A method for preparing multi-layer metallization on the surface of ceramic heat sink

Abstract

The present invention provides a method for preparing multilayer metallization on the surface of a ceramic heat sink, which includes depositing a layer of silicon-based compound film on the surface of a ceramic substrate by plasma enhanced chemical vapor deposition to provide a strong adhesion foundation and reduce the risk of the metal layer falling off or peeling off; depositing a titanium metal layer by molecular beam epitaxy, and depositing a nano-quantum dot structure on the titanium metal surface to enhance the high temperature resistance and thermal stability of the metallization layer; using a spray pyrolysis method to deposit a layer of silicon dioxide to provide effective electrical isolation and improve the anti-puncture ability of the metallization layer; then depositing a metallization layer on the silicon dioxide layer by photolithography technology, and controlling the conductive path of the metallization layer by an adaptive morphology optimization algorithm; depositing a solder layer by micro-sized solder particles to ensure electrical connection between modules. This method effectively solves the problems of poor adhesion, insufficient electrical isolation and poor high temperature resistance of the metal layer in the prior art.

Description

Technical Field

[0001] The invention relates to a method for preparing multi-layer metallization on the surface of a ceramic heat sink. Background Art

[0002] As the functions of electronic devices become increasingly complex, the demand for thermal management systems is increasing. Ceramic heat sinks have become one of the commonly used heat dissipation materials in electronic devices due to their excellent thermal conductivity and mechanical strength. However, due to the brittleness of ceramics themselves and the difficulty in effectively connecting with metals, the surface metallization of ceramic heat sinks has always been a technical problem.

[0003] Although the existing ceramic heat sink metallization technology can provide certain electrical conductivity and thermal conductivity, it has problems such as weak adhesion of the metallization layer, poor high temperature resistance, and incomplete electrical isolation, especially in high-precision and high-voltage applications. In addition, as miniaturized electronic devices have higher requirements for heat sink volume and power density, traditional metallization methods are difficult to meet the increasingly stringent performance requirements.

[0004] Therefore, how to achieve multi-layer metallization on the surface of the ceramic heat sink and solve the problems of poor adhesion, insulation and high temperature resistance of the metal layer in the prior art are technical problems that need to be solved. Summary of the invention

[0005] The purpose of the present invention is to solve the above shortcomings of the prior art and provide a method for preparing a ceramic heat sink surface multilayer metallization, so as to solve the problems of poor adhesion, insufficient electrical isolation and poor high temperature resistance of the metal layer in the prior art, and significantly improve the reliability and performance of the electronic module. This purpose of the present invention is achieved as follows:

[0006] The present invention provides a method for preparing multi-layer metallization on the surface of a ceramic heat sink, comprising: depositing a silicon-based compound film on the surface of a ceramic substrate by plasma enhanced chemical vapor deposition; depositing a titanium metal layer by molecular beam epitaxial deposition, and depositing a nano-quantum dot structure on the surface of the titanium metal layer; depositing a silicon dioxide layer on the surface of the titanium metal layer by spray pyrolysis; depositing a metallization layer on the silicon dioxide by photolithography technology, and controlling the conductive path of the metallization layer by an adaptive morphology optimization algorithm; and depositing a solder layer on the metallization layer by micro-sized solder particles.

[0007] Furthermore, the method of depositing a layer of silicon-based compound film on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition includes: cleaning the ceramic surface with argon or nitrogen; selecting a chemical gas containing dimethylsilane or silicon tetrachloride, exciting the chemical gas and depositing it on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition to form a uniform silicon-based compound film.

[0008] Furthermore, the method of depositing a titanium metal layer by molecular beam epitaxy deposition and depositing a nano-quantum dot structure on the surface of the titanium metal layer includes: selecting titanium tetrachloride as a titanium metal source; depositing a titanium metal source molecular beam onto the surface of a ceramic substrate by molecular beam epitaxy deposition in a high vacuum environment; selecting cadmium sulfide or gallium nitride as a quantum dot material, and uniformly depositing the quantum dot material on the surface of the titanium metal layer by evaporation deposition or solution immersion method; and heat treating or light irradiating the titanium metal layer.

[0009] Furthermore, the deposition of a layer of silicon dioxide by spray pyrolysis includes: preparing a precursor solution containing silane or tetramethylsilane, and atomizing it into fine particles by a spray pyrolysis device; spraying the atomized precursor solution onto the surface of the titanium metal, and heating the precursor solution to decompose and deposit a silicon dioxide film at high temperature.

