan of the final product. When the metal heat sink substrate 100 is made of aluminum or aluminum alloy, the ceramic pillar 20 is an AlN ceramic pillar 20, and the first sintering treatment adopts the DBA process, the wettability of aluminum and aluminum nitride is poor, making direct bonding difficult. Surface modification of the AlN ceramic pillar 20 (such as forming a reaction layer containing transition metal elements such as nickel and titanium) can significantly improve the wetting and spreading ability of molten aluminum, allowing aluminum to fully encapsulate and penetrate the surface of the ceramic pillar 20, thereby achieving effective metallurgical bonding.

[0061] refer to Figure 3 As shown, another embodiment of this application provides a heat dissipation substrate 100, which is made by the preparation method described above. It includes a metal substrate 10 and a plurality of ceramic pillars 20. The metal substrate 10 is provided with a plurality of mounting holes 11 along the thickness direction. Each ceramic pillar 20 is embedded in the corresponding mounting hole 11 and fixedly connected to the metal substrate 10. The end face of the ceramic pillar 20 is flush with the surface of the metal substrate 10 or located in the metal substrate 10.

[0062] The heat dissipation substrate 100 provided in this application embodiment has excellent coefficient of thermal expansion (CTE) matching, and the coefficient of thermal expansion can be flexibly adjusted to adapt to the metallized ceramic substrate 200, significantly reducing the stress caused by thermal mismatch, and effectively suppressing the warping and deformation caused by the difference in the coefficient of thermal expansion between the metal and the metallized ceramic substrate 200 when the temperature changes. This is conducive to achieving both the reduction of the thermal resistance layer and the preservation of heat dissipation effect, and provides strong support for solving the "heat dissipation bottleneck" and "reliability problem" in high-end chips 60, especially in the fields of high-power LEDs, IGBTs, and radio frequency devices.

[0063] refer to Figure 2 and Figure 3 As shown, another embodiment of this application provides a heat dissipation structure 1, which is made by attaching at least one metallized ceramic substrate 200 along the thickness direction to the heat dissipation substrate 100 as described above, and then performing a second sintering process; wherein, the metallized ceramic substrate 200 includes two metal layers 40 spaced apart along the thickness direction and a ceramic layer 30 bonded between the two metal layers 40, and at least one metal layer 40 is bonded to the heat dissipation substrate 100 along the thickness direction.

[0064] In this embodiment of the application, in the heat dissipation structure 1, there may be one or more metallized ceramic substrates 200 on the heat dissipation substrate 100. The metallized ceramic substrates 200 may be bonded to the top surface of the heat dissipation substrate 100 along the thickness direction, or to the bottom surface of the heat dissipation substrate 100 along the thickness direction, or even both sides of the heat dissipation substrate 100 along the thickness direction may be bonded with metallized ceramic substrates 200.

[0065] Since the metal layer 40 of the metallized ceramic substrate 200 is bonded to the heat dissipation substrate 100 along the thickness direction, there is no brazing layer 50 between them, which reduces the thermal resistance interface. Furthermore, since the thermal expansion coefficient of the heat dissipation substrate 100 is compatible with that of the metallized ceramic substrate 200, no deformation or cracking will occur during the second sintering process, thereby achieving the integration of the metallized ceramic substrate 200 and the heat dissipation substrate 100.

[0066] In some embodiments, the metallized ceramic substrate 200 includes any one of a direct copper clad (DBC) substrate, an active metal brazing (AMB) substrate, a direct aluminum clad (DBA) substrate, a direct electroplated copper (DPC) substrate, a thin-film metallized substrate, or a thick-film printed substrate; the DBC substrate, AMB substrate, DBA substrate, DPC substrate, thin-film metallized substrate, or thick-film printed substrate refers to the formation of a metal layer 40 on the surface of the ceramic layer 30 along the thickness direction by the DBC process, AMB process, DBA process, DPC process, thin-film metallization process, or thick-film printing process, respectively.

[0067] In some embodiments, the second sintering process employs any one of the following: direct copper plating (DBC), active metal brazing (AMB), direct aluminum plating (DBA), direct copper plating (DPC), thin film metallization, or thick film printing. Depending on the materials of the metal layer 40 and the metal substrate 10, a suitable bonding process can be selected for the second sintering process to achieve the integration of the metallized ceramic substrate 200 and the heat dissipation substrate 100.

