Tungsten filament bus preparation method and preparation system

Abstract

The invention discloses a tungsten filament bus preparation method and system, and the preparation method comprises the steps: carrying out the mixing granulation of raw materials containing tungsten powder to form spherical agglomerated powder, carrying out the extrusion molding of the spherical agglomerated powder, and carrying out the sintering to obtain a tungsten rod; a straight pulling process is adopted, the tungsten rod is extruded and stretched for multiple times, and a tungsten filament bus with the first target wire diameter is prepared; and the tungsten filament bus with the first target wire diameter is extruded and stretched for multiple times by adopting a winding and wire drawing process, and a tungsten filament bus with a second target wire diameter is prepared. The preparation system comprises an extrusion forming mechanism, a straight pulling mechanism and a winding and wire drawing mechanism. The invention discloses a tungsten filament bus preparation method and system, which can be used for preparing a tungsten filament bus with thinner wire diameter, higher breaking force and longer service life, breaks through the bottleneck of wire thinning, and is low in preparation energy consumption, high in yield and not easy to break.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic slicing, and in particular relates to a tungsten filament busbar preparation method and preparation system. Background Art

[0002] With the advancement of diamond wire thinning, the diameter of traditional diamond wire busbars has rapidly decreased from 80μm to 40μm, significantly increasing the number of wafers produced per kilogram. However, due to the influence of the diamond wire busbar's material, the reduction in wire diameter also means a decrease in its breaking strength, resulting in a significant increase in the wire breakage rate, and a bottleneck in the development of thinning. Unlike diamond wire, tungsten wire has a much higher breaking strength, showing great potential for thinning. my country is a major tungsten resource country with abundant reserves, and tungsten wire waste can be recycled and used in tungsten metal products. Therefore, replacing diamond wire busbar with tungsten wire is a necessary step for the development of the photovoltaic wafering industry.

[0003] Since tungsten metal has a melting point of up to 3420°C and high hardness, it cannot be cold-drawn at room temperature, and the area reduction rate of a single drawing is only 10%. Therefore, it requires multiple drawing processes from thick rods to thin wires, which results in high energy consumption and low yield.

[0004] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0005] The object of the present invention is to provide a tungsten busbar preparation method and preparation system, which can prepare tungsten busbars with smaller wire diameters, break through the bottleneck of thinning, have low preparation energy consumption, high yield, and are not prone to wire breakage.

[0006] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0007] A method for preparing a tungsten wire busbar, characterized in that the method comprises:

[0008] The raw materials containing tungsten powder are mixed and granulated to form spherical agglomerated powder, and the spherical agglomerated powder is extruded and sintered to obtain a tungsten rod;

[0009] The tungsten rod is extruded and stretched multiple times using a direct-pull process to prepare a tungsten busbar with the first target wire diameter.

[0010] The winding wire drawing process is adopted to perform multiple extrusion and stretching on the tungsten wire busbar of the first target wire diameter to prepare the tungsten wire busbar of the second target wire diameter.

[0011] In one or more embodiments of the present invention, the first target wire diameter is 1.5 mm to 2 mm, and the second target wire diameter is 20 μm to 35 μm.

[0012] In one or more embodiments of the present invention, in the straight drawing process, the area reduction rate of the tungsten rod during each extrusion and stretching process is 7% to 10%; and / or,

[0013] In the winding wire drawing process, the area reduction rate of the tungsten wire busbar is 7% to 10% during each extrusion and drawing process.

[0014] In one or more embodiments of the present invention, the preparation method further comprises:

[0015] During the Czochralski process, the tungsten rod is heated by electricity to raise the temperature of the tungsten rod to 1300°C to 1600°C; and / or,

[0016] During the winding and drawing process, the tungsten wire busbar is energized and heated so that the temperature of the tungsten wire busbar is raised to 1300°C to 1600°C.

[0017] In one or more embodiments of the present invention, the preparation method further comprises:

[0018] The tungsten busbar having the second target wire diameter is annealed.

[0019] In one or more embodiments of the present invention, during the annealing process, the tungsten busbar is energized and heated, so that the temperature of the tungsten busbar is increased to 1300° C. to 1600° C.

[0020] In one or more embodiments of the present invention, the preparation method further comprises: performing surface polishing on the tungsten wire busbar of the second target wire diameter.

[0021] In one or more embodiments of the present invention, the average particle size of the tungsten powder is 0.5 μm to 10 μm; and / or,

[0022] The raw materials further include a toughening additive and a molding agent, wherein the toughening additive includes one or more metals selected from lanthanum, rhenium, nickel, molybdenum, and cobalt, and the mass content of the toughening additive is 0.001% to 5%, and the molding agent includes one or more selected from paraffin and polyethylene glycol; and / or,

[0023] The spherical agglomerated powder has a purity of 99% to 99.9999% and an average size of 0.5 mm to 3 mm; and / or,

[0024] The diameter of the tungsten rod is 3 mm to 10 mm, and the length is 0.1 m to 10 m.

