Preparation method of superfine high-strength diamond wire bus

Abstract

The invention discloses a preparation method of a superfine high-strength diamond wire bus. The preparation method comprises the following steps: selecting a copper-plated steel wire, wherein the diameter D of the copper-plated steel wire is 16-20 times of the diameter d of a finished steel wire; the step pulley wire drawing machine and the slippage-free wire drawing machine are loaded, the slippage-free wire drawing machine comprises a plurality of groups of guide wheels which are correspondingly arranged, a wire drawing die is arranged among the plurality of groups of guide wheels, and electric brushes are arranged on two sides of the wire drawing die; the pulse voltage U of the electric brush is set to be 3-13V, and the pulse frequency f is set to be 100-750Hz; the drawing pass n of the cone pulley wire drawing machine is set to be 26-34, the area reduction rate q of each pass is 10%-22%, and the total compression rate Q is larger than or equal to 98%; the drawing pass n'of the non-slip wire drawing machine is set to be 10, and the area reduction rate q 'of each pass is 5%-15%; the superfine high-strength diamond wire bus is prepared by drawing through a cone pulley wire drawing machine and matching with low-pulse-voltage non-slip drawing of a non-slip wire drawing machine, and the diameter d ranges from 15 microns to 30 microns, the tensile strength Rm ranges from 5.8 GPa to 7.9 GPa, the number of torsion turns N is larger than or equal to 120, the free circle diameter W is larger than or equal to 60 mm, and the warping degree L is smaller than or equal to 20 mm.

Description

Technical Field

[0001] The invention relates to a solar cell preparation technology, in particular to a crystalline silicon preparation technology and its use equipment, and specifically to a method for preparing an ultra-fine high-strength diamond wire busbar. Background Art

[0002] The successful development of monocrystalline silicon solar cells has played a milestone role in the history of solar cell development. As the most important raw material of the solar photovoltaic industry, crystalline silicon has increasingly higher processing requirements. Diamond cutting wire, referred to as diamond wire, is a new type of hard and brittle material cutting tool. Due to its efficient cutting ability, it is used in the processing of monocrystalline silicon.

[0003] Diamond wire busbar is the base material of diamond wire, mainly tungsten wire and carbon steel wire. Tungsten wire has high elastic modulus and high strength characteristics, which can reach more than 6GPa. In addition, the heating drawing method can produce products with specifications of 30 microns and below, which is gradually favored by the market.

[0004] Due to the high price of tungsten powder raw materials and long processing flow, the comprehensive production cost is much higher than that of carbon steel wire, and further reducing the wire diameter and increasing the strength have encountered bottlenecks, which hinders its further market penetration. Carbon steel wire, as the traditional diamond wire substrate, has been used for more than ten years. It has low cost and mature process flow. It is made of high-carbon steel wire rod through large drawing-heat treatment-medium drawing-heat treatment-copper zinc plating-wet drawing. The wire diameter is between 30 and 40 microns. With the increase of strain, the tensile strength increases almost linearly. The strength of the current product can reach 5GPa. The theoretical strength of carbon steel wire can reach 13GPa, and the market share exceeds 80%. In the process of cutting silicon wafers, diamond wires with higher strength, thinner wire diameter and lower cost are required, so the further improvement of carbon steel wire will be solved.

[0005] From the perspective of preparation equipment, traditional tower pulley equipment can no longer meet the production requirements of specifications below 30 microns due to its technical principle of slipping and pulling, and new non-slip equipment is needed to further reduce its diameter. From the perspective of production technology, the strength of carbon steel wire produced by the pure wet-drawing process is difficult to improve, and new process steps are needed to improve its strength.

[0006] Therefore, it is necessary to provide a method for preparing an ultra-fine high-strength diamond wire busbar to solve the above problems. Summary of the invention

[0007] The purpose of the invention is to provide a method for preparing an ultra-fine high-strength diamond wire busbar.

