Production process of high-hardness planar sputtering copper target

Abstract

The application relates to the target production field and provides a production process of a high-hardness planar sputtering copper target, in which high-purity electrolytic copper plates are heated and melted through a power-frequency induction heating furnace, the melted solution is crystallized into copper rods with a diameter of 20 mm through a crystallizer, the copper rods with a diameter of 20 mm are extruded and thickened into copper rods with a diameter of 25 mm to realize primary crushing of internal crystal grains of the copper rods, the copper rods with a diameter of 25 mm are extruded and thickened into copper rods with a diameter of 30 mm to realize secondary crushing of the internal crystal grains of the copper rods, the copper rods with a diameter of 30 mm are infinitely extended and extruded into copper bars, the copper bars are gradually lengthened through continuous feeding, the copper bars are formed into long and regular copper plates, the copper plates are corrected through a fixed-length drawing machine, the copper plates are sawed, straightened to completely remove internal stress, finally, flaw detection, machining and welding with back plates are carried out to obtain the sputtering copper target; the crystal grains are uniformly controlled, energy consumption is small, and the yield is large.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of target material production, in particular to a production process of high-hardness planar sputtering copper target material. BACKGROUND

[0002] Sputtering target materials can be divided into planar target materials, multi-arc target materials and rotary target materials according to shapes. The planar target materials include planar copper target materials. The planar copper target materials need to be first made into copper bars. At present

[0003] Traditional production method of planar sputtering copper bars: smelting-forging-rolling-heat treatment-machine tool processing

[0004] Since the sputtering copper target material has a technical requirement on oxygen content, which must be less than or equal to 10 ppm, the copper ingot must be cast by using a vacuum smelting device or a high-end downward drawing device during smelting;

[0005] Defects of traditional smelting:

[0006] The smelting uses electric energy or natural gas, the smelting process is relatively long, the energy consumption is high, the temperature requirement is relatively high, the process is complex, and the smelting safety risk is also relatively large;

[0007] The efficiency is slow, the vacuum smelting vacuumizing time and the holding time are relatively long, and the efficiency is relatively slow; the downward drawing ingot also has a length limit, and the conversion and quantity control of the material are also relatively cumbersome;

[0008] The copper ingot is forged into a square blank of a required size and the crystal grains are preliminarily broken by using the upsetting and drawing forging process combined with the intermediate heat treatment production mode;

[0009] Defects of forging:

[0010] The ingot needs to be heated at a high temperature in the early stage of the forging process, generally at 800 degrees. The black oxide skin of the copper ingot will fall off during high-temperature forging, and if the cleaning is not clean, the oxide skin will be easily embedded into the copper ingot to form internal defects;

[0011] The copper target is prone to cracking during forging, increasing the risk of finished products,

[0012] When the copper target is forged to reach the target material use level, the hot forging and cold forging need to be combined, the annealing and water cooling need to be crossed, and the process control is relatively complex;

[0013] The copper ingot after forging is subjected to hot rolling and cold rolling by a rolling mill to reach the size designed by the process, and then the grain control requirement is reached by combining the shape variable and temperature setting;

[0014] Defects of rolling:

[0015] The rolling process needs multiple passes of deformation, and the deformation amount is generally not more than 30%, which will make the surface grain crushing degree greater than the core, especially in the cold rolling stage, the cracking risk is relatively high, the deformation amount will be designed to be smaller, and the grain differentiation is more obvious, so that the hardness will be greatly different due to the uneven grain size;

[0016] After rolling, the grains are in a fibrous structure, and need to be heat treated to form grains and remove internal stress, during the internal stress removal process, the product as a whole will be soft, the hardness is less than 70HV, the overall strength is poor, and the normal use effect is affected;

[0017] After the copper target is rolled, there is a risk of twin crystal inside, which will absorb energy during use, recrystallize, and affect the sputtering rate;

[0018] Finally, the target material is processed to the size required by the customer's drawing by a machine tool,

[0019] Finally, the target material is welded with the back plate of the special material and the customer, and is sent to the customer for use after processing;

[0020] The above-mentioned process has high cost consumption, complex process, uneven grain size, large hardness difference, and affects the mechanical properties of the material. SUMMARY

[0021] Therefore, the purpose of the present application is to provide a production process of high-hardness planar sputtering copper target material to solve the problems in the background art.

