Transfer module, solar cell, and method for manufacturing the same

Abstract

To provide a transfer module, a solar cell, and a manufacturing method for the same, which enable easy manufacture of a narrow grid line and are advantageous in reducing the loss of conductive paste.SOLUTION: A transfer module 10 includes a carrier 11 and a first conductive wire 12. The carrier 11 has a first surface 111. On the first surface 111, a first concave groove 11a is provided. At least a part of the first conductive wire 12 is provided inside the first concave groove 11a. The first conductive wire 12 and a groove wall of the first concave groove 11a define a first housing cavity 11b on a side closer to a notch of the first concave groove 11a of the first conductive wire 12. That is to say, in the first concave groove 11a, the first housing cavity 11b is formed on the side closer to the notch of the first concave groove 11a of the first conductive wire 12. The first housing cavity 11b is to house the conductive paste and the first conductive wire 12 is configured to be detachable from the first concave groove 11a by external energy.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and particularly to a transfer module, a solar cell, and a manufacturing method thereof.

Background Art

[0002] Facing the serious problem that non-renewable energy is almost consumed worldwide, the development of renewable clean energy has been strongly advocated in various countries. The photovoltaic industry that can convert solar energy into electrical energy is迎来 unprecedented development opportunities.

[0003] In the current manufacturing technology of silicon solar cells, the metal grid lines of silicon solar cells are mainly manufactured by a screen printing process or an electroplating process. However, it is difficult to manufacture grid lines with a width of less than 25 μm by the screen printing process, and the manufacturing cost of the electroplating process is high.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Based on this, it is necessary to provide a transfer module, a solar cell, and a manufacturing method thereof.

Means for Solving the Problems

[0005] In a first aspect, a transfer module according to an embodiment of the present application includes a carrier and a first conductor, the carrier has a first surface, a first concave groove is provided on the first surface, at least a part of the first conductor is provided in the first concave groove, the first conductor and the groove wall of the first concave groove define a first accommodating cavity on a side close to the notch of the first concave groove of the first conductor, the first accommodating cavity is for accommodating paste, and the first conductor is configured to be detachable from the first concave groove by external energy.

[0006] The transfer module according to the embodiment of the present invention is manufactured by transferring grid lines. On the one hand, it is advantageous in reducing manufacturing costs compared to the electroplating process. On the other hand, compared to the screen printing process, it is advantageous in controlling the width of the grid lines because paste is filled into the grooves, making it easier to manufacture grid lines with a narrow width. Furthermore, by providing a first conductor in the grooves, it is advantageous in reducing paste loss.

[0007] In one embodiment, the entire first conductor is located within the first groove.

[0008] In one embodiment, a portion of the first conductor extends from the notch of the first groove, and the cross-section of the first conductor has one end that is away from the first groove, and the distance between this end and the notch of the first groove is greater than 0 μm and 200 μm or less.

[0009] In one embodiment, the carrier has a second surface facing the first surface, the direction from the first surface to the second surface is defined as the first direction, the outer surface of the first conductor includes an inner portion close to the second surface, the inner portion is bonded to a groove wall of a part of the first groove, and the dimension of the first conductor along the first direction is less than or equal to the dimension of the first groove along the first direction.

[0010] In one embodiment, the outer surface of the first conductor includes an outer portion separated from the second surface, and the minimum distance between the outer portion and the notch is 0 to 200 μm.

[0011] In one embodiment, if the maximum distance between the outer portion and the notch is L1, and the minimum distance between the outer portion and the notch is L2, then L2 and L1 are,

number

[0012] In one embodiment, the dimension of the notch of the first groove along the second direction is greater than or equal to the dimension of the first conductor along the second direction, and the second direction is perpendicular to the first direction.

[0013] In one embodiment, the dimension of the first conductor along the first direction is 1 μm to 220 μm.

[0014] In one embodiment, the dimension of the first conductor along the second direction is 5 μm to 220 μm.

[0015] In one embodiment, the first surface of the carrier is provided with a plurality of first grooves spaced apart along a second direction, the transfer module includes a plurality of first wires spaced apart along the second direction, each of the first wires and each of the first grooves extends along a third direction, and each of the first wires corresponds one-to-one and is at least partially located in each of the first grooves.

[0016] In one embodiment, the distance between any two adjacent first conductors is a first distance, and the first distance is between 200 μm and 2000 μm.

[0017] In one embodiment, the first conductor includes a connected main body and a large diameter portion, and the dimension of the large diameter portion along the second direction is greater than the dimension of the main body along the second direction.

[0018] In one embodiment, the carrier has a central region and edge regions located on both sides of the central region along the second direction, the first groove includes a central groove and an edge groove, the first conductor includes a central conductor and an edge conductor, the central groove and the central conductor within it are located in the central region, and the edge groove and the edge conductor within it are located in the edge region.

[0019] In one embodiment, the edge region includes at least two edge concave grooves and at least one retreat region spanning at least two edge conducting lines therein. The edge concave grooves and the edge conducting lines therein are separated in the retreat region, forming at least two sub-concave grooves and at least two sub-conducting lines spaced apart from each other.

[0020] In one embodiment, a connection concave groove is further provided on the first surface of the transfer module. The transfer module further includes a connection conducting line, and the connection conducting line is at least partially installed in the connection concave groove. The connection concave groove and the connection conducting line therein are installed at the edge of the retreat region. The connection concave groove communicates with the sub-concave grooves on the same side among the at least two edge concave grooves, and the connection conducting line is connected to the sub-conducting lines on the same side among the at least two edge conducting lines. The connection conducting line and the groove wall of the connection concave groove define a connection accommodation cavity for accommodating paste on the side close to the notch of the connection concave groove of the connection conducting line. The connection conducting line is arranged to be detachable from the connection concave groove under the action of external energy.

