A binding sealing structure for a rotating target

Abstract

The present invention relates to the technical field of magnetron sputtering target material preparation, and in particular to a binding sealing structure of a rotating target material. The sealing structure includes a gap gasket arranged between two adjacent target tubes, the gap gasket is bonded to the end faces of the upper and lower target tubes, a circle of high-temperature tape is bonded to the outer walls of the two target tubes at the gap, and also includes a heat-conducting metal sheet bonded to the outer periphery of the high-temperature tape and a fastening layer surrounding the metal sheet, and the metal sheet and the fastening layer are fixed to the outer periphery of the target tube through a clamp. The binding sealing structure of the rotating target material seals the gaps between the multiple target tubes, reduces the oxygen content in the gaps, makes it difficult for metal indium to oxidize in the air during the binding process, and improves the bonding rate between indium and the target material / back tube. A heat-conducting metal sheet is also bonded to the high-temperature tape on the outer walls of the two target tubes, and then a fastening layer is arranged outside the metal sheet. The metal sheet provides support for the binding sealing structure to prevent the target tube from being deformed by heat and causing sealing failure, thereby enhancing the sealing performance.

Description

Technical Field

[0001] The invention relates to the technical field of magnetron sputtering target material preparation, and in particular to a binding sealing structure of a rotating target material. Background Art

[0002] In recent years, thin film materials prepared by sputtering have been favored by industries such as flat panel displays, electronic controllers, glass coating, and optical films due to their high density and excellent adhesion. With the rapid development of the above fields, the demand for sputtering targets has increased dramatically. According to the shape of the sputtering surface, targets can generally be divided into planar targets, rotating targets, and special-shaped targets. The sputtering rate of planar targets can reach 30% to 40%, while the sputtering rate of rotating targets can reach 80%. Rotating targets are hollow cylindrical and can rotate around a fixed magnetron sputtering device. They can evenly etch the target surface 360 ​​degrees. Such uniform use makes the target surface smooth, reduces the occurrence of "nodule" phenomenon, improves the uniformity of coating, and increases the utilization rate of targets, thereby reducing coating costs. Therefore, rotating targets are a major trend in future development.

[0003] In the preparation process of rotating targets, for ceramic targets and certain metal targets that cannot be produced by spraying and casting, the target to be sputtered needs to be bound to the back tube by a binding method (binding). At present, most of the binding methods are to put the outer tube target with a larger diameter on the back tube with a relatively smaller diameter, fill the gap between the two with solder with good electrical and thermal conductivity such as metal indium or conductive glue, and weld the outer tube target and the back tube. The method of binding with metal indium requires that indium be heated and maintained above the melting point before injection. Metal indium is easily oxidized in the air, resulting in a low bonding rate between indium and the target / back tube. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a binding sealing structure for a rotating target material, which can improve the bonding rate between indium and the target material / back tube in the binding process.

[0005] Provided is a binding sealing structure for a rotating target material. The rotating target material comprises a back tube and a multi-section annular target tube. The sealing structure comprises a gap gasket arranged between two adjacent target tube sections, the gap gasket is bonded to the end faces of the upper and lower target tubes, a circle of high-temperature tape is bonded to the outer walls of the two target tube sections at the gap, and the sealing structure also comprises a heat-conducting metal sheet bonded to the outer periphery of the high-temperature tape and a fastening layer surrounding the metal sheet. The metal sheet and the fastening layer are fixed to the outer periphery of the target tube through a clamp.

[0006] Preferably, the gap gasket is a Teflon gasket in the shape of a snap ring opening in the radial direction.

[0007] Preferably, the gap between the target tubes is 0.2-0.4 mm, and the thickness of the gap gasket is 0.3-0.8 mm.

[0008] Preferably, the Teflon gasket is respectively connected to the bottom end surface and the top end surface of the two target tubes by means of high-temperature double-sided adhesives bonded to the upper and lower surfaces.

[0009] Preferably, the upper and lower sides of the high temperature tape are coated with thermosetting adhesive respectively.

