Efficient recovery method of heterogeneous metal target material

Abstract

The invention relates to the technical field of material recycling, and provides an efficient heterogeneous metal target recycling method which comprises the following steps: preparing a crack propagation source between a to-be-recycled metal target and a back plate; refrigerating the metal target material, heating the back plate, and meanwhile, applying relative high-frequency vibration to a combined body formed by the metal target material and the back plate; applying secondary vibration to the combined body for a preset duration; a relatively low frequency vibration is applied to the crack propagation source by means of a specified tool until the metal target and the backing plate are separated from each other. According to the above configuration, the physical means with small temperature rising / cooling amplitude is combined with multiple ultrasonic vibration, and no extra impurities are introduced, so that the high purity of the target material obtained through separation is ensured, the loss inevitably caused by machining is avoided, and the high-efficiency recovery of the metal target material with specific components is realized.

Description

Technical Field

[0001] This invention relates to the field of material recycling technology, and in particular to an efficient method for recycling heterogeneous metal targets. Background Technology

[0002] Currently, the backplanes of most commercially available integrated circuit boards are primarily made of copper or copper alloys. Based on this, magnetron sputtering is used to sputter metal targets of specific compositions onto the backplane to form the desired integrated circuit board. During the manufacturing process of integrated circuit boards, stringent requirements are placed on the quality stability, microstructure control precision, and purity of the sputtered metal targets. Furthermore, due to the limitations of the magnetron sputtering principle, the actual utilization rate of the targets is approximately 30%, meaning that a large amount of high-quality metal is wasted and difficult to recycle. Regardless of whether the integrated circuit board is still usable or has reached the end of its service life, the metal targets on it (including targets in use and residual targets) still have considerable economic and recycling value. Existing technologies have developed methods to separate the metal targets and backplane using machining, physical or chemical methods, or even combinations thereof, to recover the metal targets for reuse.

[0003] However, given that metal targets and backplates are primarily fixed together using diffusion welding, existing machining / physical / chemical separation methods or combinations thereof are limited by application scenarios and lack universality. For example, the method for recycling sputtering targets disclosed in CN104342618A is difficult to separate brittle targets from copper and copper alloy backplates; the low-cost, high-efficiency recycling method for sputtering targets disclosed in CN118996349A utilizes the difference in linear expansion coefficients between the target and backplate, rapidly cooling and heating it to generate microcracks, and then using asymmetric rolling to separate the target—a complex and lengthy process. Therefore, a significant portion of existing methods for separating metal targets and backplates are constrained by the mechanical and / or material properties of both. Under these circumstances, forcibly separating the metal target and backplate could potentially degrade or damage the purity of the metal target or the integrity of the backplate. Summary of the Invention

[0004] This invention provides an efficient method for recovering heterogeneous metal targets, which solves the problem that the existing methods for separating metal targets and backing plates are limited by the mechanical and / or material properties of both, and realizes a method for separating metal targets and backing plates applicable to a wide range of target materials.

[0005] This invention provides a method for the efficient recovery of heterogeneous metal targets, comprising: A crack propagation source is prepared between the metal target to be recycled and the backing plate; The metal target is cooled, the back plate is heated, and a relatively high-frequency vibration is applied to the combination of the metal target and the back plate. Secondary vibrations are applied to the assembly and sustained for a preset duration; Using a designated tool, relatively low-frequency vibrations are applied to the crack propagation source until the metal target and the backing plate separate from each other.

[0006] The efficient recovery method for heterogeneous metal targets provided by the present invention further includes the step of applying relatively low-frequency vibrations to the crack propagation source using a designated tool: The applied relative low-frequency vibrations satisfy the following relationship: in, Indicates the depth or width of the crack; Indicates the number of stress cycles; Indicates the material coefficient; Indicates the range of stress intensity factor variation; Indicates the crack propagation index related to the backing material; This represents the vibration frequency, and its value range is no greater than 50kHz. Represents the natural constant; This represents the activation energy for crack propagation. Represents the gas constant; Indicates temperature; to adjust the vibration frequency and / or stress cycle number accordingly.

[0007] The efficient recycling method for heterogeneous metal targets provided by the present invention further includes the step of preparing a crack propagation source between the metal target to be recycled and the backing plate: Drill holes at the interface between the metal target and the backing plate to create a crack propagation source.