[0025] Another specific embodiment of the present invention provides a technical solution as follows:

[0026] A tungsten wire busbar preparation system, comprising:

[0027] An extrusion molding mechanism is used to mix and granulate raw materials containing tungsten powder to form spherical agglomerated powder, and to extrude and sinter the spherical agglomerated powder to prepare a tungsten rod;

[0028] A straight-pull mechanism is used to perform multiple extrusion and stretching on the tungsten rod to prepare a tungsten wire busbar of the first target wire diameter;

[0029] The winding and drawing mechanism is used to extrude and draw the tungsten wire busbar of the first target wire diameter multiple times to prepare the tungsten wire busbar of the second target wire diameter.

[0030] In one or more embodiments of the present invention, the straight-pulling mechanism includes a straight-pulling mold, which includes a hollow cylinder, one end of the cylinder is a feed end, and the other end of the cylinder is a discharge end. The cylinder includes a plurality of first cylinders and a second cylinder connected between two adjacent first cylinders. The inner diameter of the first cylinder remains unchanged from the feed end to the discharge end, and the inner diameter of the second cylinder gradually decreases from the feed end to the discharge end. The inner diameter of the discharge end is 1.5 mm to 2 mm.

[0031] In one or more embodiments of the present invention, the ratio of the reduction of the inner diameter of the second cylinder from the feeding end to the discharging end is 7% to 10%; and / or,

[0032] The lengths of two adjacent first cylinders gradually decrease from the feeding end to the discharging end; and / or,

[0033] The straight-pull mechanism also includes a first winding mechanism for winding the tungsten busbar of the first target wire diameter. The first winding mechanism includes a first auxiliary guide wheel, a second auxiliary guide wheel, a first rocker arm, and a first winding shaft that are arranged in sequence.

[0034] In one or more embodiments of the present invention, the winding and drawing mechanism includes a base, a first tower pulley and a second tower pulley rotatably mounted on the base, and a mold bracket arranged between the first tower pulley and the second tower pulley, the mold bracket is provided with a plurality of mounting grooves and a plurality of through holes extending to both sides of the mounting grooves in a direction perpendicular to the base; the winding and drawing mechanism also includes a plurality of first eye molds fixedly mounted in the mounting grooves, the first eye molds being provided with mold holes, the inner diameter of each of the mold holes gradually decreasing in a direction perpendicular to the base, and the minimum inner diameter of the mold hole is 20μm to 35μm.

[0035] In one or more embodiments of the present invention, the reduction ratio of the inner diameters of two adjacent die holes in a direction perpendicular to the base is 7% to 10%; and / or,

[0036] The winding and drawing mechanism further includes a driving mechanism for driving the first and second step pulleys to rotate in the same direction, wherein the rotation speed of the first step pulley is less than the rotation speed of the second step pulley; and / or,

[0037] The first eye mold is further provided with at least one guide hole connected to the mold hole, and the aperture of the guide hole gradually decreases in the direction toward the mold hole.

[0038] In one or more embodiments of the present invention, the tungsten busbar preparation system further includes an electric heating device for electrically heating the tungsten rod in the straight drawing mechanism and / or the tungsten busbar in the winding drawing mechanism.

[0039] In one or more embodiments of the present invention, the extrusion molding mechanism includes a die sleeve, an extrusion sleeve, a second eye die and a punch slidably installed in the die sleeve, which are connected in sequence. The die sleeve, the extrusion sleeve and the second eye die are fixedly installed by a mother mold, and the inner diameter of the extrusion sleeve gradually decreases from the die sleeve toward the second eye die.

[0040] In one or more embodiments of the present invention, the tungsten wire busbar preparation system also includes an annealing and polishing mechanism, which includes a protective tube, an annealing mechanism, a polishing mechanism, and a second winding mechanism arranged in sequence, the annealing mechanism includes a feed port and a discharge port, the protective tube is inserted in the feed port, and the discharge port is arranged opposite to the polishing mechanism, the annealing and polishing mechanism also includes a second winding mechanism for winding up the tungsten wire busbar of the second target wire diameter, the second winding mechanism includes a third auxiliary guide wheel, a fourth auxiliary guide wheel, a second rocker arm, and a second winding shaft arranged in sequence.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention discloses a tungsten busbar preparation method and system, which can produce a tungsten busbar with a thinner wire diameter, higher breaking strength, and longer service life. By using tungsten busbar to replace diamond busbar, the limitations of materials and the bottleneck of thinning can be overcome. The method has the advantages of low energy consumption, high yield, and low breakage.

[0043] Tungsten busbars with thinner wire diameters can cut silicon wafers with higher yields and smaller thicknesses, and can significantly reduce the loss rate of silicon materials during the cutting process;

[0044] In addition, discarded tungsten wire busbars can be recycled and used in tungsten metal products, realizing waste recycling without causing pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 Schematic diagram of the process of preparing the tungsten filament busbar of the present invention;

[0047] Figure 2 Schematic diagram of the structure of the extrusion molding mechanism in the second embodiment of the present invention;

[0048] Figure 3 This is a structural diagram of the straight-pull mechanism in the second embodiment of the present invention;

[0049] Figure 4 Schematic diagram of the structure of the winding and drawing mechanism in the second embodiment of the present invention;

[0050] Figure 5 This is a structural diagram of the mold support in the second embodiment of the present invention;

[0051] Figure 6 Schematic diagram of the structure of the first eye mold in the second embodiment of the present invention;

[0052] Figure 7 This is a structural diagram of the annealing and polishing mechanism in Example 2 of the present invention. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0054] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0055] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0056] The technical solution of the present invention will be described below with reference to the accompanying drawings.

