JP2018168465A - Method for cleaning target material, device therefor, method for manufacturing target material, target material, method for manufacturing recycled ingot, and recycled ingot - Google Patents

Abstract

To provide a target material cleaning method capable of simply removing a joint material from a used target material without using acid or media, a device therefor, a method for manufacturing a target material using them, a target material, a method for manufacturing a recycled ingot with a reduced amount of impurities derived from the joint material and a support member, and a recycled ingot.SOLUTION: The present invention can provide: a target material cleaning method for removing a joint material from a target material by separating a target material from a support member of a sputtering target made by coupling the target material mainly made of metal and the support member with a joint material, and spraying water to a surface of at least the target material adhered to the joint material; a device therefor; a method for manufacturing the target material and a recycled ingot using them; a recycled material; and a recycled ingot.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for cleaning a target material in a recycling process of a used sputtering target, an apparatus therefor, a method for producing a target material using them, a target material, a method for producing a recycled ingot, and a recycled ingot.

  In a sputtering target, a target material generally composed of ceramics such as metal, alloy, and oxide and a support member such as a backing plate or backing tube composed of metal or alloy are bonded with a bonding material such as solder material (bonding). A thin film such as a metal or an oxide can be formed on the substrate by subjecting such a sputtering target to sputtering. Regardless of the type of target material, it is not completely consumed by sputtering, but is recovered after its use. For example, a metal such as aluminum or copper is again melted and cast to produce an ingot (slab, ingot). ) Can be reused (recycled).

  Regarding recycling of the sputtering target, for example, Patent Documents 1 to 3 disclose the removal of surface deposits on the sputtering target by mechanical removal such as acid treatment or blast treatment.

JP 2005-23350 A JP 2005-23349 A International Publication No. 2015/151498 Pamphlet

  Treatments such as acid treatment and blast treatment are laborious and time consuming and are very complicated. In addition, the thickness of the bonding material remaining on the used target material is mainly not uniform, and is particularly remarkable for a target material for a flat panel display having a large size. Therefore, it is difficult to completely remove the bonding material by acid treatment or blasting with dilute nitric acid, and there is a risk that the bonding material remains in part. Further, in the blasting process, a medium made of metal or ceramic collides with the processing unit, so there is a concern about the remaining of the medium. In particular, when the target material is a high-purity product, contamination by the medium becomes a problem. Therefore, in the ingot obtained by melting and casting the used target material, the components derived from the media and the bonding material can be mixed as impurities, so the recovered material has the same quality as the original target material. It was difficult to regenerate the target material. In addition, components derived from support members such as a backing plate and a backing tube may be mixed as impurities.

  Therefore, in the present invention, a target material cleaning method capable of easily removing a bonding material from a used target material without using an acid or a medium, an apparatus therefor, a method for producing a target material using them, and It is an object of the present invention to provide a method for manufacturing a recycled ingot in which the amount of impurities derived from the target material, the bonding material, and the support member is reduced, and to provide the recycled ingot.

  As a result of earnest research, the inventor has separated the target material from the support member after the use in the sputtering target in which the target material mainly composed of metal and the support member are bonded by the bonding material, and then the target It has been found that the adhered bonding material can be easily removed from the target material by washing the target material by spraying water onto the surface where the bonding material of the material adheres and remains. Further, the present inventors have found that the amount of impurities derived from the bonding material and the support member can be greatly reduced by obtaining a recycled ingot using the target material treated by such a method as a raw material, and the present invention has been completed.

  The present invention is characterized in that the following target material cleaning method, apparatus therefor, target material manufacturing method and target material using them, and target material, and a recycled ingot is obtained using the target material treated by the cleaning method or apparatus as a raw material However, the present invention is not limited to the following.

[1]
The target material is separated from the support member of a sputtering target (or a sputtering target after use) in which a target material mainly composed of metal and a support member are bonded with a bonding material, and at least the bonding of the target material A method for cleaning a target material, wherein the bonding material is removed from the target material by spraying water onto a surface to which the material is adhered (or a surface remaining after adhering).
[2]
The method for cleaning a target material according to the above [1], wherein the water pressure is 90 MPa or more.
[3]
The method for cleaning a target material according to the above [1] or [2], wherein the metal is aluminum or copper.
[4]
The manufacturing method of a target material (or used target material) including processing a target material with the washing | cleaning method of any one of said [1]-[3].
[5]
The element contained in the impurities derived from the bonding material and the supporting member of the sputtering target in which the target material and the supporting member are bonded by the bonding material is not substantially detected by energy dispersive X-ray fluorescence analysis. Target material after cleaning (or used target material).
[6]
A recycle ingot including the metal by casting the metal using a target material (or a used target material) obtained from the production method according to the above [4] as a raw material. Production method.
[7]
A recycled ingot, wherein the total amount of impurities derived from a bonding material and a supporting member of a sputtering target formed by bonding a target material and a supporting member with a bonding material is less than 10 ppm on a weight basis.
[8]
The recycled ingot according to [7] above, wherein the metal as a main component of the recycled ingot is aluminum or copper.
[9]
The recycled ingot according to [8] above, wherein the metal as a main component of the recycled ingot is aluminum, and the total amount of the impurities is less than 5 ppm on a weight basis.
[10]
Water is sprayed onto at least the surface of the target material separated from the support member of the sputtering target formed by joining a target material mainly composed of metal and the support member with a bonding material. Is an apparatus used to remove the bonding material from the target material,
At least one nozzle head comprising at least one injection port for injecting water onto the target material;
An actuator for operating the nozzle head;
An apparatus comprising: a processing chamber in which the actuator is disposed and for storing and processing the target material.
[11]
The apparatus according to [10], further including a clamp for fixing the target material in the processing chamber.
[12]
The apparatus according to [10] or [11], further including a reversing mechanism for reversing the target material.
[13]
Any one of the above-mentioned [10] to [12], which includes a drainage mechanism for collecting and draining water ejected from the ejection port and separating a processed material including the bonding material removed from the target material. The device according to item.

  According to the present invention, it is possible to provide a cleaning method and a cleaning apparatus for a target material that can easily remove a bonding material by spraying water. Moreover, the amount of impurities derived from the bonding material and the support member can be greatly reduced by obtaining a recycled ingot using the target material processed by such a method or apparatus as a raw material. For example, when the target material is mainly composed of aluminum or copper, the total amount of impurities can be less than 10 ppm on a weight basis.

It is the schematic which shows the outline | summary of this invention. It is the schematic which shows the coupling | bonding of the target material of a sputtering target, and a supporting member. It is the schematic which shows the coupling | bonding of the target material and support member of another sputtering target. It is the schematic which shows the coupling | bonding of the target material and support member of another sputtering target. It is a schematic perspective view which shows typically embodiment of the apparatus which can be used in this invention. It is a schematic top view which shows typically embodiment of the apparatus which can be used in this invention. It is the schematic which shows the cross section in AA of the apparatus shown in FIG. It is the schematic which shows the cross section in BB of the apparatus shown in FIG. It is the schematic which shows typically the relationship between the actuator 103 and the nozzle head 102 which are shown in FIGS. It is the schematic which shows typically the membrane separation type solid-liquid separation apparatus as an example of a drainage mechanism. It is the schematic which shows typically the multistage type sedimentation tank as an example of a drainage mechanism.

  The present invention relates to a method for cleaning a target material, an apparatus therefor, a method for manufacturing a target material using them, a target material, a method for manufacturing a recycled ingot using a target material processed by the cleaning method or apparatus, and the manufacturing The present invention relates to a recycled ingot manufactured by the method.

  For example, as shown in the schematic diagram of FIG. 1, a sputtering target generally melts a metal and processes an ingot obtained by casting (for example, after subjecting the obtained ingot to plastic processing such as rolling and extrusion, A target material having a shape such as a flat plate type or a cylindrical type is manufactured by machining such as cutting and polishing, and a bonding material is attached to the target material and a backing plate, a backing tube, or the like, which are separately prepared support members. It can be produced by using or bonding or joining. As will be described in detail below, the sputtering target is used in sputtering and then separated into a target material and a support member, and the used target material is a bonding material that is washed by spraying water. Can be made into an ingot by melting and casting again (hereinafter referred to as “recycled ingot”), and the target material can be produced again by processing the recycled ingot.

Cleaning method of target material In the present invention, the "sputtering target" is a target material mainly composed of a metal (element) and a support member bonded together with a bonding material, and can be used for sputtering. If there is no particular limitation. When the sputtering target is a flat plate type, a flat backing plate can be used as the support member. When the sputtering target is cylindrical, a cylindrical backing tube can be used as the support member. Here, a cylindrical backing tube can be inserted into the cylindrical target material, and the inner peripheral portion of the cylindrical target material and the outer peripheral portion of the backing tube can be joined by a bonding material.

  The “target material” can be mainly composed of a metal (element), for example, aluminum (Al), copper (Cu), chromium (Cr), iron (Fe), tantalum (Ta), titanium (Ti ), Zirconium (Zr), tungsten (W), molybdenum (Mo), niobium (Nb), silver (Ag), cobalt (Co), ruthenium (Ru), platinum (Pt), palladium (Pd), gold (Au ), Rhodium (Rh), iridium (Ir), and nickel (Ni), and may include an alloy containing the above metal and have a Vickers hardness of 200 or less. The metal or alloy is preferably 100 or less, more preferably 50 or less. In particular, it is preferably composed mainly of aluminum (purity 99.99% (4N) or more, preferably 99.999% (5N) or more) or copper (purity 99.99% (4N) or more). The Vickers hardness can be confirmed by a Vickers hardness test (JIS Z 2244: 2003). There are no particular restrictions on the size, shape and structure of the target material. It is preferable to use a plate-like material as the target material.