[0008] The efficient recovery method for heterogeneous metal targets provided by the present invention includes an ultrasonic vibrating rod as the designated tool, and the step of applying relatively low-frequency vibration to the crack propagation source by means of the designated tool further includes: An ultrasonic vibrating rod is placed in the hole, and the shapes of the ultrasonic vibrating rod and the hole are complementary. Start the ultrasonic vibrator to apply relatively low-frequency vibration to the hole, wherein the vibration frequency and / or the number of stress cycles are adjustable.

[0009] According to the efficient recovery method for heterogeneous metal targets provided by the present invention, the power of the applied relatively low-frequency vibration is no greater than 20 W / cm. 2 .

[0010] The efficient recovery method for heterogeneous metal targets provided by the present invention further includes the steps of cooling the metal target while heating the back plate: The external cooling equipment is placed on the side closest to the metal target material in the assembly; The external heating device should be placed on the side closest to the back panel of the assembly.

[0011] According to the efficient recycling method for heterogeneous metal targets provided by the present invention, the surface temperature of the external cooling equipment during operation is not higher than 25°C; the back plate is heated to the range of 100°C to 900°C by the external heating equipment.

[0012] The efficient recovery method for heterogeneous metal targets provided by the present invention further includes the step of applying secondary vibration to the assembly for a preset duration: The frequency range of the applied secondary vibration is no greater than 100kHz, and the preset duration is no greater than 60min.

[0013] The efficient recovery method for heterogeneous metal targets provided by the present invention further includes: After separating the metal target, the original connection interfaces of the metal target and the backing plate corresponding to each other are machined and / or pickled.

[0014] According to the efficient recycling method for heterogeneous metal targets provided by the present invention, the metal targets to be recycled include targets whose sputtering life has expired, targets whose sputtering life has not ended, targets whose expiration date has expired, and targets that are substandard.

[0015] The present invention provides a highly efficient method for recovering heterogeneous metal targets. This method involves forming a crack propagation source at the interface between the metal target and the backing plate. First, stress concentration is achieved by combining relatively high-frequency vibration with a small heating / cooling amplitude, thereby initiating microcracks. Then, secondary vibration is applied to the assembly of the metal target and backing plate (e.g., an integrated circuit board). The extremely high cycle frequency significantly accelerates the accumulation of fatigue damage. Next, at the crack propagation source, relatively low-frequency ultrasonic vibration is applied using a designated tool, causing the cracks generated along the crack propagation source to further expand until the metal target and backing plate separate. Throughout the separation process, no additional impurities are introduced, thus ensuring the high purity of the separated target material. Furthermore, the metal material does not necessarily require machining of the metal target or backing plate, thereby avoiding the inevitable losses caused by machining. This method achieves highly efficient recovery of metal targets with specific compositions, improving efficiency by more than 40% compared to other recovery methods. Furthermore, the efficient recycling method for heterogeneous metal targets provided by this invention applies vibrations of different frequencies to concentrate stress at the interface between the metal target and the backing plate. This, in turn, utilizes the differences in the mechanical and / or material properties of the two to reproduce the boundary between them at the interface, thereby obtaining a high-purity target and a complete backing plate. Compared with existing recycling methods, the metal target and backing plate obtained by this method have higher reusability and economic benefits. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the efficient recovery method for heterogeneous metal targets provided by the present invention.

[0018] Figure 2 This is a schematic diagram of the assembly provided by the present invention.

[0019] Figure 3 yes Figure 2 A magnified view of detail A shown.

[0020] Figure label: 1. Assembly; 2. Metal target; 3. Backing plate; 4. Crack propagation source. Detailed Implementation

[0021] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0022] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections, wherein a fixed connection can include an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0024] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0026] The following is combined Figures 1 to 3 This invention describes a method for the efficient recovery of heterogeneous metal targets.

[0027] This invention primarily targets backplates made of copper or copper alloys, wherein the coefficient of linear expansion of copper and copper alloys at room temperature is 16~19×10⁻⁶. -6 / ℃, which can be calculated using the following formula: Where, Δ L Indicates the change in length; α Indicates the average linear expansion coefficient; L 0 Indicates the initial length of the line; Δ T This indicates the amount of temperature change. For example, when copper or a copper alloy is heated to 700°C, its expansion length is 12.65 mm / m, that is, the expansion rate is 1.265%.