[0068] In some embodiments, the metal layer 40 is made of a single metal or an alloy of multiple metals; the metal layer 40 is made of any one of copper, aluminum, copper alloys or aluminum alloys.

[0069] In some embodiments, the metal layer 40 is made of the same material as the metal substrate 10, so that there is no heterogeneous interface layer between the metallized ceramic substrate 200 and the heat dissipation substrate 100 after integration, which further reduces the number of thermal resistance interface layers and significantly improves the heat dissipation performance of the chip 60 in the electronic device.

[0070] In some embodiments, the ceramic layer 30 is made of any one of alumina (Al2O3), aluminum nitride (AlN), zirconia-toughened alumina (ZTA), silicon nitride (Si3N4), or silicon carbide (SiC).

[0071] In some embodiments, before the metallized ceramic substrate 200 is bonded to the heat dissipation substrate 100 along its thickness direction, a second surface modification treatment is performed on the mating surfaces of the metallized ceramic substrate 200 and the heat dissipation substrate 100 to form a transition layer, thereby facilitating the integration of the metallized ceramic substrate 200 and the heat dissipation substrate 100 during the second sintering process. For example Figure 2 As shown, the metallized ceramic substrate 200 is a direct copper-clad ceramic substrate, and the metal substrate 10 of the heat dissipation substrate 100 is made of copper or copper alloy. Before the metallized ceramic substrate 200 is attached to the heat dissipation substrate 100 along the thickness direction, the mating surfaces of the metallized ceramic substrate 200 and the heat dissipation substrate 100 are oxidized to form a copper oxide layer (i.e., a transition layer).

[0072] For example, the second surface modification treatment includes: when the metallized ceramic substrate 200 is a direct aluminum-clad ceramic substrate and the metal substrate 10 of the heat dissipation substrate 100 is made of copper or a copper alloy, the second surface modification treatment may use an active metal solder to form a transition metal element layer; or, when the metallized ceramic substrate 200 is a direct aluminum-clad ceramic substrate and the metal substrate 10 of the heat dissipation substrate 100 is made of aluminum or an aluminum alloy, the second surface modification treatment may use solder coating, electroplating, or sputtering to form a transition film containing aluminum or an aluminum alloy; or, when the metallized ceramic substrate 200 is a direct copper-clad ceramic substrate and the metal substrate 10 of the heat dissipation substrate 100 is made of copper or a copper alloy, the second surface modification treatment may use an oxidation treatment to form a copper oxide layer.

[0073] refer to Figure 3 Another embodiment of this application provides an electronic device packaging structure 1000, including a chip 60, a solder layer 50 and a heat dissipation structure 1 as described above. The solder layer 50 is connected to the surfaces of the metal layer 40 of the chip 60 and the heat dissipation structure 1 on both sides along the thickness direction.

[0074] It can be observed that in the electronic device packaging structure 1000 provided in this application embodiment, the heat of the chip 60 can be conducted sequentially in the thickness direction by the chip 60, the solder layer 50, the metallized ceramic substrate 200 (metal layer 40, ceramic layer 30, metal layer 40) and the heat dissipation substrate 100. The thermal resistance interface layer between the metal layer 40 and the heat dissipation substrate 100, which was originally caused by the solder layer 50, is eliminated, so that the electronic device packaging structure 1000 has higher heat dissipation efficiency and overall stability.

[0075] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all reagents and raw materials used in the embodiments are commercially available or synthesized by conventional methods, and the instruments used in the embodiments are also commercially available. Example 1

[0076] 1. Preparation of Cu-Al2O3 heat dissipation substrate 100: (1) Metal substrate 10 processing step: Using CNC machining, 120 through holes with a diameter of φ1mm are machined on a 50*95*3 (mm) copper metal substrate 10, forming a 10*12 arrangement matrix with a hole spacing of 2mm. Oxygen elements are introduced into the hole walls by chemical oxidation (wet oxidation) to oxidize the hole wall surface.