When the target material is plate-like, the length in the longitudinal direction of the target material is, for example, 500 mm to 4000 mm, preferably 1000 mm to 3200 mm, and more preferably 1200 mm to 2700 mm.
The dimension in the width direction (direction perpendicular to the longitudinal direction) is, for example, 50 mm to 1200 mm, preferably 150 mm to 750 mm, and more preferably 170 mm to 300 mm.
The thickness is, for example, 5 mm to 35 mm, preferably 10 mm to 30 mm, and more preferably 12 mm to 25 mm.
In the present invention, for example, even a target material for a large flat panel display can be easily processed.

When the support member is a “backing plate”, mainly copper (Cu), chromium (Cr), aluminum (Al), titanium (Ti), tungsten (W), molybdenum (Mo), tantalum (Ta), niobium It includes a metal (element) selected from the group consisting of (Nb), iron (Fe), cobalt (Co) and nickel (Ni), and may be an alloy including the above metals, Copper (oxygen-free copper), chromium copper alloy, aluminum alloy and the like are preferable. There is no particular limitation on the size, shape, and structure of the backing plate as long as the target material can be placed on the plate.
When the support member is a “backing tube”, the constituent metal is the same as in the case of the above-described backing plate, and among these, stainless steel (SUS), titanium, titanium alloy, and the like are preferable. Since the dimensions of the backing tube are inserted and joined inside the cylindrical target material, it is usually longer than the cylindrical target material, and the outer diameter of the backing tube is preferably slightly smaller than the inner diameter of the cylindrical target material. .

The “bonding material” is not particularly limited as long as it can be used to form a sputtering target by contributing to the bonding between the target material and the support member (FIG. 2). Examples of the bonding material include solder material and brazing material.
The “solder material” is a material containing a metal or alloy having a low melting point (for example, 723 K or less), for example, indium (In), tin (Sn), zinc (Zn), lead (Pb), silver (Ag). , Copper (Cu), bismuth (Bi), cadmium (Cd) and antimony (Sb), or a material containing a metal or an alloy thereof. More specifically, In, In—Sn, Sn—Zn, Sn—Zn—In, In—Ag, Sn—Pb—Ag, Sn—Bi, Sn—Ag—Cu, Pb—Sn, Pb—Ag, Zn-Cd, Pb-Sn-Sb, Pb-Sn-Cd, Pb-Sn-In, Bi-Sn-Sb, and the like can be given.
As the “brazing material”, a target material and a support member can be bonded, and any metal or alloy having a melting point lower than that of the target material and the support member can be used without any particular limitation.
As the bonding material, it is preferable to use a solder material such as In or In alloy, Sn or Sn alloy which generally has a low melting point.

  For example, the solder material can be bonded by forming a diffusion layer (alloy layer) with a metal (element) contained in the target material on the bonding surface with the target material by heating. In addition, the solder material can also form a bonding layer (alloy layer) and a metal (element) contained in the support member and bond them on the joint surface with the support member. Therefore, a solder layer can be formed by using such a solder material, and a target material and a support member can be combined (FIG. 3).

  In general, if only the solder material is placed on the target material or the support member, an oxide film that may be present on the surface of the target material or the support member is affected, so that sufficient bonding strength may not be obtained. Therefore, first, a metallized layer may be provided in order to improve the wettability of the solder material with respect to those surfaces.

  “Metallization” is a processing method that can be generally used to form a metal film on a non-metallic surface. In the present invention, for example, when a target material or a support member has an oxide film, solder for metallization is used. A metallized layer is formed by bonding with a target material or a support member using a material. The metallized layer, for example, using an ultrasonic soldering iron, while destroying the oxide film of the target material and the support member by ultrasonic vibration energy (cavitation effect), by heating, along with oxygen atoms in the oxide film, It can be formed by chemically bonding metal atoms contained in the metallization solder material and metal atoms contained in the target material or the support member.

  The metallized layers (5, 5 ′) (see FIG. 4) that can be formed in this way can also be bonded to the solder layer (4), and between the target material (1) and the solder layer (4). Position between the support member (2) and the solder layer (4) to firmly bond the target material (1) and the solder layer (4) and the support member (2) and the solder layer (4) Can be fulfilled.

The thickness of the solder layer is, for example, in the range of 50 μm to 500 μm for the flat plate type and 250 μm to 1500 μm for the cylindrical type.
The thickness of the metallized layer is, for example, in the range of 10 μm to 100 μm for both the flat plate type and the cylindrical type.

  Solder materials that can be used for metallization include, for example, indium (In), tin (Sn), zinc (Zn), lead (Pb), silver (Ag), copper (Cu), bismuth (Bi), cadmium ( A material including a metal selected from the group consisting of Cd) and antimony (Sb) or an alloy thereof, and more specifically, In, In—Sn, Sn—Zn, Sn—Zn—In, In—Ag. Sn-Pb-Ag, Sn-Bi, Sn-Ag-Cu, Pb-Sn, Pb-Ag, Zn-Cd, Pb-Sn-Sb, Pb-Sn-Cd, Pb-Sn-In, Bi-Sn -Sb etc. are mentioned. What is necessary is just to select a material with high affinity with a target material or a supporting member suitably.

  In the present invention, for example, as shown in the schematic diagram of FIG. 1, after the sputtering target is used in sputtering, the target material is separated (peeled) from the support member. There is no particular limitation on the method for separating the target material from the support member. For example, heat (for example, 180 ° C. to 300 ° C.) is applied to a bonding layer (or bonding layer) that can be formed from the bonding material described above, and the bonding layer is physically formed as necessary while softening or melting the bonding layer. The target material can be separated from the support member by breaking.

  In the case where the target material is a flat plate type, in the separated target material, the surface on the side that is bonded (or bonded) to the backing plate (hereinafter also referred to as “bonded surface” or “bonded surface”) At least a part of the bonding material remains attached. Note that even if the bonding material adhering to the bonded surface after separation is scraped off with a spatula (for example, a silicone spatula), the adhering bonding material cannot be completely removed. In addition, the bonding material may adhere and remain on the sputtering surface of the target material. As the cause, for example, the bonding material melted at the time of separation of the target material adheres to the sputtering surface, and the separated used target materials are stacked and stored so that the bonding surface and the sputtering surface are in contact with each other. For example, the bonding material on the bonding surface may adhere to the sputtering surface. Therefore, the cleaning method may be applied to the sputtering surface.

  When the target material is cylindrical, since the cylindrical target material can be bonded to the outer periphery of the cylindrical backing tube using a bonding material, the target material after separation is combined as in the case of the plate target described above. The bonding material adheres to the surface (inner periphery) and cannot be completely removed. In addition, the bonding material may adhere and remain on the sputtering surface of the target material. Furthermore, components derived from the backing tube may be mixed as impurities. Therefore, the cleaning method may be applied to the outer peripheral portion and the inner peripheral portion, which are sputtering surfaces, also in the cylindrical target material.

  The presence of bonding material adhering to the target material after separation can be confirmed by, for example, energy dispersive X-ray fluorescence analysis (EDXRF). In addition, a metal element may diffuse from the support member to the target material, and such a metal element can be similarly confirmed by EDXRF. In addition, wavelength dispersive X-ray fluorescence analysis (WDXRF), electron probe microanalysis (EPMA), Auger Electron Spectroscopy (AES), X X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), laser irradiation type inductively coupled plasma mass spectrometry (LA-) Impurities originating from the bonding material and the support member can be confirmed by analysis methods such as ICP-MS: Laser Ablation Inductively Coupled Plasma Mass Spectrometry (XRD) and X-ray Diffraction Analysis (XRD). Confirmation with EDXRF or WDXRF is preferred because of its simplicity and wide analysis range.

  Here, an ingot (hereinafter sometimes referred to as “slab” or “ingot”) is manufactured by melting and casting in the subsequent recycling process using the separated target material to which the bonding material has adhered. When the target material is manufactured again from the ingot, impurities derived from the attached bonding material components are mixed. In some cases, a metal element diffuses from the support member to the target material and is mixed as an impurity, and such a metal element may also be mixed into the ingot as an impurity.

  Therefore, in the present invention, after separating the used target material from the support member, the target material is cleaned by spraying water onto at least the surface where the bonding material of the target material adheres and remains, and the adhered bonding material Can be removed from the target material (FIG. 1).

  Although there is no restriction | limiting in particular in the injection method of water, It is preferable to inject water on the following conditions.

  The water can be injected using, for example, a pump, and water is preferably injected at a high pressure (hereinafter, sometimes referred to as “water jet”). The pressure which injects water is 90 MPa or more, for example, Preferably it is 90 MPa-350 MPa, More preferably, it is 150 MPa-280 MPa, More preferably, it is 150 MPa-250 MPa. If the spray pressure is low, the cleaning effect may not be sufficient to remove the bonding material, especially the chemically strong metallization layer. Conversely, if the spray pressure is too high, the target material itself will be deepened beyond the metallization layer. It may be shaved, resulting in poor yield and high equipment costs.

  It is preferable that the water is ejected using a rotary (or rotatable) nozzle head having a plurality of ejection ports (or nozzles). The shape of the nozzle head is not particularly limited, and the shape of the surface facing the target material of the nozzle head (or the surface on which the nozzle is installed) is, for example, a polygon such as a triangle or a rectangle, a circle, Although it is an ellipse, it is preferably a regular polygon such as a circle and a square, and more preferably a perfect circle, since it is rotated and jets water. Further, when processing the joining surface of the flat plate type target material, it is necessary to use a nozzle head to which an injection port can be attached so that water is injected in a direction substantially parallel to the rotation axis of the nozzle head. preferable. When processing the joint surface (inner periphery) of a cylindrical target material, use a nozzle head that can be attached with an injection port so that water is injected in a direction substantially perpendicular to the rotation axis of the nozzle head. It is preferable to do.

