Preparation method of tungsten-copper composite film for heat sink material
By using magnetron sputtering technology to prepare tungsten copper composite films at room temperature, the substrate damage and process complexity caused by high-temperature treatment in the prior art are solved, and the preparation and process simplification of high-quality films are achieved.
Patent Information
- Application Number
- CN202411954176.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-18
AI Technical Summary
The existing tungsten-copper composite film preparation technology has problems such as high-temperature treatment that causes thermal damage to the substrate, complex process and high energy consumption, and insufficient bonding performance between the film and the substrate.
Magnetically controlled sputtering technology is used to prepare tungsten copper composite films at room temperature. Preheating, sample transfer and annealing are avoided by performing specific pretreatment of the substrate and luminous, presputtering and formal sputtering operations on tungsten and copper targets.
The high-quality preparation of tungsten-copper composite film is achieved, which avoids damage to the substrate by high temperature, simplifies the process flow, reduces energy consumption and cost, and improves the interface bonding strength and thermal conductivity of the film.
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Figure CN119843231A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of thermal management, and in particular to a method for preparing a tungsten-copper composite film for a heat sink material. Background Art
[0002] As an advanced material, tungsten-copper composite film has demonstrated its unique advantages in the field of thermal management. Compared with a single material, tungsten-copper composite film can not only significantly improve the overall thermal conductivity, but also has the characteristics of providing excellent structural stability in high-temperature environments, which makes it an ideal choice for high-power electronic devices, semiconductor packaging and high-temperature thermal management systems. By regulating the thickness of tungsten and copper and the microstructure of the film, specific performance can be optimized for different application requirements, thereby adapting to various complex application scenarios. These research results provide important theoretical basis and technical support for the development of new thermal management materials, and promote the continuous innovation and progress of high-performance thermal management materials. At present, the mainstream preparation technology of tungsten-copper composite film is chemical vapor deposition and evaporation coating. Among them, the former usually needs to be carried out under high temperature conditions (usually between 500°C and 1000°C) to ensure that the reaction precursor can be decomposed and deposited as a film. This will bring challenges to some temperature-sensitive substrate materials, which may easily cause thermal damage or deformation of the substrate material. For the latter, the material needs to be heated to its evaporation temperature to achieve coating. As a high melting point metal, tungsten makes the evaporation process of tungsten extremely challenging and energy-intensive, resulting in significant deficiencies in the economy and feasibility of the process. In addition, the insufficient interface bonding performance between the film and the substrate is also an urgent problem to be solved. During the film preparation process, the interface bonding between the film and the substrate is poor. This insufficient bonding can cause the film to warp, crack or fall off under thermal cycles, mechanical loads or external environmental stresses, seriously affecting the reliability and service life of the film. Therefore, it is necessary to improve the interfacial bonding strength between the film and the substrate through specific surface modification steps. Magnetron sputtering is a physical vapor deposition technology used to deposit thin films on various substrates. It uses the interaction of magnetic fields and electric fields in a vacuum environment to sputter out atoms or molecules of the target material and deposit them on the substrate to form a thin film. However, the tungsten-copper composite films currently prepared by magnetron sputtering require preheating of the substrate, magnetron sputtering under insulation, and additional heat treatment.
[0003] Disadvantages of existing technology:
[0004] At present, the preparation methods of tungsten-copper composite thin films mainly include the following categories: chemical vapor deposition, electroplating, salt bath coating and vacuum evaporation coating.
[0005] Chemical vapor deposition requires high temperatures (usually above 500°C), high heat resistance requirements for the substrate material, which may cause deformation or damage to the substrate and a complex process requiring precise control of gas flow and reaction conditions.
[0006] For electroplating, the coating quality is greatly affected by the solution composition and current density, and it is difficult to obtain a uniform and dense coating. In addition, the coating may contain impurities, which reduces the purity and thermal conductivity of the film.
[0007] For salt bath coating, the coating thickness and uniformity are difficult to control precisely, resulting in large fluctuations in coating performance.
[0008] For vacuum evaporation coating, it is difficult to evaporate high melting point metals (such as tungsten), which requires extremely high temperatures, complex equipment, and high energy consumption. In addition, the adhesion of the coating is weak because the vapor particles have low kinetic energy during deposition and cannot penetrate well into the substrate surface. Summary of the invention
[0009] In view of this, the present invention provides a method for preparing a tungsten-copper composite film for a heat sink material, so as to achieve the purpose of low cost, high efficiency, high safety, good structural integrity and high interface bonding strength.