[0021] In one embodiment, the first conducting line includes a conductive core wire and an antioxidant layer covering the outer periphery of the conductive core wire, and the antioxidant layer includes a metal material.

[0022] In one embodiment, the material of the conductive core wire includes copper or aluminum.

[0023] In one embodiment, the material of the antioxidant layer includes at least one of silver, tin, lead, titanium, and nickel.

[0024] In one embodiment, the carrier is configured as a flexible member.

[0025] In one embodiment, a second concave groove intersecting with the first concave groove is further provided on the first surface of the carrier. The transfer module further includes a second conductive line that intersects the first conductive line, at least a part of the second conductive line is provided in the second concave groove, and the second conductive line and the groove wall of the second concave groove define a second accommodation cavity on a side of the second concave groove of the second conductive line close to the notch, and the second accommodation cavity is for accommodating paste. The second conductive line is configured to be detachable from the second concave groove by external energy.

[0026] In a second aspect, the solar cell according to the embodiment of the present application includes a cell and a first grid line. The cell has a first surface and a second surface provided opposite to each other. A plurality of the first grid lines are provided at intervals on both the first surface and the second surface. Each of the first grid lines includes a stacked first metal layer and a first conductive line, and the first metal layer is connected to the cell.

[0027] The grid line of the solar cell according to the embodiment of the present application can be manufactured by a transfer module. On the one hand, the manufacturing cost can be reduced compared with the grid line manufactured by an electroplating process. On the other hand, compared with the grid line manufactured by a screen printing process, since paste is filled into the concave groove, it is advantageous for controlling the width of the grid line, and it is easy to manufacture a grid line with a small width. Further, by providing the first conductive line in the concave groove, it is advantageous for reducing the loss of paste.

[0028] In one embodiment, the orthographic projection of the first conductive line on the cell is within the range of the orthographic projection of the first metal layer on the cell.

[0029] In one embodiment, on the same side of the cell, the distance between two adjacent first grid lines is a first distance, and the first distance is 200 μm to 2000 μm.

[0030] In one embodiment, the minimum distance between the first grid line and the edge of the cell is 50 μm to 1500 μm.

[0031] In one embodiment, the first grid line includes a connected main body and a large diameter portion, the width of which is greater than the width of which is which.

[0032] In one embodiment, the cell has a central region and edge regions located on both sides of the central region, and the first grid line includes a central grid line located in the central region and edge grid lines located in the edge regions.

[0033] In one embodiment, the edge region includes at least one receding region that spans at least two edge grid lines, and the edge grid lines are separated in the receding region and form at least two spaced-apart subgrid sections.

[0034] In one embodiment, the solar cell further includes a second grid line, wherein at least one of the first surface and the second surface is provided with the second grid line electrically connected to the first grid line.

[0035] In one embodiment, the orthographic projection of the second grid line onto the cell and the orthographic projection of the large diameter portion of the first grid line onto the cell have an overlapping region, or a portion of the orthographic projection of the second grid line onto the cell lies within the retracted region.

[0036] In one embodiment, the cell includes a first transparent conductive layer, a first doped layer, a first intrinsic semiconductor layer, a silicon substrate, a second intrinsic semiconductor layer, a second doped layer, and a second transparent conductive layer, which are stacked in order, wherein the first surface is located on the side of the first transparent conductive layer away from the silicon substrate, and the second surface is located on the side of the second transparent conductive layer away from the silicon substrate.

[0037] In the third aspect, the method for manufacturing a solar cell according to the embodiment of the present application is as follows: The steps include providing a cell and a transfer module as described in any embodiment of the first aspect, The steps include filling the first housing cavity of the transfer module with paste, The steps include: placing the transfer module on the transfer surface of the cell, applying energy to the transfer module to transfer the first wire and the paste to the transfer surface; The process includes the step of performing a hardening treatment on the paste in the cell. [Effects of the Invention]

[0038] The solar cell manufacturing method according to the embodiment of the present invention manufactures grid lines by transfer, which is advantageous in reducing manufacturing costs compared to the electroplating process, and on the other hand, compared to the screen printing process, it is advantageous in controlling the width of the grid lines because the paste is filled into the grooves, making it easy to manufacture grid lines with a narrow width. Furthermore, by providing a first conductor in the groove, it is advantageous in reducing paste loss.

[0039] To more clearly describe the technical means in the embodiments or exemplary embodiments of the present application, the drawings that may be used to describe the embodiments or exemplary embodiments are briefly described below. As will be apparent, the drawings in the following description are only a few embodiments of the present application, and those skilled in the art can obtain other drawings based on these without any creative work. [Brief explanation of the drawing]

[0040] [Figure 1] This is a schematic diagram showing the cross-sectional structure of a transfer module according to one embodiment of the present invention. [Figure 2] Figure 1 is a schematic diagram showing the cross-sectional structure of the transfer module after paste application. [Figure 3] Figure 1 is a schematic diagram showing the use of the transfer module. [Figure 4] This is a schematic diagram showing the cross-sectional structure of a transfer module according to another embodiment of the present invention. [Figure 5] This is a schematic diagram showing the cross-sectional structure of a transfer module according to yet another embodiment of the present invention. [Figure 6]This is a schematic diagram showing the cross-sectional structure of a transfer module according to yet another embodiment of the present invention. [Figure 7] Figure 6 is a plan view of the transfer module. [Figure 8] This is a plan view of a transfer module according to yet another embodiment of the present invention. [Figure 9] This is a schematic diagram showing a partial cross-sectional structure of a solar cell according to one embodiment of the present invention. [Figure 10] This is a plan view of a solar cell according to one embodiment of the present invention. [Figure 11] This is a schematic diagram of the structure of part I in Figure 10. [Figure 12] This is another schematic diagram of the structure of part I in Figure 10. [Figure 13] This is a schematic diagram showing the cross-sectional structure of a solar cell according to another embodiment of the present invention. [Figure 14] This is a flowchart of a method for manufacturing a solar cell according to one embodiment of the present invention. [Figure 15] Figure 14 is a schematic diagram of the manufacturing process. [Modes for carrying out the invention]