  There is no restriction | limiting in particular in the number (or number of nozzles) of the injection nozzle provided in one nozzle head, For example, it is 1 or more, Preferably it is 1-15, More preferably, it is 3-10. The number of nozzles may be appropriately determined in accordance with the size of the nozzle head. If the number of nozzles is small, there may be cases where uncut parts can be left or the processing time becomes long. Further, since the total discharge amount increases when the number of nozzles is large, a larger and more expensive pump is required, and the equipment cost may be increased. When a plurality of ejection ports are provided in the nozzle head, the ejection ports may be disposed at the same diameter position of the nozzle head or at different diameter positions. Moreover, the combination of same diameter arrangement | positioning and different diameter arrangement | positioning may be sufficient.

  The dimension (nozzle diameter) of the injection port is, for example, 0.1 mm or more, preferably 0.15 mm to 0.50 mm, and more preferably 0.2 mm to 0.35 mm. The nozzles with the same diameter may be attached to the nozzle head, or the nozzles with different diameters may be attached to the nozzle head.

  The discharge amount of water (or the amount of water) varies depending on the pressure of water to be sprayed and the dimensions of the spray port, and the larger the value, the higher the cleaning effect. The total discharge amount of water ejected from all the ejection ports of one nozzle head is, for example, 2.0 L / min or more, preferably 2.0 L / min to 42 L / min, more preferably 5.0 L / min to 30 L / min, more preferably 5.0 L / min to 20 L / min.

  It is preferable that the water is ejected by moving in a strip shape (line shape) in the horizontal direction at a constant speed while maintaining a constant distance with respect to the processing surface of the target material. In addition, water injection may be performed several times, preferably 1 to 3 times in the same place. Alternatively, when the treatment width in one water injection is smaller than the target width, the water may be jetted by overlapping (overlapping) partially in a line shape.

  The moving speed of the nozzle head is, for example, 100 mm / min or more, preferably 500 mm / min to 7000 mm / min, more preferably 900 mm / min to 5000 mm / min. If the moving speed is low, the processing time becomes long. If the moving speed is high, the cleaning effect may not be sufficient.

The rotational speed of the nozzle head is, for example, 500 min ⁻¹ or more, preferably 500 min ^{−1 to} 4000 min ⁻¹ , more preferably 900 min ^{−1 to} 2500 min ⁻¹ . If the rotation speed is too low, water may not be applied to the entire surface of the target material depending on the number of nozzles, and it may be left uncut.If the rotation speed is too high, the impact when hitting the target material will be small. The cleaning effect may not be obtained.

  The distance (or nozzle distance) between the nozzle head and the target material is, for example, 10 mm or more, preferably 15 mm to 100 mm, more preferably 20 mm to 70 mm. If the distance is too close, it may be affected by the water that bounces off the target material and may not provide a sufficient cleaning effect.If the distance is too large, the impact when it hits the target material will be small. The cleaning effect may not be obtained.

  The water to be sprayed is not particularly limited as long as it does not contain particulate impurities, dust, or the like that clog the nozzle, and examples thereof include use of tap water and pure water. Further, a filter may be provided between the pump and the nozzle, and water may be ejected through the filter.

  The direction of water injection is not particularly limited as long as it is an angle at which water hits the target material, and may be perpendicular or oblique to the target material. For example, the angle of the injection port (the angle formed by the central axis of the injection port and the perpendicular to the target material) is 0 ° to 60 °, preferably 0 ° to 45 °, more preferably 5 ° to 45 °, and even more preferably. Is 5 ° to 30 °, more preferably 8 ° to 30 °, and particularly preferably 10 ° to 25 °. When water is jetted obliquely with respect to the target material, the processing width becomes larger than when jetted vertically because the nozzle head is rotating. Further, since the water hitting the target material does not stay on the treated surface and escapes to the outside, an improvement in the cleaning effect is also expected. Further, when water is jetted obliquely from the nozzle head, the side surface can be cleaned with the nozzle head positioned above the target material. Since it is not necessary to reset the target material or change the position of the nozzle head for the processing of the bonding surface of the target material, the processing of the sputtering surface, and the processing of the side surface, the processing time can be shortened. However, if the angle is too large, the distance between the target material and the nozzle increases. Further, since the impact when hitting the target material is reduced, there is a possibility that a sufficient cleaning effect cannot be obtained. When a plurality of injection ports are provided in the nozzle head, the angles of the nozzles may be the same or different. What is necessary is just to determine suitably the angle of each injection port so that it may not leave the shaving by the desired processing width and water not contacting.

  The nozzle head may simultaneously scan a plurality of nozzle heads in order to shorten the processing time per target material.

  In the above description, the case where the rotary nozzle head is used has been described. However, when the target material can be rotated or when the flat type nozzle head in which water is sprayed linearly is used, the fixed nozzle head is used. Even if the target material is used, the target material can be efficiently cleaned.

When the bonding material and the metallized layer are sufficiently removed from the bonding surface of the used target material by cleaning, the cleaned surface can be a satin finish. In addition, periodic processing marks (such as scales and spirals) corresponding to the movement of the nozzle head during cleaning may be formed. When it becomes a satin finish, for example, the regular reflectance at a wavelength of 300 nm to 1500 nm of the cleaned surface is 1.0% or less, and it is confirmed that impurities derived from the bonding material and the support member are sufficiently removed. Is preferably 0.7% or less. Furthermore, the rate of change in regular reflectance with respect to the wavelength of each incident light at wavelengths of 300 nm to 1500 nm (regular reflectance of the cleaned surface / regular reflectance of the surface before cleaning) is 0.025 or more and 0.85 or less, preferably Is from 0.05 to 0.75, more preferably from 0.08 to 0.60, and even more preferably from 0.10 to 0.40, impurities derived from the bonding material and the support member Can be confirmed to be sufficiently removed, and the target material can be prevented from being excessively shaved.
The arithmetic average roughness Ra is 5 μm or more, preferably 10 μm or more for confirming that impurities derived from the bonding material and the support member have been sufficiently removed, and the arithmetic average roughness Ra before and after cleaning. The rate of change in thickness Ra (arithmetic average roughness Ra of the cleaned surface / arithmetic average roughness Ra of the surface before cleaning) is 4 or more and 80 or less, preferably 5 or more and 50 or less, more preferably 7.5 or more and 20 In the following, it is preferable to perform the cleaning treatment so that the viscosity is 10 or more and 15 or less. Usually, the arithmetic average roughness Ra is 100 μm or less, preferably 50 μm or less. If the arithmetic average roughness Ra is too large, foreign substances such as dust and sand are likely to adhere, and the thickness of the oxide film increases, which may increase impurities in the recycled ingot.

  According to the cleaning method of the present invention, the lower limit of detection of EDXRF (normally, the lower limit of detection varies depending on the element. For example, the lower limit of detection of impurities derived from the bonding material is about 0.01% by weight. The amount of impurities derived from the bonding material and the support member can be reduced to a value lower than 0.01% by weight), and the target material after cleaning includes the impurities derived from the bonding material and the support member. The target element after the cleaning is not substantially detected (or the target material after cleaning does not substantially contain the element contained in the impurities derived from the bonding material and the support member).

  In the present invention, “the element contained in the impurities derived from the bonding material and the support member is not substantially detected” (or “the element contained in the impurities derived from the bonding material and the support member is not substantially included”) As described above, means that the amount of elements contained in the impurities derived from the bonding material and the support member is reduced to a level that is smaller than the lower detection limit of EDXRF and cannot be detected by EDXRF.

  Also, the cleaning method of the present invention is different from the method of processing into a flat surface at a certain height, such as cutting with a milling cutter, and the surface of the target material (or workpiece) that has been sprayed with water. Since the target material can be efficiently scraped off, it can be processed with a high yield even if the target material has irregularities and distortions. The target has not only the bonding surface of the target material but also irregularities formed by sputtering. It is also suitable for cleaning the sputtering surface of the material and the joint surface inside the cylindrical target. Furthermore, since the cleaning method of the present invention can set a workpiece without worrying about the height of the processing surface, it can be easily performed without requiring time for setting and cleaning. Compared with many advantages.

Apparatus The present invention also relates to an apparatus that can be used in the above-described cleaning method. Specifically, at least the bonding material of the target material (or the used target material) separated from the supporting member of the sputtering target in which the above-described target material mainly composed of metal and the supporting member are bonded with the bonding material. The present invention relates to an apparatus used to remove a bonding material from a target material by spraying water on the adhering surface (hereinafter, sometimes simply referred to as “cleaning apparatus”).

The cleaning apparatus may include at least the following configurations (a) to (c).
(A) at least one nozzle head provided with at least one injection port for injecting water onto the target material; (b) an actuator for operating or moving the nozzle head; and (c) an actuator is disposed to accommodate the target material. Processing chamber for processing

For example, as shown in FIGS.
At least one nozzle head 102 comprising at least one injection port (not shown) capable of injecting water onto the used target material (or workpiece) 101;
An actuator that can operate (or move) the nozzle head 102, preferably an X-axis slider 103X, a Y-axis slider 103Y, and a Z-axis slider 103Z, includes the nozzle head 102 in any direction of the XYZ axes. An actuator 103 configured to be movable;
And a processing chamber 104 in which the actuator can be disposed and the target material 101 can be accommodated and processed (or cleaned).
In the illustrated embodiment, the target material 101 is described as a flat plate type, but the target material 101 that can be used in the apparatus 100 is not limited to the flat plate type.