[0010] The present invention provides the following technical solution: a method for preparing a tungsten-copper composite film for a heat sink material, comprising the following steps:
[0011] Pre-process the substrate and install the tungsten and copper targets into the magnetron sputtering machine;
[0012] Carry out ignition, pre-sputtering and formal sputtering operations on tungsten target and copper target respectively;
[0013] Turn off all devices and take out the tungsten target or copper target.
[0014] Furthermore, pre-treating the substrate includes: ultrasonically cleaning the substrate with isopropanol, acetone and alcohol for a set time respectively, and drying with nitrogen.
[0015] Furthermore, pre-treating the substrate also includes: cleaning the surface of the substrate with an ion cleaner, introducing a mixed gas of argon and oxygen, with a pressure of 100-200 Pa, a flow ratio of argon to oxygen of 1:3, and a cleaning time of 5-10 minutes.
[0016] Furthermore, pre-treating the substrate further comprises:
[0017] Fix the cleaned substrate on the rotating table in the magnetron sputtering machine, turn on the water cooling machine and the vacuum unit, and reduce the vacuum degree of the chamber to below the preset value;
[0018] When the gas pressure in the magnetron sputtering machine drops below a preset value, the substrate is sputtered at a preset power.
[0019] Furthermore, pre-treating the substrate further comprises:
[0020] Introduce argon gas, set the output pressure to 1-2Pa, the argon flow rate to 25-30sccm, and the pressure control valve to 0.5-1Pa;
[0021] Turn on the bias power supply, perform bias cleaning on the substrate to remove impurities, and adjust the bias power supply after the cleaning is completed.
[0022] Furthermore, the ignition, pre-sputtering and formal sputtering operations of the tungsten target include:
[0023] Turn on the DC power supply, set the power to 75-150W, and start the tungsten target;
[0024] Close the baffle and pre-sputter the tungsten target to remove impurities on the surface of the tungsten target;
[0025] Open the shutter and start the rotation to start the sputtering operation on the tungsten target.
[0026] Further, the ignition, pre-sputtering and formal sputtering operations on the copper target include:
[0027] Turn off the shutter, rotation and DC power supply, and replace the tungsten target with a copper target;
[0028] Turn on the DC power supply, set the power to 75-150W, and perform ignition operation on the copper target;
[0029] Close the baffle and pre-sputter the tungsten target to remove impurities on the surface of the copper target;
[0030] Open the shutter and start the rotation to start the sputtering operation on the copper target.
[0031] Further, shutting down all devices and taking out the tungsten target or copper target specifically includes:
[0032] Turn off all power supplies and stop gas supply;
[0033] Open the vent valve to restore the chamber to atmospheric pressure and take out the tungsten target or copper target.
[0034] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted by the present invention include at least:
[0035] 1. Avoid substrate preheating
[0036] Traditional high-temperature treatment may cause thermal stress or structural changes on the substrate surface, affecting the performance of the material. In this experiment, since the substrate does not need to be preheated, the integrity and structural stability of the substrate are maintained, avoiding potential thermal damage to it by high temperature. By omitting the preheating step, the experimental process can also be simplified, energy consumption can be reduced, and experimental efficiency can be improved.
[0037] 2. Magnetron sputtering is carried out at room temperature
[0038] Magnetron sputtering operation at room temperature can prevent thermal stress or material deformation caused by high temperature in the sample, avoid the reaction between the substrate and tungsten, and tungsten and copper at high temperature, thereby improving the quality and consistency of the film.
[0039] Operating at room temperature also avoids the use of complex temperature control equipment and high-temperature protection devices, reduces the complexity and cost of the experiment, and is also more energy-efficient.
[0040] 3. No need to transfer samples to avoid oxidation and impurity contamination
[0041] The entire experimental process is completed in a closed vacuum system, and there is no need to transfer the sample from one environment to another. This can effectively avoid the oxidation reaction that may occur when the sample is exposed to air and the problem of impurity contamination affecting the film quality.
[0042] Through integrated processing in a vacuum environment, the purity of the environment during the coating process is ensured, thereby improving the purity and interface bonding strength of the film and ensuring high-quality coating effects.
