Apparatus and method for reducing internal microstructure defects in a target

Abstract

The application discloses a device and method for reducing internal organization defects of a target material, and comprises the following steps: mixing different batches of purchased raw materials for 60-90 minutes and then screening the mixed superfine powder raw materials through a 200-mesh vibrating screen; weighing the mixed raw materials and loading them into a rubber sleeve and then vacuumizing; and inserting an inner tube into the inner ring of a rubber mold to prevent the inner side of the rubber mold from being inwardly bent and deformed. The device and method for reducing internal organization defects of a target material can discharge the air inside the rubber mold 1 before filling, and then directly fill the rubber mold 1 by extruding the raw materials, so that the air cannot be discharged during the filling process of the raw materials, the residual gas inside the target material can be greatly reduced during the preparation of the target material, the internal organization defects of the target material are reduced, the compactness of the target material is improved, and surface defects of the target material caused by residual gas can be avoided.

Description

Technical Field

[0001] This invention relates to the field of rotary target processing technology, specifically to a device and method for reducing internal structural defects in targets. Background Technology

[0002] Target materials are one of the main materials for preparing thin films, primarily used in integrated circuits, flat panel displays, solar cells, recording media, and smart glass, requiring high purity and stability. Coating targets are sputtering sources that form various functional thin films by sputtering onto a substrate using magnetron sputtering, multi-arc ion plating, or other types of coating systems under appropriate process conditions. Simply put, a target material is the target material bombarded by high-energy particles. In high-energy laser weapons, different power densities, output waveforms, and wavelengths of laser light interact with different target materials, producing different destructive effects.

[0003] Rotating target materials are cylindrical magnetron sputtering targets. During sputtering, a stationary magnet is placed inside the rotating target and rotates slowly. Currently, the relatively mature process for preparing rotating targets is as follows: loading - isostatic pressing - sintering - billet heating - extrusion - annealing - finishing and straightening - inspection and machining.

[0004] During the target preparation process, defects may occur inside or on the surface of the target due to the raw materials, preparation method, and equipment. Specifically, when gas is present inside the target during processing, the internal structure of the target will become loose, thereby reducing the density of the target. In addition, during the sintering and extrusion process, the gas inside the target blank will be discharged, which will also cause defects on the surface of the target.

[0005] Therefore, this application provides an apparatus and method for reducing internal structural defects in a target material, which can greatly reduce residual gas inside the target material during the target material preparation process, reduce internal structural defects in the target material, thereby improving the density of the target material, and also avoid surface defects in the target material due to residual gas. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the existing technology and provide a device and method for reducing internal structural defects of target materials. The device and method can remove the air inside the rubber mold before filling and then directly fill the rubber mold by extruding the raw material. This avoids the problem of air not being able to be discharged during the raw material filling process. It can greatly reduce the residual gas inside the target material during the target material preparation process, reduce the internal structural defects of the target material, thereby improving the density of the target material. It can also avoid the surface defects of the target material caused by residual gas. It can effectively solve the problems in the background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for reducing internal structural defects in a target material, comprising the following steps:

[0008] S1. Preparation of ultrafine powder raw materials: Mix different batches of purchased raw materials for 60-90 minutes and then sieve them through a vibrating screen with a 200-mesh sieve to obtain mixed ultrafine powder raw materials.

[0009] S2, Powder Packing and Vacuuming: Weigh the mixed raw materials and pack them into the rubber sleeve and then vacuum them;

[0010] S3. Cold isostatic pressing: The rubber sleeve is placed inside the cold isostatic press and cold isostatically pressed under a pressure of 200MPa to 300MPa to obtain the first tube blank.

[0011] S4. Sintering: The formed billet is placed in a medium-frequency induction sintering furnace. The temperature uniformity of the medium-frequency induction sintering furnace is ≤±10℃, the heating working temperature is 1300~1400℃, the sintering time is 4~6 hours, and a second tube blank is obtained.