-Nozzle head A nozzle head can be used without a restriction | limiting especially if it is provided with at least one injection port (or nozzle) which can inject water. There is no particular limitation on the number of nozzle heads used. When using a plurality of nozzle heads, it is preferable to arrange the nozzle heads at appropriate intervals so that the water sprayed from the nozzles does not interfere with each other.
Furthermore, the apparatus of the present invention may further include a nozzle head (or a side nozzle head) for spraying water onto the side surface of the workpiece for cleaning. There is no particular limitation on the number of nozzle heads used for processing the side surfaces (XZ plane and / or YZ plane) of the workpiece and the positions where they are arranged.
As the nozzle head, those described in detail in the “target material cleaning method” described above can be appropriately used without limitation.
Moreover, you may further provide the rotary unit for rotating a nozzle head.

-Actuator An actuator that can operate or move the nozzle head using a driving force such as electricity, hydraulic pressure, or pneumatic pressure may be used. Preferably, a nozzle head that can arbitrarily and appropriately move the nozzle head in at least one direction of the X axis, Y axis, and Z axis, and more preferably in all directions of the X axis, Y axis, and Z axis is used.
More specifically, in order to move the nozzle head in all directions of the X axis, the Y axis, and the Z axis, for example, as shown in FIGS. 5 to 9 (particularly, FIG. 9), the X axis slider 103X, A three-axis combination type actuator 103 including an axis slider 103Y and a Z-axis slider 103Z can be used.

  The nozzle head 102 is configured so that it can be directly or indirectly coupled to the Z-axis slider 103Z, for example, via a rod 106 as necessary. The nozzle head 102 can be moved in a vertical direction or a direction approaching or moving away from the surface of the target material 101 (FIG. 9). In another aspect, the Z-axis slider 103Z may be configured such that the rod 106 passes through the Z-axis slider 103Z.

  The Z-axis slider 103Z is configured to be physically or mechanically coupled to the Y-axis slider 103Y. The Y-axis slider 103Y moves the nozzle head 102 together with the slider 103Z in the Y-axis direction (the target material 101). It can be moved along the traveling direction or the direction perpendicular to the longitudinal direction of the device 100 or the target material 101 shown in FIG. 9 (FIG. 9).

  The Y-axis slider 103Y is configured to be physically or mechanically coupled to the X-axis slider 103X. The X-axis slider 103X moves the nozzle head 102 together with the sliders 103Y and 103Z in the X-axis direction (target material). 101 in the traveling direction or the longitudinal direction of the apparatus 100 or the target material 101 shown in the figure (FIG. 9). Further, the end of the Y-axis slider 103Y opposite to the end coupled to the X-axis slider 103X is engaged with a support guide (or guide rail) that can be arranged in parallel with the X-axis slider 103X. Good.

  By using the actuator 103 (FIG. 9) including the sliders 103X, 103Y, and 103Z, the nozzle head 102 can be appropriately moved in the three directions of the X axis, the Y axis, and the Z axis.

  As long as the sliders 103X, 103Y, and 103Z can be slidably moved with each other using a driving force such as electricity, hydraulic pressure, and pneumatic pressure, there is no particular limitation on the driving mode and the coupling mode.

  The movement of the nozzle head and the jet of water by the actuator may be controlled by an electronic program. In that case, each slider may be appropriately connected by an electric cable or the like. It is desirable to control the moving speed of the nozzle head and the jet of water as defined in the “target material cleaning method” above.

  The actuator may be waterproof, and by being waterproof, it is possible to prevent problems due to rust and running out of oil caused by the spray of water splashing on the target material and touching the actuator. Moreover, when connecting each slider of an actuator with an electric cable, it is preferable that the electric cable is also waterproof.

  As shown in the illustrated embodiment, water may be jetted vertically downward from the nozzle head, but a mechanism that can change the angle of the nozzle head may be further arranged as necessary. In that case, the angle of the nozzle head can also be controlled by an electronic program. Further, with such a mechanism, the cylindrical target material can be more efficiently cleaned.

  As the actuator, for example, a three-axis combination type industrial robot manufactured by IAI Co., Ltd. may be used.

  The actuator that can be used in the apparatus of the present invention should not be interpreted as being limited to the above.

・ Processing chamber The processing chamber can be arranged with the above-mentioned actuator together with the nozzle head. The main purpose is to accommodate the target material and process the target material according to the above-mentioned “cleaning method of the target material”. .

  In addition, by processing the target material in the processing chamber, the water sprayed from the nozzle head hits the target material and the solid processed material (or dust) including the bonding material removed from the target material is scattered around. Thus, it is possible to prevent pollution of the environment.

  For example, as shown in FIGS. 5 to 8, the processing chamber 104 has a rectangular main body, the upper part thereof is opened, and an actuator (specifically, an actuator including the sliders 103 </ b> X, 103 </ b> Y, 103 </ b> Z shown in FIG. 9). 103) can be arranged.

  There is no particular limitation on the size of the treatment chamber 104, and it is preferable that a target material for a large sputtering target can be treated.

When the target material 101 is transported along the longitudinal direction as in the illustrated embodiment, the ratio (X / Y) of the dimension in the X axis direction to the dimension in the Y axis direction of the processing chamber 104 is, for example, 3/16. 10/1, preferably 1 / 2-10 / 3, more preferably 6 / 7-7 / 3.
The ratio (X / Z) between the dimension in the X-axis direction and the dimension in the Z-axis direction is, for example, 1/3 to 10/1, preferably 1/2 to 4/1, more preferably 5/6 to 35/12. It is.
The ratio (Y / Z) between the dimension in the Y-axis direction and the dimension in the Z-axis direction is, for example, 1/5 to 8/1, preferably 3/5 to 2/1, more preferably 5/6 to 35/24. It is.

In the above case, the dimension in the X-axis direction is specifically, for example, 750 mm to 5000 mm, preferably 1000 mm to 4000 mm, and more preferably 1500 mm to 3500 mm.
Specifically, the dimension in the Y-axis direction is, for example, 500 mm to 4000 mm, preferably 1200 mm to 2000 mm, and more preferably 1500 mm to 1750 mm.
Specifically, the dimension in the Z-axis direction is, for example, 500 mm to 2500 mm, preferably 1000 mm to 2000 mm, and more preferably 1200 mm to 1750 mm.

  In the illustrated embodiment, the target material 101 is transported along the longitudinal direction by using a transport means 105 such as a belt conveyor and a roller, which will be described in detail below, and the target material is transported inside the processing chamber 104. Although the target material 101 can be processed, the target material 101 is transported along the width direction (direction perpendicular to the longitudinal direction) of the target material 101 (for example, along the Y axis), and the target material 101 is processed inside the processing chamber 104. 101 may be processed.

When the target material 101 is transported along the width direction (direction perpendicular to the longitudinal direction), the ratio (X / Y) of the dimension in the X axis direction to the dimension in the Y axis direction of the processing chamber 104 is, for example, 3 / 16 to 10/1, preferably 1/2 to 10/3, more preferably 6/7 to 7/3.
The ratio (X / Z) between the dimension in the X-axis direction and the dimension in the Z-axis direction is, for example, 1/3 to 10/1, preferably 1/2 to 4/1, more preferably 5/6 to 35/12. It is.
The ratio (Y / Z) between the dimension in the Y-axis direction and the dimension in the Z-axis direction is, for example, 1/5 to 8/1, preferably 3/5 to 2/1, more preferably 5/6 to 35/24. It is.

In the above case, the dimension in the X-axis direction is specifically, for example, 750 mm to 5000 mm, preferably 1000 mm to 4000 mm, and more preferably 1500 mm to 3500 mm.
Specifically, the dimension in the Y-axis direction is, for example, 500 mm to 4000 mm, preferably 1200 mm to 2000 mm, and more preferably 1500 mm to 1750 mm.
Specifically, the dimension in the Z-axis direction is, for example, 500 mm to 2500 mm, preferably 1000 mm to 2000 mm, and more preferably 1200 mm to 1800 mm.

  When the transport unit 105 is used, the processing chamber 104 may have a pair of openings (a carry-in port and a carry-out port) through which the transport unit 105 and the target material 101 pass. As long as the target material 101 can be passed through, the size of the opening is not particularly limited.

  When transporting the target material 101 along its longitudinal direction as in the illustrated embodiment, the dimension of the opening in the Y-axis direction is, for example, 100 mm or more, preferably 150 mm to 1500 mm, more preferably 200 mm to 1000 mm, Still more preferably, it is 250 mm-500 mm, and the dimension of a Z-axis direction is 10 mm or more, for example, Preferably it is 12 mm-300 mm, More preferably, it is 20 mm-200 mm, More preferably, it is 45 mm-150 mm.

  When the target material 101 is conveyed along the width direction (direction perpendicular to the longitudinal direction), the dimension of the opening in the X-axis direction is, for example, 500 mm or more, preferably 750 mm to 4000 mm, more preferably 1000 mm to 3500 mm. The dimension in the Z-axis direction is, for example, 10 mm or more, preferably 12 mm to 300 mm, more preferably 20 mm to 200 mm, and still more preferably 45 mm to 150 mm.

  In the above embodiment, the apparatus capable of transporting the target material 101 has been described. However, the cleaning device of the present invention does not need to include the transport unit 105.

  In the embodiment shown in FIG. 5, the side surface (XZ plane) is shown to have an opening so that the inside of the processing chamber 104 can be clearly seen. , May or may not be present. When such an opening exists, an opening / closing door (for example, a double door) may be provided in the opening to prevent splashing or dust scattering. Providing such a door is preferable because maintenance inside the processing chamber 104 is simplified.

  At the bottom of the inside of the processing chamber 104, water (including solid processed matter (or dust) including the bonding material removed from the target material) sprayed from the nozzle head and cleaning the target material 101 (hereinafter, referred to as the following) A pool (not shown) for temporarily storing (treated water) may be provided.