[0010] Preferably, the coating height of the thermosetting adhesive is lower than the height of the metal sheet.

[0011] Preferably, the metal sheet is an aluminum sheet.

[0012] Preferably, the fastening layer is a circle of rubber sheet wrapped around the periphery of the metal sheet, and the height of the rubber sheet is higher than that of the metal sheet.

[0013] Preferably, it includes an external heating structure covering the outer periphery of the rotating target material, the external heating structure includes a plurality of annular heating covers and heating tubes respectively installed on the inner wall of each section of the heating covers, and a mounting base for fixing the bottommost annular heating cover, the adjacent annular heating covers are sealed by gaskets, and the external heating structure also includes a sealing cover, which is detachably mounted on the top of the topmost annular heating cover.

[0014] Preferably, it comprises an annular positioning tube inserted in the back tube, a sealing member for blocking the air outlet is provided at the air outlet on the top of the annular positioning tube, an air outlet pipe extends upward from the central axis of the seal, and the air outlet pipe can be moved downward to seal the seal.

[0015] Beneficial effects: The binding sealing structure of the rotating target seals the gaps between the multiple target tubes, reduces the oxygen content in the gaps, and makes it difficult for metal indium to oxidize in the air during the binding process, thereby improving the bonding rate between indium and the target / back tube. The sealing structure is provided with a gap gasket at the gap between the two target tubes, which connects and separates the two adjacent target tubes. A heat-conducting metal sheet is also bonded to the high-temperature tape on the outer wall of the two target tubes, and then a fastening layer is provided outside the metal sheet. The metal sheet provides support for the binding sealing structure to prevent the target tube from being deformed by heat and causing sealing failure, thereby enhancing the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the binding heating device of the rotating target material of the present invention.

[0017] Figure 2 It is a schematic diagram of the external heating structure of the binding heating device of the rotating target material of the present invention.

[0018] Figure 3 It is a schematic diagram of the installation structure of the internal heating structure of the binding heating device of the rotating target material of the present invention and the target material and the backing tube.

[0019] Figure 4It is a schematic diagram of the position of the binding sealing structure of the binding heating device of the rotating target material of the present invention.

[0020] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure at point A in the binding sealing structure.

[0021] Figure 6 yes Figure 5 Schematic diagram of the sealing structure sealing layer, with the sealing structure at point a enlarged inside point A in the binding sealing structure. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific implementation methods.

[0023] The binding heating device of the rotating target material of this embodiment is as follows Figure 1 and 2 As shown, the rotating target material includes a back tube 5 with an inner diameter of 125 mm and a plurality of target tubes 6. The binding process is a process of fixing each target tube 6 to the outer wall of the back tube 5 in a heat-conducting and electrically-conducting manner. In this embodiment, the binding is achieved by perfusing indium liquid (binding material) between the back tube 5 and the target tube 6, wherein the indium liquid needs to be heated to keep it flowing. The binding heating device used in this embodiment includes an internal heating structure and an external heating structure.

[0024] like Figure 2 As shown, the external heating structure includes a plurality of annular heating covers 3 and heating tubes 32 respectively installed on the inner wall of each section of the heating covers 3, and a mounting base for fixing the bottommost annular heating cover 3. The external heating structure also includes a sealing cover 4, which is detachably mounted on the top of the topmost annular heating cover 3. The more target tubes 6 to be bound, the more annular heating covers 3 need to be stacked, and the adjacent annular heating covers 3 are sealed by gaskets. Multiple target tube temperature detection devices are provided in the heating cover 3, and a high-temperature visual operation window 31 is opened on the outer wall of the heating cover 3 to observe the heating state of the target tube 6.

