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

Abstract

The application relates to the field of semiconductors, in particular to a heat dissipation substrate, a heat dissipation structure, a preparation method thereof and an electronic device packaging structure. The preparation method of the heat dissipation substrate provided by the application comprises the following steps: a metal substrate processing procedure, a metal substrate is provided, and a plurality of mounting holes are formed based on the surface in the thickness direction of the metal substrate; a column implanting procedure, a plurality of ceramic columns are provided, each ceramic column is implanted into a corresponding mounting hole and tightly matched with the hole wall, and a combined body is obtained; and a forming procedure, the combined body is subjected to a first sintering treatment, and a heat dissipation substrate is obtained. The preparation method can adjust the thermal expansion coefficient of the heat dissipation substrate, so that the heat dissipation substrate can be directly bonded on the metallized ceramic substrate without deformation, the heat resistance layer is reduced, the heat dissipation effect is not affected, and the production cost is significantly 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 the present application provides a method for preparing a heat dissipation substrate, comprising the following steps:

[0008] A metal substrate processing step, providing a metal substrate, forming a plurality of mounting holes based on the surface of the metal substrate in the thickness direction;

[0009] A column implanting step, providing a plurality of ceramic columns, implanting each ceramic column into the corresponding mounting hole and forming a close fit with the hole wall to obtain an assembly;

[0010] A forming step, performing a first sintering treatment on the assembly to obtain a heat dissipation substrate.

[0011] In some embodiments, further comprising: a surface treatment step, performing a metallization treatment on the surface of the heat dissipation substrate exposed to the ceramic columns to form a metal covering layer covering the metal substrate and the ceramic columns.

[0012] In some embodiments, the preparation method satisfies at least one of the following conditions:

[0013] A. In the metal substrate processing step, the hole wall of the mounting hole is subjected to an oxidation treatment, or an active metal solder is applied to the hole wall of the mounting hole;

[0014] B. In the metal substrate processing step, the surface of the metal substrate is subjected to a cleaning treatment before and / or after forming the plurality of mounting holes;

[0015] C. In the metal substrate processing step, the plurality of mounting holes are made based on at least one of the following processes: mechanical processing, laser processing, or chemical etching;

[0016] D. The first sintering treatment adopts any one of the following processes: direct copper plating process, active metal brazing process, or direct aluminum plating process;

[0017] E. In the forming step, a planarization treatment is performed on the surface of the heat dissipation substrate obtained after the first sintering treatment and exposed to the ceramic columns.

[0018] In some embodiments, at least one of the following conditions is satisfied:

[0019] F. The material of the metal substrate comprises a single metal or an alloy obtained by compounding multiple metals;

[0020] G. The material of the metal substrate is selected from any one of the following: copper, aluminum, copper alloy, or aluminum alloy;

[0021] H. The ceramic column comprises any one of the following: alumina ceramic column, aluminum nitride ceramic column, silicon nitride ceramic column, zirconia toughened alumina ceramic column, or silicon carbide ceramic column;

[0022] I. The mounting hole is a blind hole or a through hole;

[0023] J. the plurality of mounting holes are arranged in an array on the metal substrate;

[0024] K. the oxidation treatment comprises any one of a chemical oxidation treatment or a thermal oxidation treatment;

[0025] L. the active metal solder comprises any one of an Ag-Cu-Ti solder, a Ni-Ti-Cu solder, or a Sn-Ti-Cu solder.

[0026] In some embodiments, when the first sintering treatment adopts a direct copper plating process, the first sintering treatment is performed in an inert atmosphere; or, when the first sintering treatment adopts an active metal brazing process or a direct aluminum plating process, the first sintering treatment is performed in a vacuum environment.

[0027] In some embodiments, in the column implanting process, before each ceramic column is implanted into a corresponding mounting hole, the ceramic column is subjected to a first surface modification treatment to form an affinity layer containing a transition metal or a non-metal, and the first surface modification treatment is performed when at least one of the following conditions is met:

[0028] (1) when the material of the metal substrate is copper or a copper alloy, the ceramic column is an aluminum nitride ceramic column, and the first sintering treatment adopts a direct copper plating process;

[0029] (2) when the material of the metal substrate is copper, aluminum, a copper alloy, or an aluminum alloy, the ceramic column is an aluminum nitride ceramic column or a silicon nitride ceramic column, and the first sintering treatment adopts an active metal brazing process;

[0030] (3) when the material of the metal heat dissipation substrate is aluminum or an aluminum alloy, the ceramic column is an aluminum nitride ceramic column, and the first sintering treatment adopts a direct aluminum plating process.

[0031] A second aspect of the present application provides a heat dissipation substrate, which is made by the preparation method described above, and comprises a metal substrate and a plurality of ceramic columns. The metal substrate is provided with a plurality of mounting holes in the thickness direction. Each ceramic column is embedded in a corresponding mounting hole and fixedly connected with the metal substrate. The end surface of the ceramic column is flush with the surface of the metal substrate or located inside the metal substrate.

[0032] A third aspect of the present application provides a heat dissipation structure, which is made by bonding at least one metallized ceramic substrate to the heat dissipation substrate described above in the thickness direction after a second sintering treatment; wherein the metallized ceramic substrate comprises two metal layers arranged at intervals in the thickness direction and a ceramic layer bonded between the two metal layers. At least one metal layer is bonded to the heat dissipation substrate in the thickness direction.

