Hybrid dense solar cells and interconnects for solar modules and related manufacturing methods

Abstract

The present invention provides a solar module, the solar module comprising at least one first solar cell and at least one second solar cell, each solar cell comprising a top side and a bottom side, a bus bar, and a plurality of wires arranged on the top side, the plurality of wires extending from the bus bar and electrically connected to the bus bar. The first solar cell overlaps an area of ​​the second solar cell to be electrically connected to the second solar cell and form a shingled arrangement, and in the second solar cell, the plurality of wires are connected to the bus bar outside the area where the first solar cell overlaps the second solar cell. A method of manufacturing a solar module comprises using ECA shingled solar cells to make a hybrid dense solar cell string, the hybrid dense solar cell string comprising at least two hybrid dense solar cells in a shingled arrangement.

Description

Technical Field

[0001] The present disclosure generally relates to solar cell modules, methods of making solar cell modules, and a series of solar cells arranged in a shingled manner. Background Art

[0002] Alternative energy sources are needed to meet the world's growing energy needs. In many geographic areas, electricity generated in part by solar resources using solar (e.g., photovoltaic) cells is sufficient to meet this demand.

[0003] To accelerate the realization of widespread applications of electricity generated by solar cells, more efficient and lower cost solar cells are needed. Conventional solar cells and conventional methods of producing solar cells rely on high cost materials, which unnecessarily increase the cost of the produced cells. An alternative method of maintaining or improving solar cell efficiency using hybrid materials is needed. Summary of the invention

[0004] Hybrid dense solar cells and interconnects for solar cell modules and methods of making such devices are described herein.

[0005] In one exemplary aspect, a solar module includes at least one first solar cell and at least one second solar cell, the first solar cell and the second solar cell each including: a top side and a bottom side, a bus bar, and a plurality of wires arranged on the top side, the plurality of wires extending from the bus bar and electrically connected to the bus bar, wherein the first solar cell overlaps a region of the second solar cell to be electrically connected to the second solar cell and form a stacked arrangement, and in the second solar cell, the plurality of wires are connected to the bus bar outside the region where the first solar cell overlaps the second solar cell.

[0006] In one exemplary aspect, the bus bar of the first solar cell and the bus bar of the second solar cell are composed of a first metal, and the plurality of wires are composed of a second metal that is different from the first metal.

[0007] In one exemplary aspect, the plurality of wires are made of copper metal or an alloy thereof.

[0008] In one exemplary aspect, the bus bar is made of silver metal or an alloy thereof.

[0009] In one exemplary aspect, each bus bar includes a plurality of load pads, and each of the plurality of wires is connected to a load pad of the plurality of load pads.

[0010] In an exemplary aspect, each load pad includes a main portion and an extension portion, the main portion is disposed within the overlap region and the extension portion is at least partially disposed outside the overlap region, and each of the plurality of wires is connected to the extension portion of the corresponding load pad.

[0011] In one exemplary aspect, the extension portion of each load pad extends away from the main portion of the load pad.

[0012] In one exemplary aspect, the bus bar includes a first portion extending between main portions of the load pad, and each main portion of the load pad has a width greater than a width of the first portion of the bus bar.

[0013] In one exemplary aspect, each solar cell further includes a plurality of fingers extending in a direction perpendicular to the plurality of lines; and the plurality of lines have a resistance smaller than a resistance of the fingers.

[0014] In one exemplary aspect, each solar cell further comprises a plurality of fingers extending in a direction perpendicular to the plurality of lines; and wherein the plurality of fingers are comprised of a first metal and the plurality of lines are comprised of a second metal that is different from the first metal.

[0015] In one exemplary aspect, each solar cell further includes a plurality of fingers extending in a direction perpendicular to the plurality of lines; and wherein a spacing between the plurality of fingers is smaller than a spacing between adjacent lines of the plurality of lines.

[0016] In one exemplary aspect, a conductive adhesive connects the first solar cell to the second solar cell in the region.

[0017] In one exemplary aspect, each of the plurality of wires has a circular cross-sectional shape.

[0018] In one exemplary aspect, each of the plurality of wires has a triangular cross-sectional shape.

[0019] In an exemplary aspect, each of the plurality of lines is oriented such that the plurality of fingers are in contact with a base of a triangular cross-sectional shape.

[0020] In one exemplary aspect, the plurality of wires extend generally perpendicular to the bus bar.

