Stacked gate battery piece conductive seed layer structure

Abstract

The utility model provides a conductive seed layer structure of a stacked grid battery piece, which comprises an original battery piece and a plurality of groups of conductive seed layers arranged on the surface of the battery piece, and the plurality of groups of conductive seed layers are longitudinally arranged in parallel along the direction of a conductive wire to be welded. The width of each group of conductive seed layers does not exceed the width of the bottom edge of a conductive wire to be welded, and each group of conductive seed layers comprises a column of longitudinal main conductive seed layers and at least one auxiliary conductive seed layer outside the column of longitudinal main conductive seed layers; and the column of longitudinal main conductive seed layers and at least one auxiliary conductive seed layer form a planar support structure. According to the utility model, the inclined offset of the conductive wire is obviously improved, and the reliability of the connection between the conductive wire and the conductive seed layer is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a conductive seed layer structure of a stacked grid cell. Background Art

[0002] MBB and SMBB cells are covered with secondary grids on both sides, and a small number of main grids are perpendicular to the secondary grids. The main grids are used to collect carriers collected on the secondary grids. The increase in the number of main grids shortens the current transmission path, reduces the string resistance, and thus reduces power loss. However, as the number of main grids increases and the width is further refined, the traditional string welding machine faces the problem of increased welding difficulty, which may lead to unstable welding quality. With the continuous increase in silicon wafer size, the continuous improvement of screen printing technology, and the gradual decrease in silicon wafer costs, the proportion of silver paste costs in the solar cell manufacturing process has shown an upward trend. These factors have put forward many new requirements for electrode design. Busbar-free technology is a further optimization of SMBB. This technology completely removes the main grid and optimizes the width, spacing, and connection method of the secondary grid with the welding ribbon. In the busbar-free technology, the welding ribbon is designed to be laid vertically on the secondary grid, directly collecting current from the secondary grid, replacing the role of the main grid in traditional technology. This method further reduces the use of silver paste, thereby reducing manufacturing costs. However, since the connection point between the welding ribbon and the secondary grid depends on processes such as glue coating and welding, low reliability is a major problem. The stacked grid cell consists of an original cell with a conductive seed layer on the surface, a conductive wire parallel to the conductive seed layer, and a connecting strip between the cells that connects the conductive wires vertically. Several conductive seed layers parallel to each other are set on the surface of the stacked grid cell to extract carriers from the inside of the cell. The conductive wires are parallel to the conductive seed layer, and the current collection path is: cell surface-conductive seed layer-conductive wire. In this way, the current transmission path is only the conduction from the conductive seed layer to the conductive wire in the direction perpendicular to the cell surface, and the series resistance is reduced and the power loss is reduced. At the same time, by welding with the stacked grid welding technology, each conductive seed layer is completely covered by the back conductive wire, the effective connection points rise linearly, and the reliability is high. However, the stacked grid technology uses ultra-fine triangular conductive wires with ultra-high surface reflectivity, which can reduce the equivalent shading area of the cell surface, but also brings inevitable problems. The bottom surface of the triangular conductive wire is mounted on a conductive seed layer that is thinner than it, and it is very easy to tilt, resulting in a poor light trapping effect of the triangular conductive wire, and poor consistency in the appearance of the cell and even the component. Summary of the invention

[0003] In view of this, the utility model is committed to optimizing from the perspective of the conductive seed layer of the stacked grid battery. By designing conductive seed layer patterns with different structures, the triangular conductive wire can be stably mounted on the conductive seed layer to solve the problems of the lack of conductive wire light trapping effect and poor appearance consistency of the battery and components caused by the inclination of the conductive wire.

[0004] Therefore, the purpose of the present utility model is to provide a novel conductive seed layer structure for overlapping grid battery cells to solve the problem of stable erection of conductive wires on the conductive seed layer.

[0005] To achieve the above object, the present utility model provides the following technical solutions:

[0006] A conductive seed layer structure for overlapping grid battery cells includes an original battery cell and a plurality of groups of conductive seed layers provided on the surface of the battery cell. The conductive seed layers are longitudinally arranged in parallel according to the direction of the conductive wire to be welded. The width of each group of conductive seed layers does not exceed the bottom width of the conductive wire to be welded. Each group of conductive seed layers includes a longitudinal main conductive seed layer and at least one auxiliary conductive seed layer outside this longitudinal main conductive seed layer, so that the longitudinal main conductive seed layer and at least one auxiliary conductive seed layer outside it form a planar support structure.