[0012] S5. Tube blank heating: The sintered hollow tube blank is heated to 1300℃~1400℃ in an industrial frequency induction sintering furnace and held at that temperature for 3~4 hours.

[0013] S6. Extrusion: The insulated hollow tube blank is fed to a horizontal extrusion press for extrusion to increase the density of the tube, refine its precision, and produce a third tube blank.

[0014] S7. Annealing: Place the extruded tube blank into an annealing furnace for annealing. The annealing furnace temperature is 800℃~900℃ and the annealing time is 90~120min.

[0015] S8. Finishing and straightening: The tube blank is straightened using a rotary straightener to obtain the fourth tube blank;

[0016] S9. Flaw detection: The straightened rotating target material is inspected using an ultrasonic flaw detector.

[0017] S10. Machining: The qualified fourth-stage pipes are machined into finished pipes and then packaged using a vacuum packaging machine.

[0018] As a preferred embodiment of the present invention, in step S2, the step of vacuuming the powder pack specifically includes:

[0019] S21. Insert the inner tube into the inner ring of the rubber mold to prevent the inner side of the rubber mold from bending and deforming inward.

[0020] S22. The bottom of the rubber mold is lifted by the top ring, and the bottom of its inner cavity moves toward its opening until the bottom of the inner cavity is flush with the opening, thereby expelling the air inside the rubber mold.

[0021] S23. Place the outer tube over the outside of the rubber mold and clamp the outer wall of the rubber mold to the outer tube with clamps. Clamp the inner wall of the rubber mold to the inner tube with clamps.

[0022] S24. Fill the opening of the rubber mold with powder and press it down so that the inner cavity of the rubber mold gradually becomes deeper. At the same time, the powder fills the inner cavity of the rubber mold as the depth of the rubber mold changes. At this time, the top ring will automatically fall off. Then, the opening of the rubber mold is sealed with a sealing ring plug, and the inner tube and outer tube are removed.

[0023] S25. Place the rubber mold into the vacuum machine and vacuum it for 20 seconds. Then remove the rubber mold.

[0024] As a preferred technical solution of the present invention, in S4, after the tube blank is placed in, the sintering furnace is evacuated and hydrogen is filled into the sintering furnace as a protective gas. The purity of the hydrogen is ≥99.99%, the internal pressure of the sintering furnace is maintained at 1 to 5 kPa, and the hydrogen is supplied by purchasing gas cylinders.

[0025] As a preferred embodiment of the present invention, in step S7, the annealing furnace is filled with a protective gas, and the protective gas is hydrogen, in order to prevent the tube blank from oxidizing.

[0026] As a preferred technical solution of the present invention, a fume hood and a dust collection hood are installed in the billet heating and annealing system production process, as well as in the feed roller conveyor and discharge platform of the extruder, and the fume hood and the dust collection hood are connected to a bag filter through pipes.

[0027] An apparatus for reducing internal structural defects in a target material includes a rubber mold, a sealing ring plug, an inner tube, an outer tube, and a top ring. The rubber mold is an annular cylindrical structure with an annular groove, and the sealing ring plug is movably engaged with the opening of the rubber mold. The inner tube is movably inserted into the inner ring of the rubber mold, and the outer tube is movably sleeved on the outer side of the rubber mold. The top ring presses the bottom of the rubber mold into the annular groove of the rubber mold.

[0028] As a preferred embodiment of the present invention, the opening of the rubber mold is provided with an annular groove, and the outer side of the sealing ring plug is provided with an annular protrusion that matches the annular groove.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] The apparatus and method for reducing internal structural defects of the target material according to the present invention can expel the air inside the rubber mold 1 before filling, and then directly fill the rubber mold 1 by extruding the raw material, avoiding the inability of air to be expelled during the filling process. This can greatly reduce the residual gas inside the target material during the target material preparation process, reduce internal structural defects of the target material, thereby improving the density of the target material, and also avoid the appearance of surface defects of the target material due to residual gas. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the process flow of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the present invention;

[0033] Figure 3 This is a cross-sectional view of the rubber mold of the present invention.

