Silicon rod, photovoltaic cell and photovoltaic module

Abstract

The utility model discloses a silicon rod, a photovoltaic cell and a photovoltaic assembly, the silicon rod comprises a plurality of sub-silicon rods, the plurality of sub-silicon rods are arranged along the thickness direction of the sub-silicon rods, the surface of the sub-silicon rod along the length direction is a first surface, the surface of the sub-silicon rod along the width direction is a second surface, the first surface is a first surface, and the second surface is a second surface. The first surface is in the shape of a parallelogram, the included angle alpha between the second surface and the vertical plane is larger than or equal to 1 degree and smaller than or equal to 6 degrees; and the at least one bonding layer is arranged between the two adjacent sub silicon rods. According to the silicon rod, in the silicon rod cutting process, the silicon rod can be located in the middle of the cutting wire net, stress on the silicon rod can be more uniform, abnormal phenomena in the cutting process can be reduced, the machining time is shortened, the manufacturing process loss is low, and the cutting yield is high.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cell wafers, in particular to a silicon rod, a photovoltaic cell wafer and a photovoltaic module. Background Art

[0002] In the related art, in the use scenario of reusing the edge skin of a single crystal silicon rod, the obtained silicon blocks are mostly in the half-piece specification with a narrow width and a short length. However, when the silicon blocks in the half-piece specification are cut vertically in two rows, the space utilization rate of the diamond wire cutting machine is the highest. However, when cutting vertically in two rows, there are many and dense seams in the silicon blocks, and a wire dividing net is also required for cutting. Not only is the wiring operation complex and time-consuming, seriously affecting the production efficiency, but also when cutting two rows of spliced silicon blocks with a wire dividing net, since the seams cannot be completely aligned, the maximum value of the thicknesses on both sides must be selected on the thick slice left by the wire dividing net, resulting in additional silicon wafer loss and a significant reduction in output and wafer yield. Summary of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. For this reason, an object of the utility model is to provide a silicon rod, during the cutting process of which the silicon rod can be located in the middle of the cutting wire net, so that the force on the silicon rod is more uniform, which is beneficial to reducing abnormal phenomena during the cutting process, shortening the processing time, and having low process loss and high cutting yield.

[0004] Another object of the utility model is to provide a photovoltaic cell wafer prepared from the above-mentioned silicon rod.

[0005] An object of the utility model is to provide a photovoltaic module including the above-mentioned photovoltaic cell wafer.

[0006] The silicon rod according to the first aspect embodiment of the utility model includes: a plurality of sub-silicon rods arranged along the thickness direction of the sub-silicon rods. The surface in the length direction of each sub-silicon rod is a first surface, and the surface in the width direction of each sub-silicon rod is a second surface. The shape of the first surface is a parallelogram, and the included angle between the second surface and the vertical plane is ɑ, where ɑ satisfies: 1° ≤ ɑ ≤ 6°; at least one bonding layer provided between two adjacent sub-silicon rods.

[0007] For the silicon rod according to the embodiment of the utility model, by making the shape of the first surface in the length direction of each sub-silicon rod be a parallelogram, the included angle ɑ between the second surface in the width direction of each sub-silicon rod and the vertical plane satisfies 1° ≤ ɑ ≤ 6°. Thus, during the cutting process of the silicon rod, the silicon rod can be located in the middle of the cutting wire net, so that the force on the silicon rod is more uniform, which is beneficial to reducing abnormal phenomena during the cutting process, shortening the processing time, and having low process loss and high cutting yield.

[0008] According to some embodiments of the present utility model, α further satisfies: 1° ≤ α ≤ 2°.

[0009] According to some embodiments of the present utility model, the maximum distance between the second surface and the vertical plane is L, where L satisfies: 0.8 mm ≤ L ≤ 1.2 mm.

[0010] According to some embodiments of the present utility model, the thickness of the adhesive layer in the thickness direction of the sub-silicon rod is D, where D satisfies: 0 μm < D ≤ 300 μm.

[0011] According to some embodiments of the present utility model, D further satisfies: 50 μm ≤ D ≤ 150 μm.

[0012] According to some embodiments of the present utility model, the viscosity of the adhesive layer is β, and the bonding strength of the adhesive layer is P, where β and P respectively satisfy: β ≤ 10 Pa·s, P ≥ 10 MPa.

[0013] According to some embodiments of the present utility model, the adhesive layer is an epoxy resin layer.

[0014] According to some embodiments of the present utility model, the number of the sub-silicon rods is N, where N satisfies: 2 ≤ N ≤ 20.

[0015] According to the photovoltaic cell of the second aspect embodiment of the present utility model, the photovoltaic cell is prepared from the silicon rod according to the first aspect embodiment of the present utility model above.

[0016] According to the photovoltaic module of the third aspect embodiment of the present utility model, it includes the photovoltaic cell according to the second aspect embodiment of the present utility model above.

