An insulating adhesive and cell for enhancing welding reliability of an ownerless back contact cell

Abstract

The utility model provides a kind of insulating glue and battery of reinforcing mainless grid back contact cell welding reliability, including insulating glue body, the insulating glue body is set on the fine grid line of mainless grid back contact cell, at least one recess is provided on the insulating glue body, the recess is used to and is connected with solder strip;The recess and the connecting place of the solder strip are shape matched;The inner recess bottom surface of the recess is uneven contact surface, the bottom surface of the solder strip is uneven contact surface, and two uneven contact surfaces are matched between them.The utility model is by setting recess on insulating glue, and the inner recess bottom surface of recess is uneven contact surface, increase the connection reliability of insulating glue surface and solder strip.

Description

Technical Field

[0001] This utility model belongs to the field of improvement of gridless back contact batteries, specifically relating to an insulating adhesive and battery that enhances the welding reliability of gridless back contact batteries. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] The gridless back-contact battery, which completely eliminates the grid on the basis of the back-contact battery, reduces light shading and resistance loss, and further optimizes cost and efficiency, has attracted widespread attention.

[0004] However, in the production process of gridless back-contact solar cells, the welding precision of the solder ribbon directly affects the cell's performance and reliability. Currently, solder ribbon welding mainly relies on manual or equipment positioning, but due to the lack of effective physical restraint structures, solder ribbon misalignment is prone to occur. Solder ribbon misalignment leads to increased contact resistance, increasing the risk of short circuits in the solar cells.

[0005] To address the issue of solder strip misalignment during welding, existing technologies typically employ printing insulating adhesive on the back of the battery for auxiliary positioning. However, traditional insulating adhesives are mostly planar in structure, failing to provide effective mechanical restraint for the solder strip, resulting in limited positioning effectiveness. Some technologies attempt to fix the solder strip by adding structures such as positioning grooves, but these solutions are not only cumbersome in process but also increase costs, presenting numerous difficulties in practical applications. Utility Model Content

[0006] To address the aforementioned problems, this invention proposes an insulating adhesive and battery that enhance the welding reliability of gridless back contact batteries. This invention increases the connection reliability between the insulating adhesive surface and the welding strip by setting grooves on the insulating adhesive, with the concave bottom surface of the grooves being a non-flat contact surface.

[0007] According to some embodiments, the present invention adopts the following technical solution:

[0008] An insulating adhesive for enhancing the welding reliability of gridless back contact batteries includes an insulating adhesive body disposed on the fine grid lines of the gridless back contact battery, and the insulating adhesive body having at least one groove for connecting with the solder strip.

[0009] The groove and the weld strip are shaped to match each other;

[0010] The concave bottom surface of the groove is a non-flat contact surface, the bottom surface of the welding strip is a non-flat contact surface, and the two non-flat contact surfaces match each other.

[0011] As an alternative implementation, grooves are provided on both sides of the insulating adhesive body.

[0012] As an alternative implementation, the grooves on the insulating adhesive body are obtained by laser etching.

[0013] As an alternative implementation, the width of the groove is greater than the width of the solder strip, and the difference between the two is within a set value.

[0014] As an alternative implementation, the depth of the groove is 80~120μm.

[0015] As an alternative implementation, the concave bottom surface of the groove is an inwardly concave arc shape, and the bottom surface of the welding strip is an outwardly convex arc shape, with the two arc shapes matching each other.

[0016] As an alternative implementation, the concave bottom surface of the groove is serrated, the bottom surface of the welding strip is serrated, and the two serrations mesh with each other.

[0017] As an alternative implementation, the concave bottom surface of the groove has a porous array structure, the bottom surface of the welding strip has a multi-column array structure, and the porous array structure and the multi-column array structure are interlocked with each other.

[0018] As an alternative implementation, the two concave sides of the groove are parallel to each other.

[0019] A gridless back contact battery includes multiple fine grid lines, at least a portion of which are provided with the aforementioned insulating adhesive. Only one of the adjacent fine grid lines is provided with the insulating adhesive body, while the other fine grid line is provided with solder paste. Solder strips are connected by solder paste, and the solder strips are embedded in the grooves of the insulating adhesive body and connected to the insulating adhesive body.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] This invention increases the reliability of the connection between the insulating adhesive surface and the solder ribbon by setting a groove on the insulating adhesive, with the concave bottom surface of the groove being a non-flat contact surface and the bottom surface of the solder ribbon being a non-flat contact surface, and the two non-flat contact surfaces matching each other. This helps to improve the stability of the solder ribbon and solves the problem of solder ribbon welding misalignment in the production process of gridless back contact solar cells, which can significantly improve the manufacturing quality and overall reliability of solar cells.

