Polycrystalline silicon wafer fine wire cutting structure
By using the design of cutting roller seat, casing and columns in the polycrystalline thin wire cutting structure, the acute angle cutting line is formed and adjusted to diagonal wire cutting, the unstable cutting quality and increased line consumption in the thin wire cutting process are solved. The problem is to achieve more efficient cutting ability and stability.
Patent Information
- Application Number
- CN202420185346.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-25
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-01-25
AI Technical Summary
In the polycrystallinear thinning process, with the refinement of the steel wire diameter, the cutting quality is unstable and the cutting quality cannot be guaranteed. At the same time, the line consumption of a single-knife process is increased, and the expected number of pieces and cutting quality cannot be achieved.
A polycrystalline silicon wafer thin wire cutting structure is adopted, including a cutting roller seat, horizontally parallel cutting roller, sleeve and column. The cutting wire is wound on the sleeve and passes through the column to form an acute angle, combining the thread section and sleeve positioning cylinder and spring, adjust to diagonal mesh cutting, enhance cutting ability and stabilize the position of the steel wire in the main roller groove.
It effectively improves the stability of cutting quality, reduces process line consumption, increases the number of steel wires used, solves the problem of TTV exceeding the standard caused by weak cutting capabilities, and ensures the surface flatness of the silicon wafer.
Smart Images
Figure CN222156121U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of photovoltaic silicon slice slicing, in particular to a polycrystalline silicon slice fine-line cutting structure. Background Art
[0002] In the photovoltaic silicon wafer slicing industry, cutting steel wire and silicon materials are the largest production costs for silicon wafer companies. The profits of silicon wafer companies are accurate to the wafer level. How to increase the number of wafers per unit of silicon material without increasing the unit consumption of steel wire has always been the main technical research and development direction of silicon wafer companies.
[0003] The multi-crystalline silicon wafer thinning process technology is to increase the output rate by N% based on the original output number while using a constant single-blade process wire and keeping the average thickness of the silicon wafer unchanged, so that the thinning technology can generate positive benefits.
[0004] In the existing multi-crystalline silicon wafer thinning process, the calculation method for the number of wafers output by a single knife in the silicon wafer industry is: single knife fixed loading capacity / theoretical main roller groove pitch*yield rate = single knife number of wafers output, silicon wafer thickness = main roller groove pitch-steel wire diameter.
[0005] The method that the industry has been following to increase the number of wafers output is to reduce the denominator in the above calculation formula (i.e., the main roller groove pitch becomes smaller) so that the result of the equation (i.e., the number of wafers output by a single knife) becomes larger. At the same time, in order to ensure the complete continuity of the texturing process at the cell end, the average thickness of the silicon wafer must not change. Then the corresponding steel wire diameter must also be reduced. The final result will achieve the purpose of increasing the number of wafers output. Through this traditional process, the diameter of the steel wire used for multicrystalline silicon wafers has been reduced from 130um to 57um. While increasing the number of wafers output, the cutting quality can meet the corresponding indicators.
[0006] However, with the continuous expansion of the photovoltaic market, the thinning of multi-crystalline silicon wafers is progressing faster and faster. The diameter of polycrystalline steel wire has been thinned to 57um. As the steel wire becomes thinner, the process window becomes narrower and narrower. When thinning from 57um to 53um according to the traditional thinning method, the cutting quality fluctuates greatly and the cutting quality cannot be guaranteed. At the same time, in order to ensure the smooth completion of cutting, the single-knife process line consumption has to be increased, so that the thinning benefits cannot reach the expected target.
[0007] In order to continue to complete the thinning of polysilicon wafers, the stability of cutting quality and the maintenance of wire consumption are technical issues that need to be urgently solved. Summary of the invention
[0008] The technical problem to be solved by the utility model is to provide a polysilicon wafer fine-line cutting structure, which can effectively solve the problems in the prior art, effectively ensure the stability of the thinning cutting line in the main roller groove, and reduce process line consumption.