[0017] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0019] Figure 1 is a schematic diagram of a silicon rod according to an embodiment of the present utility model;

[0020] Figure 2 is a sectional view of a sub-silicon rod of a silicon rod according to an embodiment of the present utility model;

[0021] Figure 3 is a schematic diagram of a silicon rod and a tooling part according to an embodiment of the present utility model;

[0022] Figure 4 is a schematic view of a silicon rod and a cutting device according to an embodiment of the present utility model;

[0023] Figure 5 is a sectional view of the silicon rod according to an embodiment of the present utility model.

[0024] Reference numerals:

[0025] 100: silicon rod;

[0026] 10: sub-silicon rod; 101: first surface; 102: second surface; 20: bonding layer;

[0027] 200: tooling part; 300: cutting equipment; 301: cutting wire. Detailed implementation manners

[0028] Next, refer to Figures 1 - 5 to describe the silicon rod 100 according to the first aspect embodiment of the present utility model.

[0029] As Figures 1 - 5 shown, the silicon rod 100 according to the first aspect embodiment of the present utility model includes: a plurality of sub-silicon rods 10 and at least one bonding layer 20. In the description of the present utility model, "a plurality of" means two or more.

[0030] Specifically, the plurality of sub-silicon rods 10 are arranged along the thickness direction of the sub-silicon rod 10 (for example, Figure 1 the up-and-down direction in Figure 1 ), the surface in the length direction of each sub-silicon rod 10 (for example, Figure 1 the front-and-back direction in

[0031] For example, in the example of Figures 1 - 2 , the silicon rod 100 may include nine sub-silicon rods 10. The nine sub-silicon rods 10 are arranged along the thickness direction of the sub-silicon rod 10, and adjacent two sub-silicon rods 10 are connected by the bonding layer 20. The shape of each sub-silicon rod 10 is a parallelepiped. At this time, the shape of the first surface 101 of each sub-silicon rod 10 is a parallelogram, and the shape of the second surface 102 of each sub-silicon rod 10 is a rectangle.

[0032] Specifically, the sub-silicon rod 10 can be processed from the edge waste of the 210-size square silicon rod, and the size of the sub-silicon rod 10 can be 182.2 mm × 95.8 mm × 33 mm. Then, the adhesive layer 20 is coated on one side of the processed sub-silicon rod 10 in the thickness direction, and then the first surfaces 101 of all the sub-silicon rods 10 are aligned. After the adhesive layer 20 is cured, the silicon rod 100 is formed.

[0033] Figure 1 Nine sub-silicon rods 10 are shown for illustrative purposes, but those of ordinary skill in the art can clearly understand that after reading the technical solution of this application, applying this solution to technical solutions with other numbers of sub-silicon rods 10 also falls within the protection scope of the present utility model.

[0034] As Figures 3 - 5 shown, when processing photovoltaic cells, two silicon rods 100 can be vertically arranged with a gap of about 1 mm between the two silicon rods 100, and the two silicon rods 100 are aligned at the ends. Then, the inclined surfaces of the silicon rods 100 (i.e., the second surfaces 102 of the sub-silicon rods 10) are aligned with the long-edge end faces of the tooling part 200 and the resin plate to obtain a silicon rod sample. Finally, the silicon rod sample is placed on the cutting line 301 of the cutting device. At this time, the angle between the inclined surface of the silicon rod 100 and the cutting line 301 is ɑ, and the silicon rod 100 is roughly in the middle of the cutting line 301 net. When cutting the silicon rod 100, some of the sub-silicon rods 10 at the adhesive layer 20 after cutting, one of the two obtained silicon rods 100 has a penetrating adhesive layer 20. As the cutting position changes, the above-mentioned penetrating adhesive layer 20 also changes (as Figure 5 shown), there is a cutting mode of full silicon wafer - presence of adhesive layer 20 - full silicon wafer, which makes there be no any abnormality during the cutting process of the silicon rod 100.

[0035] As Figure 2 shown, the angle between the second surface 102 and the vertical plane is ɑ, where ɑ satisfies: 1° ≤ ɑ ≤ 6°. When ɑ < 1°, first, the angle between the second surface 102 and the vertical plane is too small, which is not convenient for processing; second, it will cause the angle between the adhesive layer 20 of the silicon rod 100 and the cutting line 301 to be too small, and multiple high lines will appear at the adhesive layer 20 during the cutting process, resulting in an increase in the breakage rate of the cutting line 301, and thus a decrease in the cutting yield. When ɑ > 6°, due to the too large angle between the adhesive layer 20 of the silicon rod 100 and the cutting line 301, the breakage rate of the cutting line 301 will also increase, and the cutting yield and process loss (i.e., the part of the silicon rod 100 that cannot be processed into a photovoltaic cell) are not advantageous. Therefore, by making the angle ɑ between the second surface 102 and the vertical plane satisfy 1° ≤ ɑ ≤ 6°, while ensuring that there is no any abnormality during the cutting process and the breakage rate of the cutting line 301 is at a normal level, the cutting yield and process loss have certain advantages.