[0041] To make the above-mentioned objectives, features, and advantages of the present application clearer and easier to understand, specific embodiments of the present application will be described below in detail with reference to the accompanying drawings. The following description will include many specific details in order to provide a complete understanding of the present application. However, the present application can be implemented in many other forms different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application; therefore, the present application is not limited by the specific embodiments disclosed below.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application pertains. In the description of this application, terms used herein are solely for the purpose of illustrating specific embodiments and are not intended to limit this application.

[0043] When an element or layer is referred to as "...on," "...adjacent to," "...connected to," or "...combined with" another element or layer, it should be understood that there may be elements or layers directly on, adjacent to, connected to, or interposed to the other element or layer. Conversely, when an element is referred to as "directly...on," "directly adjacent to," "directly connected to," or "directly...combined with" another element or layer, it means that there are no interposing elements or layers. Terms such as 1st, 2nd, 3rd, etc., are used to describe various elements, components, regions, layers, doping types, and / or parts, but it should be understood that these elements, components, regions, layers, doping types, and / or parts should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, doping type, or part from another element, component, region, layer, doping type, or part. Therefore, without departing from the teachings of this application, the first element, component, region, layer, doping type, or part discussed below may be referred to as the second element, component, region, layer, doping type, or part.

[0044] Spatial relation terms, such as "below," "located below," "below," "below," "above," and "upper," are used herein to describe the relationship between one element or feature shown in a drawing and another element or feature. It should be understood that spatial relation terms include not only the orientation shown in the drawing, but also different orientations of the element or feature in use and operation. For example, if an element or feature in a drawing is reversed, an element or feature described as "below another element," "below it," or "below" will become "above" the other element or feature. Therefore, the exemplary terms "located below" and "below" may include both upward and downward orientations. Furthermore, an element or feature may include additional orientations (e.g., a 90-degree rotation or other orientations), and the spatial relation terms used herein shall be interpreted accordingly.

[0045] As used herein, the singular forms “one,” “one,” and “the said / the said” may also include the plural form unless the context clearly indicates otherwise. Terms such as “contains / includes” or “have” identify the presence of a described feature, whole, step, action, component, part, or combination thereof, but should be understood not to exclude the possibility of the presence or addition of one or more other features, wholes, steps, actions, components, parts, or combinations thereof. On the other hand, in this specification, the term “and / or” includes any and all combinations of the items listed in relation.

[0046] Here, embodiments of the present application will be described with reference to a schematic cross-sectional view of an ideal embodiment (and intermediate structure) of the present application, so that variations in the shown shape due to manufacturing techniques and / or tolerances can be anticipated, for example. Therefore, embodiments of the present application should not be limited to specific shapes of the regions shown herein, but include, for example, deviations in shape due to manufacturing techniques. Accordingly, the regions shown in the figures are substantially schematic, and their shapes do not represent the actual shapes of the regions of the device and do not limit the scope of the present application.

[0047] In a first embodiment, as shown in Figure 1, an embodiment of the present application provides a transfer module 10 for manufacturing grid lines for a solar cell 20. Specifically, the transfer module 10 includes a carrier 11 and a first conductor 12, the carrier 11 having a first surface 111, the first surface 111 having a first groove 11a, and at least a portion of the first conductor 12 being provided in the first groove 11a. The first conductor 12 and the groove wall of the first groove 11a define a first housing cavity 11b on the side of the first conductor 12 closer to the notch of the first groove 11a, that is, a first housing cavity 11b is formed within the first groove 11a on the side of the first conductor 12 closer to the notch of the first groove 11a. The first housing cavity 11b houses a paste, and the first conductor 12 is configured to be able to detach from the first groove 11a by external energy.

[0048] As shown in Figures 2 and 3, when manufacturing grid lines, first, paste is applied to the first housing cavity 11b, then the transfer module 10 is placed on the cell 21 with the notch of the first groove 11a facing the transfer surface of the cell 21, and external energy is applied to the transfer module 10, for example, by irradiating the transfer module 10 with a laser to dislodge the first conductor 12 and paste from the first groove 11a and bring them into contact with the transfer surface of the cell 21, so that the first conductor 12 together with the paste constitutes the grid lines.

[0049] The material of the first conductor 12 includes metallic materials, and exemplarily, the material of the first conductor 12 may be copper, aluminum, etc. In some embodiments, the first conductor 12 may be formed directly on the groove wall of the first groove 11a by a manufacturing process known to those skilled in the art.

[0050] The transfer module 10 according to the embodiment of the present invention is manufactured by transferring grid lines, and on the one hand, it is advantageous in reducing manufacturing costs compared to the electroplating process. On the other hand, compared to the screen printing process, it is advantageous in controlling the width of the grid lines because paste is filled into the grooves, and it is easy to manufacture grid lines with a narrow width. In addition, by providing the first conductor 12 in the grooves, it is advantageous in reducing paste loss.