  Further, the treatment chamber 104 may have a discharge port (not shown) for discharging the treated water. Although the discharge port may be disposed on the bottom surface of the processing chamber 104, there is a possibility that the processing object accumulates and closes the discharge port, so that the interval from the bottom surface is, for example, 1 mm to 50 mm, preferably 10 mm to 25 mm. It can also be opened and placed on the side. The discharge port is not particularly limited in shape, size, and structure as long as the treated water can be discharged.

  Furthermore, a shower mechanism for washing away the processing object attached to the inner wall surface of the processing chamber 104 may be optionally provided inside the processing chamber 104.

  The processing chamber that can be used in the apparatus of the present invention should not be interpreted as being limited to the above.

Other Configurations The device may include other configurations in addition to the above configuration.

-Clamp The apparatus of the present invention may further include a clamp for fixing the target material in the processing chamber. By fixing the target material with a clamp, the target material can be fixed so as not to move during the cleaning process. There is no restriction | limiting in particular in the position which arrange | positions a clamp in a process chamber. It is preferable to fix the side surface of the target material from both sides. By fixing in such a manner, water can be jetted over the entire surface of the target surface without being covered with the clamp.
In addition, when the target material is deformed, for example, when it is bent like a bow, when the water is sprayed from the upper side of the target material, the target material may vibrate and the performance of the cleaning process may deteriorate. As described above, the vibration of the target material can be suppressed by fixing the side surface of the target material with a clamp.
In addition, when there is little warpage of the target material or when there is a base on the lower side of the target material, water is injected from above the target material so that the target material does not move from a predetermined position. Just fix it.
In addition, by fixing the target material to a predetermined position with a clamp (target material positioning), there is an advantage that it is not necessary to perform zero point adjustment (designation of the processing range) when operating the nozzle head. It is done.
Although there is no restriction | limiting in the shape and dimension of a clamp, etc., it is preferable to use the clamp which can fix the side surface of a target material from the both sides as mentioned above. For example, it is possible to use Imao Corporation, a side clamp manufactured by Tsudakoma Corporation. There is no particular limitation on the number of clamps and the position where the clamps are arranged, and it may be determined as appropriate according to the target material.
The clamp mechanism may be automatic or manual, but in order to simplify the work of fixing a large target material, when the target material is installed at a predetermined position, It is preferable to be an automatic type in which the side surface is sandwiched from both sides. Further, in the case where the clamp is a manual type, it is preferable to provide an opening, preferably an openable / closable door, on the side surface (XZ plane) of the processing chamber 104 in terms of workability.

-Conveyance mechanism The apparatus of this invention may include the conveyance mechanism which can carry in a target material in a processing chamber, and can carry out a target material from a processing chamber (for example, the conveyance means 105 shown to FIGS. 5-8). .
As the transport mechanism, any material can be used as long as it can transport the target material. For example, a conveyor such as a belt conveyor, a roller conveyor, or a caterpillar, shuttle transport, pallet transport, vacuum chuck transport, Robot arm transfer is an example.
Although there is no restriction | limiting in particular in the conveyance speed of the target material by a conveyance mechanism, For example, they are 15 m / min-60 m / min, Preferably they are 20 m / min-50 m / min, More preferably, they are 25 m / min-40 m / min.
Further, the transport mechanism may form a continuous loop so that the target material can be carried into the processing chamber again after the target material is carried out of the processing chamber.
The transport mechanism may be arbitrarily divided according to purposes such as loading, unloading, processing chamber, and loop.
Further, the transport mechanism may be provided with a target material supply mechanism on the inlet side of the processing chamber, and may be provided with a target material reversal mechanism on the outlet side of the processing chamber.

Target Material Supply Mechanism The apparatus of the present invention may include a target material supply mechanism so that the target material can be appropriately supplied to the above-described transport mechanism. The target material supply mechanism is not particularly limited as long as the target material can be appropriately supplied. Further, the target material supply mechanism may include a cassette for storing a plurality of target materials, and from there, the target material may be appropriately supplied as necessary. . A commercially available automatic supply apparatus may be used as the target material supply mechanism.

-Target material reversing mechanism The apparatus of the present invention may further include a reversing mechanism for reversing the target material, preferably a mechanism capable of reversing the target material in a fixed state (for example, clamped). Good. By including such a reversing mechanism, the target surface of the target material can be arbitrarily reversed. There is no particular limitation on the dimensions of the reversing mechanism.
A commercially available automatic reversing device may be used. For example, an automatic reversing device manufactured by Adpec Co., Ltd. can be used.

-Drainage mechanism Since the treated water after washing the target material includes a solid processed material (or dust) including the bonding material removed from the target material, the apparatus of the present invention is required as necessary. It may include a drainage mechanism that can collect and drain only water from the treated water, and separate a solid treated material such as a bonding material.
Any drainage mechanism can be used without particular limitation as long as it can separate a solid and a liquid. In this field, a generally well-known solid-liquid separation device or the like can be appropriately used as necessary.
The drainage mechanism is preferably connected to a discharge port that can be provided inside the processing chamber.

  For example, a membrane-separated solid-liquid separator that can be generally used for water treatment can be used. In a membrane separation type solid-liquid separation device, by using at least one of a plurality of membrane cartridges including a membrane capable of solid-liquid separation, the water is suction filtered with a pump through a water collecting pipe connected to the membrane cartridge. The collected water can be drained to the outside (FIG. 10). At this time, the processed product can be precipitated at the bottom of the tank, so that it can be separately collected and reused.

  Moreover, you may utilize the precipitation tank which can isolate | separate solid and a liquid by precipitation as a drainage mechanism. For example, a hopper type sedimentation tank that can be generally used for water treatment, a circular sedimentation tank with a center drive scraper, a cross flow type sedimentation tank, and the like can be mentioned. By using such a sedimentation tank, it is possible to separately collect a solid processed product including the bonding material removed from the target material.

Or you may isolate | separate a solid and a liquid using a multistage precipitation tank as shown in FIG. The multistage settling tank has a plurality of settling tanks, and can drain water from a settling tank having a high water level to a settling tank having a low water level, and sequentially from above the settling tank to a lower settling tank. The treated product is precipitated at the bottom of each settling tank, and can be separately collected and reused.
There are no particular restrictions on the number of precipitation tanks and the capacity of each precipitation tank. Further, drainage from the settling tank to the next settling tank may be performed using a pump.

-Side nozzle head The apparatus of this invention may contain at least 1 side nozzle head which has an at least 1 nozzle for injecting water to the side surface of a target material in a process chamber. As the side nozzle head, the nozzle head described in the above-mentioned “target material cleaning method” can be used in the same manner as described above. The side nozzle head may be fixed or movable. When the side nozzle head is movable, it is preferable to use the side nozzle head by moving it along the X axis or the Y axis.
There are no particular restrictions on the position and number of side nozzle heads.
By using such a side nozzle head as necessary, not only the main surface of the target material but also its side surfaces can be three-dimensionally cleaned.

-Pump The apparatus of this invention may contain the pump which can supply water to the above-mentioned nozzle head and / or side nozzle head. As the pump, for example, the pump described in the above “target material cleaning method” can be used.
The pump can be connected to the nozzle head and / or the side nozzle head through a line capable of fluid connection, preferably a pressure resistant line. Such a line can be arranged arbitrarily, for example, along the rod 106 shown in FIGS. Such a pump may be disposed inside or outside the processing chamber, but is preferably disposed outside the processing chamber. Further, the number of pumps to be used is not particularly limited, and a plurality of pumps may be used.

Control Unit Any of the above-described configurations can be appropriately controlled using the control unit. Examples of the control means include those provided with a CPU, ROM, RAM, and the like. The above configuration can be arbitrarily selected and electrically connected, and the configuration can be controlled by the control means using an electronic program as necessary.

-Drying mechanism The apparatus of this invention may include the drying mechanism for removing rapidly the water adhering to the used target material after washing | cleaning inside and outside a process chamber. By removing the water, it is possible to prevent inconveniences such as mixing of foreign matters caused by water adhering to the raw material when the used target material after cleaning is melted and cast as the raw material.
As a drying mechanism, for example, a drying mechanism by blowing air such as dry air or nitrogen gas onto a used target material after cleaning, and blowing off water adhering to the target material, or by heating on hot air or a hot plate A drying mechanism can be employed. In the case where the processing chamber 104 has an opening (a carry-out port) through which the transfer means 105 and the target material 101 pass, it is preferable to provide a drying mechanism by blowing air at either the inside or outside of the opening.

[Preferred Embodiment of Cleaning Device]
In a preferred embodiment, the device is
A nozzle head;
An actuator,
A processing chamber;
And at least one component selected from the group consisting of a clamp, a side nozzle head, a reversing mechanism, a drainage mechanism, a drying mechanism, and a transport mechanism.

  The apparatus of the present invention should not be construed as being limited to those including the above-described configuration.

Recycled ingot manufacturing method The target material processed according to the cleaning method and / or the cleaning apparatus of the present invention can be manufactured by melting and casting as shown in FIG. 1, for example.

  As a method for producing the recycled ingot, a known method may be used, which can be produced through a melting and casting process. As a melting method, it may be melted in the atmosphere or in a vacuum in an electric furnace or a combustion furnace, and as a casting method, a continuous casting method, a semi-continuous casting method, a die casting method, a precision casting method, a hot top A casting method, a gravity casting method, or the like can be employed. Moreover, you may perform a degassing process and an inclusion removal process between a melt | dissolution and a casting process.

  What is necessary is just to determine suitably the manufacturing conditions of recycling ingot, especially temperature according to the metal (element) mainly contained in a target material.