[0034] In the diagram: 1. Rubber mold, 2. Sealing ring plug, 3. Inner tube, 4. Outer tube, 5. Top ring. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figure 1-3 The present invention provides a technical solution: a method for reducing internal structural defects in a target material, comprising the following steps:

[0037] S1. Preparation of ultrafine powder raw materials: Mix different batches of purchased raw materials for 60-90 minutes and then sieve them through a vibrating screen with a 200-mesh sieve to obtain mixed ultrafine powder raw materials.

[0038] S2, Powder Packing and Vacuuming: Weigh the mixed raw materials and pack them into the rubber sleeve and then vacuum them;

[0039] S3. Cold isostatic pressing: The rubber sleeve is placed inside the cold isostatic press and cold isostatically pressed under a pressure of 200MPa to 300MPa to obtain the first tube blank.

[0040] S4. Sintering: The formed billet is placed in a medium-frequency induction sintering furnace. After the tube blank is placed in, the sintering furnace is evacuated and filled with hydrogen as a protective gas. The hydrogen purity is ≥99.99%. The internal pressure of the sintering furnace is maintained at 1-5 kPa. The hydrogen supply is provided by an externally purchased gas cylinder group. The temperature uniformity of the medium-frequency induction sintering furnace is ≤±10℃. The heating working temperature is 1300-1400℃. The sintering time is 4-6 hours, and a second tube blank is obtained. The furnace temperature of the sintering furnace is increased by thermal radiation and thermal convection to sinter the billet. The material is heated evenly during the sintering process, and the density of the sintered tube blank is uniform.

[0041] S5. Tube blank heating: The sintered hollow tube blank is heated to 1300℃~1400℃ in an industrial frequency induction sintering furnace and held at that temperature for 3~4 hours.

[0042] S6. Extrusion: The insulated hollow tube blank is fed to a horizontal extrusion press for extrusion to increase the density of the tube, refine its precision, and produce a third tube blank.

[0043] S7. Annealing: The extruded tube blank is placed in an annealing furnace for annealing. The annealing furnace is filled with a protective gas, which is hydrogen, to prevent the tube blank from oxidizing. The annealing furnace temperature is 800℃~900℃ and the annealing time is 90~120min.

[0044] S8. Finishing and straightening: The tube blank is straightened using a rotary straightener to obtain the fourth tube blank;

[0045] S9. Flaw detection: The straightened rotating target material is inspected using an ultrasonic flaw detector.

[0046] S10. Machining: The qualified fourth-stage pipes are machined into finished pipes and then packaged using a vacuum packaging machine.

[0047] Using powder metallurgy, through isostatic pressing, followed by low-temperature pre-sintering and high-temperature sintering, the metal particles are small and uniform, which can eliminate low-boiling-point metal impurities and achieve metal densification. Rotary targets are produced by sintering hollow tube blanks-extrusion, which can improve the density of the finished powder metallurgy target, refine its grains, and achieve high production efficiency, high yield, and short process flow, and achieve the density required for sputtering targets of high-definition display panels.

[0048] Furthermore, the specific steps of vacuum packing and evacuating the powder include:

[0049] S21. Insert the inner tube 3 into the inner ring of the rubber mold 1 to prevent the inner side of the rubber mold 1 from bending and deforming inward.

[0050] S22. The bottom of the rubber mold 1 is lifted by the top ring 5, and the bottom of its inner cavity moves toward its opening until the bottom of the inner cavity is flush with the opening, thereby venting the air inside the rubber mold 1.

[0051] S23. Place the outer tube 4 on the outside of the rubber mold 1, and clamp the outer wall of the rubber mold 1 to the outer tube 4 with a clamp, and clamp the inner wall of the rubber mold 1 to the inner tube 3 with a clamp.