[0010] Furthermore, the deposition of a metallization layer on silicon dioxide by photolithography technology includes: coating a photoresist on the silicon dioxide insulating layer, and using ultraviolet light to expose the photoresist according to a designed pattern; removing unexposed areas of the photoresist through a development process to form a pattern of a metallization area; depositing a metal material in the exposed area, and uniformly depositing the metal material on the photoresist pattern by evaporation or sputtering to form a metallization layer.

[0011] Furthermore, controlling the conductive path by the adaptive morphology optimization algorithm includes: simulating the conductive path, and obtaining the shape and layout of the conductive path according to heat conduction, current density and electrical isolation requirements.

[0012] Furthermore, the method of depositing a solder layer on the metallization layer using micro-sized solder particles includes: uniformly distributing the solder particles on the surface of the metallization layer by solution immersion or spraying; and heating the solder particles to their melting point using ultrasonic welding technology to form a uniform solder layer on the surface of the metallization layer.

[0013] Furthermore, the micro-sized solder particle material is Sn-Ag-Cu alloy or Sn-Pb alloy.

[0014] Compared with the prior art, the beneficial effects of the present invention are: by depositing a silicon-based compound film, a strong adhesion foundation is provided for the metallization layer, effectively reducing the risk of the metal layer falling off or peeling off; by depositing a silicon dioxide layer by spray pyrolysis, effective electrical isolation is provided, the anti-puncture capability of the metallization layer is improved, and electrical safety is ensured; by depositing a titanium metal layer by molecular beam epitaxy and combining it with the deposition of a nano-quantum dot structure, the high temperature resistance and thermal stability of the metallization layer are enhanced, solving the problem of material performance degradation caused by temperature changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1The present invention is a schematic flow chart of a method for preparing multi-layer metallization on the surface of a ceramic heat sink. DETAILED DESCRIPTION

[0016] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0017] like Figure 1 As shown, an embodiment of the present invention provides a method for preparing multi-layer metallization on the surface of a ceramic heat sink, including: S1, depositing a layer of silicon-based compound film on the surface of a ceramic substrate by plasma enhanced chemical vapor deposition to provide a strong adhesion basis for the subsequent metallization process, reduce the risk of shedding or peeling of the metallization layer, and improve the stability of the overall structure.

[0018] S2. Deposit a titanium metal layer by molecular beam epitaxial deposition, and deposit a nano-quantum dot structure on the surface of the titanium metal layer to allow the titanium metal layer to be evenly combined with the surface of the ceramic substrate, provide good electrical conductivity and thermal conductivity, and make the surface of the metal layer smoother to facilitate subsequent nano-quantum dot deposition.

[0019] S3. Depositing a layer of silicon dioxide on the surface of the titanium metal layer by spray pyrolysis to uniformly deposit a layer of silicon dioxide on the titanium metal layer, thereby providing effective electrical isolation and enhancing the breakdown voltage resistance and thermal stability of the metallization layer.

[0020] S4. Deposit a metallization layer on silicon dioxide by photolithography technology, and control the conductive path of the metallization layer by an adaptive morphology optimization algorithm to simulate the thermal conduction, current density and electrical isolation requirements of the conductive path, and optimize the shape and layout of the conductive path.

[0021] S5. A solder layer is deposited on the metallization layer by micro-sized solder particles to form a uniform solder layer, thereby effectively achieving electrical connection between different modules without affecting the electrical performance and thermal conductivity of the metallization layer.

[0022] In this embodiment, a silicon-based compound film is deposited by PECVD to provide a strong adhesion basis for the metallization layer, effectively reducing the risk of the metal layer falling off or peeling off; a silicon dioxide layer is deposited by spray pyrolysis to provide effective electrical isolation, thereby improving the anti-puncture capability of the metallization layer and ensuring electrical safety; a titanium metal layer is deposited by molecular beam epitaxy and combined with the deposition of a nano-quantum dot structure to enhance the high temperature resistance and thermal stability of the metallization layer and solve the problem of material performance degradation caused by temperature changes.