[0025] See Figure 3The internal heating structure includes an annular positioning tube 81 for the back tube 5 to be bound and sleeved outside its tube wall. The outer diameter of the annular positioning tube 81 is about 90 mm. The annular positioning tube 81 is vertically fixed on the mounting base in a manner that the central axis is vertical. The bottom of the annular positioning tube 81 is an air inlet. The air inlet pipe 82 passes through the mounting base from the bottom of the mounting base and then extends between the annular positioning tube 81 and the back tube 5, thereby providing hot air heating for the back tube 5. The top of the annular positioning tube 81 is an air outlet. The seal 7 is installed at the air outlet to block the top surface of the air outlet. An air outlet pipe 71 extends upward from the central axis of the seal 7. The bottom side wall of the air outlet pipe 71 is provided with an air hole. The hot air blocked by the seal 7 enters the air outlet pipe 71 from the air hole and is discharged outward. The internal heating structure also includes a back tube temperature detection device arranged on the outer wall of the annular positioning tube 81.

[0026] Among them, see Figure 3 A binding material feeding device 83 is also fixed on the mounting base. The binding material feeding device 83 feeds materials from the side opening 831 and discharges materials from the top opening 832. When the back tube 5 is mounted outside the annular positioning tube 81 and the target tube 6 is sleeved outside the back tube 5 in sections, the top opening 832 of the binding material feeding device 83 is aligned with the gap between the target tube 6 and the back tube 5. The side opening 831 of the binding material feeding device 83 is also connected to an air supply device (external heat circulation heating fan).

[0027] Among them, an inwardly sealed through groove is provided at the center of the binding material feeding device 83 so that the main body of the binding material feeding device 83 forms an annular structure, and a heating tube is wound around the outer wall of the annular main body. The above-mentioned air inlet pipe 82 extends upward from the through groove into between the annular positioning tube 81 and the back tube 5.

[0028] On the one hand, the external heat circulation heating fan supplies hot air to the internal heating structure. The hot air flows in from the air inlet pipe 82 and then flows to the space between the annular positioning pipe 81 and the back tube 5 to heat the back tube 5. On the other hand, the heating fan supplies air to the external heating structure from bottom to top, driving the hot air between the heating cover 3 and the outer wall of the target tube 6 to rise. The hot air channel of the internal heating structure and the heating pipe 32 of the external heating structure work synchronously to heat the inner wall of the back tube 5 and the outer wall of the target tube 6 respectively, and proportional air valves are respectively set in the air supply ducts leading to the heating of the inner wall and the outer wall. When the temperature of the inner wall and the outer wall is different or the difference reaches / exceeds the preset value (such as the outer wall is 5°C higher than the inner wall), the opening of the proportional air valve is automatically adjusted through the PLC automatic control mode to achieve the change of the flow rate, so that the inner and outer temperatures of the back tube 5 are within the preset difference range, and the inner and outer temperatures are adjusted. In this way, the inner and outer temperatures of the target tube 6 to be bound are kept consistent, reducing the risk of the outer tube target material cracking.

[0029] The outer wall of the annular positioning tube 81 and the interior of the heating cover 3 are both provided with spiral upward guide vanes, so that the heat flow rises in a spiral shape, so as to maintain a uniform radial temperature in the heating device.

[0030] The binding heating device of the rotating target material is provided with an internal heating structure and an external heating structure: the annular positioning tube of the internal heating structure is used to limit the position of the back tube to be bound on the one hand, and is a heat-conducting material on the other hand. After hot air is passed through the annular positioning tube, the annular positioning tube quickly heats up and transfers heat to the back tube, thereby realizing rapid heating of the back tube; the external heating structure is a multi-section annular heating cover, each of which can be sealed and stacked to accommodate targets of different heights. The sealing cover of the external heating structure can be detachably installed on the top of the uppermost annular heating cover, and the external heating structure and the mounting base together form a fully sealed structure, covering the back tube and the target material inside. The hot air channel of the internal heating structure and the heating tube of the external heating structure work synchronously, so that the internal and external temperatures of the back tube are within the preset difference range, so that the internal and external temperatures of the target tube to be bound are consistent, reducing the probability of the target material of the outer tube from cracking.

[0031] Among them, the back tube should have good electrical conductivity and thermal conductivity, and can be made of metal or alloy, such as stainless steel, Ti, Cu, etc. The target tube can be made of ceramic or metal, such as ITO, AZO, Si, SiO, SiP, MoNb, ZnO, Al, Cr, Co, etc.