[0033] In some embodiments, at least one of the following conditions is met:

[0034] a. The metalized ceramic substrate comprises any one of a direct copper clad substrate, an active metal brazing substrate, a direct aluminum clad substrate, a direct electroplated copper substrate, a thin film metallization substrate, or a thick film printed substrate;

[0035] b. The second sintering process adopts any one of a direct copper clad process, an active metal brazing process, a direct aluminum clad process, a direct electroplated copper process, a thin film metallization process, or a thick film printed process;

[0036] c. The metal layer material is a single metal or an alloy obtained by compounding multiple metals; the metal layer material comprises any one of copper, aluminum, a copper alloy, or an aluminum alloy; the metal layer and the metal substrate are of the same material;

[0037] d. The ceramic layer material is any one of alumina, aluminum nitride, zirconia toughened alumina, silicon nitride, or silicon carbide;

[0038] e. Before the metalized ceramic substrate is attached to the heat dissipation substrate along the thickness direction, the abutting surfaces of the metalized ceramic substrate and the heat dissipation substrate are respectively subjected to a second surface modification process to form a transition layer.

[0039] The fourth aspect of the present application provides an electronic device packaging structure comprising a chip, a solder layer, and a heat dissipation structure as described above, the solder layer being connected to the surfaces of the metal layer of the chip and the heat dissipation structure along the thickness direction.

[0040] Compared with the prior art, the heat dissipation substrate, the heat dissipation structure, the preparation method thereof, and the electronic device provided by the present application have at least the following beneficial effects:

[0041] In the preparation process of the heat dissipation substrate, mounting holes are formed on the metal substrate and ceramic columns are implanted. The ceramic columns have a lower thermal expansion coefficient than the metal substrate, which can reduce the thermal expansion coefficient of the heat dissipation substrate. Thus, based on the thermal expansion coefficient of the metalized ceramic substrate required for bonding, the mounting hole position, size, shape, and number of features on the metal substrate can be designed, and after the corresponding ceramic columns are implanted, the thermal expansion coefficient of the heat dissipation substrate can be close to that of the metalized ceramic substrate, avoiding the deformation and cracking phenomenon caused by excessive thermal stress due to the mismatch of thermal expansion coefficients when the heat dissipation substrate and the metalized ceramic substrate are directly bonded without a solder layer, and promoting the sintering integration of the heat dissipation substrate and the metalized ceramic substrate. Moreover, the elimination of the solder layer between the heat dissipation substrate and the metalized ceramic substrate can reduce the thermal resistance interface layer, thereby improving the chip heat dissipation capacity of the electronic device packaging structure, and further achieving the reduction of the thermal resistance layer without affecting the heat dissipation effect.

[0042] Therefore, the preparation method of the application can adjust the thermal expansion coefficient of the heat dissipation substrate, reduce the packaging thermal resistance interface of the power electronic device from at least 6 layers to at least 4 layers, significantly improve the heat dissipation performance, realize the reduction of the thermal resistance interface, and meet the requirements of non-deformation and cracking when the metalized ceramic substrate is directly bonded to the heat dissipation substrate, thereby improving the reliability of the power electronic device. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0044] Figure 1 FIG. 1 is a structural schematic diagram of an IGBT packaging structure in the prior art;

[0045] Figure 2 FIG. 2 is a preparation flowchart of a heat dissipation substrate and a heat dissipation structure provided exemplarily by an embodiment of the application;

[0046] Figure 3 FIG. 3 is a structural schematic diagram of an electronic device packaging structure provided exemplarily by an embodiment of the application.

[0047] Reference signs:

[0048] 100, heat dissipation substrate;

[0049] 10, metal substrate; 11, mounting hole; 20, ceramic column;

[0050] 1, heat dissipation structure;

[0051] 200, metalized ceramic substrate;

[0052] 30, ceramic layer; 40, metal layer;

[0053] 1000, electronic device packaging structure;

[0054] 50, brazing layer; 60, chip. DETAILED DESCRIPTION

[0055] 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.

[0056] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0057] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0058] 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.

[0059] 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.

[0060] If not specifically stated, the term "or" in this application is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following satisfy the condition "A or B": A is true (or present) and B is false (or not present); A is false (or not present) and B is true (or present); or both A and B are true (or present).

[0061] The term "heat sink" in this application, i.e. the heat dissipation substrate 100, is mainly used to conduct heat from a heat source (such as electronic components, chips 60, etc.) to a larger heat dissipation area, thereby achieving heat dissipation.

[0062] The term "Direct Bonded Copper (DBC)" process in this application refers to the process of introducing oxygen elements between copper and ceramic during sintering to form a copper-oxygen eutectic liquid, and at the same time, reacting with the ceramic to generate CuAlO2 or CuAl2O4 composite oxides as solder, so that the interface between copper and ceramic is wetted, thereby bonding the ceramic and copper. This process can be carried out in an inert atmosphere with an oxygen content of 10-100 ppm, and the applicable ceramics are aluminum oxide (Al2O3) ceramics and pre-oxidized aluminum nitride (AIN) ceramics.

[0063] The term "Active Metal Brazing (AMB)" process in this application refers to the process of using active metals such as titanium and nickel as solder to wet and react the interface between ceramic and metal, thereby improving the wettability of the ceramic and bonding the ceramic and metal. This process is usually carried out in high vacuum to prevent the active metal (such as Ti) from being oxidized and losing effectiveness before the reaction, and is particularly suitable for aluminum nitride (AIN) ceramics and silicon nitride (Si3N4) ceramics.

[0064] The term "Direct Bonded Aluminum (DBA)" process in this application refers to the process of contacting the surface of the ceramic with liquid aluminum, which can quickly wet the surface of the ceramic, i.e. the aluminum has good wettability with the ceramic, thereby bonding the ceramic and aluminum. It usually heats the aluminum to above its melting point in vacuum or protective atmosphere, so that it reacts with the ceramic to achieve bonding.