[0051] In one embodiment, as shown in Figures 1 and 4, the entire structure of the first conductor 12 is located within the first groove 11a, that is, the first conductor 12 does not extend from the notch of the first groove 11a. In this way, when applying paste to the first housing cavity 11b, the first conductor 12 does not interfere with the paste application device, and the difficulty of applying the paste can be reduced.

[0052] In another embodiment, as shown in Figure 5, a portion of the structure of the first conductor 12 extends from the notch of the first groove 11a, and the cross-section of the first conductor 12 has one end that is away from the first groove 11a, and the distance L6 between this end and the notch of the first groove 11a is greater than 0 μm and less than or equal to 200 μm. Exemplarily, L6 may be 1 μm, 50 μm, 80 μm, 120 μm, 160 μm, 175 μm, or 200 μm.

[0053] In this way, the volume of the first conductor 12 can be increased, reducing the amount of paste used, which is advantageous for cost reduction, while ensuring the ohmic contact effect between the grid line and the cell 21.

[0054] In one embodiment, as shown in Figure 1, the carrier 11 has a second surface 112 facing a first surface 111, and the first groove 11a extends from the first surface 111 toward the interior of the carrier 11. The direction from the first surface 111 to the second surface 112 is called the first direction X. The outer circumferential surface of the first conductor 12 includes an inner portion close to the second surface 112, and this inner portion is bonded to a part of the groove wall (e.g., the bottom wall) of the first groove 11a. The dimension L3 of the first conductor 12 along the first direction X is less than or equal to the dimension L4 of the first groove 11a along the first direction X. In Figure 1, the first direction X is the thickness direction of the carrier 11, the dimension L4 of the first groove 11a is considered to be the depth of the first groove 11a, and the dimension L3 of the first conductor 12 may be the diameter or thickness of the first conductor 12.

[0055] In this way, the entire structure of the first conductor 12 is provided within the first groove 11a. In this manner, when paste is applied to the first housing cavity 11b, the first conductor 12 does not interfere with the paste application device, and the difficulty of applying the paste can be reduced.

[0056] In one embodiment, as shown in Figure 1, the outer surface of the first conductor 12 includes an outer portion separated from the second surface 112, and the minimum distance L2 between the outer portion and the notch is 0 to 200 μm. Exemplarily, L2 may be 0 μm, 50 μm, 80 μm, 100 μm, 120 μm, 160 μm, 180 μm, or 200 μm.

[0057] In this way, when applying paste to the first containment cavity 11b, the first conductor 12 does not interfere with the paste application device, reducing the difficulty of applying the paste, while also avoiding an increase in the size of the first containment cavity 11b and reducing the amount of paste used.

[0058] In one embodiment, if the maximum distance between the outer portion of the outer surface of the first conductor 12 and the notch is L1, and the minimum distance between the outer portion of the outer surface of the first conductor 12 and the notch is L2, then L2 and L1 are

number

[0059] Furthermore, the smaller the difference between the minimum spacing L1 and the maximum spacing L2, the more uniform the paste in the first containment cavity 11b becomes, that is, the more uniform the thickness of the paste in the first containment cavity 11b becomes. In addition, the uniformity of the distribution of the paste between the first conductor 12 and the surface of the cell 21 in the second direction Y is improved. Thus, in the process of transferring the grid lines, the bonding force between the first conductor 12 and the cell 21 can be made uniform in the second direction Y, thereby improving the connection stability between the grid lines and the cell 21. Therefore, by making L2 and L1 satisfy the above relationship, it is advantageous to improve the connection stability between the grid lines and the cell 21 while also being advantageous to reduce the amount of paste used.

[0060] In one embodiment, as shown in Figures 1 and 4, the dimension W1 of the notch of the first groove 11a along the second direction Y is greater than or equal to the dimension W2 of the first conductor 12 along the second direction Y, and the second direction Y is perpendicular to the first direction X and the extending direction of the first groove 11a. Here, the extending direction of the first groove 11a is the longitudinal direction of the first groove 11a.

[0061] Thus, during the process of transferring the grid lines, the first conductor 12 is prone to falling out of the first groove 11a.

[0062] In one embodiment, as shown in Figure 1, the dimension L3 of the first conductor 12 along the first direction X is 1 μm to 220 μm. Here, the dimension of the first conductor 12 along the first direction X means the maximum dimension of the first conductor 12 along the first direction X. Exemplarily, L3 may be 1 μm, 10 μm, 30 μm, 50 μm, 80 μm, 110 μm, 150 μm, 175 μm, 200 μm, 210 μm, or 220 μm.

[0063] In this way, the thickness or diameter of the first conductor 12 can be increased to improve the carrier collection capability of the grid wire, while the amount of paste used can be reduced, thereby lowering costs.

[0064] In one embodiment, as shown in Figure 4, the dimension W2 of the first conductor 12 along the second direction Y is 5 μm to 220 μm. Here, the dimension of the first conductor 12 along the second direction Y means the maximum dimension of the first conductor 12 along the second direction Y. Exemplarily, W2 may be 5 μm, 15 μm, 30 μm, 45 μm, 65 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 190 μm, 205 μm, or 220 μm.

[0065] Thus, assuming the carrier collection capability of the grid lines is guaranteed, the width of the grid lines can be kept within a reasonable range, thereby reducing the shielding of sunlight by the grid lines.

[0066] In one embodiment, as shown in Figures 6 and 7, the first surface 11 of the carrier 11 is provided with a plurality of first grooves 11a spaced apart along the second direction Y, and the transfer module 10 includes a plurality of first conductors 12 spaced apart along the second direction Y, each first conductor 12 and each first groove 11a extending along the third direction Z, and each first conductor 12 is at least partially located in each first groove 11a in a one-to-one correspondence. The third direction Z intersects the second direction Y.