[0021] In one exemplary aspect, a method for manufacturing a solar module includes: providing at least one first solar cell and at least one second solar cell, the first solar cell and the second solar cell each including: a top side and a bottom side, a bus bar, and a plurality of wires arranged on the top side, the plurality of wires extending from the bus bar and electrically connected to the bus bar; and arranging the first solar cell to overlap with an area of ​​the second solar cell to be electrically connected to the second solar cell and form a stacking arrangement, wherein in the second solar cell, the plurality of wires are connected to the bus bar outside the area.

[0022] In one exemplary aspect, the method further includes attaching each of the plurality of wires to a corresponding solar cell using infrared radiation (IR) welding.

[0023] In one exemplary aspect, the method further includes printing a conductive adhesive onto the plurality of wires to attach each of the plurality of wires to a corresponding solar cell.

[0024] In one exemplary aspect, the method further includes coating each of the plurality of wires with a coating material; and heating the coating material to attach the plurality of wires to the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] A more complete appreciation of the various aspects of the present disclosure and its attendant advantages will be more readily obtained by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0026] Figure 1 is a side view of a super cell formed by a string of stacked hybrid compact solar cells according to an exemplary aspect of the present disclosure;

[0027] Figure 2a shows a front view of a first solar module according to an exemplary aspect of the present disclosure, the first solar module comprising a plurality of interconnected super cells;

[0028] Figure 2b showing a front view of a second solar module including a plurality of interconnected super cells according to an exemplary aspect of the present disclosure;

[0029] Figure 3 shows a front surface metallization pattern of a hybrid compact solar cell according to an exemplary aspect of the present disclosure;

[0030] Figure 4a is an enlarged view of a solar cell according to an exemplary aspect of the present disclosure, the solar cell including a bus bar and a load pad;

[0031] Figure 4bis an enlarged view of a solar cell according to an exemplary aspect of the present disclosure, the solar cell including a bus bar and a load pad;

[0032] Figure 4c is an enlarged view of a solar cell according to an exemplary aspect of the present disclosure, the solar cell including only a load pad and not a bus bar;

[0033] Figure 5 is a cross-sectional view of two hybrid compact solar cells attached in a shingled arrangement according to an exemplary aspect of the present disclosure;

[0034] Figure 6 According to an exemplary aspect of the present disclosure Figure 5 A magnified view of the overlapping portion of a hybrid compact solar cell;

[0035] Figure 7 showing a circular cross-sectional shape of a wire according to an exemplary aspect of the present disclosure;

[0036] Figure 8 showing a triangular cross-sectional shape of a wire according to an exemplary aspect of the present disclosure;

[0037] Fig. 9 According to an exemplary aspect of the present disclosure, Figure 8 An enlarged cross-sectional view of a hybrid compact solar cell having a triangular cross-sectional shape of a line;

[0038] Fig.10 shows a front surface metallization pattern of a hybrid compact solar cell according to an exemplary aspect of the present disclosure;

[0039] Fig.11 According to an exemplary aspect of the present disclosure Fig.10 A magnified view of a hybrid compact solar cell before attaching wires;

[0040] Fig.12 According to an exemplary aspect of the present disclosure Fig.10 A magnified view of a hybrid compact solar cell after attaching wires;

[0041] Fig.13 is a cross-sectional view of two hybrid compact solar cells attached in a shingled arrangement according to an exemplary aspect of the present disclosure;

[0042] Fig.14 shows a front surface metallization pattern of a hybrid compact solar cell according to an exemplary aspect of the present disclosure;

[0043] Fig.15 According to an exemplary aspect of the present disclosure Fig.14 A magnified view of a hybrid compact solar cell;

[0044] Fig.16 showing a cross-sectional view of two hybrid compact solar cells attached in a shingled arrangement according to an exemplary aspect of the present disclosure;

[0045] Fig.17 is a block diagram of a method for manufacturing a super energy battery according to an exemplary aspect of the present disclosure;

[0046] Fig.18 shows a hybrid dense solar cell wafer including several hybrid dense solar cells before attaching wires according to an exemplary aspect of the present disclosure; and

[0047] Fig.19 A hybrid dense solar cell wafer including several hybrid dense solar cells is shown after attaching wires according to an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0048] The following detailed description should be read with reference to the accompanying drawings, in which the same reference numerals refer to similar elements throughout the different drawings. The accompanying drawings (not necessarily drawn to scale) depict exemplary aspects and are not intended to limit the scope of the present disclosure. The detailed description illustrates, by way of example and not limitation, exemplary principles that enable one skilled in the art to make and use the apparatus and methods defined by the claims. Of course, as will be appreciated by one of ordinary skill in the art, the present disclosure and the appended claims cover numerous variations and arrangements of the features described herein.