  For example, when the metal contained as the main component in the target material is aluminum, the target material after cleaning is carbonized at 670 to 1200 ° C., preferably 750 to 850 ° C. under vacuum (for example, 0.03 Torr) or air. A recycled ingot can be manufactured by dissolving in a crucible such as aluminum or alumina, stirring in the air as necessary to remove dross, and then cooling in the air.

  In the case where the metal contained as the main component in the target material is copper, the target material after cleaning may be carbon or carbon at 1100 to 1500 ° C., preferably 1150 to 1200 ° C. under vacuum (for example, 0.03 Torr) or in the air. A molten ingot can be produced by melting in a crucible such as alumina, stirring in the atmosphere as necessary to remove dross, and then cooling in the atmosphere.

  For the production of the recycled ingot, it may be produced only with the target material after washing, or a mixture of conventional raw metal and the target material after washing may be used together. When the raw material metal and the target material after cleaning are mixed, the mixing ratio of the target material after cleaning is usually 20% by weight or more, and is 50% by weight or more for suppressing the ratio of the raw material cost in the manufacturing cost. It is preferable.

Recycled ingot The recycled ingot that can be produced according to the method of the present invention is characterized in that it contains substantially no elements contained in impurities derived from the bonding material and the support member as described above. ) It may have substantially the same composition as the target material. Therefore, a target material having substantially the same composition as the original target material can be manufactured again from such a recycled ingot. Here, “having substantially the same composition as the original target material” means that the main metal (element) is the same, and may contain impurities in the same amount as the impurities originally contained in the original target material. Means that. For example, the total amount of impurities that can be derived from the bonding material and the support member is less than 10 ppm, preferably 0.1 ppm to 8 ppm, more preferably 5 ppm or less (or less), and even more preferably 0.1 ppm to 5 ppm on a weight basis. More preferably 0.1 ppm to 2 ppm, and the total amount of impurities is less than 50 ppm, preferably 0.1 ppm to 20 ppm, more preferably 0.1 ppm to 10 ppm, more preferably 5 ppm or less (or less), The case where it exists in the range of 0.1 ppm-5 ppm more preferably is mentioned. The impurities originally contained in the original target material and the amount thereof can depend on the type of metal contained in the target material as a main component and the method of manufacturing the original target material. In addition, the recycled ingot may be used for applications other than the target material. For example, it may be used as a raw material for products that require high purity such as aluminum electrolytic capacitors, hard disk substrates, corrosion resistant materials, and high purity alumina. it can.

  For example, when the metal contained as the main component in the target material is aluminum, the total amount of impurities derived from the bonding material and the support member contained in the recycled ingot is, for example, less than 10 ppm on a weight basis, preferably 0. 0.1 ppm to 8 ppm, more preferably 5 ppm or less (or less), still more preferably 0.1 ppm to 5 ppm, and even more preferably 0.1 ppm to 2 ppm. Depending on the application, for example, an aluminum target material for a flat display is usually 50 ppm or less, preferably 0.1 ppm to 20 ppm, more preferably 0.1 ppm to 10 ppm, and even more preferably 5 ppm or less (or less). If it is known that the amount of impurities is in this range, there is no particular problem with sputtering.

  Moreover, when the metal contained as a main component in the target material is copper, the total amount of impurities derived from the bonding material and the support member contained in the recycle ingot is, for example, less than 10 ppm, preferably 0. It is 05 ppm to 9 ppm, more preferably 0.05 ppm to 8 ppm. Although it depends on the application, for example, an oxygen-free copper target material for a flat display is known to contain impurities of usually 100 ppm or less, preferably 0.1 ppm to 75 ppm, more preferably 0.1 ppm to 50 ppm. If the amount of impurities is about this level, there is no particular problem in sputtering.

  In addition, since the amount of impurities contained in the recycled ingot is extremely small, the amount of such impurities can be measured using glow discharge mass spectrometry (GDMS). Although the lower limit of quantification of GDMS varies depending on the main element of the target material and the element to be detected, for example, when the metal contained as the main component of the target material is aluminum, it is usually 0.001 ppm to 0.1 ppm. For example, indium is 0.01 ppm.

  As described above, according to the present invention, the used target material can be easily cleaned, and the target material after cleaning is substantially free of elements contained in impurities derived from the bonding material and the support member. From the above, by reusing (or recycling) the used target material treated by such a cleaning method, it is possible to obtain a recycled ingot that is substantially free of elements contained in impurities derived from the bonding material and the support member. And a target material having substantially the same composition as the original target material can be easily regenerated.

  Further, in the present invention, by using a used target as a target material mainly composed of metal, it is possible to efficiently remove bonding materials such as solder material and brazing material existing on the surface layer of the target material. The water pressure of the water jet needs to be increased (for example, increased to 90 MPa or more) according to the bonding condition of the bonding material on the surface layer of the target material. Even if the contact is applied, the bonding material can be removed without damaging the target material itself.

  EXAMPLES Hereinafter, although an Example of this invention is given and this invention is demonstrated in detail, this invention is not limited to a following example.

Example 1
A flat plate target material made of aluminum (purity: 99.999%, Vickers hardness: 15 to 17, dimensions: 2000 mm × 200 mm × 15 mm) and an oxygen-free copper backing plate (purity: 99.99%, dimensions: 2300 mm × 250 mm × 15 mm) and a sputtering target formed by joining with an In solder material (solder layer thickness: 350 μm) (using a Sn—Zn—In solder material for metallization of the target material) is applied to sputtering. Then, the target material was separated from the backing plate by heating (280 ° C.) the bonding layer. The solder material adhering to the joint surface of the target material was scraped off with a silicone spatula, and the solder material was recovered as much as possible. After separation from the backing plate, the target material was cut to a size of about 300 mm × 200 mm × 15 mm.

Nozzle diameter: 0.25 mm (manufactured by Sugino Machine Co., Ltd., model number: DN-0825), 0.30 mm (manufactured by Sugino Machine Co., Ltd., model number: DN-0830) Using a true circular nozzle head (model number: MNH-2506CH manufactured by Sugino Machine Co., Ltd.) equipped with 0.30 mm nozzles at the three outer locations of the nozzle head and 0.25 mm nozzles at the inner three locations) Then, water was sprayed onto the bonding surface and sputtering surface of the target material to clean the entire surface (water pressure: 245 MPa, water amount: 11.6 L / min, distance between the target material and the nozzle head: 55 mm, scanning: twice, (Overlap: 5 mm, nozzle head rotation speed: 1500 min ⁻¹ , nozzle head movement speed: 3000 mm / min). At this time, the nozzle head and the used target material are arranged so that the center axis of the nozzle head and the joining surface of the used target material are vertical, and the nozzle head is scanned in the long side direction of the used target material (nozzle Since the surface of the head on which water is ejected has a downwardly convex crest structure, the nozzle faces obliquely with respect to the joint surface, and the water strikes the joint surface obliquely). The bonding material and the metallized layer were removed from the surface of the target material after the cleaning, and a satin finish was obtained. The specular reflectance in the wavelength range of 300 nm to 1500 nm on the mated joint surface was measured with an ultraviolet visible near infrared spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation). Using a 5 ° regular reflection accessory, the sample is irradiated with incident light with an incident angle of 5 °, and the reflectance of the reflected light reflected at the reflection angle of 5 ° with respect to the incident light is determined in increments of 100 nm. It was. The maximum was 0.4% when the wavelength of incident light was 1300 nm, 0.3% when the wavelength was 500 nm, and 0.2% when the wavelength was 1000 nm. In addition, the regular reflectance in the whole wavelength range of 300 nm to 1500 nm of the bonding surface to which the bonding material before treatment is attached is about 2-3% when the wavelength of incident light is 1300 nm, and is 1 to 3 when the wavelength is 500 nm. At 2% and 1000 nm, it was 1 to 2%. Moreover, the joint surface which became a satin-like surface by arithmetic mean roughness Ra by the method prescribed | regulated to JISB0601 (2001) using contact type surface roughness meter (Mitutoyo Corporation make, surf test SJ-301). When three points were measured, the average value of Ra was 19 μm. In addition, the arithmetic average roughness Ra of the bonding surface to which the bonding material before the treatment adhered was 1.7 μm on average.

Using an EDXRF analyzer (EDX-700L, detection limit: about 0.01 wt% in In) manufactured by Shimadzu Corporation, the bonded surface of the used target material after cleaning was analyzed (semi-quantitative analysis) under the following conditions. . As a result, it was not possible to detect any Sn, Zn, In derived from the solder material, or Cu derived from the backing plate on the bonded surface of the used target material after cleaning. At that time, the presence or absence of X-ray peak detection was also confirmed for the elements of the components of the bonding material and the backing plate.
In addition, when the joint surface of the used target material before washing | cleaning is analyzed by EDXRF similarly to the above, Sn, Zn, and In originating from a solder material are 10 weight% or less, 10 weight% or less, 1 weight%-70 respectively. Cu present in weight%, and Cu derived from the backing plate is present in an amount of 1% to 50% by weight. By the cleaning method of the present invention, the used target material after cleaning is derived from the solder material and the backing plate. It turned out that the element contained in an impurity is not included substantially.
<Analysis conditions>
X-ray irradiation diameter: 10mmφ
Excitation voltage: 10 kV (Na to Sc), 50 kV (Ti to U)
Current: 100 μA
Measurement time: 200 seconds (100 seconds measurement at each excitation voltage)
Atmosphere: He
Tube: Rh target Filter: None Measurement method: Fundamental parameter method Detector: Si (Li) semiconductor detector

Further, the used target material after washing is melted under vacuum (for example, 0.03 Torr) at 850 ° C., stirred in the air to remove dross, and then cooled in the air, thereby recycling ingots. Manufactured.
The amount of impurities contained in the recycled ingot was subjected to microanalysis for Sn, Zn, In and Cu using GDMS (VG Elemental, VG9000). The results are shown in Table 1 below together with the analysis results of the ingot produced by the same method from the used target material (before cleaning) and the unused target material (before joining).