[0077] (2) Column planting process: Clean the Al2O3 ceramic column 20, insert 120 cleaned Al2O3 ceramic columns 20 into the through hole to obtain the assembly. The ceramic column 20 has a specification of φ1mm*3mm. (3) Molding process: The assembly is placed in a nitrogen-protected tunnel furnace, and the perforated Cu metal substrate 10 and Al2O3 ceramic pillar 20 are sintered together using the DBC process to form a Cu-Al2O3 heat dissipation substrate 100. The sintering conditions are as follows: the maximum temperature is 1080℃; the holding time is 20min; and the oxygen content in the furnace is about 100ppm. After the upper and lower surfaces of the heat dissipation substrate 100 are smoothed by chemical mechanical polishing (CMP), it is cleaned.

[0078] (4) Surface treatment process: The copper surfaces on the upper and lower surfaces of the Cu-Al2O3 heat dissipation substrate 100 are oxidized by chemical oxidation (wet oxidation). The copper foil is then sintered onto the upper and lower surfaces of the Cu-Al2O3 heat dissipation substrate 100 again using the DBC process to form a metal covering layer covering the metal substrate 10 and the ceramic pillar 20. The copper foil has a specification of 60*100*0.3 (mm), and the sintering conditions are the same as in step (3).

[0079] 2. Preparation of heat dissipation structure 1: Four Al2O3-DBC metallized ceramic substrates 200 (ceramic layer 30 is Al2O3, metal layer 40 is copper) were sintered onto the metal capping layer of a Cu-Al2O3 heat dissipation substrate 100 using the DBC process. The Al2O3-DBC metallized ceramic substrate 200 has dimensions of 40*20*0.38 (mm) and is copper-clad on both sides. The sintering conditions are the same as in step (3). Example 2

[0080] 1. Preparation of Cu-Si3N4 heat dissipation substrate 100: (1) Metal substrate 10 processing step: using a laser cutting machine, 60 through holes with a diameter of φ1mm are processed on a 91*31*3 (mm) copper metal substrate 10, forming a 10*6 arrangement matrix with a hole spacing of 2mm. Oxygen elements are introduced into the hole walls by chemical oxidation (wet oxidation) to oxidize the hole wall surface.

[0081] (2) In the pillar implantation process, an Ag-Cu-Ti solder layer containing a transition metal is formed by coating the Si3N4 ceramic pillar 20 with the first surface modification treatment. The 60 surface-modified Si3N4 ceramic pillars 20 are then implanted into the through holes to obtain the assembly. The specifications of the Si3N4 ceramic pillars 20 are φ1*3 (60 pillars).

[0082] (3) Molding process: The assembly is placed in a nitrogen-protected tunnel furnace, and the perforated Cu metal substrate 10 and Si3N4 ceramic pillar 20 are sintered together using the DBC process to form a Cu-Si3N4 heat dissipation substrate 100. The sintering conditions are as follows: the maximum temperature is 1065℃; the holding time is 20min; and the oxygen content in the furnace is about 5ppm. After the upper and lower surfaces of the Cu-Si3N4 heat dissipation substrate 100 are smoothed by chemical mechanical polishing (CMP), it is cleaned.

[0083] 2. Preparation of heat dissipation structure 1: The copper surfaces of the upper and lower surfaces of the heat dissipation substrate 100 are oxidized using a chemical oxidation (wet oxidation) process. Two AlN-DBC metallized ceramic substrates 200 (ceramic layer 30 is AlN, metal layer 40 is copper) are sintered onto the Cu-Si3N4 heat dissipation substrate 100 using the DBC process. The AlN-DBC metallized ceramic substrate 200 has dimensions of 42.5*23*0.635 (mm) and is copper-clad on both sides. The sintering conditions are the same as in step (3). Example 3

[0084] 1. Preparation of Al-AlN heat dissipation substrate 100: (1) Metal substrate 10 processing process: Select an aluminum metal substrate 10 with a specification of 60*120*6 (mm), and use CNC to process 160 blind holes with φ2mm*3.1mm, which are arranged in a 20*8 matrix with a hole spacing of 2mm, and are arranged in the middle of the aluminum metal substrate 10 in a symmetrical state.