[0032] When the number of target tubes 6 is two or more, the gap between two adjacent target tubes 6 is as follows: Figure 4 The binding seal structure shown at A in the middle realizes sealing, see Figure 5 And the enlarged point a inside Figure 6 The implementation process of the binding sealing structure is as follows: a Teflon gasket 60 is placed between the two target tubes 6, and the Teflon gasket 60 is respectively connected to the bottom and top end surfaces of the two target tubes 6 by high-temperature double-sided adhesive 66 bonded to the upper and lower surfaces, and a circle of high-temperature adhesive tape 65 is bonded on the outer wall of the joint of the two target tubes 6 to seal the outer side surface of the Teflon gasket 60, and a circle of thermosetting adhesive 64 is coated on the upper and lower sides of the high-temperature adhesive tape 65, and then an aluminum sheet 63 is surrounded on the outer surface of the high-temperature adhesive tape 65 and the thermosetting adhesive 64, and finally a circle of rubber sheet is surrounded outside the aluminum sheet 63 to form a rubber fastening layer 62, and three clamps 61 are used to clamp the rubber fastening layer 62, and the range of the thermosetting adhesive 64 coating exceeds the height of the aluminum sheet 63 but does not exceed the height of the rubber sheet, and the thermosetting adhesive 64 has a surplus of bonding the rubber fastening layer but will not be exposed outside the binding sealing structure. The binding sealing structure not only isolates the air from the outside so that the indium liquid in the gap will not be oxidized, but also blocks the indium liquid in the gap so that it will not overflow. The aluminum sheet 63 is wrapped around the outer wall, which can provide a better spacing effect on the one hand; on the other hand, compared with the bonding force between the thermosetting adhesive 64 and the high-temperature adhesive tape 65, the bonding force between the aluminum sheet 63 and the thermosetting adhesive 64 and between the aluminum sheet 63 and the high-temperature adhesive tape 65 is smaller, which is convenient for removing the sealing structure after the binding is completed.

[0033] A Teflon gasket (gap gasket 60) with a thickness of 0.3-0.8 mm is used to separate two adjacent target tubes 6 to prevent the two target tubes 6 from being squeezed and stressed by each other due to thermal expansion. Among them, the lower target tube 6 is subjected to greater pressure from other upper target tubes 6, so the thickness of the lower Teflon gasket is thicker. There are 4 layers of Teflon gaskets in the five-section target tube 6. The thickness of the upper two layers of Teflon gaskets is 0.5 mm, and the thickness of the lower two layers of Teflon gaskets is 0.8 mm. The thicker Teflon gaskets in the lower two layers provide stronger buffering force for the adjacent two target tubes. The Teflon gasket is a snap ring-shaped gap ring with a radial opening, and the outer wall of the target tube 6 is partially exposed at the opening, which is convenient for removal and can be recycled. After binding is completed, the gap between adjacent target tubes 6 is 0.2-0.4 mm, and the optimal is 0.3 mm.

[0034] The following will describe in detail the process of binding and heating the rotating target material by means of the above-mentioned binding and heating device and binding sealing structure of the rotating target material.

[0035] (1) The annular positioning tube 81 and the back tube 5 are mounted on the mounting base, and the multiple target tubes 6 are sequentially sleeved outside the back tube 6 and the sealing between adjacent target tubes 6 is achieved by binding the sealing structure. After the target tubes 6 are installed, the sealing member 7 is installed at the air outlet at the top of the annular positioning tube 81 to seal the upper end gap between the target tube 5 and the back tube 5, and the air outlet pipe 71 is in a closed state to the outside.

[0036] (2) Install an external heating structure around the target material, connect the air outlet of the external heat circulation heating fan to the air inlet pipe 82 and the binding material feeding device 83 on the mounting base, open the air valve leading to the binding material feeding device 83 and close the air valve leading to the air inlet pipe 82.