[0007] In one embodiment, the longitudinal main conductive seed layer is a longitudinal continuous linear conductive seed layer.

[0008] In another embodiment, the longitudinal main conductive seed layer is a set of a series of discontinuous conductive seed layers located on a longitudinal line.

[0009] In the above cases, the set of the series of discontinuous conductive seed layers includes a uniform or non-uniform dotted line shape, dot shape or dot-line shape set.

[0010] In the above solutions, the auxiliary conductive seed layer is at least one continuous linear conductive seed layer parallel to the main conductive seed layer or a set of a series of discontinuous conductive seed layers, or a combination of the above two.

[0011] In another solution, the auxiliary conductive seed layer is a series of lines or dots or a combination thereof that are not parallel to the main conductive seed layer.

[0012] In the above solutions, the auxiliary conductive seed layer is a series of lines perpendicular to the main conductive seed layer.

[0013] Compared with the prior art, the beneficial effects of the present utility model are:

[0014] 1. Compared with the conductive seed layer pattern of a single straight line for overlapping grid batteries, the present utility model significantly improves the inclination and offset of the conductive wire, effectively improving the reliability of the connection between the conductive wire and the conductive seed layer;

[0015] 2. Compared with the conductive seed layer pattern of a single straight line for overlapping grid batteries, the present utility model can optimize the angle orientation of the conductive wire after the composite conductive seed layer, making it face the light source direction, optimizing the light trapping effect and thus improving the efficiency of the battery and the module;

[0016] 3. Compared with the conductive seed layer pattern of a single straight line in a tandem grid cell, the utility model can make the tandem grid cell and module have higher consistency in all directions and more beautiful appearance.

[0017] 4. Compared with the electrode pattern structure of a main grid cell, the utility model combines the tandem grid technology, reduces the consumption of silver paste and the cost. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the conductive seed layer structure of the prior art;

[0019] Figure 2 is a schematic diagram of the deflection of the conductive wire under the conductive seed layer structure of the prior art;

[0020] Figures 3 to 6 is a schematic diagram of some exemplary structures where the main conductive seed layer and the auxiliary conductive seed layer of the utility model intersect;

[0021] Figure 7 is a schematic diagram of the relative relationship between the conductive wire and the conductive seed layer when the main conductive seed layer and the auxiliary conductive seed layer intersect;

[0022] Figures 8 to 12 is a schematic diagram of some exemplary structures where the main conductive seed layer and the auxiliary conductive seed layer of the utility model are parallel;

[0023] Figure 13 is a schematic diagram of the relative relationship between the conductive wire and the conductive seed layer when the main conductive seed layer and the auxiliary conductive seed layer are parallel.

[0024] In the figure: 1. Battery cell; 2. Conductive seed layer; 3. Conductive wire; 4. Main conductive seed layer; 5. Auxiliary conductive seed layer. Detailed Embodiments

[0025] The advantage of the utility model is that it can stably support the triangular conductive wire on the conductive seed layer. The conductive seed layer of the prior art has a single straight line structure. As Figure 1 shown, the initial design of the conductive seed layer pattern of the tandem grid cell is a single straight line. When the triangular conductive wire covers it, since the width of the conductive seed layer is smaller than the bottom width of the triangular conductive wire, the triangular conductive wire is prone to tilt, as Figure 2 shown. This defect leads to a lower reliability of the connection between the two and a poorer consistency in the appearance of the battery and module. If the width of the conductive seed layer is directly increased, the silver consumption will increase and the cost advantage is not obvious.

[0026] The present utility model changes the conductive seed layer structure of the prior art. By adding lateral support points to a single conductive seed layer or splitting it into two parallel lines, the total width of the contact surface between the conductive seed layer and the triangular conductive wire is widened. This method can strengthen the structural stability of both the conductive seed layer and the conductive wire while enhancing the electrical connection after welding. Therefore, on the premise of ensuring low silver paste consumption, the present utility model innovates in the conductive seed layer pattern. By adding lateral support points to a single conductive seed layer or splitting it into two parallel lines, the purposes of reducing the inclination rate of the triangular conductive wire, enhancing the current collection ability of the conductive seed layer, improving the reliability of the connection between the conductive wire and the conductive seed layer, and achieving higher consistency in the appearance of the battery and components are achieved.

[0027] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0028] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the accompanying 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, and thus should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" 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 utility model can be understood according to specific circumstances.