  From the results shown in Table 1, the amount of impurities (In, Sn, Zn derived from the solder material, Cu derived from the backing plate) contained in the recycled ingot produced using the used target material after washing is It was found that both were reduced to the same extent as the unused target material (before joining).

Example 2
Oxygen-free copper flat target material (purity: 99.99%, Vickers hardness: 90, dimensions: 2000 mm x 200 mm x 15 mm) and oxygen-free copper backing plate (purity: 99.99%, dimensions: 2300 mm x 250 mm) × 15 mm) and a sputtering target formed by joining with an In solder material (solder layer thickness: 350 μm) (using a Sn—Zn—In solder material for metallization of the target material) and using it for sputtering. Then, the target material was separated from the backing plate by heating (280 ° C.) the bonding layer. The solder material adhering to the joint surface of the target material was scraped off with a silicone spatula, and the solder material was recovered as much as possible. After separation from the backing plate, the target material was cut to a size of about 300 mm × 200 mm × 15 mm.

Nozzle diameter: 0.30 mm (Model number: MNH-2506CH, manufactured by Sugino Machine Co., Ltd.) equipped with six nozzles having a nozzle of 0.30 mm (Model number: DN-0830 manufactured by Sugino Machine Co., Ltd.) Then, water was sprayed onto the joint surface of the target material to clean the entire surface (water pressure: 245 MPa, water amount: 13.7 L / min, distance between target material and nozzle head: 25 mm, scanning: 3 times, overlap) : 5 mm, nozzle head rotation speed: 1500 cm ⁻¹ , nozzle head movement speed: 100 mm / min). At this time, the nozzle head and the used target material are arranged so that the central axis of the nozzle head and the joining surface are vertical, and the nozzle head is scanned in the long side direction of the used target material (water from the nozzle head is ejected). Since the surface on the side to be formed has a downwardly convex crest structure, the nozzle faces in an oblique direction with respect to the joint surface, and water strikes the joint surface obliquely). The bonding material and the metallized layer were removed from the surface of the target material after the cleaning, and a satin finish was obtained. When the regular reflectance in the entire region of the wavelength of 300 nm to 1500 nm on the mated joint surface was measured under the same conditions as in Example 1, the maximum was 0.5% when the wavelength of incident light was 1300 nm, and the wavelength was 500 nm. Was 0.1% at 1000 nm, and 0.3% at 1000 nm. In addition, the regular reflectance in the wavelength range of 300 nm to 1500 nm of the bonded surface to which the bonded body before the treatment is adhered becomes maximum when the wavelength of incident light is 1300 nm, about 2-3%, and is 1 to 2 when the wavelength is 500 nm. %, When the wavelength was 1000 nm, it was 1 to 2%. Moreover, when arithmetic mean roughness Ra was measured similarly to Example 1, the average value of Ra was 17 micrometers. The arithmetic average roughness Ra of the bonded surface to which the bonded body before treatment adhered was 2.1 μm on average.

  Using the EDXRF analyzer (EDX-700L) manufactured by Shimadzu Corp., the joint surface of the used target material after cleaning was analyzed under the same conditions as in Example 1. As a result, Sn, Zn, and In derived from the solder material could not be detected at all on the bonded surface of the used target material after cleaning.

  When the bonding surface of the used target material before cleaning is analyzed by EDXRF in the same manner as described above, Sn, Zn, and In derived from the solder material are 1 wt% to 20 wt%, 1 wt% to 20 wt%, respectively. It was found that the used target material after cleaning was substantially free of impurities derived from the solder material by the cleaning method of the present invention.

Further, the used target material after cleaning is melted at 1200 ° C. under vacuum (for example, 0.03 Torr), stirred in the atmosphere to remove dross, and then cooled in the atmosphere, thereby recycling ingots. Manufactured.
The amount of impurities contained in the recycled ingot was analyzed for Sn, Zn, and In using GDMS (VG 9000, manufactured by VG Elemental). The results are shown in Table 2 below together with the analysis results of the ingot produced by the same method from the unused target material (before joining).

  From the results shown in Table 2, the amount of impurities (In, Sn, Zn derived from the solder material) contained in the recycled ingot produced using the used target material after cleaning is determined based on the unused target material (joining Although a slight increase was observed compared to the previous case, the total increase was about 1.4 ppm (weight basis), and it was found that the amount of impurities was greatly reduced.

  From the results of Example 2, even in the used target material containing copper as a main component, when the cleaning method according to the present invention is performed, the used target material after cleaning having substantially the same composition as the original target material is obtained. I was able to get it. It was also found that a recycled ingot with a greatly reduced amount of impurities can be obtained by melting and casting the used target material after washing as a raw material.

Example 3
A flat plate target material made of aluminum (purity: 99.999%, Vickers hardness: 15 to 17, dimensions: 2000 mm × 200 mm × 15 mm) and an oxygen-free copper backing plate (purity: 99.99%, dimensions: 2300 mm × 250 mm × 15 mm) and the following solder material (solder layer thickness: 350 μm) is used by sputtering, and after the sputtering target is used, the bonding layer is heated (280 ° C.) to obtain the target material. Was separated from the backing plate. The solder material adhering to the joint surface of the target material was scraped off with a silicone spatula, and the solder material was recovered as much as possible. After separation from the backing plate, the target material was cut to a size of about 300 mm × 200 mm × 15 mm.
The bonded surface of the target material was cleaned under the following conditions 1 to 10. Under any of the conditions, the bonding material and the metallized layer were removed from the surface of the target material after washing, resulting in a satin finish. About the target material after washing | cleaning, the used target material after washing | cleaning on the conditions similar to Example 1 using the EDXRF analyzer (EDX-700L, detection limit: About 0.01 weight% in In) by Shimadzu Corporation The joint surface was analyzed. As a result, no In, Sn, Zn derived from the solder material or Cu derived from the backing plate could be detected at all on the joint surface of the used target material after cleaning. In particular, for the used target material after washing obtained under the following conditions 1 to 8, the target material is dissolved under vacuum (for example, 0.03 Torr) at 850 ° C. and stirred in the atmosphere to remove dross. After that, a recycled ingot was produced by cooling in the air.
The amount of impurities contained in an ingot produced by the same method from an unused target material (before joining), the recycled ingot, and a used target material (before washing) was determined by GDMS (VG Elemental, VG9000, respectively). ). The results are shown in Tables 3 and 4 below.

Condition 1
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm (manufactured by Sugino Machine, model number: DN-0825)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 1000mm / min
Line treatment: 1 time Overlap: 5 mm
Cleaning treatment: Bonding surface

Condition 2
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm (manufactured by Sugino Machine, model number: DN-0825)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 1000mm / min
Line treatment: 1 time Overlap: 22 mm
Cleaning treatment: bonding surface and sputtering surface

Condition 3
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.30 mm (manufactured by Sugino Machine, model number: DN-0830)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 1000mm / min
Line treatment: 1 time Overlap: 22mm
Cleaning treatment: bonding surface and sputtering surface

Condition 4
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm (manufactured by Sugino Machine, model number: DN-0825)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 2000mm / min
Line treatment: 2 times Overlap: 22mm
Cleaning treatment: bonding surface and sputtering surface

Condition 5
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm (manufactured by Sugino Machine, model number: DN-0825)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 2000mm / min
Line treatment: 2 times Overlap: 5 mm
Cleaning treatment: bonding surface and sputtering surface

Condition 6
Solder material for bonding: Sn-Zn
Solder material for metallization: Sn-Zn-In
Water pressure: 200 MPa
Water volume: 8.5L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm (manufactured by Sugino Machine, model number: DN-0825)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 1000mm / min
Line treatment: 2 times Overlap: 5mm
Cleaning treatment: bonding surface and sputtering surface

Condition 7
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 245 MPa
Water volume: 11.6L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm, 0.30 mm (3 nozzles each, manufactured by Sugino Machine Co., Ltd., model number: DN-0825, DN-0830, 0.30 mm nozzles on the outside of the nozzle head, 3 insides 0.25mm nozzle is placed on the
Nozzle distance: 55mm
Rotational speed: 1500 min ^-1
Movement speed: 4000mm / min
Line treatment: 2 times Overlap: 5mm
Cleaning treatment: bonding surface and sputtering surface

Condition 8
Solder material for bonding: Sn-Zn
Solder material for metallization: Sn-Zn-In
Water pressure: 245 MPa
Water volume: 11.6L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.25 mm, 0.30 mm (3 nozzles each, manufactured by Sugino Machine Co., Ltd., model number: DN-0825, DN-0830, 0.30 mm nozzles on the outside of the nozzle head, 3 insides 0.25mm nozzle is placed on the
Nozzle distance: 55mm
Rotational speed: 1500 min ^-1
Movement speed: 3000mm / min
Line treatment: 2 times Overlap: 5 mm
Cleaning treatment: bonding surface and sputtering surface

Condition 9
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 150 MPa
Water volume: 7.3 L / min
Number of nozzles: 3 (nozzle head is manufactured by Sugino Machine Co., Ltd., arranged at a pitch circle diameter (PCD) of 20 mm, water is jetted in the vertical direction)
Nozzle diameter: 0.35 mm (manufactured by Sugino Machine, model number: DN-0835)
Nozzle distance: 25mm
Rotational speed: 1000 min ^-1
Movement speed: 1000mm / min
Line treatment: 1 time Overlap: 5 mm
Cleaning treatment: Joint surface

Condition 10
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 245 MPa
Water volume: 3.4 L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506CH is used)
Nozzle diameter: 0.15 mm (manufactured by Sugino Machine, model number: DN-0815)
Nozzle distance: 25mm
Rotational speed: 1500 min ^-1
Movement speed: 1000mm / min
Line treatment: 1 time Overlap: 5 mm
Cleaning treatment: Bonding surface

  From the results of Examples 1 and 3, when the cleaning method according to the present invention is performed on a used target material containing aluminum as a main component, a recycled ingot having substantially the same composition as the original target material is obtained. I understood it.