[0023] Specifically, during the metallization process of the ceramic substrate, the ceramic surface is relatively smooth or fragile, resulting in poor adhesion of the metal layer. Traditional metallization methods, such as direct deposition of the metal layer or the use of simple metallization treatment, often fail to ensure the firm adhesion between the metal layer and the ceramic substrate, and are prone to falling off or peeling. A layer of silicon-based compound film is deposited on the surface of the ceramic substrate by PECVD, which provides a strong adhesion basis and effectively enhances the bonding between the metal layer and the ceramic substrate. The compactness and uniformity of the silicon-based compound film reduce the risk of metal layer peeling and improve the stability of the overall structure. During the multi-layer metallization process of the ceramic heat sink, the electrical isolation between the metal layers is insufficient, especially under high-voltage environments, which is prone to short circuits or electrical breakdown, resulting in system performance degradation or damage. A layer of silicon dioxide is deposited on the surface of the titanium metal layer by spray pyrolysis, which can effectively isolate the electrical connection between the metallization layers. The spray pyrolysis method allows the silicon dioxide layer to be uniformly deposited on the surface of the titanium metal layer, thereby providing reliable electrical isolation, solving the problem of electrical isolation between metallization layers, and enhancing the electrical safety and reliability of the system. After the ceramic substrate is metallized, the metal layer is prone to performance degradation in a high temperature environment, especially the connection between the metal layer and the ceramic substrate will fail due to the mismatch of thermal expansion coefficients, resulting in structural damage. A titanium metal layer is deposited by molecular beam epitaxy deposition, and a nano-quantum dot structure is deposited on the surface of the titanium metal layer. The deposition of the nano-quantum dot structure can improve the thermal conductivity and electron mobility of the titanium metal layer, thereby enhancing the thermal stability and high temperature resistance of the metallization layer. The conductive path is controlled by photolithography technology and an adaptive morphology optimization algorithm to reduce the risk of failure due to overheating. It can also reduce heat accumulation through precise layout and further improve thermal stability. The deposition of the titanium metal layer and the nano-quantum dot structure effectively improves the high temperature resistance of the metal layer and reduces the risk of failure of the metal layer in a high temperature environment. The adaptive morphology optimization algorithm effectively avoids material fatigue and performance degradation caused by thermal expansion.

[0024] It should be noted that plasma enhanced chemical vapor deposition, abbreviated as PECVD deposition, is a thin film deposition technology that uses high-energy plasma to stimulate chemical reactions, decompose reactants in the gas and deposit them on the surface of the substrate. In this process, the plasma provides high-energy electrons, enhances the reactivity of the reactants, and thus achieves deposition at a lower temperature; molecular beam epitaxial deposition is a material deposition technology under high vacuum conditions, which uses a molecular beam source to evaporate titanium metal and introduce it into a deposition chamber, and then deposits titanium atoms on the substrate surface through a high vacuum environment; spray pyrolysis is a method in which a liquid precursor solution is atomized into fine particles by a sprayer and pyrolyzed and deposited in a high-temperature environment. In this method, a solution containing a silicon source is sprayed onto the surface of the titanium metal layer, and the silicon source is decomposed and deposited into a silicon dioxide film by heating; photolithography technology uses photoresist to coat the silicon dioxide surface, and transfers the design pattern to the photoresist by ultraviolet light exposure.

[0025] Furthermore, the deposition of a layer of silicon-based compound film on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition includes: using argon or nitrogen to clean the ceramic surface; selecting a chemical gas containing dimethylsilane or silicon tetrachloride, exciting and depositing the chemical gas on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition to form a uniform silicon-based compound film. Specifically, using argon or nitrogen to clean the surface of the ceramic substrate to remove impurities and oxides on the surface to ensure the surface is clean; exciting silicon-containing gases such as dimethylsilane or silicon tetrachloride and depositing them on the ceramic surface to form a uniform and dense silicon-based compound film. The deposition of the silicon-based film improves the adhesion of the metallization layer and further reduces the peeling and shedding problems between the metal layer and the ceramic substrate. For example, a dimethylsilane film with a thickness of about 200nm is deposited on the surface of the ceramic substrate.

[0026] Further, the method of depositing a titanium metal layer by molecular beam epitaxy deposition and depositing a nano-quantum dot structure on the surface of the titanium metal layer includes: selecting titanium tetrachloride as a titanium metal source; depositing the titanium metal source molecular beam onto the surface of the ceramic substrate by molecular beam epitaxy deposition under a high vacuum environment; selecting cadmium sulfide or gallium nitride as a quantum dot material, and uniformly depositing the quantum dot material on the surface of the titanium metal layer by evaporation deposition or solution impregnation; and heat treating or light irradiating the titanium metal layer. Specifically, titanium tetrachloride is used as a titanium metal source, and titanium molecules are uniformly deposited on the ceramic surface by molecular beam epitaxy technology; the titanium metal layer can be uniformly combined with the ceramic surface, further providing good electrical conductivity and thermal conductivity, ensuring the smoothness of the metal layer, and facilitating the subsequent deposition of the quantum dot structure, for example, in a high vacuum environment, a titanium layer is deposited by molecular beam epitaxy, the thickness of which is controlled to be 50-100nm, and then a cadmium sulfide quantum dot material is deposited on the titanium surface by evaporation to form a quantum dot structure.