[0065] The term "Direct Plated Copper (DPC)" process in this application refers to the process of sputtering copper on ceramic using semiconductor process technology, thereby bonding the ceramic and copper, i.e. first sputtering a layer of copper on the ceramic, and then forming circuit patterns through processes such as photolithography, electroplating thickening, and etching.

[0066] The term "thick film printing process" in the present application refers to a process of printing a paste made of metal powder (such as Au, Ag, Ag-Pd, Cu), glass powder and organic carrier onto a ceramic substrate by screen printing technology, and then sintering at high temperature to burn off the organic carrier and melt the glass powder to bond the metal particles together and adhere to the ceramic substrate.

[0067] The term "thin film metallization process" in the present application refers to a process of depositing a thin metal layer 40 (such as Ti / Ni / Cu, Cr / Cu / Au) on a ceramic substrate by semiconductor technology (such as sputtering, electron beam evaporation, electroplating / chemical plating), and then forming a fine circuit pattern by photolithography and etching technology.

[0068] As described above, the metal substrate 10 in the prior art electronic device packaging structure 1000 is relatively thick, and its thermal expansion coefficient is significantly higher than that of the metallized ceramic substrate 200, which 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 be adjusted, changing the composition of the metal substrate 10 to control the thermal expansion coefficient will affect the heat dissipation effect. To this end, the general concept of the embodiments of the present application is to design the heat dissipation substrate 100 and its preparation method. By forming a plurality of mounting holes 11 on the metal substrate 10, and implanting ceramic columns 20 into the mounting holes 11, the ceramic columns 20 have a lower thermal expansion coefficient than the metal substrate 10. After the ceramic columns 20 are combined with the metal substrate 10 to form the heat dissipation substrate 100, the thermal expansion coefficient can be reduced. By changing the position, size, shape and number of the implanted ceramic columns 20, the thermal expansion coefficient of the heat dissipation substrate 100 can be flexibly designed between the metal substrate 10 and the metallized ceramic substrate 200, so that the thermal expansion coefficient of the heat dissipation substrate 100 is more matched with the metallized ceramic substrate 200, thereby reducing the deformation and cracking phenomenon caused by high-temperature sintering during the process of directly bonding 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, the heat dissipation substrate 100 and the metallized ceramic substrate 200 do not need a brazing layer 50, so as to achieve the reduction of thermal resistance layer and the non-influence on heat dissipation effect, and improve the reliability of power electronic devices.

[0069] Referring to FIGS. 1 to 4, Figure 2 and Figure 3 Based on the above concept, the embodiments of the present application provide a preparation method of a heat dissipation substrate 100, which comprises the following steps:

[0070] A metal substrate 10 processing step is provided, and a plurality of mounting holes 11 are formed on the surface of the metal substrate 10 in the thickness direction of the metal substrate 10;

[0071] The planting step provides a plurality of ceramic columns 20, and each ceramic column 20 is planted into a corresponding mounting hole 11 and tightly fitted with the hole wall to obtain an assembly;

[0072] The forming step performs a first sintering treatment on the assembly to obtain the heat dissipation substrate 100.

[0073] It can be understood that in the embodiment of the present application, a plurality of mounting holes 11 are formed on the surface of the metal substrate 10 in the thickness direction, and the mounting holes 11 are mainly used for the installation of the ceramic columns 20. Therefore, the size and shape of the mounting holes 11 are adapted to the height of the ceramic columns 20 to be planted, for example, the diameter of the mounting hole 11 and the ceramic column 20 has a tolerance of 0-0.2 mm, which ensures that each ceramic column 20 is planted into the corresponding mounting hole 11 and tightly fitted with the hole wall to form a metallurgical bond through the first sintering treatment. Through flexible design of the position, size, shape and number of the mounting holes 11, the thermal expansion coefficient of the heat dissipation substrate 100 can be adjusted after the ceramic columns 20 are planted in the mounting holes 11 and the heat dissipation substrate 100 is manufactured. Since the thermal expansion coefficient of the ceramic column 20 is lower than that of the metal substrate 10, that is, the more or larger ceramic columns 20 are planted, the thermal expansion coefficient of the heat dissipation substrate 100 is reduced more significantly, so as to realize flexible design of the thermal expansion coefficient between the traditional metal substrate 10 and the metalized ceramic substrate 200. Moreover, according to the different planting positions, the local or overall thermal expansion coefficient of the heat dissipation substrate 100 can also be adjusted. For example, the interface edge of the heat dissipation substrate 100 bonded with the metalized ceramic substrate 200 is subjected to a larger thermal stress during the integrated sintering process. Therefore, more or larger mounting holes 11 can be provided at the interface edge to facilitate the reduction of thermal stress during sintering.

[0074] Since the metal in the manufactured heat dissipation substrate 100 is a continuum and is not interrupted by the ceramic columns 20, the existence of the ceramic columns 20 has little effect on the heat conduction of the metal substrate 10, so as to realize the change of the thermal expansion coefficient of the heat dissipation substrate 100 while considering the heat dissipation performance. During the direct sintering of the manufactured heat dissipation substrate 100 and the metalized ceramic substrate 200 to form a metallurgical bond, the heat dissipation substrate 100 can match the thermal expansion coefficient of the metalized ceramic substrate 200, so as to avoid deformation and cracking of the two during the integrated sintering. The heat dissipation structure 1 obtained by the present application does not have the soldering layer 50 between the heat dissipation substrate 100 and the metalized ceramic substrate 200, so that the thermal resistance interface layer formed by the upper and lower surfaces of the original soldering layer 50 due to the heterogeneous interface is cancelled, thereby reducing the original at least 6-layer thermal resistance interface layer to at least 4-layer, and promoting the heat dissipation performance of the chip 60 to be significantly improved. Since the heat dissipation substrate 100 and the metalized ceramic substrate 200 do not have the soldering layer 50, the use of the raw material of the soldering layer 50 can be further saved, so that the production cost is reduced.