[0008] The present invention achieves the above object through the following technical solutions:

[0009] A method for preparing an ultra-fine high-strength diamond wire busbar, comprising the steps of:

[0010] 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 16 to 20 times the diameter d of the finished steel wire;

[0011] 2) Prepare lubricating liquid; the pH value of the lubricating liquid is 8.1-8.5, and the concentration C is 5% to 6%;

[0012] 3) Loading a tower wheel wire drawing machine and a non-slip wire drawing machine, the non-slip wire drawing machine includes a number of correspondingly arranged guide wheels, a wire drawing die is arranged between the several groups of guide wheels, and brushes are arranged on both sides of the wire drawing die;

[0013] 4) Set the brush pulse voltage U to 3-13V and the pulse frequency f to 100-750Hz;

[0014] 5) Set the drawing pass number n of the tower wheel wire drawing machine to 26 to 34 passes, the surface reduction rate q of each pass to 10% to 22%, and the total compression rate Q ≥ 98%;

[0015] 6) Set the number of drawing passes n' of the non-slip wire drawing machine to 10 passes and the surface reduction rate q' of each pass to 5%-15%;

[0016] 7) Through the drawing of the tower wheel wire drawing machine and the low pulse voltage non-slip drawing of the non-slip wire drawing machine, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d ranges from 15 to 30 μm, the tensile strength Rm is 5.8 to 7.9 GPa, the number of torsion circles N ≥ 120, the free circle diameter W ≥ 60 mm, and the warpage L ≤ 20 mm.

[0017] Furthermore, the temperature T of the lubricating fluid is controlled to be 34-44°C.

[0018] Furthermore, there are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

[0019] Furthermore, the tower pulley wire drawing machine adopts tungsten steel or single crystal mold.

[0020] Furthermore, the non-slip wire drawing machine adopts a single crystal die, and the total compression rate Q' is ≤70%.

[0021] Compared with the prior art, the present invention can produce ultra-fine carbon steel wire with d of 15 to 30 μm through the two-step connecting drawing process of "tower pulley drawing + low pulse voltage non-slip drawing", especially based on the characteristics of controllable post-tensioning and non-slip in the non-slip wire drawing process; the low pulse voltage achieves a great improvement in processing plasticity, and increases the dislocation movement rate and dislocation value increase. The solution provided by the present invention can produce ultra-high strength carbon steel wire with Rm of 5.8 to 7.9 GPa; it overcomes the surface slip damage when using tower pulley to draw ultra-fine wire, reduces its surface defect sensitivity, and improves its comprehensive mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the drawing of the tower wheel wire drawing machine of the present invention;

[0023] Figure 2 It is a schematic diagram of low pulse voltage non-slip pulling of the present invention. DETAILED DESCRIPTION

[0024] Embodiment 1:

[0025] This embodiment shows a method for preparing an ultra-fine high-strength diamond wire busbar, the steps comprising:

[0026] 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 16 times the diameter d of the finished steel wire;

[0027] 2) Prepare lubricating liquid; the pH value of the lubricating liquid is 8.1, and the concentration C is 5%;

[0028] 3) Loading a tower wheel wire drawing machine 100 and a non-slip wire drawing machine 200, wherein the non-slip wire drawing machine 200 includes a plurality of correspondingly arranged guide wheels 1, a wire drawing die 2 is arranged between the plurality of guide wheels, and brushes 3 are arranged on both sides of the wire drawing die 2;

[0029] 4) Set the brush 3 pulse voltage U to 3V and the pulse frequency f to 100Hz;

[0030] 5) Set the drawing pass number n of the tower wheel wire drawing machine 100 to 34 passes, the surface reduction rate q of each pass to 10% to 20%, and the total compression rate Q ≥ 98%;

[0031] 6) Set the number of drawing passes n' of the non-slip wire drawing machine 200 to 10 and the surface reduction rate q' of each pass to 5%;

[0032] 7) After drawing by a tower wheel wire drawing machine 100 and low pulse voltage non-slip drawing by a non-slip wire drawing machine 200, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d is 15μm, the tensile strength Rm is 7.9GPa, the number of torsion circles N≥120, the free circle diameter W≥60mm, and the warpage L≤20mm.

[0033] The temperature T of the lubricating fluid was controlled at 34°C.

[0034] There are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

[0035] The tower pulley wire drawing machine 100 adopts tungsten steel or single crystal mold.

[0036] The non-slip wire drawing machine 200 adopts a single crystal die, and the total compression rate Q' is ≤70%.