[0052] S24. Powder is loaded into the opening of rubber mold 1 and pressed down, so that the inner cavity of rubber mold 1 gradually becomes deeper. At the same time, the powder fills the inner cavity of rubber mold 1 following the change in the depth of rubber mold 1. At this time, the top ring 5 automatically falls off. Then, the opening of rubber mold 1 is sealed by sealing ring plug 2, and the inner tube 3 and outer tube 4 are removed.

[0053] S25. Place the rubber mold 1 into the vacuum machine and evacuate it for 20 seconds. Then remove the rubber mold 1.

[0054] Furthermore, during the billet heating and annealing process, as well as at the feed roller conveyor and discharge platform of the extruder, fume hoods and dust collection hoods are installed to collect dust. These hoods are then connected to a bag filter via pipes to facilitate the extraction, filtration, and discharge of dust and fumes.

[0055] A device for reducing internal structural defects in a target material includes a rubber mold 1, a sealing ring plug 2, an inner tube 3, an outer tube 4, and a top ring 5. The rubber mold 1 is an annular cylindrical structure with an annular groove, and the sealing ring plug 2 is movably engaged at the opening of the rubber mold 1. The inner tube 3 is movably inserted into the inner ring of the rubber mold 1, and the outer tube 4 is movably sleeved on the outer side of the rubber mold 1. The top ring 5 presses the bottom of the rubber mold 1 into the annular groove of the rubber mold 1.

[0056] Furthermore, the opening of the rubber mold 1 is provided with an annular groove, and the outer side of the sealing ring plug 2 is provided with an annular protrusion that matches the annular groove, which can improve the sealing effect of the sealing ring plug 2 on the opening of the rubber mold 1.

[0057] Furthermore, step 2 can also include the following operations:

[0058] 1. Insert the inner tube 3 into the inner ring of the rubber mold 1 to prevent the inner side of the rubber mold 1 from bending and deforming inward;

[0059] 2. The bottom of the rubber mold 1 is lifted by the top ring 5, and the bottom of its inner cavity moves toward its opening until the bottom of the inner cavity is flush with the opening, thereby expelling the air inside the rubber mold 1.

[0060] 3. Place the outer tube 4 on the outside of the rubber mold 1, and clamp the outer wall of the rubber mold 1 to the outer tube 4 with clamps, and clamp the inner wall of the rubber mold 1 to the inner tube 3 with clamps.

[0061] 4. Fill the opening of the rubber mold 1 with powder and press it down so that the inner cavity of the rubber mold 1 gradually becomes deeper. After reaching a certain depth, seal the opening of the rubber mold 1 with the sealing ring plug 2 and remove the inner tube 3 and the outer tube 4.

[0062] 5. Place the rubber mold 1 into the vacuum machine and vacuum it for 20 seconds, then remove the rubber mold 1.

[0063] 6. Repeat steps 3-5 above until the rubber mold 1 is filled with raw material, then seal the rubber mold 1 and perform cold isostatic pressing.

[0064] This invention can expel the air inside the rubber mold 1 before filling, and then directly fill the rubber mold 1 by extruding the raw material. This avoids the air not being able to be expelled during the raw material filling process, which can greatly reduce the residual gas inside the target material during the target material preparation process, reduce the internal structural defects of the target material, thereby improving the density of the target material, and also avoid the surface defects of the target material due to the residual gas.