[0057] Reference Figure 1As shown, the present invention discloses a method for preparing a tungsten filament busbar, comprising:

[0058] S1. Mixing and granulating raw materials containing tungsten powder to form spherical agglomerated powder, extruding the spherical agglomerated powder and sintering it to obtain a tungsten rod;

[0059] S2. Using a direct-pull process, the tungsten rod is extruded and stretched multiple times to prepare a tungsten wire busbar of the first target wire diameter;

[0060] S3. Using a winding wire drawing process, the tungsten wire busbar of the first target wire diameter is subjected to multiple extrusion and stretching to prepare a tungsten wire busbar of the second target wire diameter.

[0061] It should be noted that due to its high melting point, high hardness, and low elongation, tungsten is very difficult to process into thin filaments with diameters below 30 microns using existing technologies. The present invention can produce tungsten busbars with finer wire diameters, higher breaking strength, and longer lifespan, breaking through the bottleneck of thinning. It also reduces energy consumption, achieves a high yield, and is less prone to breakage.

[0062] The average particle size of the tungsten powder in the present invention is 0.5 μm to 10 μm. Exemplarily, the average particle size of the tungsten powder is 0.5 μm, 10 μm, or any value between 0.5 μm and 10 μm. The raw materials, in addition to the tungsten powder, also include a toughening additive and a molding agent. These are mixed by ball milling or other methods to form spherical agglomerated powder with good fluidity. The spherical agglomerated powder formed by the tungsten powder agglomerates has a purity of 99% to 99.9999% and an average size of 0.5 mm to 3 mm. These spherical agglomerates can be produced by spray drying, screening, or other methods. The toughening additive includes one or more metals selected from lanthanum, rhenium, nickel, molybdenum, and cobalt, with a mass content of 0.001% to 5%. The molding agent includes one or more of paraffin wax and polyethylene glycol. The molding agent may also include other volatile organic compounds. The tungsten rod has a diameter of 3 mm to 10 mm and a length of 0.1 m to 10 m.

[0063] Specifically, the first target wire diameter is 1.5 mm to 2 mm, and the second target wire diameter is 20 μm to 35 μm. For example, the first target wire diameter may be 2 mm, and the second target wire diameter may be 35 μm. Of course, the present application is not limited thereto, and the first target wire diameter may also be 1.5 mm, or any value between 1.5 mm and 2 mm, and the second target wire diameter may also be 20 μm, or any value between 20 μm and 35 μm.

[0064] To facilitate the production of a tungsten busbar with a first target wire diameter from a tungsten rod through extrusion and drawing, the area reduction of the tungsten rod during each extrusion and drawing process is set at 7% to 10%. Furthermore, to facilitate the production of a tungsten busbar with a first target wire diameter from a tungsten busbar with a second target wire diameter through extrusion and drawing, the area reduction of the tungsten busbar during each extrusion and drawing process is set at 7% to 10%. This design reduces the probability of wire breakage during the tungsten busbar production process.

[0065] Preferably, in order to electrically heat the tungsten rod to facilitate better extrusion and stretching of the tungsten rod, the preparation method further includes: during the Czochralski process, electrically heating the tungsten rod to raise the temperature of the tungsten rod to 1300° C. to 1600° C. For example, the temperature of the tungsten rod may be raised to 1300° C., 1600° C., or any temperature between 1300° C. and 1600° C.

[0066] Furthermore, in order to electrically heat the tungsten busbar of the first target wire diameter so as to better extrude and stretch the tungsten busbar of the first target wire diameter, the tungsten busbar is electrically heated during the winding and drawing process so that the temperature of the tungsten busbar is raised to 1300° C. to 1600° C. For example, the temperature of the tungsten busbar of the first target wire diameter can be raised to 1300° C., 1600° C., or any temperature value between 1300° C. and 1600° C.

[0067] Preferably, to eliminate internal stress in the tungsten busbar and improve its plasticity and toughness, the preparation method further includes annealing the tungsten busbar of the second target wire diameter. During the annealing process, the tungsten busbar is electrically heated to raise its temperature to 1300°C to 1600°C. Exemplarily, the temperature of the tungsten busbar during the annealing process may be raised to 1300°C, 1600°C, or any other temperature between 1300°C and 1600°C.

[0068] Furthermore, the preparation method further includes: performing surface polishing on the tungsten wire busbar of the second target wire diameter to improve surface smoothness and corrosion resistance.

[0069] The tungsten busbar preparation method and preparation system of the present invention are described in detail below with reference to specific examples.

[0070] Example 1:

[0071] The method for preparing a tungsten filament busbar in this embodiment includes the following steps:

[0072] Tungsten powder with a particle size of 0.5μm to 10μm and a purity of 99% to 99.9999% is added with toughening additives and forming agents, mixed evenly by ball milling, and granulated by spray drying, screening, etc. to produce spherical agglomerated powder with good fluidity and a diameter of 0.5mm to 3mm. The spherical agglomerated powder is then extruded to form a rod-shaped blank with a diameter of 3mm and a length of 0.1m to 10m. Under the protection of an inert gas such as argon or helium, the rod-shaped blank is fully sintered in a tubular furnace, vacuum furnace, reduction furnace, gas pressure furnace, etc., at a sintering temperature between 2500℃ and 3300℃ for a sintering time of 0.5h to 10h to produce a dense tungsten rod of about 3mm.