[0027] Furthermore, the deposition of a layer of silicon dioxide by spray pyrolysis includes: preparing a precursor solution containing silane or tetramethylsilane, and atomizing it into fine particles by a spray pyrolysis device; spraying the atomized precursor solution onto the surface of the titanium metal, and decomposing the precursor solution at high temperature by heating to deposit a silicon dioxide film. Specifically, a precursor solution containing silane or tetramethylsilane is used, and it is atomized into tiny particles by a spray pyrolysis device; the high-temperature decomposition process deposits a uniform silicon dioxide film on the surface of the titanium metal, further forming an effective electrical isolation layer, and enhancing the breakdown voltage resistance and thermal stability of the metallization layer. For example, a tetramethylsilane solution is sprayed onto the surface of the titanium metal layer by spray pyrolysis, and a silicon dioxide isolation layer with a thickness of 300nm is formed after heating.

[0028] Furthermore, the deposition of the metallization layer on the silicon dioxide by photolithography technology includes: coating a photoresist on the silicon dioxide insulating layer, and using ultraviolet light to expose the photoresist according to the designed pattern; removing the unexposed area of ​​the photoresist by a development process to form a pattern of the metallization area; depositing a metal material in the exposed area, and uniformly depositing the metal material on the photoresist pattern by evaporation or sputtering to form a metallization layer. Specifically, the photoresist is coated and exposed by ultraviolet light, and then the unexposed area is removed by development, leaving the pattern of the metallization area; by depositing the metal material in the exposed area, a precise metallization layer is formed, and this layer will become the conductive path of the circuit, further realizing the effective conduction of the current, for example, the photoresist is exposed by ultraviolet light, and after development, a 100nm copper layer is deposited in the exposed area, and a metallization pattern is formed by sputtering technology.

[0029] Furthermore, controlling the conductive path by the adaptive morphology optimization algorithm includes: simulating the conductive path, and obtaining the shape and layout of the conductive path according to heat conduction, current density and electrical isolation requirements.

[0030] In this embodiment, the conductive path of the metallization layer is simulated by using the finite element analysis method. The thermal conductivity, current density distribution and electrical isolation requirements of the conductive path are considered during the simulation process. In particular, by simulating the thermal conduction path, the stability of the metallization layer at high temperature can be ensured; by current density analysis, the uniform distribution of the current can be optimized to avoid local overheating or current concentration caused by excessive current density. The shape and layout of the conductive path are adjusted according to the simulation results using an adaptive morphological optimization algorithm. The algorithm can automatically adjust the layout of the conductive path according to the requirements of the actual use environment, such as power load, electrical isolation, thermal conduction and other factors, to achieve the best electrical and thermal performance. For example, in hotter areas, the conductive path may be designed to be thicker to disperse heat; while in areas where high electrical isolation is required, the shape of the conductive path may be designed to be more complex and fine; the conductive path optimized by the adaptive morphological optimization algorithm can not only ensure efficient current conduction, but also effectively prevent electrical breakdown, local overheating and current unevenness.

[0031] Furthermore, the method of depositing a solder layer on the metallization layer using micro-sized solder particles includes: uniformly distributing the solder particles on the surface of the metallization layer by solution immersion or spraying; and heating the solder particles to their melting point using ultrasonic welding technology to form a uniform solder layer on the surface of the metallization layer.

[0032] Furthermore, the micro-sized solder particle material is Sn-Ag-Cu alloy or Sn-Pb alloy.