[0037] Embodiment 2:

[0038] This embodiment shows a method for preparing an ultra-fine high-strength diamond wire busbar, the steps comprising:

[0039] 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 20 times the diameter d of the finished steel wire;

[0040] 2) Prepare lubricating liquid; the pH value of the lubricating liquid is 8.5 and the concentration C is 6%;

[0041] 3) Loading a tower wheel wire drawing machine 100 and a non-slip wire drawing machine 200, wherein the non-slip wire drawing machine 200 includes a plurality of correspondingly arranged guide wheels 1, a wire drawing die 2 is arranged between the plurality of guide wheels, and brushes 3 are arranged on both sides of the wire drawing die 2;

[0042] 4) Set the brush 3 pulse voltage U to 5V and the pulse frequency f to 350Hz;

[0043] 5) Set the drawing pass number n of the tower wheel wire drawing machine 100 to 26 passes, the surface reduction rate q of each pass to 13-22%, and the total compression rate Q ≥ 98%;

[0044] 6) Set the number of drawing passes n' of the non-slip wire drawing machine 200 to 10 passes and the surface reduction rate q' of each pass to 10-15%;

[0045] 7) After drawing by a tower wheel wire drawing machine 100 and low pulse voltage non-slip drawing by a non-slip wire drawing machine 200, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d is 30μm, the tensile strength Rm is 5.8GPa, the number of torsion circles N≥120, the free circle diameter W≥60mm, and the warpage L≤20mm.

[0046] The temperature T of the lubricating fluid was controlled at 44°C.

[0047] There are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

[0048] The tower pulley wire drawing machine 100 adopts tungsten steel or single crystal mold.

[0049] The non-slip wire drawing machine 200 adopts a single crystal die, and the total compression rate Q' is ≤70%.

[0050] Embodiment 3:

[0051] This embodiment shows a method for preparing an ultra-fine high-strength diamond wire busbar, the steps comprising:

[0052] 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 18 times the diameter d of the finished steel wire;

[0053] 2) preparing a lubricating liquid; the pH value of the lubricating liquid is 8.3, and the concentration C is 5.5%;

[0054] 3) Loading a tower wheel wire drawing machine 100 and a non-slip wire drawing machine 200, wherein the non-slip wire drawing machine 200 includes a plurality of correspondingly arranged guide wheels 1, a wire drawing die 2 is arranged between the plurality of guide wheels, and brushes 3 are arranged on both sides of the wire drawing die 2;

[0055] 4) Set the brush 3 pulse voltage U to 7V and the pulse frequency f to 400Hz;

[0056] 5) Set the drawing pass number n of the tower wheel wire drawing machine 100 to 32 passes, the surface reduction rate q of each pass to 12-20%, and the total compression rate Q ≥ 98%;

[0057] 6) Set the number of drawing passes n' of the non-slip wire drawing machine 200 to 10 and the surface reduction rate q' of each pass to 8%;

[0058] 7) After drawing by a tower wheel wire drawing machine 100 and low pulse voltage non-slip drawing by a non-slip wire drawing machine 200, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d is 20μm, the tensile strength Rm is 7.2GPa, the number of torsion circles N≥120, the free circle diameter W≥60mm, and the warpage L≤20mm.

[0059] The temperature T of the lubricating fluid was controlled at 39°C.

[0060] There are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

[0061] The tower pulley wire drawing machine 100 adopts tungsten steel or single crystal mold.

[0062] The non-slip wire drawing machine 200 adopts a single crystal die, and the total compression rate Q' is ≤70%.

[0063] Embodiment 4:

[0064] This embodiment shows a method for preparing an ultra-fine high-strength diamond wire busbar, the steps comprising:

[0065] 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 19 times the diameter d of the finished steel wire;

[0066] 2) preparing a lubricating liquid; the pH value of the lubricating liquid is 8.4, and the concentration C is 5.8%;

[0067] 3) Loading a tower wheel wire drawing machine 100 and a non-slip wire drawing machine 200, wherein the non-slip wire drawing machine 200 includes a plurality of correspondingly arranged guide wheels 1, a wire drawing die 2 is arranged between the plurality of guide wheels, and brushes 3 are arranged on both sides of the wire drawing die 2;

[0068] 4) Set the brush 3 pulse voltage U to 11V and the pulse frequency f to 650Hz;

