Back contact cell assembly manufacturing method and back contact cell assembly

Abstract

This invention provides a method for manufacturing a back-contact solar cell module and a back-contact solar cell module, relating to the field of photovoltaic module technology. The method includes the following steps: along a first direction, interconnecting solder strips located at both ends of the solar cell are edge solder strips, and interconnecting solder strips located between the edge solder strips are intermediate solder strips; a laser is used to break the interconnecting solder strips between adjacent solar cells; the laser power used to break the edge solder strips is higher than the laser power used to break the intermediate solder strips, so that the length of the edge solder strips protruding from the solar cell is less than the length of the intermediate solder strips protruding from the solar cell. When using a laser to break the interconnecting solder strips between adjacent solar cells, the laser power used to break the edge solder strips is higher than the laser power used to break the intermediate solder strips, so that the length of the edge solder strips protruding from the solar cell is less than the length of the intermediate solder strips protruding from the solar cell. After the edge solder strips deflect, they are less likely to encounter other edge solder strips and opposite polarity grid lines, thus preventing edge solder strips from shifting and breaking.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module technology, and in particular to a method for manufacturing a back-contact battery module and a back-contact battery module. Background Technology

[0002] Back-contact solar cells completely eliminate the light-shielding loss of the front metal grid lines by placing all P-type and N-type electrodes on the back surface of the cell, which can effectively improve the photoelectric conversion efficiency of the cell.

[0003] In existing technologies, a common approach is to first wrap the solder strips around the edge and then cut them. However, due to the short distance between the edge solder strips of adjacent solar cells, such as... Figure 1 As shown, the edge solder strips 2' of adjacent cells 1' are prone to bending and overlapping, leading to short circuits and causing photovoltaic module failure. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing a back-contact battery assembly, so as to solve the technical problem in the prior art that the edge solder strips of the battery cells are prone to bending and overlapping, leading to short circuits.

[0005] The method for manufacturing a back contact battery assembly provided by this invention includes the following steps: Along the first direction, the interconnecting solder strips located at both ends of the battery cell are called edge solder strips, and the interconnecting solder strips located between the edge solder strips are called intermediate solder strips; Lasers are used to break the interconnecting solder strips between adjacent solar cells; The laser power used to break the edge solder strip is higher than that used to break the middle solder strip, so that the length of the edge solder strip protruding from the cell is less than that of the middle solder strip.

[0006] Furthermore, the laser power for breaking the middle welding strip is A, and the laser power for breaking the edge welding strip is B, where 1.2A≤B≤1.4A.

[0007] Furthermore, the laser spot size for breaking the middle solder strip is the same as the laser spot size for breaking the edge solder strip.

[0008] Furthermore, the length of the edge weld strip protruding from the cell is C, and the length of the middle weld strip protruding from the cell is D, where 0.5D≤C≤0.7D.

[0009] Furthermore, along the first direction, the distance between the end of the broken edge solder strip and the adjacent opposite polarity gate line is ≥0.1mm.

[0010] Furthermore, the interconnecting solder strip is a circular solder strip.

[0011] Furthermore, the diameter of the interconnecting solder strip is 0.15mm-0.25mm.

[0012] Furthermore, the interconnecting solder strip is a tin-plated copper solder strip.

[0013] Furthermore, it also includes the following steps: identifying the edge and middle solder strips of the battery cell using a visual positioning device.

[0014] Another objective of this invention is to provide a back-contact battery assembly, which is manufactured by the back-contact battery assembly manufacturing method provided by this invention.

[0015] The present invention provides a method for manufacturing a back-contact solar cell module, comprising the following steps: along a first direction, the interconnecting ribbons located at both ends of the solar cell are edge ribbons, and the interconnecting ribbons located between the edge ribbons are intermediate ribbons; using a laser to break the interconnecting ribbons between adjacent solar cells; the laser power for breaking the edge ribbons is higher than the laser power for breaking the intermediate ribbons, so that the length of the edge ribbons protruding from the solar cell is less than the length of the intermediate ribbons protruding from the solar cell. When using a laser to break the interconnecting ribbons between adjacent solar cells, the laser power for breaking the edge ribbons is higher than the laser power for breaking the intermediate ribbons, so that the length of the edge ribbons protruding from the solar cell is less than the length of the intermediate ribbons protruding from the solar cell. Because the length of the edge ribbons protruding from the solar cell is relatively small, after deflection, the edge ribbons are less likely to encounter other edge ribbons and opposite-polarity grid lines, thus preventing edge ribbon offset and open circuit, and consequently preventing photovoltaic module failure. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a back-contact battery assembly in the prior art; Figure 2 This is a schematic diagram of the structure of the back contact battery assembly provided in an embodiment of the present invention.