Comparative Example 1
The used flat plate type target material similar to that in Example 1 is cut so as to have a size of about 100 mm × 200 mm × 15 mm, immersed in a 4.4 wt% nitric acid aqueous solution at room temperature for 20 hours, and the solder material is removed by chemical treatment. Went. When the regular reflectance in the entire wavelength range of 300 nm to 1500 nm on the bonding surface was measured by the same treatment as in Example 1, it was maximum when the wavelength of incident light was 1300 nm, 13%, and 6.0% when the wavelength was 500 nm. When the wavelength was 1000 nm, it was 8.0%. Moreover, when arithmetic mean roughness Ra was measured like Example 1, the average value of Ra was 1.1 micrometer. In addition, the regular reflectance in the wavelength range of 300 nm to 1500 nm of the bonded surface to which the bonded body before the treatment is adhered becomes maximum when the wavelength of incident light is 1300 nm, about 2-3%, and is 1 to 2 when the wavelength is 500 nm. %, When the wavelength was 1000 nm, it was 1 to 2%, and the arithmetic average roughness Ra of the joint surface before the treatment was 1.7 μm on average. Using a Shimadzu EDXRF analyzer (EDX-700L, detection limit: about 0.01 wt% in In), the joint surface of the used target material after chemical treatment was analyzed under the same conditions as in Example 1. did. As a result, 0.6 wt% of Cu derived from the backing plate was detected on the joint surface of the used target material after chemical treatment, and it was found that impurities could not be removed.
In addition, the used target material after the chemical treatment is melted at 850 ° C. under vacuum (for example, 0.03 Torr), stirred in the air to remove dross, and then cooled in the air for recycling. An ingot was produced.
The amount of impurities contained in the ingot produced by melting the unused target material (before joining), the recycled ingot of Comparative Example 1 and the used target material (before chemical treatment), respectively, is determined by GDMS (VG Elemental) (Manufactured by VG9000). The results are shown in Table 5 below.

  In Comparative Example 1 where only the treatment with the acid was performed, the impurities derived from the bonding material and the backing plate contained in the recycled ingot (that is, In, Sn, Zn, Cu) in spite of being treated for 20 hours. The total amount is about 19 ppm on a weight basis, and it is impossible to obtain a recycled ingot having substantially the same composition as the original target material.

Example 4
Flat plate target material made of aluminum (purity: 99.999%, Vickers hardness: 14-17, dimensions: 2000 mm × 200 mm × 15 mm), and oxygen-free copper backing plate (purity: 99.99%, dimensions: 2300 mm × 250 mm × 15 mm) and the following solder material (solder layer thickness: 350 μm) is used by sputtering, and after the sputtering target is used, the bonding layer is heated (280 ° C.) to obtain the target material. Was separated from the backing plate. The solder material adhering to the joint surface of the target material was scraped off with a silicone spatula, and the solder material was recovered as much as possible. After separating the target material from the backing plate, the target material was cut to about 300 mm × 200 mm × 15 mm.
The bonded surfaces, sputtering surfaces, and side surfaces of 55 target materials were cleaned under the following condition 11. In any case, the bonding material and the metallized layer were removed from the surface of the target material after washing, and a satin finish was obtained. Ten of the washed 55 sheets were randomly selected, and the regular reflectance in the entire wavelength range of 300 nm to 1500 nm of the matte joint surface was measured under the same conditions as in Example 1. Regardless of the target material, the regular reflectance was a maximum of about 0.4%, and the average was about 0.2% when the wavelength was 500 nm, and the average was about 0.2% when the wavelength was 1000 nm. Moreover, when 10 arithmetic mean roughness Ra selected at random was measured by the method similar to Example 1, the average value of Ra was 20 micrometers. In addition, the regular reflectance in the wavelength range of 300 nm to 1500 nm of the bonded surface to which the bonded body before the treatment is adhered becomes maximum when the wavelength of incident light is 1300 nm, about 2-3%, and is 1 to 2 when the wavelength is 500 nm. %, When the wavelength was 1000 nm, it was 1 to 2%, and the arithmetic average roughness Ra of the bonded surface before the treatment was 1.8 μm on average. About target material after cleaning Used target material 55 after cleaning under the same conditions as in Example 1 using an EDXRF analyzer (EDX-700L, detection limit: about 0.01 wt% in In) manufactured by Shimadzu Corporation The joining surfaces of the sheets were analyzed. As a result, no In, Sn, Zn derived from the solder material or Cu derived from the backing plate could be detected at all on the joint surface of the used target material after cleaning. Moreover, when the yield was calculated | required from the weight difference before and behind washing | cleaning of 55 target materials, it was 98% on average and it confirmed that it was able to process with a high yield.
Next, 25 processed target materials (about 50 kg) were melted at 800 ° C. in a vacuum to remove dross, and then the molten metal was poured into a carbon mold in the atmosphere. Recycled ingots were produced by cooling. The amount of impurities contained in the recycled ingot was measured using GDMS (VG9000 (model number) manufactured by VG Elemental). The results are shown in Table 4 above.

Condition 11
Solder material for bonding: In
Solder material for metallization: Sn-Zn-In
Water pressure: 245 MPa
Water volume: 18.6 L / min
Number of nozzles: 6 (Nozzle head manufactured by Sugino Machine Co., Ltd., model number: MNH-2506-15C is used (nozzle is placed at the position of PCD36 mm))
Nozzle diameter: 0.35 mm (manufactured by Sugino Machine, model number: DN-0835)
Nozzle distance: 60mm
Rotational speed: 2000 min ^-1
Movement speed: 4000mm / min
Line treatment: 2 times Overlap: 5mm
Cleaning treatment: bonding surface, sputtering surface and side surface

As shown in the results of Table 4 (Table 4), the cleaning process of the present invention is not affected by the variation in the thickness of the solder material of the used target, and is suitable for processing a large amount of used target. It became clear.
Moreover, about the said Example and comparative example, although the flat type target material was demonstrated, the same result is obtained by performing the same process also about the cylindrical target material joined using a joining material to a backing tube. be able to.

  This application claims the priority on the basis of Japanese Patent Application No. 2017-068470 for which it applied in Japan on March 30, 2017, The content of all is used by reference in this specification. .

  According to the present invention, for example, by using the above-described apparatus to wash the used target material as described above, the elements contained in the impurities derived from the bonding material and the support member such as the backing plate and the backing tube can be obtained. A recycle ingot having substantially the same composition as the original target material can be obtained by producing a used target material substantially free of the target material and manufacturing the ingot again from such a used target material. Can be obtained. According to the present invention, since a target material having substantially the same composition as the original target material can be regenerated from such a recycled ingot, it is useful for recycling the target material.

1 target material 2 support member 3 bonding material (or bonding layer)
4 Solder layer 5, 5 ′ Metallized layer 10, 20, 30 Sputtering target 100 Device 101 Target material (or workpiece)
102 Nozzle head 103 Actuator 103X X-axis slider 103Y Y-axis slider 103Z Z-axis slider 104 Processing chamber 105 Conveying means 106 Rod

Claims (13)

  A target material mainly composed of metal and a support member are separated from the support member of the sputtering target formed by bonding with a bonding material, and at least the surface of the target material to which the bonding material is attached A method for cleaning a target material, wherein the bonding material is removed from the target material by spraying water.   The method for cleaning a target material according to claim 1, wherein the water pressure is 90 MPa or more.   The method for cleaning a target material according to claim 1, wherein the metal is aluminum or copper.   The manufacturing method of a target material including processing a target material with the washing | cleaning method of any one of Claims 1-3.   The element contained in the impurities derived from the bonding material and the supporting member of the sputtering target in which the target material and the supporting member are bonded by the bonding material is not detected by energy dispersive fluorescent X-ray analysis. Target material.   A method for producing a recycled ingot, comprising: obtaining a recycled ingot containing the metal by casting the metal using a target material obtained from the production method according to claim 4 as a raw material.   A recycled ingot, wherein the total amount of impurities derived from a bonding material and a supporting member of a sputtering target formed by bonding a target material and a supporting member with a bonding material is less than 10 ppm on a weight basis.   The recycled ingot according to claim 7, wherein the metal that is a main component of the recycled ingot is aluminum or copper.   The recycled ingot according to claim 8, wherein the metal that is a main component of the recycled ingot is aluminum, and a total amount of the impurities is less than 5 ppm by weight. Water is sprayed onto at least the surface of the target material separated from the support member of the sputtering target formed by joining a target material mainly composed of metal and the support member with a bonding material. Is an apparatus used to remove the bonding material from the target material,
At least one nozzle head comprising at least one injection port for injecting water onto the target material;
An actuator for operating the nozzle head;
An apparatus comprising: a processing chamber in which the actuator is disposed and for storing and processing the target material.   The apparatus of claim 10, further comprising a clamp for securing the target material in the processing chamber.   The apparatus according to claim 10 or 11, further comprising a reversing mechanism for reversing the target material.   It collect | recovers and discharges | emits the water injected from the said injection port, and the drainage mechanism for isolate | separating the processed material containing the joining material removed from the said target material is included in any one of Claims 10-12. Equipment.

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