[0030] As described above, the conductive seed layer structure of the tandem grid battery of the present utility model includes an original battery cell and a plurality of groups of conductive seed layers disposed on the surface of the battery cell. The conductive seed layers are arranged longitudinally and parallel to the direction of the conductive wire to be welded. The width of each group of conductive seed layers does not exceed the width of the welding surface of the conductive wire to be welded. Each group of conductive seed layers includes a column of longitudinal main conductive seed layers 4 and at least one auxiliary conductive seed layer 5 outside this column of longitudinal main conductive seed layers, so that this column of longitudinal main conductive seed layers and at least one auxiliary conductive seed layer outside form a planar support structure.

[0031] The main conductive seed layer and the auxiliary conductive seed layer may be in a parallel relationship or an intersecting relationship.

[0032] Figures 3-6 A series of embodiments of the intersecting relationship. In Figures 3-6 As shown in a series of intersecting relationships, there are four instances of the scheme of adding transverse support points on a single main conductive seed layer as the auxiliary conductive seed layer. In this structure, the cross-sectional view after the conductive wire is connected to the conductive seed layer is as shown in Figure 7 .

[0033] It should be understood that although Figures 3-6 shows the relationship of perpendicular intersection between the main conductive seed layer and the auxiliary conductive seed layer, it should be understood that this is only an example of selecting a relatively easy-to-fabricate scheme in the process. In actual situations, as long as the relationship between the main conductive seed layer and the auxiliary conductive seed layer is a non-parallel relationship, it can be regarded as the intersecting relationship of the present utility model. Those skilled in the art can also easily think of other intersecting relationships and connection methods after reading the present utility model. Therefore, other intersecting relationships should also be included in the protection scope of the present utility model, and the specific protection scope shall be subject to the claims.

[0034] In the conductive seed layer structure of the tandem grid battery cell, the conductive seed layer can be a continuous linear shape or a discontinuous pattern. Therefore, in the present utility model, the main conductive seed layer can be a continuous linear shape, as shown in Figure 3 and Figure 5 shown, or it can be a discontinuous pattern, as shown in Figure 4 and Figure 6 shown.

[0035] Figure 3 and Figure 5 On the continuous linear main conductive seed layer structure, short line segments extending transversely are added at regular intervals on each main conductive seed layer as the auxiliary conductive seed layer. As shown in the example of Figure 3 shown, a pair of left-right symmetric horizontal line segments are added at regular intervals on each main conductive seed layer to widen the total width of a single conductive seed layer, as shown in Figure 7As shown. In fact, the spacing distance and the number of horizontal line segments determine the silver consumption during electrode printing and whether the present utility model can stably support the triangular conductive wire. Therefore, the specific spacing distance and the number of additional horizontal line segments can be adjusted according to the actual situation.

[0036] Such as Figure 5 the illustrated example, on each main conductive seed layer, half a horizontal line segment is intermittently added to the left and right at a certain distance, and the purpose of increasing the total width of a single conductive seed layer can also be achieved. And in this example, silver can be further saved Figure 3 on the basis of. Similarly, there are no restrictions on the specific spacing distance and the added horizontal line segments.

[0037] Figure 4 and Figure 6 while adding short line segments extending horizontally, a disconnection design is made for the original conductive seed layer. The purpose of saving silver is further achieved.

[0038] In the above-exemplified examples, regardless of whether the original conductive seed layer is changed, and regardless of the number, length, width, and spacing distance of the added horizontal line segments, essentially the key point is to increase the horizontal support points on a single conductive seed layer, so as to increase the total width of a single conductive seed layer to ensure that the conductive seed layer can stably support the triangular conductive wire on the premise of saving silver. Any other electrode pattern with horizontal line segments added to the conductive seed layer should be included in the protection scope of the present utility model.

[0039] Figures 8-12 A series of embodiments in which the main conductive seed layer and the auxiliary conductive seed layer are in a parallel relationship. These embodiments can be regarded as a scheme of splitting a single conductive seed layer into two lines. The cross-sectional view after the conductive wire is connected to the conductive seed layer is as Figure 13 shown.

[0040] Similarly, the main conductive seed layer and the auxiliary conductive seed layer can be in a continuous linear shape or a discontinuous pattern, such as a broken line shape, a dotted line shape, or a series of points. Figure 8 The illustrated example is an example of a conductive seed layer structure in which a single main conductive seed layer and an auxiliary conductive seed layer are in a parallel two-line arrangement. These two conductive seed layers jointly support a single conductive wire. The cross-sectional view after the conductive wire is connected to the conductive seed layer is as Figure 13 . The height, width, and the distance between the two parallel lines of the conductive seed layer can all be adjusted according to the actual situation.