[0028] In contrast, the coefficient of linear expansion of tungsten and tungsten alloys at room temperature is 4.3~4.6×10⁻⁶. -6 At room temperature, the coefficient of linear expansion of tantalum is 6~7×10⁻⁶℃. -6 At room temperature, the coefficient of linear expansion of molybdenum-silicon alloy is 8~9×10⁻⁶℃. -6 At ℃, the coefficient of linear expansion of chromium at room temperature is 6~8×10⁻⁶. -6At room temperature, the coefficient of linear expansion of cobalt-iron-boron alloys, titanium, and titanium alloys is 8~9×10⁻⁶℃. -6 / ℃. This means that when the target material made of the above materials is heated to the same temperature as the back plate, it expands by 3.26mm to 6.12mm per meter, that is, the expansion rate is 0.326 to 0.612%, which is much smaller than the expansion rate of copper and copper alloys.

[0029] Furthermore, copper and copper alloys have a thermal conductivity of 400 W / m·K, meaning they possess high thermal conductivity and can rapidly conduct heat to the entire backplate during heating. Tungsten has a thermal conductivity of 160–170 W / m·K, tantalum 50–60 W / m·K, molybdenum-silicon alloys no more than 10 W / m·K, chromium 90–100 W / m·K, cobalt-iron-boron alloys 10–17 W / m·K, and titanium and titanium alloys 15–16 W / m·K. The thermal conductivity of these materials is lower than that of copper and copper alloys. This results in a larger temperature difference between the metal target made of these materials and the backplate during heating, further increasing the difference in expansion rates between the metal target and the backplate, thereby increasing the internal stress at the interface.

[0030] Figure 1 This is a flowchart of the efficient recovery method for heterogeneous metal targets provided by the present invention, as shown below. Figure 1 As shown, the efficient recovery method for heterogeneous metal targets of the present invention includes at least the following steps: S1 - Prepare a crack propagation source 4 between the metal target 2 to be recycled and the backing plate 3; S2 - Cool the metal target 2, heat the back plate 3, and simultaneously apply a relatively high-frequency vibration to the assembly 1 consisting of the metal target 2 and the back plate 3. S3 - Apply secondary vibration to assembly 1 and continue for a preset duration; S4 - Using a specified tool, apply relatively low-frequency vibrations to the crack propagation source 4 until the metal target 2 and the backing plate 3 separate from each other.

[0031] Figure 2 This is a schematic diagram of the assembly provided by the present invention, such as... Figure 2 As shown, for step S1, in order to separate the metal target 2 and the backplate 3, a crack propagation source 4 is first prepared between the metal target 2 and the backplate 3, particularly at the interface between the two. The crack propagation source 4 can be prepared by drilling a hole at the interface between the metal target 2 and the backplate 3. For example, if the assembly 1 (e.g., an integrated circuit board) composed of the metal target 2 and the backplate 3 is a circular disk, the hole can be formed radially along the assembly 1; if the assembly 1 has other shapes, the method of forming the hole can be adapted accordingly.

[0032] Figure 3 yes Figure 2 An enlarged schematic diagram of detail A is shown, as follows: Figure 3 As shown, the crack propagation source 4 can be formed as one or more of the following: square hole, round hole, tapered hole, threaded hole, wedge hole, and irregular hole.

[0033] In step S2, after the crack propagation source 4 has been formed, the metal target 2 is cooled while the back plate 3 is heated simultaneously. Furthermore, the applied relatively high-frequency vibration has a frequency of not less than 100 kHz. During the simultaneous heating, cooling, and relatively high-frequency vibration, stress will concentrate at the crack propagation source 4, thus microcracks preferentially initiate at this location.

[0034] Furthermore, in order to simultaneously cool the metal target 2 and heat the backplate 3, step S2 further includes: S21 - Place the external cooling device on the side close to the metal target 2 in the assembly 1; S22 - Place the external heating device on the side near the back plate 3 in the assembly 1.

[0035] External cooling equipment can be a cooling table, cooling plate, or other similar devices. External heating equipment can be an induction coil or other similar devices. Utilizing the large thermal conductivity difference between the metal target 2 and the back plate 3, the back plate 3 is heated while the metal target 2 is cooled, increasing the expansion difference caused by the temperature difference between the two and increasing the internal stress between the metal target 2 and the back plate 3.