[0073] The dense tungsten rod of about 3mm is repeatedly extruded and stretched by the direct drawing process. During the extrusion and stretching process, the tungsten rod is heated by electricity to raise the temperature of the tungsten rod to 1300℃~1600℃. The area reduction rate of the tungsten rod during each extrusion and stretching is 7%~10%, so as to prepare a tungsten wire busbar of 1.5mm~2mm;

[0074] A tungsten busbar with a diameter of 1.5 mm to 2 mm is repeatedly extruded and stretched by a winding wire drawing process, and the tungsten busbar is heated by electricity during the extrusion and stretching process to raise the temperature of the tungsten busbar to 1300° C. to 1600° C. The area reduction rate of the tungsten busbar during each extrusion and stretching is 7% to 10%, so as to prepare a tungsten busbar with a diameter of 20 μm to 35 μm;

[0075] Under the protection of inert gas (such as argon or helium), the 20μm ~ 35μm tungsten busbar is electrified and heated to raise the temperature of the tungsten busbar to 1300℃ ~ 1600℃. The high-temperature tungsten busbar is annealed in pure water to eliminate internal stress and improve its plasticity and toughness.

[0076] Polishing the surface of the annealed tungsten wire busbar;

[0077] The polished tungsten wire busbar is inspected for appearance to check whether it has burrs, defects and other appearance defects. At the same time, it is subjected to mechanical tests, including tensile, impact, bending, flattening, hardness and fatigue tests, to confirm parameters including yield strength and tensile strength, so as to confirm whether the polished tungsten wire busbar meets the technical requirements;

[0078] The tungsten busbar that meets the technical requirements is packaged, rolled into a shaft and protected with a protective device to prevent the tungsten busbar from being damaged by impact. The protective device can be moisture-proof paper or moisture-proof cloth.

[0079] The packaged tungsten wire busbar bobbins are placed in a warehouse and stored in a specific environment with constant temperature and humidity, waiting for shipment.

[0080] Example 2:

[0081] Reference Figures 2 to 4 As shown, this embodiment discloses a tungsten busbar preparation system. The tungsten busbar preparation system in this embodiment includes: an extrusion molding mechanism 1 , a straight drawing mechanism 2 , and a winding drawing mechanism 3 .

[0082] Among them, the extrusion molding mechanism 1 is used to mix and granulate the raw materials containing tungsten powder to form spherical agglomerated powder, extrude the spherical agglomerated powder into shape and sinter it to prepare a tungsten rod; the straight pulling mechanism 2 is used to extrude and stretch the tungsten rod multiple times to prepare a tungsten wire busbar with a first target wire diameter; the winding and drawing mechanism 3 is used to extrude and stretch the tungsten wire busbar with a first target wire diameter multiple times to prepare a tungsten wire busbar with a second target wire diameter.

[0083] Based on this design, the tungsten wire busbar preparation system can be used to produce tungsten wire busbars with thinner wire diameters, higher breaking strength, and longer lifespan, breaking through the bottleneck of thin wire production. The system has low energy consumption, high yield, and is not prone to wire breakage.

[0084] Reference Figure 2 As shown, the extrusion molding mechanism 1 in this embodiment includes a die sleeve 11, an extrusion sleeve 12, a second eye die 13, and a punch 14 slidably mounted within the die sleeve 11. The die sleeve 11, extrusion sleeve 12, and second eye die 13 are fixedly mounted via a mother die 15. The inner diameter of the extrusion sleeve 12 gradually decreases from the die sleeve 11 toward the second eye die 13. After passing through the second eye die 13, the spherical agglomerated powder can be prepared into a rod-shaped blank with a diameter of 3 mm to 10 mm. The radial cross-section of the second eye die 13 is circular, and the inner diameter of the second eye die 13 needs to be slightly larger than the diameter of the rod-shaped blank. Since the diameter of the rod-shaped blank is 3 mm to 10 mm, for example, when the diameter of the rod-shaped blank is 3 mm, the inner diameter of the second eye die 13 can be greater than 3 mm. When the diameter of the rod-shaped blank is 10 mm, the inner diameter of the second eye die 13 can be greater than 10 mm. The rod-shaped blank is fully sintered in a tubular furnace, vacuum furnace, reduction furnace, or pressure furnace at a temperature between 2500°C and 3300°C for 0.5 to 10 hours to produce a dense tungsten rod with a diameter of 3 mm to 10 mm. During the sintering process, the tubular furnace, vacuum furnace, reduction furnace, or pressure furnace is filled with an inert gas such as argon or helium, and the internal pressure is 0.2 MPa to 1 MPa. For example, the diameter of the tungsten rod produced in this embodiment is 3 mm, 10 mm, or any other diameter value between 3 mm and 10 mm.