[0049] Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" used in this specification and the appended claims include plural referents. In addition, the term "parallel" is used to mean "parallel or approximately parallel", covering slight deviations from parallel geometry, and does not require that any parallel arrangement described herein is completely parallel. The term "perpendicular" is used to mean "perpendicular or approximately perpendicular", covering slight deviations from perpendicular geometry, and does not require that any perpendicular arrangement described herein is completely perpendicular. The term "square" is used to mean "square or approximately square", covering slight deviations from square, such as a generally square shape with chamfered (such as rounded or other truncated) corners. The term "rectangular" is used to mean "rectangular or approximately rectangular", covering slight deviations from rectangle, such as a generally rectangular shape with chamfered (such as rounded or other truncated) corners.

[0050] This specification describes high efficiency hybrid dense solar cells (HDSCs), HDSC interconnects, and series connected HDSC strings or "super cells," as well as front and rear surface metallization patterns of solar cells and associated interconnects that can be used in such arrangements. This specification also describes methods of making the HDSCs, HDSC interconnects, and strings or super cells. The solar cell modules can advantageously be used under "one sun" (non-concentrated) illumination, and can have physical dimensions and electrical specifications that allow them to replace crystalline silicon solar cell modules.

[0051] This specification also describes that two or more objects are "electrically connected," or that two or more elements can be in an "electrically connected" state. An electrical connection is established between two or more conductive materials so that electrons can flow substantially freely through the materials in a given direction when subjected to an electrical load. In other words, two elements are considered to be in an electrically connected state when electric current can flow easily through them.

[0052] Figure 1 A super cell 1 is shown that includes a plurality of hybrid compact solar cells 10 in a stacked arrangement according to an exemplary aspect of the present disclosure. Each solar cell 10a, 10b, 10c includes a semiconductor diode structure and its electrical contacts, through which current generated in the solar cell 10 when illuminated by light can be provided to an external load.

[0053] In one or more examples described in this specification, each solar cell 10 is a crystalline silicon solar cell having front and rear surface metallization patterns that provide electrical contacts to opposite sides of an np junction. The front surface metallization pattern is disposed on a semiconductor layer of n-type conductivity, and the rear surface metallization pattern is disposed on a semiconductor layer of p-type conductivity. However, any other suitable solar cell using any other suitable material system, diode structure, physical size, or electrical contact arrangement may replace or assist the solar cell 10 in the solar module described in this specification. For example, the front surface (sun side) metallization pattern may be disposed on a semiconductor layer of p-type conductivity, and the rear surface metallization pattern may be disposed on a semiconductor layer of n-type conductivity.

[0054] refer to Figure 1, the super cell 1 may include a string of shingled solar cells 10 connected in series such that a first solar cell 10a is positioned to overlap at least partially with at least a portion of a second solar cell 10b, which is positioned to overlap at least partially with a third solar cell 10c, and so on (not all solar cells are labeled). The degree of overlap may vary without departing from the scope of the present disclosure. For example, the amount by which the first solar cell 10a overlaps the second solar cell 10b may be approximately 2%-6% or less of the length of the solar cell 10a. Additionally, the amount by which the solar cell 10a overlaps the second solar cell 10b may exceed 2% to 6% of the length of the solar cell 10a, or any amount therebetween, without departing from the scope of the present disclosure. In one exemplary aspect, the amount by which the solar cell 10a overlaps the solar cell 10b may be in the range of about 0 mm to about 1.5 mm. In other exemplary aspects, the amount by which the solar cell 10a overlaps the solar cell 10b may be in the range of about 0.5 mm to about 1.5 mm. The amount of overlap can be determined based on various factors, including but not limited to the total length of the overlapping solar cells, the weight or thickness of the solar cells, the materials used to connect the solar cells, the flexibility content required when assembling the super-energy cell, the shape of the edges of the overlapping solar cells (e.g., linear edges, non-linear or "wavy" edges, etc.), the amount of front surface exposed to sunlight required, the conductivity required between adjacent solar cells 10, etc.

[0055] Figure 2a A front (sun-side) view of a first solar module M1 is shown, according to an exemplary aspect of the present disclosure, comprising a plurality of electrically interconnected super cells 1a, 1b, 1c, 1d, etc. (not all super cells are labeled). Solar module M1 may include any number of interconnected super cells. In the non-limiting example of FIG. 2 , six super cells are shown. Figure 2b A front (sun-side) view of a second solar module M2 is shown, including a total of five electrically interconnected super cells 2a, 2b, 2c, 2d, 2e, according to an exemplary aspect of the present disclosure.