[0043] 4. No additional annealing treatment is required
[0044] The experimental design avoids the annealing step commonly seen in traditional processes. Annealing usually requires a high temperature environment, which can easily lead to problems such as oxidation, uneven material diffusion or stress changes. By optimizing the magnetron sputtering parameters, the experiment achieved the goal of obtaining high-quality films without annealing, simplifying the process.
[0045] Eliminating the annealing step not only saves time and energy, but also reduces reliance on high-temperature equipment, thereby reducing experimental costs and energy consumption, while avoiding additional contamination that may be introduced during high-temperature processes.
[0046] 5. Improve experimental efficiency and film consistency
[0047] By eliminating the need for preheating, transfer and annealing, the entire experimental process is simple and efficient, and the sample coating can be completed quickly. This improves experimental efficiency and is suitable for high-throughput material preparation and testing.
[0048] At the same time, keeping the samples processed in the same environment ensures the stability of the experimental conditions, thereby ensuring the uniformity and consistency of the film. BRIEF DESCRIPTION OF THE DRAWINGS
[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0050] Figure 1 It is a flowchart of an embodiment of the present invention. DETAILED DESCRIPTION
[0051] The embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0052] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.
[0053] like Figure 1 As shown, the present invention provides a method for preparing a tungsten-copper composite film for a heat sink material, comprising the following steps:
[0054] Pre-process the substrate and install the tungsten and copper targets into the magnetron sputtering machine;
[0055] Carry out ignition, pre-sputtering and formal sputtering operations on tungsten target and copper target respectively;
[0056] Turn off all devices and take out the tungsten target or copper target.
[0057] The present invention pre-treats the substrate by a specific process method, and prepares a high-quality tungsten-copper composite film with excellent interface bonding, good uniformity and compactness by a magnetron sputtering method. Compared with the prior art, the magnetron sputtering method of the present invention has outstanding advantages such as low cost, high efficiency, high safety, good structural integrity, and high interface bonding strength.
[0058] The following is an explanation based on a specific embodiment, which is described in detail as follows.
[0059] Example 1: Install the tungsten target and the copper target into the magnetron sputtering machine, and clean and surface activate the diamond substrate. The magnetron sputtering machine can use the JCP500B model magnetron sputtering machine developed by Beijing Techno Technology Co., Ltd., and the tungsten and copper targets can use the targets produced by Zhongnuo New Materials (Beijing) Technology Co., Ltd., with a purity of 99.99%. The substrate can use the single crystal diamond sheet produced by Henan Yellow River Cyclone Co., Ltd., with a crystal face (100) and a thickness of 1mm. The purchased diamond sheet is ultrasonically cleaned for 10 minutes using isopropanol, acetone and alcohol respectively, and the substrate is blown dry using a nitrogen gun. The diamond is cleaned on its surface using an ion cleaner. During the cleaning process, the gas introduced into the cleaning chamber is a mixture of argon and oxygen. The pressure needs to be maintained between 100 and 200 Pa, and the flow ratio of argon to oxygen is 1:3, and the cleaning time is 5 to 10 minutes. The diamond sample after ion cleaning then needs to undergo a coating procedure. The specific method is as follows: fix the substrate in the center of the rotating table in the magnetron sputtering machine, then turn on the water cooling machine and the vacuum unit, and evacuate to 5×10 4 Pa or less to remove oxygen and water vapor in the chamber. Reduce the gas pressure in the magnetron sputtering machine to the preset value and sputter the substrate at the preset power. Start to introduce argon, open the stop valve and the argon cylinder, and set the cylinder output pressure to 1Pa, set the argon flow rate to 30sccm, and set the machine pressure control valve to 1Pa. Turn on the machine bias power supply, set the bias power supply to 800V, 70%, and bias clean for ten minutes to remove impurities and oxide layers on the diamond substrate. After cleaning, set the bias power supply to 100V, 70%, and set the machine pressure control valve to 0.5Pa. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5min to remove impurities on the surface of the tungsten target. Open the baffle, start the rotation, and start the formal sputtering. After the sputtering of the tungsten target is completed, close the baffle, turn off the rotation, turn off the DC power supply, and replace the target position to prepare for sputtering of the copper target. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5 minutes to remove impurities on the surface of the copper target. Open the baffle, turn on the autogenerator, and start formal sputtering. After the sputtering of the copper target is completed, close the baffle, turn off the autogenerator, turn off the DC power supply, turn off the bias power supply, set the air intake to 0sccm, close the gas cylinder, and shut down automatically. After shutdown, open the vent valve, restore the magnetron sputtering machine chamber to atmospheric pressure, open the hatch, take out the sample, and obtain a tungsten intermediate layer reinforced copper-based diamond composite material. In this case, a diamond substrate was used as the coating substrate, but it did not affect the film quality. The sample film is uniform and the interface bonding is good. Its surface roughness is 1.55nm and the interface thermal conductivity is 302MW / (m 2 ·K).