[0022] In order to achieve the above purpose, the present application provides a production process of high-hardness planar sputtering copper target material, comprising the following steps:

[0023] Step one, preheat the prepared high-purity ≥4N 1# electrolytic copper plate;

[0024] Step two, place the preheated electrolytic copper plate into the melting chamber of the power frequency induction heating furnace, adjust the temperature to 1200±20℃ for heating, after the electrolytic copper plate is melted, the solution enters the heat preservation chamber of the power frequency induction heating furnace:

[0025] Step three, insert the crystallizer into the solution in the heat preservation chamber, and the solution enters the crystallizer to solidify into a copper rod which is continuously discharged outward;

[0026] Step four, connect one end of the copper rod with a diameter of 20mm drawn out to the collecting machine for traction collection;

[0027] Step five, extrude the copper rod with a diameter of 20mm into a copper rod with a diameter of 25mm, and the internal grains of the copper rod are initially crushed by extrusion deformation;

[0028] Step six, the diameter of 25 mm copper rod continues to be extruded to increase the diameter of 30 mm copper rod, through the second extrusion deformation, the crystal grains are crushed for the second time;

[0029] Step seven, the diameter of 30 mm copper rod is subjected to infinite extension extrusion to form a long strip-shaped regular copper plate, and the copper plate is wound;

[0030] Step eight, after winding, the copper plate is transported to a sizing drawing machine, and the copper plate is loaded into a drawing die to correct the size of the copper plate, and a surface allowance is reserved for subsequent machine tool processing;

[0031] Step nine, the copper plate is sawn, and the sawn copper plate is subjected to straightening by a multi-rod stress relief straightening machine to completely remove internal stress;

[0032] Step ten, after straightening, a non-destructive testing instrument is used for testing to detect whether the copper plate has defects;

[0033] Step eleven, the qualified copper plate is transported to a machining place for machining, and the machined plate and the back plate are welded to obtain a sputtering copper target material.

[0034] Preferably, the diameter of 20 mm copper rod in step five is extruded to increase the diameter of 25 mm copper rod by an extruder with an extrusion wheel nominal diameter of Φ550mm-Φ600mm.

[0035] Preferably, the diameter of 30 mm copper rod in step seven is subjected to infinite extension extrusion by being loaded into an extrusion die of an extruder with an extrusion wheel nominal diameter of ≥Φ700mm.

[0036] Preferably, the extrusion die of the extruder with an extrusion wheel nominal diameter of ≥Φ700mm in step seven is preheated, the temperature is 600℃±10℃, the copper rod generates heat through the friction between the rollers, enters the extrusion die, and forms a copper row through the action of the extrusion die. The copper row is gradually lengthened by the continuous entry of the subsequent material to form a long strip-shaped regular copper plate.

[0037] Preferably, the copper row is rapidly cooled after exiting the die opening of the extrusion die, and nitrogen is used for rapid cooling at a distance of 1 meter from the die.

[0038] Preferably, the solution upper end of the melting chamber and the holding chamber of the power frequency induction heating furnace needs to be covered with charcoal combustion for oxygen isolation.

[0039] Preferably, the drawing opening of the sizing drawing machine in step eight is preheated using an annular high-frequency coil, the frequency of the high-frequency coil is ≥4000HZ, and the preheating temperature is ≤340℃, which is used for preliminary stress removal.

[0040] The beneficial effects of the present application are as follows: the high-purity electrolytic copper plate is first heated and melted by a power frequency induction heating furnace, then the melted solution is crystallized into copper rods with a diameter of 20 mm by a crystallizer, then the copper rods with a diameter of 20 mm are extruded and thickened into copper rods with a diameter of 25 mm to realize primary crushing of the internal grains of the copper rods, then the copper rods with a diameter of 25 mm are extruded and thickened into copper rods with a diameter of 30 mm to realize secondary crushing of the internal grains of the copper rods, at this time, the copper rod grains are ≤25 um and the grain size distribution is uniform, then the copper rods with a diameter of 30 mm are infinitely extended and extruded into copper bars, the copper bars are gradually elongated by continuous feeding, forming regular long strip-shaped copper plates, the copper bars are quickly cooled after being discharged from the die, thereby reducing the grain growth time, effectively controlling the size of the grains, the copper plates are then corrected by a fixed-length drawing machine, the drawing opening of the fixed-length drawing machine is preheated by a high-frequency coil for stress removal, and a surface allowance is reserved for subsequent machine tool processing, the copper plates are then sawn, then straightened by a multi-rod stress relief straightening machine to completely remove internal stress, and finally subjected to flaw detection, machining, and welding with a back plate to obtain a sputtering copper target; the grains are uniformly controlled, the average grain difference is <10 um, and the maximum grain is <150 um; the surface and back hardness are uniform, the process setting determines the uniformity of the grains, the uniform grains determine the uniform hardness, and the difference is small; in the entire extrusion process, no separate heat source is needed except for the heat required for preheating the die, and the energy consumption is small; the entire equipment is continuously fed by the copper rods, and copper bars are output, so that continuous production can be realized, and the output is large, with a production capacity of more than 2 tons per hour. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to specific embodiments.