[0056] Figure 3 A front metallization pattern of a solar cell 10 according to an exemplary aspect of the present disclosure is shown. The solar cell 10 may include a semiconductor layer 102, a bus bar 104, a finger 106, and a wire 108. Free electrons in the semiconductor layer move from the semiconductor layer through the finger 106 to the wire 108, and then to the bus bar 104. Electrons may move from the bus bar 104 to adjacent connected solar cells, thereby forming an electric current through the super cell 1. In some exemplary aspects, the bus bar 104 may be made of silver or tin material.

[0057] In one exemplary aspect, the front surface metallization pattern including the busbars 104, discrete contact pads or load pads 110, and / or fingers 106 can be formed from, for example, a silver paste used for such purposes and deposited by, for example, a screen printing method. In one exemplary aspect, a continuous busbar having a continuous width along the edge of the solar cell (e.g., Figure 4b Instead of having a combination of bus bars and load pads with different widths along the edge of the battery (as shown in Figure 4a In one exemplary aspect, a portion or all of the front surface metallization pattern may be formed of electroplated copper. In other exemplary aspects, other suitable materials and processes may also be used to form the metallization pattern. In one exemplary aspect in which the front surface metallization pattern is formed of silver, separate front surface contact pads or load pads 110 (such as Figure 4c 104 along the edge of the cell to reduce the silver content on the solar cell, which can advantageously reduce costs by reducing the amount of material used for the metallization pattern. In other exemplary aspects where the front surface metallization pattern is formed of copper or another conductor that is less expensive than silver, a continuous bus bar 104 with or without discrete contact pads or continuous pads 110 can be used without cost disadvantages. Other conductive materials suitable for conducting electrons from one solar cell to an adjacent connected solar cell can be used alone or in combination with the bus bar 104 and / or load pad 110. For example, an electrically conductive adhesive (ECA) can be used to form the bus bar 104 and / or load pad 110 to perform the current collecting function of the bus bar, contact pad and / or load pad.

[0058] In one exemplary aspect, the bus bar 104 can be printed onto the semiconductor layer using a metal printing method. In some exemplary aspects, the bus bar 104 can extend parallel to the fingers 102. In addition, the bus bar 104 can include intermittently spaced load pads 110 that can be used to connect adjacent solar cells 10 in a stacked arrangement (see FIG. 1 ). Figure 5). In some exemplary aspects, the load pad 110 is made of substantially the same material as the bus bar 104. In other exemplary aspects, the load pad 110 is made of a different material from the rest of the bus bar 104, or the load pad 110 is partially made of the same or different material as the bus bar 104. In some exemplary aspects, the bus bar and / or the load pad may be at least partially configured as an electrically conductive adhesive (ECA) so that the ECA performs part or all of the current collecting function of the bus bar and / or the load pad. In an exemplary aspect, the ECA may be a variety of materials characterized by high electrical conductivity, and examples include silver paste, acrylic conductive adhesive, and / or epoxy conductive adhesive. In an exemplary aspect, the ECA may be an electrically conductive and thermally conductive adhesive material. For example, the thermal conductivity of the ECA perpendicular to the solar cell may be greater than or equal to about 1.5 W / (mK). In an exemplary aspect, a combination of ECA materials may be applied and cured in the same bonding step. For example, the first ECA may have a shear modulus of less than or equal to about 800 MPa and the second conductive adhesive may have a shear modulus of greater than or equal to about 2000 MPa, both of which may be applied and cured in the same bonding step. In one exemplary aspect, the conductive bond between overlapping solar cells formed from the ECA material also provides mechanical compliance to the super cells that accommodates thermal expansion mismatches between super cells over a temperature range of about -40°C to about 105°C without damaging the solar module.

[0059] In one exemplary aspect, the shingled configuration eliminates any physical gaps between pairs of shingled solar cells 10. In one exemplary aspect, in the shingled configuration, the busbars 104 and / or load pads 110 are hidden beneath the overlapping portions of adjacent solar cells. Thus, the super cell 1 is efficiently shaped to maximize the effective utilization of space in the solar module while maintaining high electrical conductivity along the length of the super cell. Specifically, a greater portion of the surface area of ​​the super cell is available for power generation (i.e., capable of capturing sunlight) compared to protruding solar cell arrangements and solar cell arrangements that include many visible busbars or fingers on the illuminated surface of the solar cell.