[0067] In one embodiment, the distance between any two adjacent first conductors 12 is a first distance L5, and the first distance L5 is between 200 μm and 2000 μm. Exemplarily, the first distance L5 may be 200 μm, 300 μm, 500 μm, 700 μm, 900 μm, 1000 μm, 1300 μm, 1600 μm, 1800 μm, 1900 μm, or 2000 μm.

[0068] Thus, assuming the carrier collection capability of the grid lines is guaranteed, the grid line arrangement density can be kept within a reasonable range, thereby reducing the shielding of sunlight by the grid lines.

[0069] In one embodiment, the first conductor 12 includes a connected main body and a large diameter portion, and the dimension of the large diameter portion along the second direction Y is larger than the dimension of the main body along the second direction Y. In this way, the grid line after transfer can be electrically connected to the main grid line or solder ribbon by the large diameter portion, thereby reducing the difficulty of electrical connection.

[0070] As can be understood, the dimension of the first groove 11a corresponding to the large diameter portion along the second direction Y is larger than the dimension of the first groove 11a corresponding to the main body portion along the second direction Y.

[0071] In one embodiment, the carrier 11 has a central region and edge regions located on both sides of the central region along a second direction Y. The first groove includes a central groove and an edge groove, and the first conductor includes a central conductor and an edge conductor, with the central groove and the central conductor within it located in the central region, and the edge groove and the edge conductor within it located in the edge region.

[0072] In one embodiment, the edge region includes at least one retraction region, the retraction region spans at least two edge grooves and at least two edge conductors within them, the edge grooves and edge conductors within them are separated in the retraction region and form at least two spaced sub-grooves and at least two sub-conductors.

[0073] In this way, the retraction area can be used to recede the main grid lines or solder ribbons, reducing the thickness of the main grid lines or solder ribbons at the edges of the cell and reducing the risk of chipping.

[0074] In some embodiments, the extended length of each first groove 11a is the same as the extended length of the corresponding first conductor 12.

[0075] In one embodiment, a connection groove is further provided on the first surface of the transfer module, the transfer module further includes a connecting conductor, the connecting conductor is at least partially installed in the connection groove, the connection groove and the connecting conductor therein are installed at the edge of a retractable area, the connection groove communicates with the same-side sub-grooves of the at least two edge grooves, the connecting conductor is connected to the same-side sub-conductor of the at least two edge conductors, the connecting conductor and the groove wall of the connection groove define a connection receiving cavity for accommodating paste on the side of the connecting conductor closer to the notch of the connection groove, and the connecting conductor is arranged to be detachable from the connection groove by the action of external energy. In some embodiments, the connection groove and the connecting conductor therein may further extend to an adjacent central groove having a central conductor. Thus, the sub-portions of the edge conductors may be electrically connected by the connecting conductor to adjacent first conductors 12, for example, adjacent central conductors.

[0076] In one embodiment, as shown in Figure 1, the first conductor 12 includes a conductive core wire 121 and an oxidation-preventive layer 122 covering the outer circumference of the conductive core wire 121, the oxidation-preventive layer 122 containing a metallic material. As can be understood, the oxidation-preventive capacity of the oxidation-preventive layer 122 is greater than that of the conductive core wire 121, and by providing the oxidation-preventive layer 122 on the outer circumference of the conductor, oxidation of the conductive core wire 121 can be avoided and the conductive performance of the conductive core wire 121 can be guaranteed. The oxidation-preventive capacity can be expressed by the oxidation rate, with a faster oxidation rate resulting in weaker oxidation-preventive capacity and a slower oxidation rate resulting in stronger oxidation-preventive capacity.

[0077] In one embodiment, the material of the conductive core wire 121 includes copper or aluminum. In this way, the conductivity of the first conductor 12 can be increased while reducing costs.

[0078] In one example, the conductive core wire 121 is a copper wire or an aluminum wire.

[0079] In another example, the conductive core wire 121 includes a plurality of conductive particles, wherein adjacent conductive particles are in contact with each other. Exemplarily, the conductive particles may be at least one of copper particles and aluminum particles.

[0080] Furthermore, voids exist between adjacent conductive particles, and these voids are filled with organic material.

[0081] In one embodiment, the material of the antioxidant layer 122 includes at least one of silver, tin, lead, titanium, and nickel.

[0082] As can be understood, the first conductor 12 may be a copper wire or an aluminum wire. The first conductor 12 may also contain a plurality of conductive particles arranged in contact with each other within the first groove 11a. Furthermore, voids exist between adjacent conductive particles, and these voids are filled with an organic material.

[0083] As shown in Figures 4 and 5, the cross-sectional shape of the first conductor 12 may be cylindrical or triangular. To be understood, the cross-sectional shape of the first conductor 12 may be any shape, such as a trapezoid, rectangle, or square.

[0084] In one embodiment, the carrier 11 is configured as a flexible member. For example, the material of the carrier 11 may be a high-temperature resistant polymer material.

[0085] By making the carrier 11 a flexible member, the transfer module 10 is made easier to wind up and store, reducing the difficulties in the transportation and storage process of the transfer module 10. However, during the transfer process, the carrier 11 deforms after receiving heat, making it easier for air to enter between the first conductor 12 and the groove wall of the first groove 11a. After the air is heated, it generates thrust, which makes it easier for the first conductor 12 to fall out of the first groove 11a.

[0086] As can be understood, the carrier 11 may be a rigid structural member. In the embodiments of this application, the material of the carrier 11 is not limited.

