A back-contact solar cell module encapsulated using a perforated interconnect film

Abstract

This utility model discloses a back-contact solar cell module encapsulated using a perforated interconnect film, comprising, from bottom to top: a front photovoltaic glass; a first encapsulating layer covering the front photovoltaic glass; at least one set of back-contact solar cells, each having a horizontal fine grid and a vertical main grid on its back side; a perforated interconnect film covering the back side of the back-contact solar cells, the perforated interconnect film consisting of a substrate organic polymer film, copper wires grown and attached to the surface of the organic polymer film, and adhesive overflow holes arranged on both sides of the copper wires; a second encapsulating layer covering the perforated interconnect film; and a backplate located on the outermost layer. By fabricating copper wires on an organic polymer film and punching small holes to form the perforated interconnect film, the adhesive overflow from the encapsulating film during lamination acts as a riveting mechanism, ensuring the copper wires remain tightly attached to the solar cells, forming a good ohmic contact. This also allows for the encapsulation of multiple busbars, increasing module power and reducing silver paste costs.

Description

Technical Field

[0001] This utility model relates to the field of solar cells, and more particularly to a back-contact solar cell module encapsulated using a perforated interconnect film. Background Technology

[0002] In existing technologies, the stringing of solar cells involves using a stringing machine to lay the solder strip flat on the surface of the solar cell's main grid position and forming ohmic contacts through processes such as thermal welding. Due to limitations in mechanical structure and the stretching properties of the solder strip, the number of solder strips cannot be set too high, the clamp space is insufficient, the precision is inadequate, and the solder strip cannot be too thin, otherwise it is easy to break. All of these problems affect the metallization pattern design and stringing scheme design of solar cells. Utility Model Content

[0003] To address the aforementioned issues, this invention provides a back-contact solar cell module encapsulated using a perforated interconnect film, which enables multi-busbar encapsulation, increases module power, and reduces silver paste costs.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a back-contact solar cell module encapsulated with a perforated interconnect film, comprising, arranged from bottom to top, the following:

[0005] Front-facing photovoltaic glass;

[0006] The first encapsulating adhesive layer covers the front photovoltaic glass;

[0007] At least one set of back-contact solar cells, with a horizontal fine grid and a vertical main grid on the back;

[0008] A perforated interconnect film is applied to the back side of the back contact solar cell. The perforated interconnect film consists of a substrate organic polymer film, copper wires grown and attached to the surface of the organic polymer film, and adhesive overflow holes arranged on both sides of the copper wires. The width of the organic polymer film substrate is the same as the width of the solar cell. Multiple copper wires are attached to the surface of the substrate in parallel and are arranged to correspond to the position of the main grid of the solar cell.

[0009] A second encapsulating adhesive layer covers the perforated interconnect film;

[0010] Back panel, located on the outermost layer;

[0011] In this process, a portion of the material in the second encapsulating adhesive layer passes through the overflow hole to form a rivet structure, which allows the copper wire to be tightly bonded to the main grid of the battery cell.

[0012] Furthermore, the organic polymer film substrate is made of PET, PVDF or ETFE, and has a thickness of 20μm–200μm.

[0013] Furthermore, the distance between the edge of the overflow hole and the edge of the copper wire is D1≤2mm, the distance between the inner edges of two adjacent copper wires is D2, and the radius R1 of the overflow hole satisfies 2×R1. <D2。

[0014] Furthermore, the basis weight of the second encapsulating adhesive layer is 100g / m²–500g / m², and the basis weight to substrate thickness ratio is ≥2:1.

[0015] As can be seen from the above description of the structure of this utility model, compared with the prior art, this utility model has the following advantages:

[0016] 1. This utility model uses a method of preparing copper wires on an organic polymer film and punching small holes to form a perforated interconnect film. The perforated interconnect film is bonded to several battery cells and covered with an encapsulating film. During lamination, the encapsulating film overflows into the small holes, acting as a riveting action, so that the copper wires on the interconnect film are kept in close contact with the battery cells, forming a good ohmic contact.

[0017] 2. This invention allows interconnects to be directly fabricated on polymer films, enabling the encapsulation of multiple busbars. Furthermore, the cross-sectional size of the copper wires can be reduced without being limited by the mechanical structure of the equipment, thereby increasing component power. At the same time, as the number of busbars increases, the conductivity of the silver paste in the fine grid can be further reduced, thus lowering the cost of the silver paste. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of the stacked cross-sectional structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the laminated cross-sectional structure of this utility model;

[0021] Figure 3 This is a schematic diagram illustrating the battery string formed by stacking the interconnecting film and battery cells according to an embodiment of the present invention.