[0085] (2) In the pillar implantation process, Ag-Cu-Ti solder is applied to the AIN ceramic pillar 20 through a first surface modification treatment to form an affinity layer containing a transition metal. 160 surface-modified AIN ceramic pillars 20 are then implanted into blind holes, so that the end plane of the AIN ceramic pillar 20 is lower than the surface of the aluminum metal substrate 10, thus obtaining the assembly. The AIN ceramic pillar 20 has a specification of φ2mm*3mm.

[0086] (3) Molding process: The assembly is placed in a vacuum furnace, and the perforated aluminum metal substrate 10 and AlN ceramic pillar 20 are sintered together using the DBA process to form an Al-AlN heat dissipation substrate 100. The sintering conditions are as follows: the maximum temperature is 650℃; the holding time is 30min; and the vacuum degree inside the vacuum furnace is maintained below 5*10-2Pa. The upper and lower surfaces of the obtained Al-AlN heat dissipation substrate 100 are mechanically ground and polished to keep the end face of the AlN ceramic pillar 20 and the surface of the aluminum metal substrate 10 on the same plane.

[0087] 2. Preparation of heat dissipation structure 1: A layer of aluminum-containing solder was printed on the bonding surface (non-patterned surface) of the AlN-DBA metallized ceramic substrate 200 (ceramic layer 30 is AlN, metal layer 40 is aluminum) using screen printing, and then dried. The AlN-DBA metallized ceramic substrate 200 with aluminum-containing solder was placed on the Al-AlN heat dissipation substrate 100 and placed in a vacuum furnace. The AlN-DBA metallized ceramic substrate 200 was sintered onto the Al-AlN heat dissipation substrate 100 using the DBA process, thus completing the integration of the AlN-DBA metallized ceramic substrate 200 and the Al-AlN heat dissipation substrate 100. The AlN-DBA metallized ceramic substrate 200 has dimensions of 42.5*23*0.635 (mm) and is double-sided aluminum-coated. The sintering conditions were the same as in step (3).

[0088] By applying solder to the metal layer 40 of the heat dissipation structure 1 obtained in Examples 1 to 3 and then bonding the chip 60 together, a brazing layer 50 is formed between the chip 60 and the metal layer 40 after the solder solidifies, thereby obtaining the electronic device packaging structure 1000.

[0089] Therefore, the preparation method of this application embodiment can adjust the thermal expansion coefficient of the heat dissipation substrate 100, reduce the thermal resistance interface of the power electronic device from at least 6 layers to at least 4 layers, significantly improve the heat dissipation performance, reduce the thermal resistance interface, and meet the requirement of no deformation or cracking when the metallized ceramic substrate 200 is directly bonded to the heat dissipation substrate 100, thereby improving the reliability of the power electronic device.

[0090] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a heat dissipation substrate, characterized in that, Includes the following steps: A metal substrate processing step involves providing a metal substrate and forming multiple mounting holes on the surface of the metal substrate along its thickness direction. The column planting process involves providing multiple ceramic columns, inserting each ceramic column into a corresponding mounting hole, and forming a tight fit with the hole wall to obtain an assembly. In the molding process, the assembly undergoes a first sintering treatment to obtain a heat dissipation substrate.

2. The method for preparing a heat dissipation substrate according to claim 1, characterized in that, Also includes: The surface treatment process involves metallizing the surface of the heat dissipation substrate with exposed ceramic pillars to form a metal overlay covering the metal substrate and the ceramic pillars.

3. The method for preparing a heat dissipation substrate according to claim 1 or 2, characterized in that, The preparation method satisfies at least one of the following conditions: A. In the metal substrate processing step, the wall of the mounting hole is oxidized, or an active metal solder is applied to the wall of the mounting hole. B. In the metal substrate processing step, the surface of the metal substrate is cleaned before and / or after forming multiple mounting holes; C. In the metal substrate processing step, the plurality of mounting holes are made based on at least one of the following processes: machining, laser processing, or chemical etching; D. The first sintering process adopts any one of the following: direct copper plating process, active metal brazing process, or direct aluminum plating process. E. In the molding process, the surface of the heat dissipation substrate with exposed ceramic pillars obtained from the first sintering process is flattened.