[0037] (3) The gap between the target tube 5 and the backing tube 5 is evacuated by the binding material feeding device 83, and then filled with inert gas, and the above steps of evacuating and filling with inert gas are cyclically performed, thereby reducing the oxygen content in the binding gap (approaching 0), avoiding oxidation of indium liquid to form indium oxide during the filling process, and improving the binding bonding rate. In the above cycle, the heater at the binding material feeding device 83 is also turned on to heat the gas filled into the gap, thereby achieving preheating of the backing tube and the target tube.

[0038] (4) Close the air valve of the external heat circulation heating fan leading to the binding material feeding device 83, transfer the side opening 831 of the binding material feeding device 83 to the outlet of the indium liquid input pump, and fill the gap with indium liquid. Open the air valve at the air inlet pipe 82, and synchronously start the heating pipe 32 of the external heating structure to heat the inner wall of the back tube 5 and the outer wall of the target tube 6 respectively. The temperature inside and outside the binding device is controlled by the preset temperature control program to keep the temperature inside and outside the target tube 6 to be bound consistent.

[0039] (5) When the indium liquid is about to be filled, the air outlet pipe 71 is pulled upward for a short distance to allow the high-temperature and high-pressure inert gas compressed in the gap to be discharged outward. After the indium liquid is filled, the heating tube 32 is turned off, and the heating temperature and wind speed of the external heat circulation heating fan are gradually reduced to reduce the temperature inside and outside the target tube in a smooth manner, thereby avoiding premature solidification of the indium liquid filled in the gap, facilitating the uniformity of the indium liquid injection, enhancing the connection performance, and reducing the risk of target cracking.

[0040] The above is only an implementation method of the invention, and does not limit the scope of patent protection. Those skilled in the art can make non-substantial changes or substitutions based on the invention, which still fall within the scope of patent protection.

Claims

1. A binding sealing structure of a rotating target, wherein the rotating target comprises a back tube and a multi-section annular target tube, wherein: The sealing structure comprises a gap gasket arranged between two adjacent target tubes, the gap gasket is a Teflon gasket in the shape of a clamp ring opening in the radial direction, the gap gasket is bonded to the end faces of the upper and lower target tubes, a circle of high-temperature tape is bonded to the outer walls of the two target tubes at the gap, and also comprises a heat-conducting metal sheet bonded to the outer periphery of the high-temperature tape and a fastening layer surrounding the metal sheet, the fastening layer is a circle of rubber sheet wrapped around the outer periphery of the metal sheet, the height of the rubber sheet is higher than the metal sheet, the bonding is specifically as follows: the upper and lower sides of the high-temperature tape are respectively coated with thermosetting glue, the metal sheet surrounds the outer surface of the high-temperature tape and the thermosetting glue, the metal sheet is an aluminum sheet; the range of the thermosetting glue coating exceeds the height of the aluminum sheet but does not exceed the height of the rubber sheet, and the metal sheet, the thermosetting glue and the fastening layer are fixed to the outer periphery of the target tube through a clamp.

2. The binding sealing structure of the rotating target according to claim 1 is characterized in that: The thickness of the gap gasket is 0.3-0.8 mm.

3. The binding sealing structure of the rotating target according to claim 1 is characterized in that: The Teflon gasket is respectively connected to the bottom end surface and the top end surface of the two target tubes through high-temperature double-sided adhesives bonded to the upper and lower surfaces.

4. The binding sealing structure of the rotating target according to claim 1 is characterized in that: The invention comprises an external heating structure covering the outer periphery of a rotating target material, wherein the external heating structure comprises a plurality of annular heating covers and heating tubes respectively installed on the inner wall of each section of the heating covers, and a mounting base for fixing the bottommost annular heating cover, and adjacent annular heating covers are sealed by gaskets. The external heating structure also comprises a sealing cover, and the sealing cover is detachably installed on the top of the topmost annular heating cover.

5. The binding sealing structure of the rotating target according to claim 1 is characterized in that: It comprises an annular positioning tube inserted in the back tube, wherein a sealing member for blocking the air outlet is arranged at the air outlet on the top of the annular positioning tube, an air outlet pipe extends upward from the central axis of the sealing member, and the air outlet pipe can be moved downward to seal the sealing member.

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