[0060] Figure 4a Show Figure 3 FIG. 1 is an enlarged view of a portion of a solar cell 10. Figure 4aAs shown, the exemplary bus bar 104 includes a load pad 110 having a width greater than the width of the non-load pad portion of the bus bar 104. The exemplary load pad 110 may include a main portion 112 and an extension portion 114 extending away from the main portion 112 and at least approximately parallel to the line 108. The main portion 112 may be rectangular, circular, elliptical, or any other polygonal shape that allows the main portion 112 to support the load of adjacent overlapping solar cells and determine the desired electrical connection. Preferably, the main portion is generally rectangular in shape and extends approximately parallel to the fingers 106 in the length direction of the main portion 112. The extension portion 114 extends approximately perpendicular to the main portion 112 and is approximately parallel to the line 108. Although the extension portion 114 is shown as being generally rectangular, other suitable shapes (e.g., elliptical, circular, pointed, etc.) may also be used. The main portion 112 may be used to electrically connect adjacent solar cells (e.g., solar cells 10a, 10b) so that electrons can move from one solar cell to another to form an electric current. The extension 114 can be used to electrically connect the load pad 110 to the adjacent connection line 108. Figure 4a As shown, the extension portion 114 may extend to contact the wire 108. Alternatively, the extension portion 114 may overlap the wire 108, or a small gap may exist between the wire 108 and the extension portion 114. In the case where there may be a gap between the extension portion 114 and the wire 108, another conductive material (e.g., ECA) may be applied to electrically connect the extension portion 114 and the wire 108. Therefore, the load pad 110 can be used to electrically connect adjacent overlapping solar cells 10 in the super energy cell 1.

[0061] Figure 4b and Figure 4c 1 shows another configuration of the bus bar 104 and / or the load pad 110 according to an exemplary aspect of the present disclosure. As described above, Figure 4b A solar cell 10 is shown including a bus bar 104b having a constant width such that a load pad 110b and the bus bar have substantially the same width, except for the region of the load pad where the extension 114b is located. Since the bus bar 104b and the load pad 110b have substantially the same width, manufacturing time (and thus cost) may be reduced because the bus bar 104b has a more consistent shape (compared to the load pad 110b). Figure 4a The bus bar 104b and the load pad 110b may be applied to the solar cell 10 through fewer steps compared to the bus bar 104b and the load pad 110 of the solar cell 10.

[0062] Figure 4c FIG. 1 shows a solar cell 10 having only a load pad 110 c and no bus bar 104 according to an exemplary aspect of the present disclosure. Figure 4cIn the solar cell, no material is used to form the bus bar, so the manufacturing cost can be reduced.

[0063] refer to Figure 3 , the fingers 106 may extend approximately parallel to the bus bar 104 and approximately parallel to the long edge 105 of the solar cell 10 (for example, in the case where the solar cell 10 is approximately rectangular, it includes a short edge and a long edge). Alternatively, the fingers 106 may extend at a small angle to the bus bar 104 and / or the long edge 105 of the solar cell. For example, the small angle may be an angle of 1 to 5 degrees. In some exemplary aspects, the fingers 106 may contact the bus bar 104. In other exemplary aspects, each finger 106 may be slightly non-parallel to the other fingers. The fingers are configured to transfer free electrons from the semiconductor layer to the line 108. In some exemplary aspects, the fingers 106 may be printed as thin lines on the semiconductor layer and made of a silver material. However, other conductive materials (for example, tin, copper, screen-printed silver, screen-printed aluminum) may be used. In one exemplary aspect, the fingers 106 may be as thin as a width of about 10 μm. In one exemplary aspect, the fingers can have a width in the range of about 10 μm to about 90 μm or in the range of about 40 μm to about 50 μm. In one exemplary aspect, the finger height is in the range of about 10 μm to about 30 μm. Alternatively, the fingers 106 can be wider to improve conductivity.

[0064] The fingers 106 extend substantially in the entire height direction of the solar cell 10. In some exemplary aspects, the fingers 106 may be decomposed such that a first finger 106 extends only partially over the length of the solar cell 10, and a second finger may be connected or not connected to the first finger and extend over the remaining length of the solar cell 10. In addition, the fingers 106 may be uniformly spaced apart over the semiconductor layer so that free electrons are uniformly captured in the semiconductor layer 102. Alternatively, the fingers 106 may be placed at different distances from each other without departing from the scope of the present disclosure. For example, a first finger 106a may be spaced apart from an adjacent second finger 106b by a first distance D1, and the second finger 106b may be spaced apart from a third finger 106c by a second distance D2 (see FIG. 1 ) that is different from the first distance D1. Figure 4a ) are spaced apart. In some exemplary aspects, the first distance D1 and / or the second distance D2 are in a range of about 1.2 mm to about 2 mm. In other exemplary aspects, the first distance D1 and / or the second distance D2 are in a range of about 0.624 mm to about 0.780 mm. In some exemplary aspects, the fingers 106 may be arranged to have a smaller spacing (e.g., D1, D2) between adjacent fingers relative to the spacing D3 between adjacent lines 108. For example, the ratio between the finger spacing D1 / D2 and the line spacing D3 may be between about 20:1 to about 5:1. Figure 4a In a non-limiting example, the ratio of the spacing between the fingers 106 and the lines 108 may be approximately 15:1.