[0085] Specifically, refer to Figure 3As shown, the straight-pull mechanism 2 in this embodiment includes a straight-pull mold, which includes a hollow cylinder 21, one end of the cylinder 21 is a feed end 2101, and the other end of the cylinder 21 is a discharge end 2102. The cylinder 21 includes a plurality of first cylinders 211 and a second cylinder 212 connected between two adjacent first cylinders 211. The inner diameter of the first cylinder 211 remains unchanged from the feed end 2101 to the discharge end 2102, and the inner diameter of the second cylinder 212 gradually decreases from the feed end 2101 to the discharge end 2102. The inner diameter of the discharge end 2102 is 1.5 mm to 2 mm. Exemplarily, the cylinder 21 in this embodiment includes three first cylinders 211 and two second cylinders 212 connected between two adjacent first cylinders 211. Of course, the present application is not limited to this, as long as the number of first cylinders 211 is greater than two and the number of second cylinders 212 is greater than one. The end of the first first cylinder 211 away from the second cylinder 212 is the feed end 2101, and the end of the last first cylinder 211 away from the second cylinder 212 is the discharge end 2102. The inner diameter of the feed end 2101 needs to be able to accommodate the tungsten rod, so the inner diameter of the feed end 2101 must be larger than the diameter of the tungsten rod. Since the diameter of the tungsten rod is 3mm to 10mm. For example, when the diameter of the tungsten rod is 3mm, the inner diameter of the feed end 2101 can be greater than 3mm, and when the diameter of the tungsten rod is 10mm, the inner diameter of the feed end 2101 can be greater than 10mm. It can be understood that since the first target wire diameter is 1.5mm to 2mm, the inner diameter of the discharge end 2102 is slightly larger than the first target wire diameter, so that the tungsten wire busbar of the first target wire diameter can be prepared by extrusion and stretching of the last first cylinder 211.

[0086] Further, refer to Figure 3 As shown, in this embodiment, the inner diameter of the second barrel 212 decreases by 7% to 10% from the feed end 2101 to the discharge end 2102. That is, the inner diameter of two adjacent first barrels 211 decreases by 7% to 10% from the feed end 2101 to the discharge end 2102. For example, the inner diameter of the second barrel 212 decreases by 7%, 10%, or any percentage value between 7% and 10% from the feed end 2101 to the discharge end 2102. Based on this design, a tungsten rod can be gradually prepared into a tungsten wire busbar of the first target wire diameter through multiple extrusion and stretching.

[0087] Preferably, the lengths of two adjacent first cylinders 211 gradually decrease from the feed end 2101 toward the discharge end 2102. The length reduction is based on the need to ensure that the resistance value of each section of the first cylinder 211 is the same. To facilitate the gradual extrusion and stretching of the tungsten rod to the tungsten wire busbar of the first target wire diameter, the angle between the extension direction of the wall of the second cylinder 212 in this embodiment and the horizontal direction is 20° to 40°. Exemplarily, the angle can be 20°, 30°, 40°, or any value between 20° and 40°.

[0088] Preferably, the tungsten busbar preparation system in this embodiment further includes an electric heating device (not shown) for electrically heating the tungsten rod in the straight-draw mechanism 2 and / or the tungsten busbar in the winding wire drawing mechanism 3. Specifically, the electric heating device can apply voltage to the feed end 2101 and the discharge end 2102 of the cylinder 21, thereby energizing the tungsten rod, causing the temperature of the tungsten rod to rise to 1300°C to 1600°C. The heated tungsten rod can be extruded and stretched more conveniently and energy-efficiently to produce a tungsten busbar of the first target wire diameter. Since the cylinder 21 is conductive, in order to prevent safety accidents, an insulating layer needs to be coated on the outer wall of the cylinder 21.

[0089] Preferably, in order to facilitate the winding of the tungsten busbar of the first target wire diameter, thereby facilitating the transmission of the tungsten busbar of sufficient length to the winding and drawing mechanism 3, refer to Figure 3 As shown, the straight-pull mechanism 2 in this embodiment further includes a first winding mechanism 22 for winding a tungsten busbar having a first target wire diameter. The first winding mechanism 22 comprises a first auxiliary guide wheel 221, a second auxiliary guide wheel 222, a first swing arm 223, and a first winding shaft 224, which are sequentially arranged. According to this design, after exiting the discharge end 2102 of the barrel 21, the tungsten busbar having the first target wire diameter passes through the first auxiliary guide wheel 221, the second auxiliary guide wheel 222, and the first swing arm 223 in sequence before being wound around the first winding shaft 224.

[0090] Among them, reference Figure 3 As shown, a cooling device 23 is installed between the straight-draw die and the first winding mechanism 22 to cool the heated tungsten busbar. The straight-draw die is made of very hard polycrystalline or diamond material. To facilitate the transfer of the tungsten rod, two opposing guide wheels 24 are installed on the feed end 2101 of the barrel 21. These guide wheels 24 compress the tungsten rod, slowly pushing it into the barrel 21 through friction.