[0009] In order to solve the above technical problems, the technical solution adopted by the utility model is: a polycrystalline silicon wafer fine wire cutting structure, comprising a cutting roller seat, on which two horizontal and parallel cutting rollers are arranged, a sleeve is sleeved on the cutting roller, a column is arranged on the sleeve, and a cutting wire is wound around the two sleeves and passed through the column;
[0010] An acute angle is formed between the cutting line in the cutting area formed above the cutting line and the central axis of the cutting roller.
[0011] In a preferred solution, one end of the cutting roller is fixed on the cutting roller seat, and a threaded section is provided on the portion close to the other end, a sleeve positioning tube is sleeved on the threaded section, and an internal thread matching the threaded section is provided on the inner wall of the sleeve positioning tube.
[0012] In a preferred solution, a spring is provided on one end of the sleeve close to the cutting roller seat, and the spring is sleeved on the cutting roller.
[0013] In a preferred solution, the columns on a single sleeve include two groups, an upper group and an lower group, and the two groups of columns are respectively fixedly arranged on the upper and lower sides of the sleeve and are vertically arranged.
[0014] In a preferred solution, a single group of columns includes a plurality of column groups for fixing the cutting line, and the column group includes two columns, and the cutting line is arranged to pass through between the two columns.
[0015] The utility model provides a polysilicon wafer fine-wire cutting structure, which ensures the single-blade wire consumption and enhances the cutting capacity by adopting the above structure. A new reverse cutting process with a forward amount less than a return amount is used at the end of the process, which increases the number of times the steel wires that were used less in the early stage and still have cutting capacity are used, and the cutting is carried out normally while ensuring the single-blade wire consumption. In addition, the wire mesh is adjusted to an oblique wire mesh during cutting, which increases the stability of the wire mesh and solves the problem that the steel wire cannot complete the cutting immediately due to the weakening of the cutting capacity. The steel wire will gradually accumulate a downward force, and the unreleased downward force will produce a left and right displacement, causing the steel wire to swing in the main roller groove, and finally form an ups and downs performance on the surface of the silicon wafer, causing the problem of TTV exceeding the standard. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The utility model is further described below in conjunction with the accompanying drawings and embodiments:
[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0018] Figure 2 This is a schematic diagram of the casing structure of the utility model.
[0019] In the figure: cutting roller seat 1, cutting roller 2, threaded section 201, sleeve 3, column 4, sleeve positioning tube 5, internal thread 501, spring 6, cutting line 7. DETAILED DESCRIPTION
[0020] like Figure 1-2 A polycrystalline silicon wafer fine wire cutting structure includes a cutting roller seat 1, on which two horizontal and parallel cutting rollers 2 are arranged, on which a sleeve 3 is sleeved, on which a column 4 is arranged, and a cutting wire 7 is wound around the two sleeves 3 and passed through the column 4;
[0021] An acute angle is formed between the cutting line 7 and the center axis of the cutting roller 2 in the cutting area formed above the cutting line 7 .
[0022] In the preferred embodiment, one end of the cutting roller 2 is fixed on the cutting roller seat 1, and a threaded section 201 is provided on the portion close to the other end. A sleeve positioning tube 5 is sleeved on the threaded section 201, and an internal thread 501 matching the threaded section 201 is provided on the inner wall of the sleeve positioning tube 5.
[0023] In a preferred solution, a spring 6 is provided on one end of the sleeve 3 close to the cutting roller seat 1 , and the spring 6 is sleeved on the cutting roller 2 .
[0024] In a preferred solution, the columns 4 on a single sleeve 3 include two groups, upper and lower. The two groups of columns 4 are respectively fixedly arranged on the upper and lower sides of the sleeve 3 and are vertical.
[0025] In a preferred solution, a single group of columns 4 includes a plurality of column groups for fixing the cutting line 7 , and the column group includes two columns 4 , and the cutting line 7 is arranged to pass through between the two columns 4 .
[0026] In this novel invention, the specific related processes used are as follows:
[0027] (1) Slot distance control
[0028] To ensure the accuracy of the sheet thickness, this application still follows the calculation rule of wire diameter + 190um = main roller groove pitch, and the main roller diameter of diamond wire 53um + 190um = 243um, ensuring that the sheet thickness is within the normal range.