[0042] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the usual meanings understood by those skilled in the art to which the present application belongs. The terms "first", "second", and similar terms used in the present application do not represent any order, number, or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like only represent relative positional relationships, which can change accordingly when the absolute positions of the described objects change.

[0043] The present embodiment provides a production process of a high-hardness planar sputtering copper target, which comprises the following steps:

[0044] S1, the prepared high purity ≥4N 1# electrolytic copper plate is preheated;

[0045] S2, the electrolytic copper plate after preheating is put into the melting chamber of the power frequency induction heating furnace, the temperature is adjusted to 1200±20℃ for heating, after the electrolytic copper plate is melted, the solution enters the holding chamber of the power frequency induction heating furnace, the solution upper end of the melting chamber and the holding chamber of the power frequency induction heating furnace needs to be covered with charcoal combustion for oxygen isolation, the melting chamber and the holding chamber of the power frequency induction heating furnace are communicated through a communicating vessel, the communication is located at the middle position of the melting chamber and the holding chamber, so that the solution with higher purity enters the holding chamber, according to the principle of density, the impurities with small density will float on the upper end, and the impurities with large density will deposit at the bottom, and the solution in the middle part has higher purity;

[0046] S3, the crystallizer is inserted into the solution in the holding chamber, the solution enters the crystallizer and solidifies into copper rods which are continuously discharged outside, the crystallizer is a D20 crystallizer;

[0047] S4, one end of the copper rod with a diameter of 20mm is connected to the take-up machine for traction and take-up, and the weight of each disc is 5 tons;

[0048] S5, the copper rod with a diameter of 20mm is extruded and thickened to a copper rod with a diameter of 25mm through an extruder with a nominal diameter of Φ550mm-Φ600mm, and the internal crystal grains of the copper rod are crushed for the first time by extrusion deformation, and the extruder is an MFCCE600 extruder;

[0049] S6, the copper rod with a diameter of 25mm is continuously extruded and thickened to a copper rod with a diameter of 30mm, and the crystal grains are crushed for the second time by second extrusion deformation, at this time, the crystal grains of the deformed copper rod are ≤25um, and the crystal grain size distribution is uniform, and the extruder is an MFCCE600 extruder;

[0050] S7, the copper rod with a diameter of 30mm is extruded and stretched without limit by being loaded into an extruder with a nominal diameter of ≥Φ700mm, and the extruder is an MFCCE700 extruder, the extruder extrusion die with a nominal diameter of ≥Φ700mm is preheated, the temperature is 600℃±10℃, the copper rod generates heat through the friction between the rollers, enters the extrusion die, and forms a copper row through the action of the extrusion die. The copper row is continuously fed by the subsequent material and gradually lengthened to form a long and regular copper plate. After the copper row is discharged from the die opening of the extrusion die, it is rapidly cooled, nitrogen is used for rapid cooling at a distance of 1 meter from the die, and the copper row is wound up;

[0051] S8, after the winding is completed, it is transported to a sizing drawing machine, and the size of the copper plate is corrected by loading into a drawing die. The size of the drawing die is 95-97% of the size (length and width) of the extrusion die. The drawing opening of the sizing drawing machine is preheated by using a ring-shaped high-frequency coil. The frequency of the high-frequency coil is greater than or equal to 4000HZ, and the preheating temperature is less than or equal to 340 DEG C. The preheating is used to preliminarily remove stress, so that the plate can pass through the drawing die opening better. This process is used to correct the size, and a surface allowance is reserved for subsequent machine tool processing;

[0052] S9, the copper plate is sawn, and the sawn copper plate is straightened by a multi-rod stress relief straightening machine to completely remove internal stress;

[0053] S10, after straightening, a non-destructive testing instrument is used for testing. The probe M of the non-destructive testing instrument is greater than or equal to 10M, and whether the copper plate has defects is detected;

[0054] S11, the qualified copper plate is transported to a machine processing place for processing. The upper and lower surfaces and the periphery are processed. The processed plate and the back plate are welded to obtain a sputtering copper target material.