[0091] Specifically, refer to Figures 4 to 6As shown, the winding and drawing mechanism 3 in this embodiment includes a base 31, a first step pulley 32 and a second step pulley 33 rotatably mounted on the base 31, and a die support 34 disposed between the first and second step pulleys 32, 33. The outer diameters of the first and second step pulleys 32, 33 gradually decrease in a direction perpendicular to the base 31. The die support 34 is provided with a plurality of mounting slots 341 and a plurality of through holes 342 extending through both sides of the mounting slots 341 in a direction perpendicular to the base 31. The winding and drawing mechanism 3 also includes a plurality of first eye dies 35 fixedly mounted in the mounting slots 341. The first eye dies 35 are provided with die holes 351. The inner diameter of each die hole 351 gradually decreases in a direction perpendicular to the base 31, with the minimum inner diameter of the die hole 351 being between 20μm and 35μm. Since the second target wire diameter is between 20μm and 35μm. For example, when the second target wire diameter is 20 μm, the inner diameter of the feed end 2101 can be greater than 20 μm, and when the second target wire diameter is 35 μm, the inner diameter of the feed end 2101 can be greater than 35 μm. Among them, the use of the first pulley 32 and the second pulley 33 can ensure the tightness of the winding of the tungsten wire busbar during the extrusion and stretching process. The first pulley 32, the second pulley 33, and the mold support 34 correspond to each other in a straight line. The material of the first eye mold 35 is a cemented carbide mold, a polycrystalline mold or a diamond mold. It can be understood that the tungsten wire busbar is wound in the order of the first pulley 32, the first first eye mold 35, the second pulley 33, and the next first eye mold 35, until the last time it passes through the second pulley 33, and the tungsten wire busbar of the specified second target wire diameter can be directly produced.

[0092] Furthermore, to facilitate the conversion of a tungsten busbar having a first target diameter into a tungsten busbar having a second target diameter through extrusion and stretching, the ratio of reduction in the inner diameter of two adjacent die holes 351 along a direction perpendicular to the base 31 is 7% to 10%. For example, the ratio of reduction in the inner diameter of two adjacent die holes 351 along a direction perpendicular to the base 31 is 7%, 10%, or any other percentage value between 7% and 10%. Based on this design, a tungsten busbar having a first target diameter can be gradually converted into a tungsten busbar having a second target diameter through multiple extrusion and stretching operations.

[0093] Preferably, the electric heating device in this embodiment can apply voltage to the first tower pulley 32 and the second tower pulley 33. Since the tungsten wire busbar is wound thereon, the first tower pulley 32 and the second tower pulley 33 form a parallel closed loop with the tungsten wire busbar, and the tungsten wire busbar can be energized so that the temperature of the tungsten wire busbar is increased to 1300℃~1600℃. The heated tungsten wire busbar can be extruded and stretched more conveniently and energy-savingly to make a tungsten wire busbar of the second target wire diameter.

[0094] In order to prevent the tungsten busbar from being stretched thin after passing through the first eye die 35 and thus becoming too long to be tightly wound around the first and second tower pulleys 32 and 33, Figure 4As shown, the winding and drawing mechanism 3 in this embodiment also includes a drive mechanism 36 for driving the first and second step pulleys 32 and 33 to rotate in the same direction, wherein the rotation speed of the first step pulley 32 is lower than the rotation speed of the second step pulley 33. Specifically, the drive mechanism 36 in this embodiment includes a first transmission wheel 361 coaxially arranged with the first step pulley 32, a second transmission wheel 362 coaxially arranged with the second step pulley 33, a synchronous belt 363 connecting the first and second transmission wheels 361 and 362, and a drive motor 364 installed in conjunction with the synchronous belt 363. The drive motor 364 drives the synchronous belt 363 to rotate, thereby respectively driving the first and second transmission wheels 361 and 362 to rotate, ultimately driving the first and second step pulleys 32 and 33 to move. The diameter of the first transmission wheel 361 is larger than the diameter of the second transmission wheel 362. Based on this design, the rotation speed of the first transmission wheel 361 is lower than the rotation speed of the second transmission wheel 362.

[0095] In order to facilitate the passage of the tungsten wire busbar through the first eye die 35 and the extrusion and stretching, refer to Figure 6 As shown, the first eye mold 35 of this embodiment is further provided with at least one guide hole 352 connected to the die hole 351. The diameter of the guide hole 352 gradually decreases in the direction toward the die hole 351. The angle between the extension direction of the hole wall of the guide hole 352 and the axial direction of the die hole 351 is 20° to 40°. For example, the angle can be 20°, 30°, 40°, or any value between 20° and 40°. According to this design, the tungsten wire busbar can be extruded and stretched through the hole wall of the guide hole 352, and the tungsten wire with a smaller diameter can pass through the die hole 351.

[0096] Further, in order to anneal, polish, and coil the tungsten wire busbar of the second target wire diameter, refer to Figure 7 As shown, the tungsten wire busbar preparation system in this embodiment also includes an annealing and polishing mechanism 4, which includes a protective tube 41, an annealing mechanism 42, a polishing mechanism 43, and a second winding mechanism 44 arranged in sequence. The annealing mechanism 42 includes a feed port and a discharge port. The protective tube 41 is inserted into the feed port, and the discharge port is arranged opposite to the polishing mechanism 43. The annealing and polishing mechanism 4 also includes a second winding mechanism 44 for winding up a tungsten wire busbar of a second target wire diameter. The second winding mechanism 44 includes a third auxiliary guide wheel 441, a fourth auxiliary guide wheel 442, a second rocker arm 443, and a second winding shaft 444 arranged in sequence.