[0060] Example 2: Install the tungsten target and the copper target into the magnetron sputtering machine, and clean and activate the silicon substrate. The magnetron sputtering machine can use the JCP500B model magnetron sputtering machine developed by Beijing Techno Technology Co., Ltd., and the tungsten and copper targets can use the targets produced by Zhongnuo New Materials (Beijing) Technology Co., Ltd., with a purity of 99.99%. The silicon substrate is cleaned on its surface using an ion cleaner. During the cleaning process, the gas introduced into the cleaning chamber is a mixture of argon and oxygen. The pressure needs to be maintained between 100 and 200 Pa, and the flow ratio of argon to oxygen is 1:3, and the cleaning time is 5 to 10 minutes. The sample after ion cleaning needs to undergo a coating procedure next. The specific method is as follows: Fix the substrate silicon wafer in the center of the rotating table in the magnetron sputtering machine, then turn on the water cooler and the vacuum unit, and evacuate to 5×10 4 Pa or less to remove oxygen and water vapor in the chamber. Reduce the gas pressure in the magnetron sputtering machine to the preset value and sputter the substrate at the preset power. Start to introduce argon, open the stop valve and the argon cylinder, and set the cylinder output pressure to 2Pa, set the argon flow rate to 30sccm, and set the machine pressure control valve to 1.0Pa. Turn on the machine bias power supply, set the bias power supply to 800V, 70%, and bias clean for ten minutes to remove impurities and oxide layers on the silicon substrate. After cleaning, set the bias power supply to 150V, 70%, and set the machine pressure control valve to 0.5Pa. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5min to remove impurities on the surface of the tungsten target. Open the baffle, start the rotation, and start the formal sputtering. After the sputtering of the tungsten target is completed, close the baffle, turn off the rotation, turn off the DC power supply, and replace the target position to prepare for sputtering of the copper target. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5 minutes to remove impurities on the surface of the copper target. Open the baffle, turn on the autogenerator, and start formal sputtering. After the sputtering of the copper target is completed, close the baffle, turn off the autogenerator, turn off the DC power supply, turn off the bias power supply, set the air intake to 0sccm, close the gas cylinder, and automatically shut down. After shutdown, open the vent valve, restore the magnetron sputtering machine chamber to atmospheric pressure, open the hatch, take out the sample, and obtain a tungsten intermediate layer reinforced copper-based silicon composite material. In this case, a silicon-based substrate was used, but it did not affect the film quality. The sample film is uniform and the interface bonding is good. Its surface roughness is 1.35nm, and its interface thermal conductivity is 278MW / (m 2 ·K).