[0065] The exemplary methods described herein can advantageously reduce costs by reducing the amount of material used to efficiently conduct current along a solar cell string or super cell. For example, wire 108 can be formed as copper wire or copper ribbon (or formed of another conductive material that is less expensive than silver) to reduce the series resistance Rs in the solar cell string, thereby improving the power of the solar module and reducing costs by reducing the amount of silver consumption. The exemplary methods described herein can also advantageously enable high power, low cost solar modules that include shingled solar cells interconnected in series via an ECA with a wire combination extending along one or more super cells of the solar module.

[0066] like Figure 3 and Figure 4a-4c As shown, the solar cell 10 may further include a wire 108 that extends generally perpendicular to the fingers 106, the busbars 104, and / or the long edges of the solar cell 10. The wire 108 may be attached to the top of the finger 106 by printing or other application methods so that the wire 108 and the finger 106 are electrically connected. In other exemplary aspects, the wire may be glued by ECA via IR or hot air; soldered by induction soldering; or in the case where the wire has a low-temperature coating (e.g., tin-bismuth, etc.), the wire may be attached by hot air or by utilizing the temperature of the heated laminate when laminating the super-energy battery. Therefore, the wire 108 may not include any sheath or covering that prevents efficient electrical connection with the finger 102 or the load pad 110. In addition, the wire 108 may extend to the busbar 104 and may be electrically connected to the busbar 104 through the load pad 110. Thus, wires 108 provide an electrical connection between fingers 106 and bus bar 104 so that free electrons in the semiconductor layer can travel from fingers 106 through wires 108 and to bus bar 104 to form an electric current.

[0067] Wire 108 is connected to extension 114 of load pad 110. In some exemplary aspects, wire 108 can be connected to load pad 110 by direct overlapping physical contact. In other exemplary aspects, wire 108 and load pad 110 can be connected adjacent to each other to form an electrical connection. In other exemplary aspects, wire 108 and load pad 110 may not be in direct physical contact, and an additional material (such as ECA) can be used to establish an electrical connection between load pad 110 and wire 108. In some exemplary aspects, wire 108 is made of copper. In other exemplary aspects, wire 108 is made of other conductive materials, including but not limited to gold, silver, tin, etc.

[0068] Figure 5An enlarged cross-section of overlapping solar cells 10a, 10b is shown according to an exemplary aspect of the present disclosure. Figure 5 , the wire 108 does not extend completely to the main portion 112 of the load pad 110. Instead, the wire 108 contacts the extended portion 114 of the load pad 110. Due to this configuration, the wire 108 does not substantially receive the load force L of the overlapping solar cell 10a. In other words, the overlapping solar cell 10a does not contact the wire 108 from above and load the wire 108. In this way, the solar cells 10a and 10b are advantageously protected from being broken or damaged due to the weight of the overlapping solar cell 10a being concentrated on a specific point. In other words, since the wire 108 is not below the overlapping solar cell 10a, the weight of the solar cell 10a is evenly distributed between the load pads, and point loads (e.g., on the wire or the bottom of the overlapping solar cell 10a) can be substantially avoided. Therefore, by preventing unnecessary damage, the service life of the super energy battery 1 can be extended. It should be noted that in some exemplary aspects, as long as the load force L is not substantially transferred to the wire 108 without departing from the scope of the present disclosure, the wire 108 can be slightly extended to the bottom of the overlapping solar cell 10a.

[0069] in addition, Figure 5 Solar cells 10a, 10b are shown, which may further include a load pad 116 at the bottom side of the semiconductor layer 102. The load pad 116 may be made of the same or different material as the load pad 110. In addition, the solar cells 10a, 10b may be attached to each other using an ECA material. Thus, the load plates 114, 116 are used in conjunction with the ECA to electrically connect the solar cell 10a and the solar cell 10b. In an exemplary aspect, the distance H between the overlapping solar cells 10a, 10b is in the range of about 40 μm to about 100 μm.