[0018] Icons: 1-Battery cell; 11-Beveled structure; 12-Connection point; 2-Edge solder strip; 3-Middle solder strip; 1'-Battery cell; 2'-Edge solder strip. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides a method for manufacturing a back contact battery module and a back contact battery module. Several embodiments are given below to describe in detail the method for manufacturing a back contact battery module and the back contact battery module provided by this invention.

[0021] The back contact battery assembly manufacturing method provided in this embodiment, such as Figure 2 As shown, it includes the following steps: Along the first direction, the interconnecting solder strips located at both ends of the battery cell 1 are edge solder strips 2, and the interconnecting solder strips located between the edge solder strips 2 are intermediate solder strips 3; The interconnecting solder strips between adjacent solar cells 1 are broken using a laser; The laser power used to break the edge solder strip 2 is higher than the laser power used to break the middle solder strip 3, so that the length of the edge solder strip 2 protruding from the cell 1 is less than the length of the middle solder strip 3 protruding from the cell 1.

[0022] Along the extension direction of the interconnecting ribbon, the interconnecting ribbon is connected to two spaced-apart battery cells 1; along the first direction, multiple interconnecting ribbons are spaced apart on the back of each battery cell 1, the interconnecting ribbons at both ends of the battery cell 1 are edge ribbons 2, and the interconnecting ribbons between two edge ribbons 2 are middle ribbons 3.

[0023] When using a laser to break the interconnecting strips between adjacent solar cells 1, the laser power used to break the edge strip 2 is higher than that used to break the middle strip 3, so that the length of the edge strip 2 protruding from the solar cell 1 is less than the length of the middle strip 3 protruding from the solar cell 1. Because the length of the edge strip 2 protruding from the solar cell 1 is relatively small, after the edge strip 2 deflects, it is less likely to collide with other edge strips 2 and opposite polarity grid lines, which can prevent the edge strip 2 from shifting and breaking the circuit, thereby preventing photovoltaic module failure.

[0024] The interconnect solder strips extend in a direction perpendicular to the first direction. The extension direction of the interconnect solder strips is as follows: Figure 2 The direction indicated by the middle arrow ab, the first direction is as follows: Figure 2 The direction indicated by the middle arrow cd. The back contact battery assembly includes multiple battery cells 1, which are spaced apart along a first direction and along the extension direction of the edge solder strip 2.

[0025] The back contact battery module manufacturing method provided in this embodiment only requires adjusting the partition power parameters of the laser system. It does not require adding materials and processes such as insulating adhesive and pre-cut welding strips, nor does it require modifying the main production line equipment structure. It can be directly adapted to existing back contact battery module string welding production lines. The process has low implementation cost, strong adaptability, high mass production compatibility, and significant cost reduction.

[0026] In addition, the length of the edge solder strip 2 protruding from the cell 1 is less than the length of the middle solder strip 3 protruding from the cell 1, which can improve the reliability of the edge solder strip 2 welding, thereby improving the production yield and long-term operational stability of the back contact cell module.

[0027] It should be noted that the corner of the solar cell 1 is provided with a chamfered structure 11, and the edge weld strip 2 extends through the edge of the chamfered structure 11 along the extension direction of the edge weld strip 2. The distance between the chamfered structures 11 between two adjacent solar cells 1 is relatively large. The relatively large spacing provides manufacturing space for the edge weld strip 2 to be broken by a larger laser power, preventing the laser from damaging the solar cell 1.

[0028] Furthermore, the laser power for breaking the middle welding strip 3 is A, and the laser power for breaking the edge welding strip 2 is B, where 1.2A≤B≤1.4A.

[0029] Where B can be any suitable value such as 1.2A, 1.3A or 1.4A.

[0030] The value of 1.2A≤B≤1.4A ensures that the length of the edge solder strip 2 protruding from the cell 1 is kept at a suitable value. After the edge solder strip 2 deflects, it is not easy to come into contact with other edge solder strips 2 and opposite polarity grid lines. This can prevent the edge solder strip 2 from deflecting and breaking the circuit, thereby preventing the photovoltaic module from failing and preventing the laser from damaging the cell 1.