[0087] Furthermore, the carrier 11 may be manufactured from a transparent material, thereby broadening the selectable range of laser wavelengths when laser transfer is performed. As can be seen, the carrier 11 may be manufactured from a translucent or opaque material.

[0088] In one embodiment, as shown in Figure 8, the first surface of the carrier 11 is further provided with a second groove 11c that intersects with the first groove 11a. The transfer module 10 further includes a second conductor 13 that intersects with the first conductor 12, and at least a portion of the second conductor 13 is provided in the second groove 11c. The second conductor 13 and the groove wall of the second groove 11c define a second containment cavity on the side of the second conductor 13 closer to the notch of the second groove 11c, and the second containment cavity contains the paste. The second conductor 13 is configured to be able to detach from the second groove 11c by external energy.

[0089] Thus, after the transfer is complete, the first conductor 12 and the paste in the first housing cavity 11b constitute the microgrid lines, and the second conductor 13 and the paste in the second housing cavity constitute the main grid lines. The main grid lines are used to connect to an external circuit or another solar cell via a solder ribbon. In the embodiment of the present invention, the main grid lines and microgrid lines are manufactured simultaneously in the same transfer process, thereby reducing the manufacturing cost of the solar cell 20.

[0090] The arrangement of the second conductor 13 may be the same as that of the first conductor 12, and the arrangement of the second groove 11c may be the same as that of the first groove 11a. In this embodiment, the arrangement of the second conductor 13 and the second groove 11c will not be described.

[0091] In a second embodiment, as shown in Figures 9 to 13, the embodiment of the present application provides a solar cell 20, which may be a heterojunction solar cell, a Topcon cell, or the like. Specifically, the solar cell includes a cell 21 and a plurality of first grid lines 22, the cell 21 having a first surface 21a and a second surface 21b that are provided opposite to each other. A plurality of first grid lines 22 are provided on both the first surface 21a and the second surface 21b, spaced apart from each other.

[0092] Each first grid line 22 includes a stacked first metal layer 221 and a first conductor 12, the first metal layer 221 being made of paste and connected to the cell 21.

[0093] Here, the first conductor 12 is the first conductor 12 of the transfer module 10 in the embodiment of the first aspect, and the first metal layer 221 is formed by transferring the paste filled in the first housing cavity 11b of the transfer module 10.

[0094] The grid lines of the solar cell 20 according to the embodiment of the present invention can be manufactured by the transfer module 10, and on the one hand, the manufacturing cost can be reduced compared to grid lines manufactured by an electroplating process. On the other hand, compared to grid lines manufactured by a screen printing process, it is advantageous for controlling the width of the grid lines because the paste is filled into the grooves, making it easier to manufacture grid lines with a narrow width. On the other hand, by providing the first conductor 12 in the grooves, it is advantageous for reducing paste loss.

[0095] In one embodiment, as shown in Figure 9, the orthographic projection of the first conductor 12 onto cell 21 is within the range of the orthographic projection of the first metal layer 221 onto cell 21. This may include both a first type, where the orthographic projection of the first metal layer 221 onto cell 21 completely overlaps with the orthographic projection of the first conductor 12 onto cell 21, and a second type, where the area of ​​the orthographic projection of the first metal layer 221 onto cell 21 is larger than the area of ​​the orthographic projection of the first conductor 12 onto cell 21.

[0096] Because the adhesion between the first metal layer 221 and the cell 21 is greater than the adhesion between the first conductor 12 and the cell 21, the first metal layer 221 can be positioned completely between the first conductor 12 and the cell 21, thereby improving the bonding force between the first grid line 22 and the cell 21.

[0097] In one embodiment, the distance between two adjacent first grid lines 22 on the same side of cell 21 is the first distance, and the first distance is 200 μm to 2000 μm. Here, as shown in Figure 7, the first distance is L5. Exemplaryly, the first distance L5 may be 200 μm, 300 μm, 500 μm, 700 μm, 900 μm, 1000 μm, 1300 μm, 1600 μm, 1800 μm, 1900 μm, or 2000 μm.

[0098] Thus, assuming the carrier collection capability of the first grid line 22 is guaranteed, the arrangement density of the first grid line 22 can be kept within a reasonable range, thereby reducing the shielding of sunlight by the first grid line 22.

[0099] In one embodiment, as shown in Figure 10, the first grid line 22 has a minimum spacing S between it and the edge of the cell 21, and the minimum spacing S is 50 μm to 1500 μm. Exemplarily, the minimum spacing S may be 50 μm, 65 μm, 75 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 300 μm, 500 μm, 600 μm, 800 μm, 1000 μm, 1200 μm, 1400 μm, or 1500 μm.

[0100] By setting the minimum interval S within the above range, the risk of short-circuiting of cell 21 is reduced, while the arrangement area of ​​the first grid line 22 can be maximized, thereby improving the carrier collection capability of the first grid line 22.

[0101] In one embodiment, as shown in Figure 11, the first grid line 22 includes a connected main body portion 22a and a large diameter portion 22b, and the width of the large diameter portion 22b is greater than the width of the main body portion 22a.

[0102] In this way, the main grid line or solder ribbon can be electrically connected to the first grid line 22 by the large diameter portion 22b, thereby reducing the difficulty of electrical connection.

[0103] In one embodiment, the width of the large diameter portion 22b is L7, and L7 is 15 μm to 1000 μm. Exemplarily, L7 may be 15 μm, 100 μm, 200 μm, 350 μm, 500 μm, 650 μm, 720 μm, 840 μm, 900 μm, 950 μm, or 1000 μm.