[0070] Figure 6 for Figure 5 An enlarged view of the cross section is shown. Figure 6 In FIG. 1 , solar cell 10a includes an overlapping edge 122 positioned above solar cell 10b. In addition, line 108 of solar cell 10b includes edge 120 that terminates on or near extended portion 114 of load pad 110. Figure 6, a gap G1 is shown between the overlapping edge 122 of solar cell 10a and the edge 120 of wire 108. Gap G1 ensures that even in the event that, for example, ECA 118 is compressed and solar cell 10a moves toward solar cell 10b, load forces from solar cell 10a are not transferred to solar cell 10b. In some exemplary aspects, the gap can be substantially zero, such that overlapping edges 122 and 120 are substantially aligned on the same plane. In other exemplary aspects, the gap can be a negative gap, such that wire 108 is positioned slightly below solar cell 10a, but is still protected from damage from solar cell 10a due to other mechanisms.

[0071] refer to Figure 7 In some exemplary aspects, the wire 108a can have a circular cross-sectional shape. A circular shape is easy to manufacture because wires generally have a circular cross-sectional shape. Therefore, a circular cross-sectional shape provides a cost-effective option for the wire 108.

[0072] refer to Figure 8 In some exemplary aspects, the wire 108b may have a triangular cross-sectional shape. In addition to providing high conductivity, the triangular wire 108b also improves the efficiency of the solar cell 10 by reflecting light toward the semiconductor material (see Fig. 9 ).

[0073] Fig. 9 FIG. 1 is an enlarged cross-sectional view of a solar cell 10 according to an exemplary aspect of the present disclosure. Fig. 9 , light ray R deviates from triangular line 108b and is directed toward semiconductor layer 102. Thus, light that would normally be blocked by line 108 on top of semiconductor layer 102 is at least partially redirected toward semiconductor layer 102. As a result, more light is directed toward semiconductor layer 102, resulting in more electrons being released and the efficiency of solar cell 10 being improved.

[0074] Figure 10-12 A front metallization pattern of a solar cell 20 is shown according to an exemplary aspect of the present disclosure. The solar cell 20 may include a semiconductor layer 202, bus bars 204, fingers 206, wires 208, load pads 210, 216, and an ECA 218.

[0075] Solar cell 20 differs from solar cell 10 in that load pad 210 of solar cell 20 does not directly contact wire 208 to establish an electrical connection. Fig.11 The solar cell 20 is shown before the ECA material 218 is applied to the semiconductor layer 202 to establish an electrical connection between the load pad 210 and the wire 208. Fig.11In the embodiment of the present invention, a gap G2 is left between the load pad 210 and the wire 208. The gap G2 can be as large as the distance from the load pad 210 to the next adjacent finger 206, or the end of the wire 208 can be positioned closer to the load pad 210 without departing from the scope of the present disclosure. In an exemplary aspect, the amount of overlap between the wire 208 and the load pad is in the range of about 0.5 mm to about 1 mm.

[0076] Fig.12 The solar cell 20 is shown after the ECA material 218 has been applied to the load pad 210 and the wire 208 via printing (e.g., screen printing or inkjet printing) or other ECA application or dispensing methods (e.g., spraying, dispensing, etc. through a pneumatic / mechanical screw system). Therefore, less material for the load pad 210 can be used to produce the solar cell 20. Since the load pad 210 can be made of silver metal, the ECA 218 is generally a lower cost material to use. Therefore, the use of the ECA 218 to connect the load pad 210 and the wire 208 can reduce the manufacturing cost of the solar cell 20, while the ECA still serves as a high conductivity connection between overlapping solar cells in the super cell 1.

[0077] Fig.13 An enlarged cross-section of overlapping solar cells 20a, 20b is shown according to an exemplary aspect of the present disclosure. Fig.13 In the embodiment of the present invention, as described above, the wire 208 may not extend all the way to the bus bar 210, so that the wire 208 does not bear any load from the overlapping solar cell 20a. In other words, the overlapping solar cell 20a may not cover the wire 208 from above. In this way, the wire 208 is advantageously protected from being broken or damaged due to the weight of the overlapping solar cell 20a. Therefore, by preventing unnecessary damage, the service life of the solar cell 20 can be extended.

[0078] in addition, Fig.13 Solar cells 20a, 20b are shown, which may further include a load plate 216 at the bottom side of the semiconductor layer 202. In addition, the solar cells 20a, 20b may be attached to each other using an ECA material 218. Fig.13 In the embodiment, ECA material 218 is also used to electrically connect load pad 210 and wire 208. Therefore, load pads 110, 116 are used in conjunction with ECA 218 to electrically connect solar cell 20a and solar cell 20b.