[0031] Furthermore, the laser spot size for breaking the middle solder strip 3 is the same as the laser spot size for breaking the edge solder strip 2.

[0032] The laser spot size for breaking the middle weld strip 3 is the same as the laser spot size for breaking the edge weld strip 2. When breaking the middle weld strip 3 and the edge weld strip 2, it is not necessary to change the laser spot size, which can reduce the difficulty of adjustment and the laser breaking quality is better.

[0033] Furthermore, the length of the edge welding strip 2 protruding from the battery cell 1 is C, and the length of the middle welding strip 3 protruding from the battery cell 1 is D, where 0.5D≤C≤0.7D.

[0034] Where D can be any suitable value such as 0.5D, 0.6D, or 0.7D.

[0035] With a value of 0.5D≤C≤0.7D, the length of the edge solder strip 2 protruding from the cell 1 can be kept at a suitable value. After the edge solder strip 2 deflects, it is not easy to come into contact with other edge solder strips 2 and opposite polarity grid lines. This can prevent the edge solder strip 2 from deflecting and breaking the circuit, thereby preventing photovoltaic module failure and preventing laser damage to the cell 1.

[0036] Furthermore, along the first direction, the distance between the end of the broken edge solder strip 2 and the adjacent opposite polarity grid line is ≥0.1mm.

[0037] When the end of the edge solder strip 2 deflects toward the inside of the cell 1 it belongs to, since the distance between the end of the broken edge solder strip 2 and its adjacent opposite polarity grid line is ≥0.1mm along the first direction, it can prevent the broken edge solder strip 2 from hitting its adjacent opposite polarity grid line, and can prevent the edge solder strip 2 from deflecting and breaking the circuit, thereby preventing the photovoltaic module from failing.

[0038] Furthermore, the interconnecting solder strips are circular.

[0039] Circular solder ribbon is a photovoltaic interconnect material with a cylindrical cross-section, compared to rectangular flat solder ribbon.

[0040] Furthermore, the circular solder strip deflects less under stress, making it less likely to come into contact with other edge solder strips 2 and opposite polarity grid lines, thus preventing edge solder strips 2 from shifting and breaking the circuit, thereby preventing photovoltaic module failure.

[0041] Furthermore, the diameter of the interconnecting solder strip is 0.15mm-0.25mm.

[0042] The diameter of the interconnecting solder strip can be any suitable value such as 0.15mm, 0.2mm or 0.25mm.

[0043] When the diameter of the interconnecting solder strip is 0.15mm-0.25mm, the output power of the interconnecting solder strip is better, the light-blocking area can be reduced, and the deflection after being subjected to force is smaller.

[0044] Furthermore, the interconnecting solder strip is a tin-plated copper solder strip, which has better conductivity.

[0045] Furthermore, the edge welding strip 2 and the battery cell 1 form a connection point 12; along the extension direction of the edge welding strip 2, the edge welding strip 2 outside the connection point 12 is the edge part, and the edge welding strip 2 inside the connection point 12 is the body part, and the bending angle of the edge part around the connection point 12 relative to the body part is ≤90°.

[0046] The edge welding strip 2 forms a connection point 12 with the battery cell 1. This connection point 12 can be a PAD point, and the connection point 12 is not located in the chamfered area.

[0047] Along the extension direction of the edge welding strip 2, the edge welding strip 2 with the connection point 12 facing the outer side of the battery cell 1 is the edge part, and the edge welding strip 2 with the connection point 12 facing the inner side of the battery cell 1 is the body part.

[0048] After receiving an external force, the edge can bend relative to the main body around the connection point 12. The angle between the edge and the main body after bending is the bending angle. When the bending angle is ≤90°, since the length of the edge solder strip 2 protruding from the cell 1 is relatively small, the edge solder strip 2 is less likely to come into contact with other edge solder strips 2 and opposite polarity grid lines after deflection. This can prevent the edge solder strip 2 from deflecting and breaking the circuit, thereby preventing the photovoltaic module from failing.

[0049] Furthermore, it also includes the following steps: identifying the edge solder strip 2 and the middle solder strip 3 of the battery cell 1 using a visual positioning device.