[0075] In addition, in the conventional high-power LED packaging structure, the distance between the two electrodes of the chip 60 is generally less than 200 microns, and it is difficult to meet the minimum line distance of 200 microns by using the conventional DBC, DBA, and AMB processes. Therefore, the DPC process is used to thicken the copper layer on the metallized ceramic substrate 200 to about 100 microns, so as to ensure the line distance of 200 microns. However, the copper layer with a thickness of 100 microns has poor heat conduction capacity. The heat dissipation substrate 100 provided in the present application undertakes the main heat dissipation, replaces the conventional solder layer 50 combined with an independent heat sink structure, and is suitable for reducing the thickness of the copper layer of the metallized ceramic substrate 200 to less than 50 microns by the DPC process to achieve the line distance of 200 microns, while maintaining the heat dissipation efficiency and avoiding high-temperature deformation.

[0076] In the specific application process, the two end faces of the ceramic column 20 along the axial direction can be exposed on the two surfaces of the metal substrate 10 along the thickness direction, or one end face of the ceramic column 20 along the axial direction can be exposed on one surface of the metal substrate 10 along the thickness direction, and the other end can be located in the metal substrate 10, or both end faces of the ceramic column 20 along the axial direction can be located in the metal substrate 10, which can effectively adjust the thermal expansion coefficient of the heat dissipation substrate 100.

[0077] 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 column 20 along the axial direction can be exposed on one surface of the metal substrate 10 along the thickness direction, and the other end can be located in the metal substrate 10, which is beneficial to maintaining the integrity and flatness of one surface structure of the metal substrate 10, providing space for other installation or wiring requirements, and also being able to control the cost to a certain extent and ensure the mechanical strength of the substrate. When the mounting hole 11 is a through hole, the processing is simple, the ceramic column 20 penetrates the substrate, and the thermal expansion coefficient is reduced more significantly.

[0078] In some embodiments, the plurality of mounting holes 11 are arrayed on the metal substrate 10. The arrayed distribution is beneficial to the uniformity of the heat flow density distribution, is beneficial to inhibiting the thermal stress concentration in the sintering process, and ensures the continuity of the metal material of the metal substrate 10, and realizes more efficient and uniform heat dissipation.

[0079] In some embodiments, the surface treatment process is further included. The surface of the heat dissipation substrate 100 exposed with the ceramic column 20 is subjected to a metallization treatment to form a metal covering layer covering the metal substrate 10 and the ceramic column 20.

[0080] It can be understood that the metal covering layer can encapsulate the ceramic column 20 in the metal substrate 10, so as to provide a continuous, flat and bondable surface, which supports the subsequent sintering of the upper layer metallized ceramic substrate 200 to the heat dissipation substrate 100, and ensures the firmness of the interface bonding; and the metal covering layer covers the ceramic column 20 and the metal substrate 10 with different thermal conductivity at the same time, forms a continuous piece with the metal substrate 10, can effectively spread the heat from the top of the ceramic column 20 to the surface of the entire metal substrate 10, eliminates local hot spots, and significantly improves the overall uniformity and heat dissipation efficiency.

[0081] It should be noted that when the mounting hole 11 is a blind hole, only one side of the heat dissipation substrate 100 exposed to the ceramic column 20 can be metallized, and when the mounting hole 11 is a through hole, both sides of the heat dissipation substrate 100 exposed to the ceramic column 20 can be metallized. For example, when the material of the metal substrate 10 is copper, the mounting hole 11 penetrates the metal substrate 10 in the thickness direction, and both ends of the ceramic column 20 are exposed to the end surface of the metal substrate 10. At this time, a layer of copper layer can be covered on both end surfaces of the metal substrate 10, and the copper layer covered is integrated with the metal substrate 10, so that the ceramic column 20 is completely encapsulated in the metal substrate 10.

[0082] In some embodiments, the material of the metal substrate 10 includes a single metal or an alloy obtained by compounding multiple metals; a single metal such as pure copper, pure aluminum and the like can obtain good thermal conductivity or cost advantage, and an alloy obtained by compounding multiple metals (such as chromium-zirconium-copper, 6061 aluminum alloy) can obtain higher strength, hardness or softening temperature resistance, so as to meet the comprehensive requirements of heat dissipation performance, mechanical performance and reliability in different application scenarios.

[0083] In some embodiments, the material of the metal substrate 10 is selected from any one of copper, aluminum, copper alloy or aluminum alloy; copper and its alloy have excellent thermal conductivity, which is more conducive to high-performance heat dissipation; aluminum and its alloy have the advantages of low cost and light weight.

[0084] In some embodiments, the ceramic column 20 includes any one of an aluminum oxide (Al2O3) ceramic column 20, an aluminum nitride (AlN) ceramic column 20, a silicon nitride (Si3N4) ceramic column 20, a zirconia toughened alumina (ZTA) ceramic column 20 or a silicon carbide (SiC) ceramic column 20.

[0085] In some embodiments, in the processing procedure of the metal substrate 10, the hole wall of the mounting hole 11 is subjected to oxidation treatment, or active metal solder is applied to the hole wall of the mounting hole 11, so as to ensure that the ceramic column 20 and the hole wall form a metallurgical bonding in the subsequent sintering process.