[0022] This invention not only enables the welding ribbon to be positioned more precisely on the battery cell, but also ensures the welding strength and stability of the welding ribbon through different shape designs. The corresponding groove and welding ribbon shape can be selected for different needs and scenarios, and it also helps to reduce the stress that may be generated during the welding process and avoid damage to the battery cell.

[0023] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0025] Figure 1 This is a diagram illustrating the arrangement of the insulating adhesive body on the back contact battery without a main grid in one embodiment.

[0026] Figure 2 This is a schematic diagram of the insulating adhesive body groove and the matching solder strip in the first embodiment;

[0027] Figure 3 This is a schematic diagram of the insulating adhesive body groove and the matching solder strip in the second embodiment;

[0028] Figure 4 This is a schematic diagram of the insulating adhesive body groove and the matching solder strip in the third embodiment.

[0029] Among them, 1. Insulating adhesive body, 2. Fine grid lines, 3. Pad points, 4. Concave bottom surface, and 5. Solder strip. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Where there is no conflict, the embodiments and features described in this application may be combined with each other.

[0034] Example 1

[0035] An insulating adhesive for enhancing the welding reliability of gridless back contact batteries includes an insulating adhesive body 1, which is disposed on the fine grid lines 2 of the gridless back contact battery. The insulating adhesive body 1 has at least one groove for connecting with a solder strip 5.

[0036] The groove and the weld strip 5 are shaped to match each other;

[0037] The concave bottom surface 4 of the groove is a non-flat contact surface, and the bottom surface of the welding strip 5 is a non-flat contact surface, and the two non-flat contact surfaces match each other.

[0038] In some embodiments, grooves are provided on both sides of the insulating adhesive body 1.

[0039] In this embodiment, the grooves on the insulating adhesive body 1 are obtained by laser etching.

[0040] In this embodiment, the width of the groove is within the set value of the width of the solder strip 5, that is, the width of the groove is slightly larger than the width of the solder strip 5, so that the solder strip 5 can be completely accommodated in the groove.

[0041] In this embodiment, the depth of the groove is 80~120μm.

[0042] In some embodiments, the concave bottom surface 4 of the groove is an inwardly concave arc shape, and the bottom surface of the welding strip 5 is an outwardly convex arc shape, with the two arc shapes matching each other, such as... Figure 2 As shown, the insulating adhesive groove can be U-shaped, and the rounded bottom design can reduce stress concentration. When paired with the U-shaped welding strip 5, it can improve conductivity and welding strength through wrap-around contact.

[0043] In some embodiments, the concave bottom surface 4 of the groove is serrated, and the bottom surface of the welding strip 5 is serrated, with the two serrated surfaces meshing with each other. Figure 3 As shown, the insulating adhesive groove can be a serrated groove. When combined with the toothed welding strip 5, it can prevent the welding strip 5 from slipping through mechanical interlocking, which is suitable for connections with high reliability requirements.

[0044] In some embodiments, the concave bottom surface 4 of the groove has a porous array structure, and the bottom surface of the welding strip 5 has a multi-column array structure. The porous array structure and the multi-column array structure are interlocked with each other, such as... Figure 4 As shown, the shape of the insulating adhesive groove can be a honeycomb groove. The honeycomb porous array structure can increase the contact area between the adhesive and the solder ribbon 5. When combined with the ultra-thin mesh solder ribbon 5, it can enhance heat dissipation and improve the adhesion through adhesive penetration, thereby increasing the stability of the solder ribbon 5.

[0045] Of course, in some embodiments, the shape of the concave bottom surface 4 of the groove can also be changed, such as changing it to a wavy shape or providing a small recess, as long as the shape of the concave bottom surface 4 of the groove is non-planar.

[0046] In the above embodiment, the two concave sides of the groove are parallel to each other to ensure that the welding strip 5 can be smoothly embedded into the groove.