[0104] Furthermore, the length of the large diameter portion 22b is L8, and L8 is between 100 μm and 5000 μm. For example, L8 may be 100 μm, 800 μm, 1500 μm, 2400 μm, 3000 μm, 3800 μm, 4500 μm, or 5000 μm.

[0105] In this way, the difficulty of electrical connection between the main grid line or solder ribbon and the first grid line 22 can be reduced.

[0106] In one embodiment, as shown in Figures 10 and 12, cell 21 has a central region and edge regions located on both sides of the central region. The first grid line 22 includes a central grid line located in the central region and edge grid lines located in the edge regions.

[0107] In one embodiment, the edge region includes at least one retracted region 22d that spans at least two edge grid lines, and the edge grid lines are separated in the retracted region to form at least two subgrid portions 22c that are spaced apart from each other.

[0108] In this way, the retraction area 22d can retract the main grid lines or solder ribbons, reducing the thickness of the main grid lines or solder ribbons at the edges of the cell 21 and reducing the risk of chipping.

[0109] In one embodiment, the solar cell 20 further includes a connecting grid line 22e provided within a retracted area 22d, the connecting grid line 22e being provided at the edge of the retracted area 22d and connecting the same-side subgrid portions 22c of two adjacent edge grid lines. In some embodiments, the connecting grid line 22e may further extend to an adjacent central grid line. Thus, the subgrid portions 22c of the edge grid lines may be electrically connected by the connecting grid line 22e to an adjacent first grid line 22, for example, a central grid line.

[0110] In one embodiment, the solar cell 20 further includes a second grid line, and at least one of the first surface 21a and the second surface 21b is provided with a second grid line electrically connected to the first grid line 22. Here, the second grid line corresponds to the main grid line. In one example, the orthographic projection of the second grid line onto the cell 21 and the orthographic projection of the wide-diameter portion 22b of the first grid line 22 onto the cell 21 have an overlapping region, that is, the second grid line is connected to the wide-diameter portion 22b of the first grid line 22. In this way, the difficulty of electrical connection between the second grid line and the first grid line 22 can be reduced. In another example, a portion of the orthographic projection of the second grid line onto the cell 21 is located within a retracted region 22d. In this way, the thickness of the second grid line at the edge of the cell 21 can be reduced, and the risk of chipping can be reduced.

[0111] In one embodiment, as shown in Figure 13, the cell 21 includes a first transparent conductive layer 211, a first doped layer 212, a first intrinsic semiconductor layer 213, a silicon substrate 214, a second intrinsic semiconductor layer 215, a second doped layer 216, and a second transparent conductive layer 217, which are stacked in order. The first surface 21a is located on the side of the first transparent conductive layer 211 away from the silicon substrate 214, and the second surface 21b is located on the side of the second transparent conductive layer 217 away from the silicon substrate 214. In this way, by applying the grid line structure according to the embodiment of the present application to a heterojunction solar cell, the manufacturing cost of the heterojunction solar cell can be reduced.

[0112] In one example, the first intrinsic semiconductor layer 213 may be an intrinsic amorphous silicon layer or an oxygen-containing intrinsic amorphous silicon layer, and the second intrinsic semiconductor layer 215 may be an intrinsic amorphous silicon layer or an oxygen-containing intrinsic amorphous silicon layer.

[0113] In a third embodiment, as shown in Figures 14 and 15, an embodiment of the present application provides a method for manufacturing a solar cell, the method for manufacturing the solar cell comprising the following steps S100 to S400.

[0114] Step S100 provides cell 21 and the transfer module 10 described in any of the embodiments of the first embodiment.

[0115] In step S200, paste is filled into the first containment cavity 11b of the transfer module 10. Exemplarily, paste is applied to the first surface 111 of the carrier 11 to fill the first containment cavity 11b with paste.

[0116] In step S300, the transfer module is placed on the transfer surface of the cell 21, and energy is applied to the transfer module 10 to transfer the first wire 12 and paste to the transfer surface. Here, the transfer surface may be the surface of the cell 21. For example, energy can be applied to the region of the carrier 11 where the first groove 11a is provided by heating or laser irradiation, and the first wire 12 and paste fall onto the transfer surface due to the energy and make firm contact with the transfer surface.

[0117] In step S400, the paste in cell 21 is cured. For example, cell 21 can be dried or sintered to form a metal layer from the paste, thereby forming an ohmic contact between the first conductor 12, the metal layer, and cell 21.

[0118] The solar cell manufacturing method according to the embodiment of the present invention manufactures grid lines by transfer, which is advantageous in reducing manufacturing costs compared to the electroplating process. On the other hand, compared to the screen printing process, it is advantageous in controlling the width of the grid lines because the paste is filled into the grooves, making it easier to manufacture grid lines with a narrow width. On the other hand, by providing the first conductor 12 in the grooves, it is advantageous in reducing paste loss.

[0119] Furthermore, if the solar cell 20 includes main grid lines and subgrid lines, the main grid lines and subgrid lines may be manufactured as follows: In the first method, the subgrid lines are first manufactured by the method described above, and then the main grid lines are manufactured by screen printing. In the second method, the main grid lines and subgrid lines are manufactured simultaneously by the method described above, that is, they are formed by simultaneous transfer. In the embodiments of the present application, the arrangement method of the main grid lines is not limited.

[0120] It should be understood that in the embodiments of this application, at least part of the steps in the method may include multiple steps or stages, and these steps or stages do not necessarily have to be completed at the same time, but may be performed at different times, and the order in which these steps or stages are performed does not necessarily have to be sequential, but may be performed sequentially or alternately with other steps or at least part of the steps or stages in other steps.