[0086] For example, when the first sintering process is a DBC process, the metal substrate 10 is made of copper or copper alloy, and the ceramic column 20 is made of Al2O3 ceramic column 20, ZTA ceramic column 20 or AlN ceramic column 20, a layer of cuprous oxide can be formed on the hole wall of the mounting hole 11 by oxidation treatment, so as to react with the surface of the ceramic column 20 to form a bond, thereby realizing stable connection between the hole wall and the ceramic column 20. For another example, when the ceramic column 20 is made of Si3N4 ceramic column 20 or SiC ceramic column 20, and the first sintering process is a non-DBC 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 of the ceramic column 20 and the hole wall, so as to form a firm, dense and low-thermal-resistance metallurgical bonding interface after sintering.

[0087] In some embodiments, the oxidation treatment includes any one of chemical oxidation treatment or thermal oxidation treatment. The chemical oxidation treatment is a wet oxidation process, in which oxygen elements are introduced on the surface of the metal substrate 10 (such as copper metal substrate 10) by chemical reagents. The thermal oxidation treatment is a dry oxidation process, in which a copper oxide layer is formed on the surface of copper by oxidation in a weak oxygen environment.

[0088] In some embodiments, the active metal solder includes any one of Ag-Cu-Ti solder, Ni-Ti-Cu solder or Sn-Ti-Cu solder. The Ag-Cu-Ti solder has stable performance, excellent wettability and bonding strength. The Ni-Ti-Cu solder and the Sn-Ti-Cu solder can provide different melting points, costs and mechanical properties to adapt to the sintering temperature window in different first sintering processes and subsequent process requirements, thereby increasing the process flexibility.

[0089] In some embodiments, in the metal substrate 10 processing procedure, the surface of the metal substrate 10 is subjected to cleaning treatment before and / or after the plurality of mounting holes 11 are formed. The cleaning treatment can remove defects such as burrs and flash after machining, and remove oil stains, oxide layers and machining residues on the surface, so as to improve the sintering yield, the quality and reliability of the bonding interface.

[0090] In some embodiments, in the metal substrate 10 processing procedure, the plurality of mounting holes 11 are formed based on at least one process of mechanical machining, laser machining or chemical etching. The mechanical machining removes materials on the metal substrate 10 to form holes by physical cutting (such as drill bit and milling cutter). The laser machining forms holes by melting / gasifying metals through high-energy laser beams. The chemical etching forms holes by selectively etching metals through acid / alkali solution.

[0091] In some embodiments, the first sintering process is one of a direct copper bonding (DBC) process, an active metal brazing (AMB) process, or a direct aluminum bonding (DBA) process. Based on the material of the metal substrate 10 and the ceramic post 20, a suitable joining process can be selected in the DBC process, the AMB process, or the DBA process to achieve metallurgical bonding of the ceramic post 20 and the metal substrate 10.

[0092] In some embodiments, a planarization process is performed on the surface of the heat dissipation substrate 100 obtained after the first sintering process to expose the ceramic post 20. After the first sintering process, the ceramic post 20 can not be flush with the surface of the metal substrate 10. By grinding, polishing, or planarization in a mechanical-chemical polishing manner, the end surface of the metal substrate 10 and the end surface of the ceramic can be kept in the same plane, which facilitates the subsequent bonding of the metallized ceramic substrate 200.

[0093] In some embodiments, when the first sintering process is the DBC process, the first sintering process is performed in an inert atmosphere; or when the first sintering process is the AMB process or the DBA process, the first sintering process is performed in a vacuum environment.

[0094] When the first sintering process is the DBC process, the principle relies on the eutectic reaction of copper with precisely controlled trace oxygen. A small amount of oxygen can be added in an inert gas (such as high-purity nitrogen) protective atmosphere, which can provide the required oxygen for the reaction and prevent the copper from being over-oxidized and disabled, so as to achieve high-quality DBC bonding. When the first sintering process is the AMB process or the DBA process, there are active metals (such as Ti) or easily oxidizable aluminum. These elements will be instantaneously oxidized to form an inert layer in the air, resulting in complete failure of the process. Therefore, by using a high-vacuum environment, oxygen and moisture are completely eliminated, which provides protection for the pure chemical reaction between the active metal and the ceramic and the good wetting of aluminum, thereby obtaining a reliable metallurgical bonding interface.

[0095] In some embodiments, in the post implantation process, before each ceramic post 20 is implanted into the corresponding mounting hole 11, the ceramic post 20 is subjected to a first surface modification process to form an affinity layer containing transition metals (such as nickel, chromium, etc.) or non-metals (such as silicon dioxide, aluminum oxide, etc.), and the first surface modification process is performed when any one of the following conditions is met: (1) when the material of the metal substrate 10 is copper or copper alloy, the ceramic post 20 is an aluminum nitride ceramic post 20, and the first sintering process is the DBC process; (2) when the material of the metal substrate 10 is copper, aluminum, copper alloy, or aluminum alloy, the ceramic post 20 is an aluminum nitride ceramic post 20 or a silicon nitride ceramic post 20, and the first sintering process is the AMB process; (3) when the material of the metal heat dissipation substrate 100 is aluminum or aluminum alloy, the ceramic post 20 is an aluminum nitride ceramic post 20, and the first sintering process is the DBA process.