[0041] Figure 9 、 10 The illustrated example is to perform a disconnection treatment on the basis of two lines. Figure 9 In the illustrated example, the disconnection treatments of the two parallel lines are the same, and the starting point positions, lengths, etc. of the line segments and blank segments of the conductive seed layer are all the same. Compared with Figure 8The illustrated example saves more silver. And Figure 10 In the illustrated example, the parallel double - line disconnection processing is not synchronized, and the blank segments of the two lines and the conductive seed layer line segments complement each other. Compared with Figure 9 the illustrated example, while saving silver, it has a higher current collection capacity. The height, width, line spacing, etc. of the parallel conductive seed layer line segments can all be adjusted according to the actual situation.

[0042] Figure 11 、 12 In the illustrated example, the conductive seed layer pattern is changed from parallel line segments to parallel dots. A series of parallel dots can be synchronized in parallel or staggered with each other. The specific pattern, the number of dots, the size of the dots, and the spacing between dots can all be adjusted according to the actual situation.

[0043] For the examples listed above, regardless of the height, width, and spacing of the parallel lines, regardless of whether disconnection or break - point processing is performed on the parallelism, and regardless of how the disconnections and break - points are arranged, essentially the key point is to split the single conductive seed layer into two parts to jointly and stably support the triangular conductive wire. Any other electrode pattern with two conductive seed layers corresponding to one conductive wire should be included in the protection scope of the present utility model.

[0044] Adopting the solution of the present utility model has the following effects:

[0045] 1. An additional lateral fulcrum is added on the single conductive seed layer, increasing the overall structural width of the conductive seed layer, avoiding the inclination during the attachment and contact process of the conductive wire, and improving the contact performance;

[0046] 2. By optimizing the single continuous conductive layer into different break - point structures, the material consumption of the conductive seed layer is saved;

[0047] 3. The single conductive seed layer is split into two mutually parallel conductive seed layers, increasing the overall structural width of the conductive seed layer, avoiding the inclination during the attachment and contact process of the conductive wire, and improving the contact performance;

[0048] 4. By optimizing the two parallel conductive seed layers into different discontinuous patterns, the material consumption of the conductive seed layer is reduced on the premise of ensuring that the current collection path is not affected.

[0049] For the parts not detailed in the present utility model, they are all well - known technologies in the art.

[0050] Finally, it should be noted that: The above - mentioned specific embodiments are only used to illustrate the technical solution of the present utility model rather than to limit it. Although the present utility model has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that the technical solution of the present utility model can be modified and equivalently replaced without departing from the spirit and scope of the technical solution of the present utility model, and they should all be covered within the scope of the claims of the present utility model.

Claims

1. A conductive seed layer structure for an overlapping grid cell, characterized in that, The structure includes an original cell and a plurality of groups of conductive seed layers disposed on the surface of the cell. The plurality of groups of conductive seed layers are longitudinally arranged in parallel in the direction of the conductive wire to be welded. The width of each group of conductive seed layers does not exceed the bottom width of the conductive wire to be welded. Each group of conductive seed layers includes a column of longitudinal main conductive seed layers and at least one auxiliary conductive seed layer outside the column of longitudinal main conductive seed layers, so that the column of longitudinal main conductive seed layers and at least one auxiliary conductive seed layer outside form a planar support structure.

2. The conductive seed layer structure of the stacked gate cell as described in claim 1, characterized in that, The longitudinal main conductive seed layer is a continuous linear conductive seed layer in the longitudinal direction.

3. The conductive seed layer structure of the stacked gate cell according to claim 1, characterized in that, The longitudinal main conductive seed layer is a set of a series of discontinuous conductive seed layers located on a longitudinal line.

4. The conductive seed layer structure of the tandem cell according to claim 3, wherein, The set of the series of discontinuous conductive seed layers includes a uniform or non-uniform dotted line shape, dot shape or dot-line shape set.

5. The conductive seed layer structure of the tandem cell according to any one of claims 1 to 4, characterized in that, The auxiliary conductive seed layer is at least one continuous linear conductive seed layer parallel to the main conductive seed layer or a set of a series of discontinuous conductive seed layers, or a combination of the above two.

6. The conductive seed layer structure of the tandem cell according to any one of claims 1 to 4, characterized in that, The auxiliary conductive seed layer is a series of lines or dots or a combination thereof that are not parallel to the main conductive seed layer.

7. The conductive seed layer structure of the stacked gate cell as described in claim 6, characterized in that, The auxiliary conductive seed layer is a series of lines perpendicular to the main conductive seed layer.

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