[0050] The edge solder strips 2 and the middle solder strips 3 of the battery cell 1 are identified by a visual positioning device. The laser power to break the interconnection solder strips is adjusted according to the type of interconnection solder strips identified by the visual positioning device. The operation is convenient and accurate.

[0051] The back contact battery assembly provided in this embodiment is obtained by the back contact battery assembly manufacturing method provided in this embodiment.

[0052] Specifically, the back contact battery assembly includes battery cells 1 and interconnecting ribbons. Along the extension direction of the interconnecting ribbons, the interconnecting ribbons connect two spaced-apart battery cells 1; along a first direction, multiple interconnecting ribbons are spaced apart on the back of each battery cell 1, with the interconnecting ribbons at both ends of the battery cell 1 being edge ribbons 2, and the interconnecting ribbons between two edge ribbons 2 being intermediate ribbons 3.

[0053] When using a laser to break the interconnecting strips between adjacent solar cells 1, the laser power used to break the edge strip 2 is higher than that used to break the middle strip 3, so that the length of the edge strip 2 protruding from the solar cell 1 is less than the length of the middle strip 3 protruding from the solar cell 1. Because the length of the edge strip 2 protruding from the solar cell 1 is relatively small, after the edge strip 2 deflects, it is less likely to collide with other edge strips 2 and opposite polarity grid lines, which can prevent the edge strip 2 from shifting and breaking the circuit, thereby preventing photovoltaic module failure.

[0054] The extension direction of the interconnecting solder strip is perpendicular to the first direction.

[0055] The back contact battery module provided in this embodiment only requires adjustment of the partition power parameters of the laser system. No additional materials or processes such as insulating adhesive or pre-cut welding strips are needed, and the main production line equipment structure does not need to be modified. It can be directly adapted to existing back contact battery module stringing production lines. The process has low implementation cost, strong adaptability, high mass production compatibility, and significant cost reduction.

[0056] In addition, the length of the edge solder strip 2 protruding from the cell 1 is less than the length of the middle solder strip 3 protruding from the cell 1, which can improve the reliability of the edge solder strip 2 welding, thereby improving the production yield and long-term operational stability of the back contact cell module.

[0057] It should be noted that the corner of the solar cell 1 is provided with a chamfered structure 11, and the edge weld strip 2 extends through the edge of the chamfered structure 11 along the extension direction of the edge weld strip 2. The distance between the chamfered structures 11 between two adjacent solar cells 1 is relatively large. The relatively large spacing provides manufacturing space for the edge weld strip 2 to be broken by a larger laser power, preventing the laser from damaging the solar cell 1.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a back-contact battery assembly, characterized in that, Includes the following steps: Along the first direction, the interconnecting solder strips located at both ends of the battery cell are called edge solder strips, and the interconnecting solder strips located between the edge solder strips are called intermediate solder strips; Lasers are used to break the interconnecting solder strips between adjacent solar cells; The laser power used to break the edge solder strip is higher than that used to break the middle solder strip, so that the length of the edge solder strip protruding from the cell is less than that of the middle solder strip.

2. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, The laser power for breaking the middle weld strip is A, and the laser power for breaking the edge weld strip is B, where 1.2A≤B≤1.4A.

3. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, The size of the laser spot that breaks the middle solder strip is the same as the size of the laser spot that breaks the edge solder strip.

4. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, The length of the edge weld strip protruding from the battery cell is C, and the length of the middle weld strip protruding from the battery cell is D, where 0.5D≤C≤0.7D.

5. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, Along the first direction, the distance between the end of the broken edge solder strip and the adjacent opposite polarity grid line is ≥0.1mm.

6. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, The interconnecting solder strip is a circular solder strip.

7. The method for manufacturing a back contact battery assembly according to claim 6, characterized in that, The diameter of the interconnecting solder strip is 0.15mm-0.25mm.

8. The method for manufacturing a back contact battery assembly according to claim 6, characterized in that, The interconnecting solder strip is a tin-plated copper solder strip.

9. The method for manufacturing a back contact battery assembly according to claim 1, characterized in that, It also includes the following steps: The edge and middle solder strips of the battery cells are identified using a visual positioning device.

10. A back-contact battery assembly, characterized in that, It is prepared by the back contact battery assembly manufacturing method according to any one of claims 1-9.

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