[0065] All parts not disclosed in this invention are prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for reducing internal structural defects in a target material, characterized in that: Includes the following steps: S1. Preparation of ultrafine powder raw materials: Mix different batches of purchased raw materials for 60-90 minutes and then sieve them through a vibrating screen with a 200-mesh sieve to obtain mixed ultrafine powder raw materials. S2, Powder Packing and Vacuuming: Weigh the mixed raw materials and pack them into the rubber sleeve and then vacuum them; The specific steps for vacuum packing and vacuuming powder materials include: S21. Insert the inner tube (3) into the inner ring of the rubber mold (1) so that the inner side of the rubber mold (1) will not bend or deform inward. S22. The bottom of the rubber mold (1) is lifted by the top ring (5) and the bottom of its inner cavity moves toward its opening until the bottom of the inner cavity is flush with the opening, thereby expelling the air inside the rubber mold (1). S23. Place the outer tube (4) on the outside of the rubber mold (1), and clamp the outer wall of the rubber mold (1) with the outer tube (4) using a clamp, and clamp the inner wall of the rubber mold (1) with the inner tube (3) using a clamp. S24. Powder is loaded into the opening of the rubber mold (1) and pressed down, so that the inner cavity of the rubber mold (1) gradually becomes deeper. At the same time, the powder fills the inner cavity of the rubber mold (1) according to the change in the depth of the rubber mold (1). At this time, the top ring (5) automatically falls off. Then, the opening of the rubber mold (1) is sealed by the sealing ring plug (2), and the inner tube (3) and outer tube (4) are removed. S25. Place the rubber mold (1) into the vacuum machine and vacuum it for 20 seconds. Then take out the rubber mold (1). S3. Cold isostatic pressing: The rubber sleeve is placed inside the cold isostatic press and cold isostatically pressed under a pressure of 200MPa to 300MPa to obtain the first tube blank. S4. Sintering: The formed billet is placed in a medium-frequency induction sintering furnace. The temperature uniformity of the medium-frequency induction sintering furnace is ≤±10℃, the heating working temperature is 1300~1400℃, the sintering time is 4~6 hours, and a second tube blank is obtained. S5. Tube blank heating: The sintered hollow tube blank is heated to 1300℃~1400℃ in an industrial frequency induction sintering furnace and held at that temperature for 3~4 hours. S6. Extrusion: The insulated hollow tube blank is fed to a horizontal extrusion press for extrusion to increase the density of the tube, refine its precision, and produce a third tube blank. S7. Annealing: Place the extruded tube blank into an annealing furnace for annealing. The annealing furnace temperature is 800℃~900℃ and the annealing time is 90~120min. S8. Finishing and straightening: The tube blank is straightened using a rotary straightener to obtain the fourth tube blank; S9. Flaw detection: The straightened rotating target material is inspected using an ultrasonic flaw detector. S10. Machining: The qualified fourth-stage pipes are machined into finished pipes and then packaged using a vacuum packaging machine.

2. The method for reducing internal structural defects of a target material according to claim 1, characterized in that: In S4, after the tube blank is placed in, the sintering furnace is evacuated and filled with hydrogen as a protective gas. The hydrogen purity is ≥99.99%, and the internal pressure of the sintering furnace is maintained at 1-5 kPa. The hydrogen is supplied by purchasing gas cylinders.

3. The method for reducing internal structural defects in a target material according to claim 1, characterized in that: In S7, the annealing furnace is filled with a protective gas, which is hydrogen, to prevent the tube blank from oxidizing.

4. The method for reducing internal structural defects of a target material according to claim 1, characterized in that: Dust collection hoods and fume hoods are installed in the billet heating and annealing system, as well as in the feed roller conveyor and discharge platform of the extruder. The fume hoods and dust collection hoods are connected to the bag filter through pipes.

5. An apparatus for reducing internal structural defects of a target material according to any one of claims 1-4, comprising a rubber mold (1), a sealing ring plug (2), an inner tube (3), an outer tube (4), and a top ring (5), wherein the rubber mold (1) is an annular cylindrical structure with an annular groove, and the sealing ring plug (2) is movably engaged at the opening of the rubber mold (1), the inner tube (3) is movably inserted into the inner ring of the rubber mold (1), and the outer tube (4) is movably sleeved on the outer side of the rubber mold (1), and the top ring (5) presses the bottom of the rubber mold (1) into the annular groove of the rubber mold (1).

6. The apparatus for reducing internal structural defects of a target material according to claim 5, characterized in that: The opening of the rubber mold (1) is provided with an annular groove, and the outer side of the sealing ring plug (2) is provided with an annular protrusion that matches the annular groove.

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