4. The method for preparing a heat dissipation substrate according to claim 3, characterized in that, At least one of the following conditions must be met: F. The material of the metal substrate includes a single metal or an alloy composed of multiple metals; G. The material of the metal substrate is selected from any one of copper, aluminum, copper alloy or aluminum alloy; H. The ceramic column includes any one of alumina ceramic column, aluminum nitride ceramic column, silicon nitride ceramic column, zirconia-toughened alumina ceramic column, or silicon carbide ceramic column. I. The mounting hole is a blind hole or a through hole; J. The mounting holes are arranged in an array on the metal substrate; K. The oxidation treatment includes either chemical oxidation treatment or thermal oxidation treatment; L. The active metal solder includes any one of Ag-Cu-Ti solder, Ni-Ti-Cu solder, or Sn-Ti-Cu solder.

5. The method for preparing a heat dissipation substrate according to claim 4, characterized in that, When the first sintering treatment employs a direct copper plating process, the first sintering treatment is performed under an inert atmosphere; or, When the first sintering process is performed using an active metal brazing process or a direct aluminum coating process, the first sintering process is carried out in a vacuum environment.

6. The method for preparing a heat dissipation substrate according to claim 4, characterized in that, In the column implantation process, before each ceramic column is implanted into the corresponding mounting hole, the ceramic column undergoes a first surface modification treatment to form an affinity layer containing a transition metal or non-metal, and the first surface modification treatment is performed when any of the following conditions are met: (1) When the metal substrate is made of copper or copper alloy, the ceramic pillar is an aluminum nitride ceramic pillar, and the first sintering treatment adopts a direct copper plating process; (2) When the material of the metal substrate is copper, aluminum, copper alloy or aluminum alloy, the ceramic pillar is aluminum nitride ceramic pillar or silicon nitride ceramic pillar, and the first sintering treatment adopts active metal brazing process; (3) When the material of the metal heat dissipation substrate is aluminum or aluminum alloy, the ceramic pillar is an aluminum nitride ceramic pillar, and the first sintering treatment adopts a direct aluminum coating process.

7. A heat dissipation substrate, characterized in that, The ceramic pillar is manufactured using the preparation method described in any one of claims 1 to 6, comprising a metal substrate and a plurality of ceramic pillars. The metal substrate has a plurality of mounting holes along its thickness direction. Each ceramic pillar is embedded in a corresponding mounting hole and fixedly connected to the metal substrate. The end face of the ceramic pillar is flush with the surface of the metal substrate or located within the metal substrate.

8. A heat dissipation structure, characterized in that, It is manufactured by attaching at least one metallized ceramic substrate along the thickness direction to the heat dissipation substrate as described in claim 7, and then performing a second sintering process. The metallized ceramic substrate includes two metal layers spaced apart along the thickness direction and a ceramic layer bonded between the two metal layers, and at least one of the metal layers is bonded to the heat dissipation substrate along the thickness direction.

9. The heat dissipation structure according to claim 8, characterized in that, At least one of the following conditions must be met: a. The metallized ceramic substrate includes any one of the following: direct copper-clad substrate, active metal brazing substrate, direct aluminum-clad substrate, direct electroplated copper substrate, thin film metallized substrate, or thick film printed substrate. b. The second sintering treatment adopts any one of the following processes: direct copper plating process, active metal brazing process, direct aluminum plating process, direct copper electroplating process, thin film metallization process, or thick film printing process. c. The metal layer is made of a single metal or an alloy of multiple metals; the metal layer material includes any one of copper, aluminum, copper alloy, or aluminum alloy; the metal layer is made of the same material as the metal substrate. d. The ceramic layer is made of any one of alumina, aluminum nitride, zirconium oxide-toughened alumina, silicon nitride, or silicon carbide; e. Before the metallized ceramic substrate is bonded to the heat dissipation substrate along the thickness direction, a second surface modification treatment is performed on the mating surfaces of the metallized ceramic substrate and the heat dissipation substrate to form a transition layer.

10. An electronic device packaging structure, characterized in that, It includes a chip, a solder layer, and a heat dissipation structure as described in claim 9, wherein the solder layer is connected to the metal layer surfaces of the chip and the heat dissipation structure on both sides along the thickness direction.

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