[0097] In summary, the working principle of the tungsten filament busbar preparation system of the present invention is:

[0098] The spherical agglomerated powder is placed in the die sleeve 11, and the punch 14 is slidably installed in the die sleeve 11 to squeeze the spherical agglomerated powder. After passing through the die sleeve 11, the extrusion sleeve 12, and the second eye die 13 in sequence, a rod-shaped blank with a diameter of 3 mm is prepared. The rod-shaped blank is fully sintered in a tubular furnace, a vacuum furnace, a reduction furnace, a gas pressure furnace and other equipment. The sintering temperature is between 2500°C and 3300°C, and the sintering time is 0.5h to 10h to produce a 3mm dense tungsten rod;

[0099] The tungsten rod is conveyed into the cylinder 21 of the straight-pull mechanism 2. The guide wheel 24 slowly pushes the tungsten rod through multiple first cylinders 211 and multiple second cylinders 212 in sequence. At the same time, an electric heating device applies voltage to the feed end 2101 and the discharge end 2102 of the cylinder 21 to heat the tungsten rod, raising its temperature to 1300°C to 1600°C. The heated tungsten rod is extruded and stretched multiple times until it passes through the last first cylinder 211, thereby forming a tungsten busbar with a diameter of 1.5mm to 2mm. The tungsten rod then passes through the cooling device 23 and is wound by the first winding mechanism 22.

[0100] The 1.5mm~2mm tungsten busbar wound on the first winding shaft 224 is cyclically wound on the first tower, a first eye mold 35, the second tower, and another first eye mold 35. At the same time, a voltage is applied to the first tower pulley 32 and the second tower pulley 33 through an electric heating device to energize and heat the tungsten busbar so that the temperature of the tungsten busbar is increased to 1300℃~1600℃. After the heated tungsten busbar passes through the last eye mold and then the second tower pulley 33, it can be prepared into a 20μm~35μm tungsten busbar.

[0101] The residual heat of the tungsten busbar passes through a protective tube 41 filled with a protective gas such as argon or helium, and is then transferred to an annealing mechanism 42. An electric heating device heats the tungsten busbar until its temperature reaches 1300°C to 1600°C. The tungsten busbar is then annealed in pure water and polished by a polishing mechanism 43. The polished tungsten busbar is then reeled in by a second reeling mechanism 44. After exiting the polishing mechanism 43, the tungsten busbar, with the second target diameter, passes through a third auxiliary guide pulley 441, a fourth auxiliary guide pulley 442, and a second rocker 443, before being reeled onto a second reeling shaft 444. The reeled tungsten busbar undergoes a sample appearance inspection and mechanical testing before being packaged and stored.

[0102] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0103] The present invention discloses a tungsten busbar preparation method and system, which can produce a tungsten busbar with a thinner wire diameter, higher breaking strength, and longer service life. By using tungsten busbar to replace diamond busbar, the limitations of materials and the bottleneck of thinning can be overcome. The method has the advantages of low energy consumption, high yield, and low breakage.

[0104] Tungsten busbars with thinner wire diameters can cut silicon wafers with higher yields and smaller thicknesses, and can significantly reduce the loss rate of silicon materials during the cutting process;

[0105] In addition, discarded tungsten wire busbars can be recycled and used in tungsten metal products, realizing waste recycling without causing pollution.

[0106] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0107] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing a tungsten busbar, characterized in that: The preparation method comprises: The raw materials containing tungsten powder are mixed and granulated to form spherical agglomerated powder, and the spherical agglomerated powder is extruded and sintered to obtain a tungsten rod; The tungsten rod is extruded and stretched multiple times using a direct-pull process to prepare a tungsten busbar with the first target wire diameter. The winding wire drawing process is adopted to perform multiple extrusion and stretching on the tungsten wire busbar of the first target wire diameter to prepare the tungsten wire busbar of the second target wire diameter.

2. The method for preparing a tungsten busbar according to claim 1, wherein: The first target wire diameter is 1.5 mm to 2 mm, and the second target wire diameter is 20 μm to 35 μm.

3. The method for preparing a tungsten busbar according to claim 1, wherein: In the straight drawing process, the area reduction rate of the tungsten rod during each extrusion and stretching process is 7% to 10%; and / or, In the winding wire drawing process, the area reduction rate of the tungsten wire busbar is 7% to 10% during each extrusion and drawing process.

4. The method for preparing a tungsten busbar according to claim 1, wherein: The preparation method further comprises: During the Czochralski process, the tungsten rod is heated by electricity to raise the temperature of the tungsten rod to 1300°C to 1600°C; and / or, During the winding and drawing process, the tungsten wire busbar is energized and heated so that the temperature of the tungsten wire busbar is raised to 1300°C to 1600°C.

5. The method for preparing a tungsten busbar according to claim 1, wherein: The preparation method further comprises: The tungsten busbar having the second target wire diameter is annealed.