[0096] In the embodiments of the present application, if copper or copper alloy is used as the metal substrate 10, Al2O3 or ZTA ceramic column 20 is used as the ceramic column 20, and the first sintering process is performed by the DBC process, the Al2O3 or ZTA ceramic column 20 does not need to be subjected to the first surface modification process, and can be tightly combined with the hole wall in the subsequent first sintering process. When the material of the metal substrate 10 is copper or copper alloy, the ceramic column 20 is an AlN ceramic column 20, and the first sintering process is performed by the DBC process, the AlN ceramic column 20 is chemically inert and does not react with the Cu-O eutectic liquid. By surface modification, an Al2O3 transition layer is formed on the surface of the AlN ceramic column 20, and the Al2O3 transition layer can react with the Cu-O eutectic liquid to achieve firm combination. When the material of the metal substrate 10 is copper, aluminum, copper alloy or aluminum alloy, the ceramic column 20 is an AlN ceramic column 20 or a Si3N4 ceramic column 20, and the first sintering process is performed by the AMB process, the surface energy of the AlN and Si3N4 is low, and although the AlN and Si3N4 can react with the active metal, the effect is not good. By surface modification (such as coating a slurry containing Ti or sputtering a Ti layer), the high-activity reaction elements are enriched on the surface of the ceramic column 20, which can greatly promote and strengthen the chemical reaction with the solder in the subsequent AMB process, so that a more dense, more firm and lower thermal resistance interface layer is obtained, and the thermal conductivity reliability and service life of the final product are significantly improved. When the material of the metal substrate 100 is aluminum or aluminum alloy, the ceramic column 20 is an AlN ceramic column 20, and the first sintering process is performed by the DBA process, the wettability of aluminum and aluminum nitride is poor, and direct combination is difficult. Surface modification (such as forming a reaction layer containing transition metal elements such as nickel and titanium) of the AlN ceramic column 20 can significantly improve the wettability and spreading ability of molten aluminum, so that aluminum can fully wrap and penetrate the surface of the ceramic column 20, thereby achieving effective metallurgical bonding.

[0097] Reference Figure 3 As shown in FIG. 1, another embodiment of the present application provides a heat dissipation substrate 100, which is prepared by the preparation method described above, and includes a metal substrate 10 and a plurality of ceramic columns 20. The metal substrate 10 is provided with a plurality of mounting holes 11 in the thickness direction. Each ceramic column 20 is embedded in a corresponding mounting hole 11 and fixedly connected with the metal substrate 10. The end surface of the ceramic column 20 is flush with the surface of the metal substrate 10 or located in the metal substrate 10.

[0098] The heat dissipation substrate 100 provided by the embodiments of the present application 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, thereby significantly reducing the stress caused by thermal mismatch, effectively inhibiting the warping and deformation caused by the difference in the coefficient of thermal expansion of the metal and the metallized ceramic substrate 200 when the temperature changes, and facilitating the reduction of the thermal resistance layer and the non-influence on the heat dissipation effect, thereby providing strong support for solving the "heat dissipation bottleneck" and "reliability problem" in the field of high-end chips 60, especially high-power LEDs, IGBTs, radio frequency devices and the like.

[0099] Referring to Figure 2 and Figure 3 As shown in the figure, another embodiment of the present application provides a heat dissipation structure 1, at least one metallized ceramic substrate 200 is attached to the heat dissipation substrate 100 as described above along the thickness direction, and is made after a second sintering process; wherein the metallized ceramic substrate 200 includes two metal layers 40 arranged at intervals 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.

[0100] In the embodiments of the present application, the metallized ceramic substrate 200 on the heat dissipation substrate 100 in the heat dissipation structure 1 can be one or more, and the metallized ceramic substrate 200 can be bonded to the top surface of the heat dissipation substrate 100 along the thickness direction, or can be bonded to the bottom surface of the heat dissipation substrate 100 along the thickness direction, or even both surfaces of the heat dissipation substrate 100 along the thickness direction are bonded with the metallized ceramic substrate 200.

[0101] 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 solder layer 50 between the two, which reduces the thermal resistance interface, and since the coefficient of thermal expansion of the heat dissipation substrate 100 is adapted to the metallized ceramic substrate 200, no deformation and cracking phenomenon occurs during the second sintering process, so that the metallized ceramic substrate 200 and the heat dissipation substrate 100 are integrated.

[0102] In some embodiments, the metallized ceramic substrate 200 includes any one of a direct copper bonding (DBC) substrate, an active metal brazing (AMB) substrate, a direct aluminum bonding (DBA) substrate, a direct plating copper (DPC) substrate, a thin film metallization substrate or a thick film printing substrate; the DBC substrate, the AMB substrate, the DBA substrate, the DPC substrate, the thin film metallization substrate or the thick film printing substrate respectively refers to forming the metal layer 40 on the surface of the ceramic layer 30 along the thickness direction by the DBC process, the AMB process, the DBA process, the DPC process, the thin film metallization process or the thick film printing process.

[0103] In some embodiments, the second sintering process is any one of a direct copper bonding (DBC) process, an active metal brazing (AMB) process, a direct aluminum bonding (DBA) process, a direct plating copper (DPC) process, a thin film metallization process, or a thick film printing process. Depending on the material of the metal layer 40 and the metal substrate 10, a suitable joining process can be selected for the second sintering process to integrate the metallized ceramic substrate 200 and the heat dissipation substrate 100.

[0104] In some embodiments, the metal layer 40 is a single metal or an alloy of multiple metals. The metal layer 40 can be any one of copper, aluminum, copper alloy, or aluminum alloy.

[0105] In some embodiments, the metal layer 40 is 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, further reducing the number of thermal resistance interface layers and significantly improving the heat dissipation performance of the chip 60 in the electronic device.

[0106] In some embodiments, the ceramic layer 30 is any one of aluminum oxide (Al2O3), aluminum nitride (AIN), zirconia toughened alumina (ZTA), silicon nitride (Si3N4), or silicon carbide (SiC).