[0022] Figure 4 This utility model Figure 3 A magnified view of part A. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0024] Example

[0025] refer to Figure 1-4 A back-contact solar cell module encapsulated using a perforated interconnect film includes, from bottom to top, the following components:

[0026] 2. Front photovoltaic glass;

[0027] The first encapsulating adhesive layer 4 covers the front photovoltaic glass 2;

[0028] At least one set of back-contact solar cells 6, with a horizontal fine grid and a vertical main grid on the back;

[0029] A perforated interconnect film 5 is applied to the back side of the back contact solar cell 6. The perforated interconnect film 5 consists of a substrate organic polymer film 51, copper wires 52 grown and attached to the surface of the organic polymer film, and adhesive overflow holes 53 arranged on both sides of the copper wires. The width of the organic polymer film substrate 51 is the same as the width of the solar cell. Multiple copper wires 52 are attached in parallel to the surface of the substrate 51 and are arranged to correspond to the position of the main grid of the solar cell.

[0030] The second encapsulating adhesive layer 3 covers the perforated interconnect film 5;

[0031] Back panel 1, located on the outermost layer;

[0032] In this process, a portion of the material of the second encapsulating adhesive layer 3 passes through the overflow hole 53 to form a rivet structure, which makes the copper wire 52 tightly attached to the main grid of the solar cell. Due to the adhesion and vacuum effect, the copper wire 52 on the perforated interconnect film 5 can be tightly attached to the back of the back contact solar cell 6, forming good contact with the grid line electrode on the back.

[0033] The organic polymer film substrate 51 is made of PVDF and has a thickness of 100μm. The second encapsulating adhesive layer 3 has a basis weight of 200g / m².

[0034] The distance D1 between the edge of the overflow hole 53 and the edge of the copper wire 52 is 1 mm, the distance D2 between the inner edges of two adjacent copper wires 52 is 4 mm, and the radius R1 of the overflow hole 53 is 1.5 mm, satisfying 2×R1. <D2。

[0035] During packaging, such as Figure 3 As shown, the back-contact solar cells 6 are arranged in series with the perforated interconnect film 5 and laid flat. They can be pre-fixed by applying tape or glue to avoid misalignment during transfer, forming the interconnect film battery string 7. The interconnect film battery string 7 is then stacked according to the conventional electrical layout diagram of a half-cell battery module.

[0036] This invention employs a method of fabricating copper wires on an organic polymer film, punching small holes to form a perforated interconnect film. This perforated interconnect film is then bonded to several corresponding solar cells and covered with an encapsulating film. During lamination, the encapsulating film overflows into the small holes, creating a riveting effect that ensures the copper wires on the interconnect film remain firmly attached to the solar cells, forming a good ohmic contact. This method overturns the traditional wire bonding method, allowing interconnects to be fabricated directly on the polymer film. This enables the encapsulation of numerous busbars, and the cross-sectional size of the copper wires can be reduced without being limited by the mechanical structure of the equipment, thus increasing module power. Furthermore, as the number of busbars increases, the conductivity of the silver paste in the fine grid can be further reduced, lowering the cost of the silver paste.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A back-contact solar cell module encapsulated using a perforated interconnect film, characterized in that, Including the arrangement from bottom to top: Front-facing photovoltaic glass (2); The first encapsulating adhesive layer (4) covers the front photovoltaic glass (2); At least one set of back-contact solar cells (6) with a horizontal fine grid and a vertical main grid on the back; A perforated interconnect film (5) is applied to the back side of the back contact solar cell (6). The perforated interconnect film (5) consists of an organic polymer thin film substrate (51), copper wires (52) grown and attached to the surface of the organic polymer thin film, and adhesive overflow holes (53) arranged on both sides of the copper wires. The width of the organic polymer thin film substrate (51) is the same as the width of the solar cell. Multiple copper wires (52) are attached in parallel to the surface of the organic polymer thin film substrate (51) and are arranged to correspond to the position of the main grid of the solar cell. The second encapsulating adhesive layer (3) covers the perforated interconnect film (5); Back panel (1), located on the outermost layer; In this process, a portion of the material of the second encapsulating adhesive layer (3) passes through the overflow hole (53) to form a rivet structure, so that the copper wire (52) is tightly attached to the main grid of the battery cell.

2. The back-contact solar cell module according to claim 1, characterized in that: The organic polymer film substrate (51) is made of PET, PVDF or ETFE and has a thickness of 20μm–200μm.

3. The back-contact solar cell module according to claim 1, characterized in that: The distance between the edge of the overflow hole (53) and the edge of the copper wire (52) is D1≤2mm, the distance between the inner edges of two adjacent copper wires (52) is D2, and the radius R1 of the overflow hole (53) satisfies 2×R1. <D2。 4. The back-contact solar cell module according to claim 1, characterized in that: The weight of the second encapsulating adhesive layer (3) is 100g / m²–500g / m², and the weight to substrate thickness ratio is ≥2:1.

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