[0036] For step S3, after simultaneously performing cooling and heating processes to increase the internal stress between the metal target 2 and the backing plate 3, a secondary vibration of a predetermined duration is applied to the assembly 1. Although the single-cycle stress amplitude in such secondary vibration is low, the number of cycles per unit time is extremely high; that is, the extremely high cycle frequency can greatly accelerate the accumulation process of fatigue damage. Moreover, since the higher the ultrasonic frequency and the lower its penetration, most of the energy is concentrated on the surface and connection interface of the crack propagation source 4, which is conducive to the precise initiation of microcracks / cracks at the connection interface, resulting in less thermal impact and deformation on the parent material (metal target 2 and backing plate 3).

[0037] For step S4, after sufficient secondary vibration has been applied to the assembly, a relatively low-frequency vibration is applied to the crack propagation source 4 using a designated tool, causing the crack propagation source 4 to further develop / expand until the metal target 2 and the backing plate 3 separate from each other. Where the crack propagation source 4 is formed in the form of a drilled hole, the designated tool can be in the form of engaging with the drilled hole, which will be described in detail below.

[0038] Furthermore, for step S4, the applied relative low-frequency vibration satisfies the following relationship: in, Indicates the depth or width of the crack; Indicates the number of stress cycles; Indicates the material coefficient; Indicates the range of stress intensity factor variation; This represents the crack propagation index related to the material of the back plate 3. The value depends on the material properties; This represents the vibration frequency, and its value range is no greater than 50kHz. Represents the natural constant; This represents the activation energy for crack propagation. Represents the gas constant; Indicates temperature; adjusts vibration frequency accordingly. and / or number of stress cycles As described above, the designated tool engages with the crack propagation source 4 to apply relatively low-frequency ultrasonic vibrations of no more than 50 kHz to the crack propagation source 4, gradually increasing the vibration power until the metal target 2 and the backing plate 3 separate. If the vibration power increases to 20 W / cm², the vibration power is further increased. 2 If separation still fails, stop increasing the power and instead extend the vibration time of the specified tool.

[0039] Furthermore, the designated tool may be an ultrasonic vibrating rod or other similar object. Given that the crack propagation source 4 can be formed as one or more of a square hole, round hole, conical hole, threaded hole, wedge-shaped hole, or irregularly shaped hole, the ultrasonic vibrating rod is constructed to complement its shape for meshing. In this case, step S4 further includes: S41 - Place the ultrasonic vibrator in the hole, the ultrasonic vibrator and the hole having complementary shapes; S42 - Start the ultrasonic vibrator to apply the aforementioned relatively low-frequency vibration to the hole, wherein the vibration frequency is... and / or number of stress cycles Adjustable.

[0040] Therefore, ultrasonic vibration with a frequency not exceeding 50kHz promotes dislocation slip through phonon flow, reduces the activation energy of the plastic zone at the crack tip, and thus increases the growth rate of microcracks / cracks.

[0041] Furthermore, for step S2, particularly for steps S21 and S22 above, the surface temperature of the external cooling device during operation is not higher than 25°C, so as to synchronously cool the metal target 2 near the external cooling device to the same or similar temperature level. Moreover, due to the low thermal conductivity of the metal target 2, this cooling capacity is not easily conducted to the back plate 3. Conversely, an electromagnetic induction alternating current is applied to the external heating device, so that the back plate 3 is heated to the range of 100°C to 900°C by the external heating device. Preferably, when the external heating device is an induction coil, its frequency is in the range of 40 kHz to 200 kHz, the heating power varies by 1 to 6 kW every 1 to 5 minutes, and the total heating time is limited to 5 minutes to 40 minutes.

[0042] Furthermore, step S3 also includes: S31 - The frequency range of the applied secondary vibration is no greater than 100kHz, and the preset duration is no greater than 60min.

[0043] Compared to the relatively low-frequency ultrasonic vibration applied by the ultrasonic vibrator, the secondary vibration frequency applied here is higher. As mentioned above, most of the energy of the secondary vibration is concentrated on the surface and interface of the crack propagation source 4, while the thermal effects and deformation on the parent material (metal target 2 and backing plate 3) are smaller.

[0044] Furthermore, the efficient recovery method for heterogeneous metal targets of the present invention also includes: S5 - After separating the metal target 2, the original connection interfaces of the metal target 2 and the back plate 3 corresponding to each other are machined and / or pickled.