[0047] The aforementioned design improves the reliability of solder ribbon welding by using groove structures of different shapes in combination with solder ribbons of different shapes. This structure not only optimizes the contact between the solder ribbon and the solar cell but also reduces the risk of performance degradation due to poor welding. The groove design allows for more precise positioning of the solder ribbon on the solar cell, and the different shapes ensure the welding strength and stability of the solder ribbon, allowing for the selection of appropriate groove and solder ribbon shapes for different application scenarios. Furthermore, this structural design helps reduce stress that may be generated during welding, preventing damage to the solar cell. This new design significantly improves the manufacturing quality and overall reliability of solar cells.

[0048] Example 2

[0049] A type of gridless back contact battery, such as Figure 1 As shown, it includes multiple fine grid lines 2, at least a portion of the fine grid lines 2 are provided with the above-mentioned insulating adhesive, and only one fine grid line 2 on an adjacent fine grid line 2 is provided with the insulating adhesive body, while the other fine grid line 2 is provided with solder paste. The solder paste connects to the solder ribbon 5, which is embedded in the groove of the insulating adhesive body and connected to the insulating adhesive body.

[0050] To ensure that those skilled in the art can clearly understand the solution of this utility model, a preparation method is provided, including the following steps:

[0051] S1: Surface cleaning, plasma cleaning of solar cells to remove contaminants from the electrode and silicon wafer surfaces, avoiding affecting the adhesion and insulation performance of the insulating adhesive.

[0052] S2: Groove stencil printing. Insulating adhesive in the shape of grooves is printed onto the cell grid lines using a perforated steel mesh. Alternatively, a laser-assisted molding method can be used: ordinary insulating adhesive is first printed and cured, then a UV laser is used to etch grooves and the shape of the groove bottom onto the adhesive. The groove printing width is slightly larger than the solder strip width, and the depth is 80~120μm.

[0053] S3: Curing and shaping, the insulating adhesive is UV cured and shaped while retaining a certain degree of stickiness.

[0054] S4: Print solder paste. Print solder paste on pad point 3, with the same height as the insulating adhesive.

[0055] S5: Embedding and pressing of the solder strip. The solder strip is precisely embedded into the groove of the insulating adhesive and then gently pressed to fix it.

[0056] S6: Final curing, thoroughly curing the insulating adhesive and locking the solder strip.

[0057] S7: Welding at pad point 3 to firmly connect the solder strip and pad point 3.

[0058] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made by those skilled in the art without creative effort within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An insulating adhesive for enhancing the welding reliability of gridless back contact batteries, characterized in that, The device includes an insulating adhesive body, which is disposed on the fine grid line of the battery without a main grid back contact. The insulating adhesive body has at least one groove for connecting with the solder strip. The groove and the weld strip are shaped to match each other; The concave bottom surface of the groove is a non-flat contact surface, the bottom surface of the welding strip is a non-flat contact surface, and the two non-flat contact surfaces match each other.

2. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, Grooves are provided on both sides of the insulating adhesive body.

3. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The grooves on the insulating adhesive body are obtained by laser etching.

4. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The width of the groove is greater than the width of the solder strip, and the difference between the two is within a set value.

5. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The depth of the groove is 80~120μm.

6. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The groove has an inwardly concave bottom surface, and the welding strip has an outwardly convex bottom surface, with the two arcs matching each other.

7. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The concave bottom surface of the groove is serrated, and the bottom surface of the welding strip is serrated, with the two serrated surfaces meshing with each other.

8. The insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The concave bottom surface of the groove has a porous array structure, and the bottom surface of the welding strip has a multi-column array structure, with the porous array structure and the multi-column array structure meshing with each other.

9. An insulating adhesive for enhancing the welding reliability of gridless back contact batteries as described in claim 1, characterized in that, The two concave sides of the groove are parallel to each other.

10. A gridless back contact battery, characterized in that, It includes multiple fine grid lines, at least a portion of the fine grid lines are provided with insulating adhesive as described in any one of claims 1-9, and only one fine grid line of an adjacent fine grid line is provided with insulating adhesive body, while the other fine grid line is provided with solder paste, and solder strips are connected by solder paste, the solder strips are embedded in the grooves of the insulating adhesive body and connected to the insulating adhesive body.

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