[0055] The grain control is uniform, the average grain difference is less than 10um, and the maximum grain is less than 150um. The hardness of the front and back surfaces is uniform. The process setting determines the uniformity of the grains, and the uniform grains determine the uniform hardness. The difference is small. In the entire extrusion process, except for the preheating die which needs heat, no separate heat source is needed, and the energy consumption is small. The entire equipment is continuously produced by entering the copper rod, and the output copper row can be continuously produced. The output is large, and the production capacity can reach more than 2 tons per hour.

[0056] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary and is not intended to limit the scope of the present application to these examples; under the idea of the present application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be brief, they are not provided in detail. Any omissions, modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A manufacturing process for a high-hardness planar sputtering copper target, characterized in that, It includes the following steps: Step 1: Preheat the prepared No. 1 electrolytic copper plate with a purity ≥ 4N; Step two: Place the preheated electrolytic copper plate into the melting chamber of the industrial frequency induction heating furnace, adjust the temperature to 1200±20℃ for heating. After the electrolytic copper plate melts, the solution enters the holding chamber of the industrial frequency induction heating furnace. Step 3: Insert the crystallizer into the solution in the insulation chamber. The solution enters the crystallizer and solidifies into copper rods that are continuously discharged outwards. Step 4: Connect one end of the 20mm diameter copper rod to the winding machine for winding and winding. Step 5: Extrude the 20mm diameter copper rod into a 25mm diameter copper rod. The extrusion deformation thickens the copper rod and performs the initial crushing of the internal grains. Step six: The copper rod with a diameter of 25mm is further extruded and thickened into a copper rod with a diameter of 30mm. The grains are then broken a second time through a second extrusion deformation. Step 7: Stretch and compress the 30mm diameter copper rod indefinitely to form a long, regular copper plate, and then roll it up. Step 8: After winding, the copper plate is transferred to the fixed-length drawing machine, and the drawing die is inserted to correct the size of the copper plate. The surface is reserved for subsequent machine tool processing. Step nine: The copper plate is sawn, and the sawn copper plate is straightened by a multi-roller stress-relieving straightening machine to completely remove the internal stress. Step 10: After straightening, use a non-destructive testing instrument to detect whether there are any defects inside the copper plate. Step 11: Transfer the qualified copper plate to the machining area for processing. Weld the machined plate and the back plate together to obtain the sputtering copper target.

2. The manufacturing process of a high-hardness planar sputtering copper target according to claim 1, characterized in that, In step five, the 20mm diameter copper rod is thickened into a 25mm diameter copper rod by extrusion using an extrusion press with a nominal diameter of Φ550mm~Φ600mm.

3. The manufacturing process of a high-hardness planar sputtering copper target according to claim 2, characterized in that, In step seven, a 30mm diameter copper rod is subjected to infinite stretching and extrusion by being inserted into an extrusion die with a nominal diameter of ≥700mm.

4. The manufacturing process of a high-hardness planar sputtering copper target according to claim 3, characterized in that, In step seven, the extrusion die of the extrusion press with a nominal diameter of ≥Φ700mm is preheated to a temperature of 600℃±10℃. The copper rod generates heat through friction between the rollers and enters the extrusion die. Through the action of the extrusion die, a copper busbar is formed. The copper busbar is gradually extended by the continuous feeding of subsequent materials to form a long, regular copper plate.

5. The manufacturing process of a high-hardness planar sputtering copper target according to claim 4, characterized in that, In step seven, after the copper is discharged from the die opening of the extrusion die, it is rapidly cooled using nitrogen gas at a distance of 1 meter from the die.

6. The manufacturing process of a high-hardness planar sputtering copper target according to claim 1, characterized in that, The upper part of the solution in the melting chamber and the insulation chamber of the industrial frequency induction heating furnace needs to be covered with burning charcoal to isolate oxygen.

7. The manufacturing process of a high-hardness planar sputtering copper target according to claim 1, characterized in that, In step eight, the drawing mouth of the fixed-length drawing machine is preheated using a ring-shaped high-frequency coil with a frequency ≥4000HZ and a preheating temperature ≤340℃, for the purpose of initial stress relief.