[0107] In some embodiments, before the metallized ceramic substrate 200 is attached to the heat dissipation substrate 100 along the thickness direction, a second surface modification process is performed on the abutting surfaces of the metallized ceramic substrate 200 and the heat dissipation substrate 100 to form a transition layer, 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 copper or copper alloy. Before the metallized ceramic substrate 200 is attached to the heat dissipation substrate 100 along the thickness direction, an oxidation process is performed on the abutting surfaces of the metallized ceramic substrate 200 and the heat dissipation substrate 100 to form a copper oxide layer (i.e., a transition layer).

[0108] For example, the second surface modification process 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 copper or copper alloy, the second surface modification process can form a transition metal element layer using active metal solder; 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 aluminum or aluminum alloy, the second surface modification process can form a transition film containing aluminum or aluminum alloy using soldering, electroplating, or sputtering; 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 copper or copper alloy, the second surface modification process can form a copper oxide layer using an oxidation process.

[0109] Reference Figure 3 In another embodiment of the present application, an electronic device packaging structure 1000 is provided, which comprises a chip 60, a solder layer 50 and the heat dissipation structure 1 as described above, the solder layer 50 is connected to the chip 60 and the surface of the metal layer 40 of the heat dissipation structure 1 respectively along the two sides in the thickness direction.

[0110] It can be found that in the electronic device packaging structure 1000 provided by the embodiment of the present application, the heat of the chip 60 can be conducted in the thickness direction by the chip 60, the solder layer 50, the metallized ceramic substrate 200 (the metal layer 40, the ceramic layer 30, the metal layer 40) and the heat dissipation substrate 100 in turn, and the thermal resistance interface layer originally caused by the solder layer 50 between the metal layer 40 of the heat dissipation substrate 100 and the heat dissipation substrate 100 is cancelled, so that the electronic device packaging structure 1000 has higher heat dissipation efficiency and overall stability.

[0111] The following examples more specifically describe the present disclosure, which are only used for illustrative purposes, because various modifications and changes within the scope of the present disclosure are obvious to those skilled in the art. Unless otherwise stated, all reagents and raw materials used in the examples are commercially available or synthesized according to conventional methods, and the instruments used in the examples are commercially available. Example 1

[0112] 1. Preparation of Cu-Al2O3 heat dissipation substrate 100:

[0113] (1) Metal substrate 10 processing procedure: 120 through holes 120 with a diameter of φ1mm are processed on a copper metal substrate 10 with a size of 50*95*3(mm) by CNC processing to form a 10*12 arrangement matrix, and the hole spacing is 2mm. The hole wall is oxidized by introducing oxygen elements to the hole wall by chemical oxidation (wet oxidation).

[0114] (2) Column implantation procedure: the Al2O3 ceramic column 20 is cleaned, and the 120 cleaned Al2O3 ceramic columns 20 are inserted into the through holes to obtain a combined body, and the specification of the ceramic column 20 is φ1mm*3mm;

[0115] (3) Forming procedure: the combined body is placed in a nitrogen protection tunnel furnace, and the Cu metal substrate 10 with holes and the Al2O3 ceramic column 20 are sintered together by DBC process to form a Cu-Al2O3 heat dissipation substrate 100, and the sintering conditions are as follows: the highest temperature is 1080℃; the holding time is 20min; and the oxygen content in the sintering environment is about 100ppm. After the upper and lower surfaces of the heat dissipation substrate 100 are planarized by chemical mechanical polishing (CMP), the heat dissipation substrate 100 is cleaned.

[0116] (4) Surface treatment process, the copper surface of the Cu-Al2O3 heat dissipation substrate 100 is oxidized by chemical oxidation (wet oxidation) process. The copper foil is sintered on the upper and lower surfaces of the Cu-Al2O3 heat dissipation substrate 100 by DBC process to form a metal covering layer covering the metal substrate 10 and the ceramic column 20. The copper foil has a specification of 60*100*0.3 (mm), and the sintering conditions are the same as those in step (3).

[0117] 2. Preparation of the heat dissipation structure 1:

[0118] The four Al2O3-DBC metalized ceramic substrates 200 (the ceramic layer 30 is Al2O3, and the metal layer 40 is copper) are sintered on the metal covering layer of the Cu-Al2O3 heat dissipation substrate 100 by DBC process. The Al2O3-DBC metalized ceramic substrate 200 has a specification of 40*20*0.38 (mm) and is double-sided copper-clad. The sintering conditions are the same as those in step (3). Example 2

[0119] 1. Preparation of the Cu-Si3N4 heat dissipation substrate 100:

[0120] (1) Metal substrate 10 treatment process, 60 through holes with a diameter of φ1 mm are machined on the copper metal substrate 10 with a specification of 91*31*3 (mm) by using a laser cutting machine to form a 10*6 arrangement matrix with a hole spacing of 2 mm. The hole walls are oxidized by introducing oxygen elements to the hole walls by chemical oxidation (wet oxidation).

[0121] (2) Column implantation process, the Ag-Cu-Ti solder is applied to the Si3N4 ceramic column 20 by the first surface modification treatment to form an affinity layer containing transition metals, and the 60 Si3N4 ceramic columns 20 after surface modification are implanted into the through holes to obtain a combination. The specification of the Si3N4 ceramic column 20 is φ1*3 (60).

[0122] (3) Forming process, the combination is placed in a nitrogen protection tunnel furnace, and the Cu metal substrate 10 with holes and the Si3N4 ceramic column 20 are sintered together by DBC process to form a Cu-Si3N4 heat dissipation substrate 100. The sintering conditions are as follows: the highest temperature is 1065°C; the holding time is 20 min; and the oxygen content in the sintering environment is about 5 ppm. After the upper and lower surfaces of the Cu-Si3N4 heat dissipation substrate 100 are planarized by chemical mechanical polishing (CMP), it is cleaned.