[0033] In this embodiment, first, a suitable micro-sized solder particle material is selected, such as Sn-Ag-Cu alloy or Sn-Pb alloy, and the solder particles are mixed with a suitable solvent, such as ethanol or acetone, as needed to prepare a uniform solution or suspension, and the size of the solder particles in the solution is controlled between 1 μm and 10 μm to be evenly distributed and well cover the surface of the metallization layer; a solution immersion method or a spray deposition method is used to evenly distribute the solder particles on the surface of the metallization layer. If the solution immersion method is used, the metallization layer is immersed in the solder particle solution to ensure that the solder particles are evenly attached to the surface; and the spray deposition method uses a spray device to spray the solder particle solution on the surface of the metallization layer to form a uniform A thin layer of solder particles; after the solder particles are evenly distributed, ultrasonic welding equipment is used to heat the solder particles to their melting point. Ultrasonic welding technology can transfer heat to the solder particles through high-frequency vibration, causing them to melt and flow quickly, filling the tiny gaps on the surface of the metallization layer. After the solder particles melt during the heating process, a uniform solder layer is quickly formed on the surface of the metallization layer. The thickness of the solder layer is controlled between 20μm and 50μm to ensure good connection and reliability of the solder layer; after the soldering is completed, the solder layer is gradually solidified by natural cooling or controlling the cooling rate. The solidification process of the solder layer ensures that the solder particles form a stable metal connection and does not affect the electrical properties and thermal conductivity of the metallization layer. The solder layer deposited by micro-sized solder particles can not only ensure the electrical connection between modules, but also effectively prevent defects such as bubbles and pores generated during the welding process. Ultrasonic welding technology can ensure that the solder layer is uniform and dense, and the formed solder layer has high mechanical strength and thermal stability. For example, Sn-Ag-Cu alloy micro-sized particles are used, and the solder particles are evenly distributed on the surface of the metallization layer using a solution immersion method. Then, ultrasonic welding technology is used to heat it to 220°C, and the thickness of the welding layer is 30μm, finally forming a uniform and reliable welding layer.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing multi-layer metallization on the surface of a ceramic heat sink, characterized in that: include: Depositing a silicon-based compound film on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition; A titanium metal layer is deposited by molecular beam epitaxy, and a nano-quantum dot structure is deposited on the surface of the titanium metal layer; a silicon dioxide layer is deposited on the surface of the titanium metal layer by spray pyrolysis; a metallization layer is deposited on the silicon dioxide by photolithography technology, and the conductive path of the metallization layer is controlled by an adaptive morphology optimization algorithm; a solder layer is deposited on the metallization layer by micro-sized solder particles.

2. A method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The method of depositing a layer of silicon-based compound film on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition includes: using argon or nitrogen to clean the ceramic surface; selecting a chemical gas containing dimethylsilane or silicon tetrachloride, exciting the chemical gas and depositing it on the surface of the ceramic substrate by plasma enhanced chemical vapor deposition to form a uniform silicon-based compound film.

3. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The method of depositing a titanium metal layer by molecular beam epitaxy deposition and depositing a nano-quantum dot structure on the surface of the titanium metal layer includes: selecting titanium tetrachloride as a titanium metal source; depositing a titanium metal source molecular beam onto the surface of a ceramic substrate by a molecular beam epitaxy deposition method under a high vacuum environment; selecting cadmium sulfide or gallium nitride as a quantum dot material, and uniformly depositing the quantum dot material on the surface of the titanium metal layer by evaporation deposition or solution impregnation; and heat treating or light irradiating the titanium metal layer.

4. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The method of depositing a layer of silicon dioxide by spray pyrolysis includes: preparing a precursor solution containing silane or tetramethylsilane, and atomizing it into fine particles by a spray pyrolysis device; spraying the atomized precursor solution onto the surface of titanium metal, and heating the precursor solution to decompose and deposit it into a silicon dioxide film at high temperature.

5. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The method of depositing a metallization layer on silicon dioxide by photolithography technology includes: coating a photoresist on the silicon dioxide insulating layer, and using ultraviolet light to expose the photoresist according to a designed pattern; removing the unexposed area of ​​the photoresist by a development process to form a pattern of the metallization area; depositing a metal material in the exposed area, and uniformly depositing the metal material on the photoresist pattern by evaporation or sputtering to form a metallization layer.

6. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The controlling of the conductive path by the adaptive morphology optimization algorithm includes: simulating the conductive path, and obtaining the shape and layout of the conductive path according to heat conduction, current density and electrical isolation requirements.

7. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 1, characterized in that: The method of depositing a solder layer on the metallization layer using micro-sized solder particles includes: uniformly distributing the solder particles on the surface of the metallization layer by solution immersion or spraying; and heating the solder particles to their melting point using ultrasonic welding technology to form a uniform solder layer on the surface of the metallization layer.

8. The method for preparing a ceramic heat sink surface multilayer metallization according to claim 7, characterized in that: The micro-sized solder particle material is Sn-Ag-Cu alloy or Sn-Pb alloy.

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