[0121] Each of the technical features in the above embodiments can be combined in any way, and for the sake of brevity, not all possible combinations of each technical feature in the above embodiments are described. However, as long as there is no inconsistency in these combinations of technical features, they should be considered to fall within the scope described herein.

[0122] The above embodiments illustrate only a few embodiments of the present application, and while the descriptions are more specific and detailed, this should not be understood as limiting the scope of protection of the present application. Furthermore, those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and all of these fall within the scope of protection. Therefore, the scope of protection of the present application shall be in accordance with the attached claims. [Explanation of symbols]

[0123] 10 Transfer module, 11 Carrier, 11a First groove, 11b First housing cavity, 11c Second groove, 111 First surface, 112 Second surface, 12 First conductor, 121 Conductive core wire, 122 Antioxidant layer, 13 Second conductor, 20 Solar cell, 21 Cell, 21a First surface, 21b Second surface, 211 First transparent conductive layer, 212 First dope layer, 213 First intrinsic semiconductor layer, 214 Silicon substrate, 215 Second intrinsic semiconductor layer, 216 Second dope layer, 217 Second transparent conductive layer, 22 First grid line, 221 First metal layer, 22a Main body, 22b Large diameter section, 22c Subgrid section, 22d Recessed area, 22e Connecting grid line.

Claims

1. Including the carrier and the first lead wire, The carrier has a first surface and a second surface opposite to the first surface, the direction from the first surface to the second surface is defined as the first direction, and the first surface is provided with a first groove. At least a portion of the first conductor is provided in the first groove, and the first conductor and the groove wall of the first groove define a first containment cavity on the side of the first conductor closest to the notch of the first groove, and the first containment cavity is for containing paste. The first conductor is configured to be able to detach from the first groove due to external energy, A transfer module characterized in that a portion of the first conductor extends in the first direction from a notch in the first groove, the cross-section obtained by cutting the first conductor along the first direction has one end away from the first groove, and the distance between this end and the notch in the first groove is greater than 0 μm and 200 μm or less.

2. The transfer module according to claim 1, wherein the outer surface of the first conductor includes an inner portion close to the second surface, and the inner portion is bonded to the groove wall of a part of the first recess.

3. The transfer module according to claim 2, characterized in that the dimension of the notch of the first groove along the second direction is greater than or equal to the dimension of the first conductor along the second direction, and the second direction is perpendicular to the first direction and the extending direction of the first groove.

4. The dimension of the first conductor along the first direction is 1 μm to 220 μm. The transfer module according to claim 3, characterized in that and / or the dimension of the first conductor along the second direction is 5 μm to 220 μm.

5. The first surface of the carrier is provided with a plurality of first grooves spaced apart along a second direction, and the transfer module includes a plurality of first wires spaced apart along the second direction, each of the first wires and each of the first grooves extends along a third direction, and each of the first wires corresponds one-to-one and is at least partially located in each of the first grooves. The transfer module according to any one of claims 1 to 4, characterized in that the distance between any two adjacent first conductors is a first distance, and the first distance is between 200 μm and 2000 μm.

6. The transfer module according to claim 5, characterized in that the first conductor includes a connected main body and a large diameter portion, and the dimension of the large diameter portion along the second direction is greater than the dimension of the main body along the second direction.

7. The carrier has a central region and edge regions located on both sides of the central region along the second direction, The first groove includes a central groove and an edge groove, the first conductor includes a central conductor and an edge conductor, the central groove and the central conductor within it are arranged in the central region, and the edge groove and the edge conductor within it are arranged in the edge region. The transfer module according to claim 5, wherein the edge region includes at least one retraction region spanning at least two edge grooves and at least two edge wires therein, and the edge grooves and the edge wires therein are separated in the retraction region to form at least two spaced sub-grooves and at least two sub-wires.

8. A connection groove is further provided on the first surface of the transfer module, and the transfer module further includes a connecting wire, the connecting wire being at least partially installed in the connection groove. The connecting groove and the connecting wire within it are installed at the edge of the retraction area, the connecting groove communicates with the same side sub-grooves of the at least two edge grooves, and the connecting wire is connected to the same side sub-wire of the at least two edge wires. The transfer module according to claim 7, characterized in that the connecting wire and the groove wall of the connecting groove define a connecting cavity for accommodating paste on the side of the connecting wire closest to the notch of the connecting groove, and the connecting wire is arranged to be detachable from the connecting groove by the action of external energy.

9. The transfer module according to any one of claims 1 to 4, characterized in that the first conductor includes a conductive core wire and an anti-oxidation layer covering the outer circumference of the conductive core wire, and the anti-oxidation layer includes a metallic material.

10. The material of the conductive core wire includes copper or aluminum. The transfer module according to claim 9, characterized in that the material of the oxidation-preventive layer includes at least one of silver, tin, lead, titanium, and nickel.

11. The transfer module according to any one of claims 1 to 4, characterized in that the carrier is configured as a flexible member.

12. The first surface of the carrier is further provided with a second groove intersecting the first groove, and the transfer module further includes a second conductor intersecting the first conductor, at least a portion of which is provided within the second groove, and the second conductor and the groove wall of the second groove define a second containment cavity on the side of the second conductor closer to the notch of the second groove, the second containment cavity for containing paste, The transfer module according to any one of claims 1 to 4, characterized in that the second conductor is configured to be able to detach from the second groove by external energy.

13. The steps of providing a cell and a transfer module according to any one of claims 1 to 4, The steps include filling the first housing cavity of the transfer module with paste, The steps include: placing the transfer module on the transfer surface of the cell, applying energy to the transfer module to transfer the first wire and the paste to the transfer surface; A method for manufacturing a solar cell, comprising the step of performing a curing treatment on the paste in the cell.

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