[0123] 2. Preparation of the heat dissipation structure 1:

[0124] The copper surface on the upper and lower surfaces of the heat dissipation substrate 100 is oxidized by a chemical oxidation (wet oxidation) process. Two pieces of AlN-DBC metallized ceramic substrate 200 (ceramic layer 30 is AlN and metal layer 40 is copper) are sintered on the Cu-Si3N4 heat dissipation substrate 100 by a DBC process. The AlN-DBC metallized ceramic substrate 200 has a specification of 42.5*23*0.635 (mm) and is double-sided copper-clad. The sintering conditions are the same as step (3). Example 3

[0125] 1. Preparation of Al-AlN heat dissipation substrate 100:

[0126] (1) Metal substrate 10 processing procedure: Select an aluminum metal substrate 10 with a specification of 60*120*6 (mm), and use CNC to process 160 blind holes with a diameter of φ2 mm*3.1 mm, arranged in a 20*8 matrix with a hole spacing of 2 mm, symmetrically in the middle of the aluminum metal substrate 10.

[0127] (2) Column implantation procedure: Apply Ag-Cu-Ti solder to the AIN ceramic column 20 through first surface modification treatment to form an affinity layer containing transition metals, and implant the 160 AIN ceramic columns 20 with surface modification into the blind holes, so that the end plane of the AIN ceramic column 20 is lower than the surface of the aluminum metal substrate 10, to obtain a combination. The specification of the AIN ceramic column 20 is φ2 mm*3 mm.

[0128] (3) Forming procedure: Place the combination in a vacuum furnace and use the DBA process to sinter the aluminum metal substrate 10 with holes and the AIN ceramic column 20 together to form an Al-AlN heat dissipation substrate 100. The sintering conditions are as follows: the highest temperature is 650°C; the holding time is 30 min; and the vacuum degree inside the vacuum furnace is maintained below 5*10-2 Pa. The upper and lower surfaces of the obtained Al-AlN heat dissipation substrate 100 are mechanically polished to make the end face of the AIN ceramic column 20 and the surface of the aluminum metal substrate 10 remain in the same plane.

[0129] 2. Preparation of heat dissipation structure 1:

[0130] A layer of solder containing aluminum is printed on the bonding surface (non-patterned surface) of the AlN-DBA metalized ceramic substrate 200 (ceramic layer 30 is AlN, and metal layer 40 is aluminum) by using a screen printing process, and then dried. The AlN-DBA metalized ceramic substrate 200 printed with the solder containing aluminum is placed on the Al-AlN heat dissipation substrate 100, and then placed in a vacuum furnace. The AlN-DBA metalized ceramic substrate 200 is sintered on the Al-AlN heat dissipation substrate 100 by using a DBA process, and the integration of the AlN-DBA metalized ceramic substrate 200 and the Al-AlN heat dissipation substrate 100 is completed. The AlN-DBA metalized ceramic substrate 200 has a specification of 42.5*23*0.635 (mm) and is double-sided aluminum-coated. The sintering conditions are the same as those in step (3).

[0131] The electronic device package structure 1000 is obtained by welding through the reattachment of the chip 60 on the metal layer 40 of the heat dissipation structure 1 obtained in each of embodiments 1-3 by applying solder on the metal layer 40, and the formation of the brazing layer 50 between the chip 60 and the metal layer 40 after the solidification of the solder.

[0132] Therefore, the preparation method of the embodiments of the present application can adjust the thermal expansion coefficient of the heat dissipation substrate 100, reduce the packaging thermal resistance interface of the power electronic device from at least 6 layers to at least 4 layers, significantly improve the heat dissipation performance, and realize the reduction of the thermal resistance interface while meeting the requirements of non-deformation and cracking of the metalized ceramic substrate 200 directly bonded to the heat dissipation substrate 100, thereby improving the reliability of the power electronic device.

[0133] The above-described technical features can be combined arbitrarily. Although all possible combinations of the technical features are not described, any combination of the technical features should be considered to be covered by the present specification, as long as there is no contradiction in such a combination.

[0134] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a heat dissipation substrate, characterized in that, The heat dissipation substrate is used to bond a metal layer of a metallized ceramic substrate along the thickness direction, and the preparation method 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; In the surface treatment process, the surface of the heat dissipation substrate with exposed ceramic pillars is metallized to form a metal cover layer covering the metal substrate and the ceramic pillars; wherein, the metal cover layer simultaneously covers multiple ceramic pillars and the metal substrate, and forms a continuous piece with the metal substrate.

2. The method for preparing a heat dissipation substrate according to claim 1, 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.

3. The method for preparing a heat dissipation substrate according to claim 2, 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.

4. The method for preparing a heat dissipation substrate according to claim 3, 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.

5. The method for preparing a heat dissipation substrate according to claim 3, 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 metal substrate is made of aluminum or aluminum alloy, the ceramic pillar is an aluminum nitride ceramic pillar, and the first sintering process adopts a direct aluminum coating process.

6. A heat dissipation substrate, characterized in that, Made by the preparation method according to any one of claims 1 to 5, comprising a metal substrate and a plurality of ceramic pillars, wherein the metal substrate is provided with a plurality of mounting holes along the thickness direction, each of the ceramic pillars is embedded in the corresponding mounting hole and fixedly connected to the metal substrate, and the end face of the ceramic pillar is flush with the surface of the metal substrate or located within the metal substrate.

7. 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 6, 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.

8. The heat dissipation structure according to claim 7, 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.

9. An electronic device packaging structure, characterized in that, It includes a chip, a solder layer, and a heat dissipation structure as described in claim 8, 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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