[0045] The surface of the separated metal target 2 that was originally in contact with the backing plate 3 (i.e., the original interface) is machined (e.g., turned) to remove the surface diffusion layer, and then pickled to remove the surface oxide layer. This separation process does not introduce additional impurities, ensuring the high purity of the metal target 2; moreover, it avoids excessive machining of the separated metal target 2, thus at least to some extent avoiding or even eliminating the losses caused by machining. The treatment of the backing plate 3 is similar and will not be repeated here.

[0046] The impurities at the original connection interface between the metal target 2 and the back plate 3 after machining and / or pickling are fully removed. The back plate 3 can be reused, while the metal target 2 can be remelted for reuse, which is more economical.

[0047] Furthermore, the metal targets to be recycled include targets whose sputtering life has expired, targets whose sputtering life has not ended, targets whose expiration date has passed, and substandard targets. The term "sputtering life" refers to the expected service life of the sputtering target (and the integrated circuit board it is attached to), calculated from the date of installation, for example, 1000 hours. Therefore, such metal targets can be recycled if their sputtering life has expired or if the integrated circuit board has been replaced before the end of its sputtering life. The term "expiration date" refers to the shelf life of the sputtering target (and the integrated circuit board it is attached to), calculated from the date of installation, even if the sputtering target (and the integrated circuit board it is attached to) is not used for a long period after installation (i.e., the sputtering life has not ended). For example, 1 year. Therefore, such metal targets can also be recycled if their expiration date has passed. Furthermore, in the production process of integrated circuit boards, especially in the magnetron sputtering process, it is inevitable that there may be substandard targets with sputtering position misalignment or poor sputtering target adhesion. Such substandard targets can also be recycled using the above methods.

[0048] In addition, considering the linear expansion coefficients and thermal conductivity of tungsten, tantalum, molybdenum, chromium, cobalt and titanium mentioned above, the metal target 2 includes tungsten, tantalum, cobalt, molybdenum, titanium, chromium and their alloys.

[0049] In one embodiment, the metal target 2 to be recycled is a 12-inch sputtered tungsten target, specifically 5N tungsten, with a thickness of 5 mm; the backplate 3 is made of copper alloy with a thickness of 10 mm. More than 70% of the metal target 2 in the assembly 1 (e.g., an integrated circuit board) is still recyclable. Eight uniformly distributed square crack propagation sources 4 are prepared at the heterojunction of the sputtered assembly 1. The metal target 2 is placed on a cooling stage or cooling plate and cooled to 10°C. Simultaneously, the backplate 3 is placed in an induction coil, and an electromagnetic induction alternating current is applied to heat the backplate 3 to 500°C. At the same time, a high-frequency ultrasonic vibration of 200 kHz is applied to the assembly 1. Then, a secondary vibration at a frequency of 50 kHz is applied to the assembly 1 for 40 minutes. Finally, an ultrasonic vibrator is applied to the crack propagation sources 4, with a relatively low-frequency ultrasonic vibration frequency of 25 kHz and a power of 5 W / cm². 2 The process continues until the metal target 2 separates from the backing plate 3. Preferably, the original interface of the separated metal target 2 is machined to remove the surface diffusion layer and acid-washed to remove the surface oxide layer.

[0050] In another embodiment, the metal target 2 to be recycled is an 8-inch sputtered molybdenum-silicon target, specifically a 5N molybdenum-silicon alloy with a thickness of 7 mm; the backplate 3 is made of copper alloy with a thickness of 13 mm. More than 70% of the metal target 2 can still be recycled from the assembly 1. Eight uniformly distributed square crack propagation sources 4 are prepared at the heterogeneous weld joint of the sputtered assembly 1. The metal target 2 is placed on a cooling stage or cooling plate and cooled to 5°C. Simultaneously, the backplate 3 is placed in an induction coil, and an electromagnetic induction alternating current is applied to heat the backplate 3 to 600°C. At the same time, a high-frequency ultrasonic vibration of 150 kHz is applied to the assembly 1. Then, a secondary vibration at a frequency of 60 kHz is applied to the assembly 1 for 30 minutes. Finally, an ultrasonic vibrator is applied to the crack propagation sources 4, with a relatively low-frequency ultrasonic vibration frequency of 20 kHz and a power of 8 W / cm². 2 The process continues until the metal target 2 separates from the backing plate 3. Preferably, the original interface of the separated metal target 2 is machined to remove the surface diffusion layer and acid-washed to remove the surface oxide layer.