[0069] 5) Set the drawing pass number n of the tower wheel wire drawing machine 100 to 29 passes, the surface reduction rate q of each pass to 12-21%, and the total compression rate Q ≥ 98%;

[0070] 6) Set the number of drawing passes n' of the non-slip wire drawing machine 200 to 10 passes, and the surface reduction rate q' of each pass to 5%-15%;

[0071] 7) After drawing by a tower wheel wire drawing machine 100 and low pulse voltage non-slip drawing by a non-slip wire drawing machine 200, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d is 28μm, the tensile strength Rm is 6.2GPa, the number of torsion circles N≥120, the free circle diameter W≥60mm, and the warpage L≤20mm.

[0072] The temperature T of the lubricating fluid was controlled at 42°C.

[0073] There are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

[0074] The tower pulley wire drawing machine 100 adopts tungsten steel or single crystal mold.

[0075] The non-slip wire drawing machine 200 adopts a single crystal die, and the total compression rate Q' is ≤70%.

[0076] Compared with the prior art, the present invention can produce ultra-fine carbon steel wire with d of 15 to 30 μm through the two-connection drawing process of "tower pulley drawing + low pulse voltage non-slip drawing", especially based on the characteristics of controllable post-tensioning and non-slip in the non-slip wire drawing process; the low pulse voltage achieves a great improvement in processing plasticity, and increases the dislocation movement rate and dislocation value increase. The solution provided by the present invention can produce ultra-high strength carbon steel wire with Rm of 5.8 to 7.9 GPa; it overcomes the surface slip damage when using tower pulley to draw ultra-fine wire, reduces its surface defect sensitivity, and improves its comprehensive mechanical properties.

[0077] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing an ultra-fine high-strength diamond wire busbar, characterized in that: include: 1) Selection of copper-plated steel wire: The diameter D of the copper-plated steel wire is 16 to 20 times the diameter d of the finished steel wire; 2) Loading a tower wheel wire drawing machine and a non-slip wire drawing machine, wherein the non-slip wire drawing machine includes a plurality of correspondingly arranged guide wheels, a wire drawing die is arranged between the plurality of guide wheels, and brushes are arranged on both sides of the wire drawing die; 3) Set the brush pulse voltage U to 3-13V and the pulse frequency f to 100-750Hz; 4) Set the drawing pass number n of the tower wheel wire drawing machine to 26 to 34 passes, the surface reduction rate q of each pass to 10% to 22%, and the total compression rate Q ≥ 98%; 5) Set the number of drawing passes n' of the non-slip wire drawing machine to 10 passes and the surface reduction rate q' of each pass to 5%-15%; 6) Through the drawing of the tower wheel wire drawing machine and the low pulse voltage non-slip drawing of the non-slip wire drawing machine, an ultra-fine high-strength diamond wire busbar is prepared: the diameter d ranges from 15 to 30 μm, the tensile strength Rm is 5.8 to 7.9 GPa, the number of torsion circles N ≥ 120, the free circle diameter W ≥ 60 mm, and the warpage L ≤ 20 mm.

2. The method for preparing an ultra-fine high-strength diamond wire busbar according to claim 1, characterized in that: There are two groups of guide wheels, and each group of guide wheels includes two corresponding single-body guide wheels.

3. The method for preparing an ultra-fine high-strength diamond wire busbar according to claim 2, characterized in that: The tower pulley wire drawing machine uses tungsten steel or single crystal molds.

4. The method for preparing an ultra-fine high-strength diamond wire busbar according to claim 3, characterized in that: The non-slip wire drawing machine adopts single crystal die, and the total compression rate Q'≤70%.

5. A method for preparing an ultra-fine high-strength diamond wire busbar according to any one of claims 1 to 4, characterized in that: Lubricating fluid is used for low pulse voltage non-slip drawing of tower pulley wire drawing machine and non-slip wire drawing machine.

6. The method for preparing an ultra-fine high-strength diamond wire busbar according to claim 5, characterized in that: The pH value of the lubricating liquid is 8.1-8.5, and the concentration C is 5% to 6%.

7. The method for preparing an ultra-fine high-strength diamond wire busbar according to claim 6, characterized in that: The temperature T of the lubricating fluid is controlled at 34-44°C.

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