[0061] Example 3: Install the tungsten target and the copper target into the magnetron sputtering machine, and clean and surface activate the quartz glass substrate. The magnetron sputtering machine can use the JCP500B model magnetron sputtering machine developed by Beijing Techno Technology Co., Ltd., and the tungsten and copper targets can use the targets produced by Zhongnuo New Materials (Beijing) Technology Co., Ltd., with a purity of 99.99%. The quartz glass sheet is ultrasonically cleaned for 10 minutes using isopropanol, acetone, and alcohol, respectively, and the substrate is blown dry using a nitrogen gun. The quartz glass is cleaned on its surface using an ion cleaner. During the cleaning process, the gas introduced into the cleaning chamber is a mixture of argon and oxygen. The pressure needs to be maintained between 100 and 200 Pa, and the flow ratio of argon to oxygen is 1:3, and the cleaning time is 5 to 10 minutes. After ion cleaning, the quartz glass sample needs to undergo a coating procedure next. The specific method is as follows: Fix the substrate quartz glass in the center of the rotating table in the magnetron sputtering machine, then turn on the water cooler and the vacuum unit, and evacuate to 5×10 4 Pa or less to remove oxygen and water vapor in the chamber. Reduce the gas pressure in the magnetron sputtering machine to the preset value and sputter the substrate at the preset power. Start to introduce argon, open the stop valve and the argon cylinder, and set the cylinder output pressure to 1.5Pa, set the argon flow rate to 30sccm, and the machine pressure control valve to 0.75Pa. Turn on the machine bias power supply, set the bias power supply to 800V, 70%, and bias clean for ten minutes to remove impurities and oxide layers on the quartz glass substrate. After cleaning, set the bias power supply to 150V, 70%, and set the machine pressure control valve to 0.5Pa. Turn on the machine DC power supply, set the DC power supply power to 100W, and start. Close the baffle and pre-sputter for 5min to remove impurities on the surface of the tungsten target. Open the baffle, start the rotation, and start the formal sputtering. After the sputtering of the tungsten target is completed, close the baffle, turn off the rotation, turn off the DC power supply, and replace the target position to prepare for sputtering of the copper target. Turn on the DC power supply of the machine, set the DC power supply power to 100W, and start the ignition. Close the baffle and pre-sputter for 5 minutes to remove impurities on the surface of the copper target. Open the baffle, turn on the autorotator, and start the formal sputtering. After the sputtering of the copper target is completed, close the baffle, turn off the autorotator, turn off the DC power supply, turn off the bias power supply, set the air intake to 0sccm and close the gas cylinder, and shut down automatically. After shutting down, open the vent valve, restore the magnetron sputtering machine chamber to atmospheric pressure, open the hatch, take out the sample, and obtain a tungsten intermediate layer reinforced copper-based quartz glass composite material. In this case, quartz glass is used as the coating substrate, which does not affect the film quality. The sample film is uniform and the interface bonding is good. Its surface roughness is 1.57nm and its interface thermal conductivity is 289MW / (m 2 ·K).
[0062] Embodiment 4: The tungsten target and the copper target are installed in the magnetron sputtering machine, and the diamond substrate is cleaned and surface activated. The magnetron sputtering machine can use the JCP500B model magnetron sputtering machine developed by Beijing Techno Technology Co., Ltd., and the tungsten and copper targets can use the targets produced by Zhongnuo New Materials (Beijing) Technology Co., Ltd., with a purity of 99.99%. The substrate can use the single crystal diamond sheet produced by Henan Yellow River Cyclone Co., Ltd., with a crystal face (100) and a thickness of 1mm. The purchased diamond sheet is ultrasonically cleaned for 10 minutes using isopropanol, acetone and alcohol respectively, and the substrate is blown dry using a nitrogen gun. The cleaned sample is characterized using AFM to obtain surface morphology information. If the roughness of the surface morphology is below 2nm, it can be considered not to perform polishing. If the surface morphology roughness is greater than 2nm and less than 5nm, the following steps are taken. Polishing is performed using 1.5 and 0.5 micron diamond suspensions in sequence, and the polishing time for each group is 30min. Diamonds with good roughness or that meet the standards after the polishing process are cleaned with an ion cleaner. During the cleaning process, the gas introduced into the cleaning chamber is a mixture of argon and oxygen. The pressure needs to be maintained between 100 and 200 Pa, and the flow ratio of argon to oxygen is 1:3. The cleaning time is 5 to 10 minutes. The diamond sample after ion cleaning needs to be coated next. The specific method is as follows: fix the substrate silicon wafer in the center of the rotating table in the magnetron sputtering machine, then turn on the water cooler and vacuum unit, and evacuate to 5×10 4Pa or less to remove oxygen and water vapor in the chamber. Reduce the gas pressure in the magnetron sputtering machine to the preset value and sputter the substrate at the preset power. Start to introduce argon, open the stop valve and the argon cylinder, and set the cylinder output pressure to 1.5Pa, set the argon flow rate to 30sccm, and set the machine pressure control valve to 0.75Pa. Turn on the machine bias power supply, set the bias power supply to 800V, 70%, and bias clean for ten minutes to remove impurities and oxide layers on the diamond substrate. After cleaning, set the bias power supply to 150V, 70%, and set the machine pressure control valve to 0.5Pa. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5min to remove impurities on the surface of the tungsten target. Open the baffle, start the rotation, and start the formal sputtering. After the sputtering of the tungsten target is completed, close the baffle, turn off the rotation, turn off the DC power supply, and replace the target position to prepare for sputtering of the copper target. Turn on the machine DC power supply, set the DC power supply power to 75W, and start. Close the baffle and pre-sputter for 5 minutes to remove impurities on the surface of the copper target. Open the baffle, turn on the autogenerator, and start formal sputtering. After the sputtering of the copper target is completed, close the baffle, turn off the autogenerator, turn off the DC power supply, turn off the bias power supply, set the air intake to 0sccm, close the gas cylinder, and automatically shut down. After shutdown, open the vent valve, restore the magnetron sputtering machine chamber to atmospheric pressure, open the hatch, take out the sample, and obtain a tungsten intermediate layer reinforced copper-based diamond composite material. In this case, the coating rate decreases when the bias power supply voltage is increased. This is because when the bias power supply voltage is too high, the strong ion bombardment may peel off part of the thin film material deposited on the substrate again, which will cause the actual growth rate of the film to decrease, but it does not affect the film quality. The sample film is uniform and the interface bonding is good. Its surface roughness is 1.65nm and its interface thermal conductivity is 304MW / (m 2 ·K).