[0036] For the silicon rod 100 according to the embodiments of the present utility model, by making the shape of the first surface 101 in the length direction of each sub-silicon rod 10 be a parallelogram, the angle ɑ between the second surface 102 in the width direction of each sub-silicon rod 10 and the vertical plane satisfies 1° ≤ ɑ ≤ 6°. Thus, during the cutting process of the silicon rod 100, the silicon rod 100 can be in the middle of the cutting wire mesh, enabling the silicon rod 100 to be more evenly stressed, facilitating the reduction of abnormal phenomena during the cutting process, shortening the processing time, and having low process loss and high cutting yield.

[0037] According to some embodiments of the present utility model, ɑ further satisfies: 1° ≤ ɑ ≤ 2°. With such a setting, the angle ɑ between the second surface 102 and the vertical plane is made more reasonable. While ensuring no abnormalities during the cutting process and the wire breakage rate of the cutting wire 301 being at a normal level, the cutting yield can be further improved and the process loss can be further reduced.

[0038] According to some embodiments of the present utility model, the maximum distance between the second surface 102 and the vertical plane is L, where L satisfies: 0.8 mm ≤ L ≤ 1.2 mm. When L < 0.8 mm, the maximum distance between the second surface 102 and the vertical plane is relatively small, and it is impossible to ensure that the angle ɑ between the second surface 102 and the vertical plane is between 1° and 6°; when L > 1.2 mm, the maximum distance between the second surface 102 and the vertical plane is relatively large. To ensure that the angle ɑ between the second surface 102 and the vertical plane is between 1° and 6°, too much edge waste of the square silicon rod will be cut to obtain the silicon rod 100, resulting in an increase in loss. Thus, by making the maximum distance L between the second surface 102 and the vertical plane satisfy 0.8 mm ≤ L ≤ 1.2 mm, the loss of the edge waste of the square silicon rod can be greatly reduced, and at the same time, it can be ensured that the angle ɑ between the second surface 102 and the vertical plane is between 1° and 6°, which is beneficial for subsequent cutting of the silicon rod 100.

[0039] According to some embodiments of the present utility model, in the thickness direction of the sub-silicon rod 10 (for example, Figure 1 the up-and-down direction in

[0040] Further, D further satisfies: 50μm ≤ D ≤ 150μm. When D < 50μm, the thickness of the adhesive layer 20 is relatively thin, and the adhesiveness of the adhesive layer 20 is poor, which will reduce the connection reliability between two adjacent sub-silicon rods 10, resulting in the separation of the sub-silicon rods 10 during the cutting process; when D > 150μm, the thickness of the adhesive layer 20 is relatively thick, and the cutting wire 301 will cut the same adhesive layer 20 multiple times during the cutting process, which will increase the loss of the cutting wire 301, and then cause the cutting wire 301 to break, increasing the breakage rate of the cutting wire 301. Therefore, by making the thickness of the adhesive layer 20 be D and satisfy 50μm ≤ D ≤ 150μm, while ensuring the connection reliability between two adjacent sub-silicon rods 10, the loss of the cutting wire 301 can be further reduced, and then the breakage rate of the cutting wire 301 can be further reduced.

[0041] The comparison of the specific processing data of the silicon rod 100 according to the embodiment of the present invention is as follows:

[0042] Example 1

[0043] Referring to Table 1, the angle between the second surface 102 of the silicon rod 100 and the vertical plane is controlled at 0.5°, the maximum distance between the second surface 102 and the vertical plane is controlled at 0.3mm, and the thickness of the adhesive layer 20 is controlled within 300 microns. At this time, the angle between the adhesive layer 20 and the cutting wire 301 is too small. During the cutting process, multiple high wires will appear at the seam (i.e., the adhesive layer 20), resulting in a sharp increase in the breakage rate (roughly 25.3%), and the cutting yield also drops sharply.

[0044] Example 2

[0045] Referring to Table 1, the angle between the second surface 102 of the silicon rod 100 and the vertical plane is controlled at 2°, the maximum distance between the second surface 102 and the vertical plane is controlled at 1.2mm, the angle between the adhesive layer 20 and the cutting wire 301 is moderate, and the thickness of the adhesive layer 20 is controlled within 150 microns. During the cutting process, there is no abnormality at the seam, and the breakage rate is also at a normal level (roughly 10.5%), and the cutting yield and the process loss have certain advantages.