[0029] (2) Reverse cutting process is used at the end of the cutting process
[0030] The steel wire used for silicon wafer cutting has undergone several large-scale changes, and the silicon wafer cutting process has also been upgraded accordingly. The diamond wire era is different from the single-direction feeding of the mortar wire era. Due to its increased cutting capacity, the diamond wire uses a bidirectional cutting mode to save costs. The normal process in the early stage was that the forward amount was greater than the return amount to achieve overall steel wire feeding. This also caused some steel wires to not participate in subsequent cutting after a small amount of cutting, and did not perform to their maximum potential.
[0031] In order to ensure the single-blade wire consumption and enhance the cutting capacity at the same time, the new reverse cutting process with the forward amount less than the return amount is used at the end of the process, which increases the number of times the steel wire that was used less frequently in the early stage and still has cutting capacity is used, so that the cutting can be carried out normally while ensuring the single-blade wire consumption.
[0032] (3) Adjust the wire mesh to a diagonal mesh when cutting to increase the stability of the wire mesh
[0033] As the diamond wire becomes thinner, the diamond grains accumulated per unit area of the wire decrease and its cutting ability becomes weaker accordingly. As the silicon block is fed, the steel wire cannot complete the cutting immediately due to its weakened cutting ability. The steel wire will gradually accumulate a downward force. The unreleased downward force will produce a left and right displacement, causing the steel wire to swing in the main roller groove, which will form up and down fluctuations on the surface of the silicon wafer, causing TTV to exceed the standard, failing to meet the quality requirements of the silicon wafer and seriously affecting the cutting quality.
[0034] To increase the stability of the wire mesh during cutting, change the normal vertical state of the wire mesh from vertical to inclined (such as Figure 1 As shown in the figure, an artificial force is added to make the steel wire more stable during the descent of the silicon wafer, which effectively solves the problem of TTV exceeding the standard on the surface of the silicon wafer and keeps the cutting quality under control.
[0035] In addition, in this solution, the position of the sleeve positioning tube 5 can be manually adjusted in conjunction with the provided spring 6 to achieve the tilting amplitude of the wire mesh to meet the requirements of different slice thicknesses.
Claims
1. A polycrystalline silicon wafer fine-wire cutting structure, comprising a cutting roller seat (1), characterized in that: The cutting roller seat (1) is provided with two horizontal and parallel cutting rollers (2), the cutting rollers (2) are sleeved with a sleeve (3), the sleeve (3) is provided with a column (4), and the cutting wire (7) is wound around the two sleeves (3) and passed through the column (4); An acute angle is formed between the cutting line (7) in the cutting area formed above the cutting line (7) and the center axis of the cutting roller (2).
2. A polycrystalline silicon wafer fine-wire cutting structure according to claim 1, characterized in that: One end of the cutting roller (2) is fixed on the cutting roller seat (1), and a threaded section (201) is provided on a portion close to the other end. A sleeve positioning tube (5) is sleeved on the threaded section (201), and an internal thread (501) matching the threaded section (201) is provided on the inner wall of the sleeve positioning tube (5).
3. The polycrystalline silicon wafer fine-wire cutting structure according to claim 2, characterized in that: A spring (6) is provided on one end of the sleeve (3) close to the cutting roller seat (1), and the spring (6) is sleeved on the cutting roller (2).
4. The polycrystalline silicon wafer fine-wire cutting structure according to claim 1, characterized in that: The upright posts (4) on the single sleeve (3) include two groups, upper and lower. The two groups of upright posts (4) are respectively fixedly arranged on the upper and lower sides of the sleeve (3) and are vertically arranged.
5. The polycrystalline silicon wafer fine-wire cutting structure according to claim 4, characterized in that: The single set of upright posts (4) comprises a plurality of upright post groups for fixing the cutting line (7), the upright post group comprising two upright posts (4), and the cutting line (7) is arranged to pass through between the two upright posts (4).