[0063] It should be noted that the substrate of the present invention is a basic substrate material. Various substrates such as diamond, silicon wafer, quartz glass and metal substrates, as long as magnetron sputtering is ultimately used to prepare tungsten-copper composite thin films and the coating process parameters are within the scope of this patent, should be included in the protection scope of the present invention.
[0064] The present invention completes the entire magnetron sputtering coating process at room temperature and avoids a series of complex steps in traditional processes, such as preheating, sample transfer and annealing, thereby achieving multiple advantages of simplifying the process, reducing costs, improving film quality and experimental efficiency, and ultimately preparing a tungsten-copper composite film with uniform film, good interface bonding and excellent thermal conductivity.
[0065] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A method for preparing a tungsten-copper composite film for a heat sink material, characterized in that: The following steps are involved: Pre-process the substrate and install the tungsten and copper targets into the magnetron sputtering machine; Carry out ignition, pre-sputtering and formal sputtering operations on tungsten target and copper target respectively; Turn off all devices and take out the tungsten target or copper target.
2. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 1, characterized in that: The pretreatment of the substrate includes: ultrasonically cleaning the substrate with isopropanol, acetone and alcohol for a set time respectively, and drying with nitrogen.
3. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 2, characterized in that: The pretreatment of the substrate also includes: cleaning the surface of the substrate with an ion cleaner, introducing a mixed gas of argon and oxygen, with a pressure of 100-200 Pa, a flow ratio of argon to oxygen of 1:3, and a cleaning time of 5-10 minutes.
4. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 3, characterized in that: Pre-processing the substrate also includes: Fix the cleaned substrate on the rotating table in the magnetron sputtering machine, turn on the water cooling machine and the vacuum unit, and reduce the vacuum degree of the chamber to below the preset value; When the gas pressure in the magnetron sputtering machine drops below a preset value, the substrate is sputtered at a preset power.
5. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 4, characterized in that: Pre-processing the substrate also includes: Introduce argon gas, set the output pressure to 1-2Pa, the argon flow rate to 25-30sccm, and the pressure control valve to 0.5-1Pa; Turn on the bias power supply, perform bias cleaning on the substrate to remove impurities, and adjust the bias power supply after the cleaning is completed.
6. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 5, characterized in that: The ignition, pre-sputtering and sputtering operations on tungsten targets include: Turn on the DC power supply, set the power to 75-150W, and start the tungsten target; Close the baffle and pre-sputter the tungsten target to remove impurities on the surface of the tungsten target; Open the shutter and start the rotation to start the sputtering operation on the tungsten target.
7. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 6, characterized in that: The ignition, pre-sputtering and main sputtering operations for copper targets include: Turn off the shutter, rotation and DC power supply, and replace the tungsten target with a copper target; Turn on the DC power supply, set the power to 75-150W, and perform ignition operation on the copper target; Close the baffle and pre-sputter the tungsten target to remove impurities on the surface of the copper target; Open the shutter and start the rotation to start the sputtering operation on the copper target.
8. The method for preparing a tungsten-copper composite film for a heat sink material according to claim 1, characterized in that: Shut down all devices and take out the tungsten target or copper target, including: Turn off all power supplies and stop gas supply; Open the vent valve to restore the chamber to atmospheric pressure and take out the tungsten target or copper target.