[0046] Example 3

[0047] The angle between the second surface 102 of the silicon rod 100 and the vertical plane is controlled at 5°, the maximum distance between the second surface 102 and the vertical plane is controlled at 3mm, the angle between the adhesive layer 20 and the cutting wire 301 is too large, and the thickness of the adhesive layer 20 is controlled within 150 microns. During the cutting process, there is no abnormality at the seam, and the breakage rate has increased (roughly 15.2%), and the cutting yield and the process loss do not have advantages.

[0048] Table 1

[0049]

[0050] According to some embodiments of the present utility model, the viscosity of the adhesive layer 20 is β, and the adhesive strength of the adhesive layer 20 is P, where β and P respectively satisfy: β ≤ 10 Pa·s, P ≥ 10 MPa. With such a setting, the viscosity and adhesive strength of the adhesive layer 20 are made more reasonable. While ensuring reliable connection between two adjacent sub-silicon rods 10, it is beneficial for the cutting wire 301 to smoothly cut the adhesive layer 20, and to avoid breakage of the cutting wire 301 when cutting the adhesive layer 20.

[0051] In some alternative embodiments, the adhesive layer 20 is an epoxy resin layer. Among them, the epoxy resin layer refers to an adhesive made mainly of epoxy resin. Since epoxy resin contains multiple polar groups and epoxy groups with relatively high activity, epoxy resin has a strong adhesive force with various polar materials such as metals, glasses, and cements, especially materials with relatively high surface activity. Moreover, when epoxy resin cures, basically no low-molecular volatile substances are generated, and the safety is relatively high.

[0052] According to some embodiments of the present utility model, the number of sub-silicon rods 10 is N, where N satisfies: 2 ≤ N ≤ 20, and preferably, 10 ≤ N ≤ 15. With such a setting, it is ensured that the silicon rod 100 can be placed on the cutting wire mesh of the adhesive layer 20, and interference between the silicon rod 100 and other components of the adhesive layer 20 is avoided.

[0053] According to the photovoltaic cell (not shown in the figure) of the second aspect embodiment of the present utility model, the photovoltaic cell is prepared from the silicon rod 100 according to the first aspect embodiment of the present utility model described above.

[0054] According to the photovoltaic cell of the embodiment of the present utility model, by using the above-mentioned silicon rod 100 for preparation, the production efficiency of the photovoltaic cell can be improved, and the production cost of the photovoltaic cell can be reduced.

[0055] According to the photovoltaic module (not shown in the figure) of the third aspect embodiment of the present utility model, it includes the photovoltaic cell according to the second aspect embodiment of the present utility model described above.

[0056] According to the photovoltaic module of the embodiment of the present utility model, by using the above-mentioned photovoltaic cell, the production efficiency of the photovoltaic module can be improved, the production cost of the photovoltaic module can be reduced, and thus the market competitiveness of the photovoltaic module can be improved.

[0057] The other constitutions and operations of the photovoltaic module according to the embodiment of the present utility model are known to those of ordinary skill in the art and will not be described in detail here.

[0058] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0059] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0060] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0061] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present utility model. The scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A silicon rod, characterized in that, Comprising: A plurality of sub-silicon rods, the plurality of sub-silicon rods are arranged along the thickness direction of the sub-silicon rods. The surface in the length direction of each sub-silicon rod is the first surface, and the surface in the width direction of each sub-silicon rod is the second surface. The shape of the first surface is a parallelogram, and the angle between the second surface and the vertical plane is ɑ, where ɑ satisfies: 1° ≤ ɑ ≤ 6°; At least one bonding layer, the bonding layer is arranged between two adjacent sub-silicon rods.

2. The silicon rod according to claim 1, wherein, ɑ further satisfies: 1° ≤ ɑ ≤ 2°.

3. The silicon rod according to claim 1, characterized in that, The maximum distance between the second surface and the vertical plane is L, where L satisfies: 0.8 mm ≤ L ≤ 1.2 mm.

4. The silicon rod according to claim 1, characterized in that, In the thickness direction of the sub-silicon rod, the thickness of the bonding layer is D, where D satisfies: 0 μm < D ≤ 300 μm.

5. The silicon rod according to claim 4, characterized in that, D further satisfies: 50 μm ≤ D ≤ 150 μm.

6. The silicon rod according to claim 1, characterized in that, The viscosity of the bonding layer is β, and the bonding strength of the bonding layer is P, where β and P respectively satisfy: β ≤ 10 Pa·s, P ≥ 10 MPa.

7. The silicon rod according to any one of claims 1-6, characterized in that, The bonding layer is an epoxy resin layer.

8. The silicon rod according to any one of claims 1-6, characterized in that, The number of the sub-silicon rods is N, where N satisfies: 2 ≤ N ≤ 20.

9. A photovoltaic cell, characterized in that, The photovoltaic cell is prepared from the silicon rod according to any one of claims 1-8.

10. A photovoltaic module, characterized in that, Comprising the photovoltaic cell according to claim 9.

Images