6. The method for preparing a tungsten busbar according to claim 5, characterized in that: During the annealing process, the tungsten wire busbar is energized and heated, so that the temperature of the tungsten wire busbar is increased to 1300° C. to 1600° C.

7. The method for preparing a tungsten busbar according to claim 1, wherein: The preparation method further includes: performing surface polishing on the tungsten wire busbar of the second target wire diameter.

8. The method for preparing a tungsten busbar according to claim 1, wherein: The average particle size of the tungsten powder is 0.5 μm to 10 μm; and / or, The raw materials further include a toughening additive and a molding agent, wherein the toughening additive includes one or more metals selected from lanthanum, rhenium, nickel, molybdenum, and cobalt, and the mass content of the toughening additive is 0.001% to 5%, and the molding agent includes one or more selected from paraffin and polyethylene glycol; and / or, The spherical agglomerated powder has a purity of 99% to 99.9999% and an average size of 0.5 mm to 3 mm; and / or, The diameter of the tungsten rod is 3 mm to 10 mm, and the length is 0.1 m to 10 m.

9. A tungsten busbar preparation system, characterized in that: The tungsten wire busbar preparation system includes: An extrusion molding mechanism is used to mix and granulate raw materials containing tungsten powder to form spherical agglomerated powder, and to extrude and sinter the spherical agglomerated powder to prepare a tungsten rod; A straight-pull mechanism is used to perform multiple extrusion and stretching on the tungsten rod to prepare a tungsten wire busbar of the first target wire diameter; The winding and drawing mechanism is used to extrude and draw the tungsten wire busbar of the first target wire diameter multiple times to prepare the tungsten wire busbar of the second target wire diameter.

10. The tungsten busbar preparation system according to claim 9, characterized in that: The straight-pull mechanism includes a straight-pull mold, which includes a hollow cylinder, one end of the cylinder is a feed end, and the other end of the cylinder is a discharge end. The cylinder includes multiple first cylinders and a second cylinder connected between two adjacent first cylinders. The inner diameter of the first cylinder remains unchanged from the feed end to the discharge end, and the inner diameter of the second cylinder gradually decreases from the feed end to the discharge end. The inner diameter of the discharge end is 1.5 mm to 2 mm.

11. The tungsten busbar preparation system according to claim 10, characterized in that: The ratio of the reduction of the inner diameter of the second cylinder from the feed end to the discharge end is 7% to 10%; and / or, The lengths of two adjacent first cylinders gradually decrease from the feeding end to the discharging end; and / or, The straight-pull mechanism also includes a first winding mechanism for winding the tungsten busbar of the first target wire diameter. The first winding mechanism includes a first auxiliary guide wheel, a second auxiliary guide wheel, a first rocker arm, and a first winding shaft that are arranged in sequence.

12. The tungsten busbar preparation system according to claim 9, characterized in that: The winding and drawing mechanism includes a base, a first step pulley and a second step pulley rotatably mounted on the base, and a mold bracket arranged between the first step pulley and the second step pulley, the mold bracket is provided with a plurality of mounting grooves and a plurality of through holes extending to both sides of the mounting grooves in a direction perpendicular to the base; the winding and drawing mechanism also includes a plurality of first eye molds fixedly mounted in the mounting grooves, the first eye molds are provided with mold holes, the inner diameter of each mold hole gradually decreases in a direction perpendicular to the base, and the minimum inner diameter of the mold hole is 20μm to 35μm.

13. The tungsten busbar preparation system according to claim 12, characterized in that: The reduction ratio of the inner diameters of two adjacent die holes in a direction perpendicular to the base is 7% to 10%; and / or, The winding and drawing mechanism further includes a driving mechanism for driving the first and second step pulleys to rotate in the same direction, wherein the rotation speed of the first step pulley is less than the rotation speed of the second step pulley; and / or, The first eye mold is further provided with at least one guide hole connected to the mold hole, and the aperture of the guide hole gradually decreases in the direction toward the mold hole.

14. The tungsten busbar preparation system according to claim 9, characterized in that: The tungsten busbar preparation system further includes an electric heating device for electrically heating the tungsten rod in the straight drawing mechanism and / or the tungsten busbar in the winding drawing mechanism.

15. The tungsten busbar preparation system according to claim 9, characterized in that: The extrusion molding mechanism includes a die sleeve, an extrusion sleeve, a second eye die and a punch slidably installed in the die sleeve, which are connected in sequence. The die sleeve, the extrusion sleeve and the second eye die are fixedly installed through a mother die, and the inner diameter of the extrusion sleeve gradually decreases from the die sleeve toward the second eye die.

16. The tungsten busbar preparation system according to claim 9, characterized in that: The tungsten busbar preparation system also includes an annealing and polishing mechanism, which includes a protective tube, an annealing mechanism, a polishing mechanism, and a second winding mechanism arranged in sequence. The annealing mechanism includes a feed port and a discharge port. The protective tube is inserted into the feed port, and the discharge port is arranged opposite to the polishing mechanism. The annealing and polishing mechanism also includes a second winding mechanism for winding a tungsten busbar of a second target wire diameter. The second winding mechanism includes a third auxiliary guide wheel, a fourth auxiliary guide wheel, a second rocker arm, and a second winding shaft arranged in sequence.

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