[0051] In another embodiment, the metal target 2 to be recycled is a 6-inch sputtered cobalt-iron-boron target, specifically a 4N cobalt-iron-boron target with a thickness of 3 mm; the backplate 3 is made of copper alloy with a thickness of 12 mm. More than 70% of the metal target 2 can still be recycled from the assembly 1. Four uniformly distributed square crack propagation sources 4 are prepared at the heterogeneous weld of the sputtered assembly 1. The metal target 2 is placed on a cooling stage or cooling plate and cooled to 5°C. Simultaneously, the backplate 3 is placed in an induction coil, and an electromagnetic induction alternating current is applied to heat the backplate 3 to 600°C. At the same time, a high-frequency ultrasonic vibration of 100 kHz is applied to the assembly 1. Then, a secondary vibration with a frequency of 80 kHz is applied to the assembly 1 for 30 minutes. Finally, an ultrasonic vibrator is applied to the crack propagation sources 4, with a relatively low-frequency ultrasonic vibration frequency of 20 kHz and a power of 9 W / cm². 2 The process continues until the metal target 2 separates from the backing plate 3. Preferably, the original interface of the separated metal target 2 is machined to remove the surface diffusion layer and acid-washed to remove the surface oxide layer.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the efficient recovery of heterogeneous metal targets, characterized in that, Includes at least the following steps: A crack propagation source is prepared between the metal target to be recycled and the backing plate; The metal target is cooled, the back plate is heated, and a relatively high-frequency vibration is applied to the assembly consisting of the metal target and the back plate. A secondary vibration is applied to the assembly and sustained for a preset duration; Using a designated tool, a relatively low-frequency vibration is applied to the crack propagation source until the metal target and the backing plate separate from each other.

2. The efficient recycling method according to claim 1, characterized in that, The step of applying relatively low-frequency vibrations to the crack propagation source using a specified tool further includes: The applied relative low-frequency vibrations satisfy the following relationship: in, Indicates the depth or width of the crack; Indicates the number of stress cycles; Indicates the material coefficient; Indicates the range of stress intensity factor variation; Indicates the crack propagation index related to the backing material; This represents the vibration frequency, and its value range is no greater than 50kHz. Represents the natural constant; This represents the activation energy for crack propagation. Represents the gas constant; The temperature is indicated; the vibration frequency and / or the number of stress cycles are adjusted accordingly.

3. The efficient recovery method for heterogeneous metal targets according to claim 1, characterized in that, The step of preparing a crack propagation source between the metal target to be recycled and the backing plate further includes: A hole is drilled at the interface between the metal target and the back plate to form the crack propagation source.

4. The efficient recovery method for heterogeneous metal targets according to claim 2 or 3, characterized in that, The designated tool includes an ultrasonic vibrating rod, and the step of applying relatively low-frequency vibrations to the crack propagation source by means of the designated tool further includes: The ultrasonic vibrating rod is placed in the hole, and the ultrasonic vibrating rod and the hole have complementary shapes. The ultrasonic vibrator is activated to apply relatively low-frequency vibrations to the hole, wherein the vibration frequency and / or the number of stress cycles are adjustable.

5. The efficient recovery method for heterogeneous metal targets according to claim 4, characterized in that, The power of the applied relatively low-frequency vibration is no greater than 20 W / cm. 2 .

6. The efficient recovery method for heterogeneous metal targets according to claim 1, characterized in that, The step of cooling the metal target material while heating the back plate further includes: The external cooling device is placed on the side close to the metal target material in the assembly; The external heating device is placed on the side close to the back plate in the assembly.

7. The efficient recovery method for heterogeneous metal targets according to claim 6, characterized in that, The surface temperature of the external cooling device during operation is not higher than 25°C; the back panel is heated to a temperature range of 100°C to 900°C by the external heating device.

8. The efficient recovery method for heterogeneous metal targets according to claim 1, characterized in that, The step of applying secondary vibration to the assembly and continuing it for a preset duration further includes: The frequency range of the applied secondary vibration is no greater than 100kHz, and the preset duration is no greater than 60min.

9. The efficient recovery method for heterogeneous metal targets according to claim 1, characterized in that, Also includes: After separating the metal target, the original connection interfaces of the metal target and the backing plate corresponding to each other are machined and / or pickled.

10. The efficient recovery method for heterogeneous metal targets according to claim 1, characterized in that, The metal targets to be recycled include targets whose sputtering life has expired, targets whose sputtering life has not ended, targets whose expiration date has expired, and targets that are substandard.

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