[0079] Figure 14-16 A front metallization pattern of a solar cell 30 is shown according to an exemplary aspect of the present disclosure. The solar cell 30 may include a semiconductor layer 302, a bus bar 304, fingers 306, wires 308, load pads 310, 316, and an ECA 318.

[0080] The solar cell 30 is different from the solar cells 10 and 20 in that the bus bar 304 and the load pad 310 of the solar cell 30 are both made of ECA 318. Figure 14-16 No metal, such as silver metal, is shown to be used to form bus bar 304, load pad 310, or both. Since the cost of silver for solar cells is significantly higher than the cost of ECA materials, solar cell 30 can be manufactured at a significantly lower cost.

[0081] Fig.17 FIG. 1 is a block diagram of a method of manufacturing solar cells 10, 20, 30, etc. according to an exemplary aspect of the present disclosure. Fig.17 In step S01, incoming cell wafers with busbars and fingers pre-attached are received. At step S02, the cells are loaded into a screen printing / coating machine. At step S03, the wires are attached to the received cells via IR welding or a similar method. In this step, the wires may have a low-temperature solder coating, which is heated to attach the wires. At step S04, the cells may be tested using a Grid TOUCH contact system such as a Meyer Burger tester. In other exemplary aspects, the cells may be tested using copper tape. At step S05, a laser is used to heat the solder coating and the wires are attached to the received cells. Since the wires include a low-temperature solder coating, etching of the fingers or semiconductor layers below the wires by the heat generated by the laser may be avoided. At step S06, ECA is printed onto the solar cell wafer. At step S07, the wafer is cut to form individual solar cells 10. In an exemplary aspect, the wafer is a crystalline silicon wafer, which is cut into individual crystalline silicon solar cells or roughly rectangular strips. At step S08, the solar cells 10 are arranged in a stacked arrangement (eg Figure 1 As shown) to form a stacked super battery. At step S09, the battery is heated in an oven for a predetermined time to cure the ECA. At step S10, a flexible attachment process is optionally performed, wherein a copper tape is attached along one end of the illuminated side of the super battery, and the copper tape extends over each solar cell 10. In an exemplary aspect, the flexible attachment process can be performed by an automatic process or a manual process. In an exemplary aspect, the copper tape can be attached using manual welding, IR welding, or ECA. At step S11, the manufacture of the finished product of the stacked super battery 1 is completed.

[0082] Fig.18 A hybrid dense solar cell wafer 100 is shown prior to attachment to a wire according to an exemplary aspect of the present disclosure. Fig.19 The wire 108 is shown after being attached to the wafer 100. Fig.18 In one exemplary aspect, the hybrid dense solar cell wafer 100 can be cut along the cutting lines AA and BB (eg Fig.19The solar cell wafer 100 is cut (for example, at step S07) to form the solar cells 10. The solar cell wafer 100 may also be cut, divided or otherwise separated to form the rectangular solar cells 10. Fig.19 In FIG. 1 , a solar cell wafer includes a metallization pattern for each solar cell 10 including respective bus bars, fingers, load pads and wires.

[0083] exist Fig.18 and Fig.19 In the non-limiting exemplary aspects shown, the solar cell wafer includes a metallization pattern that is preferably cut into three smaller rectangular solar sub-cells or strips. However, in some exemplary aspects, the metallization pattern can be modified so that the solar cell wafer is preferably cut into any desired number of solar sub-cells. For example, the wafer can be cut into a plurality of sub-cells ranging from 2 to 20 sub-cells without departing from the spirit of the present disclosure.

[0084] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

Claims

1. A solar module, comprising: At least one first solar cell and at least one second solar cell, each comprising: Top and bottom sides, Bus bars, and a plurality of wires disposed on the top side, the plurality of wires extending from and electrically connected to the bus bar, wherein the first solar cell overlaps a region of the second solar cell to be electrically connected to the second solar cell and form a shingled arrangement, The first solar cell includes overlapping edges, and In the second solar cell, the plurality of wires are connected to the bus bar outside the region where the first solar cell overlaps with the second solar cell; wherein each bus bar includes a plurality of top side load pads, and each of the plurality of wires is connected to a top side load pad of the plurality of top side load pads at an end of the plurality of wires; wherein each top load pad comprises a main portion and an extension portion, wherein the main portion is concealed beneath the area of ​​overlap and the extension portion is at least partially disposed outside the area of ​​overlap; wherein each bottom side includes a bottom side load pad; and There are gaps between ends of the plurality of lines of the second solar cell and the overlapping edges of the first solar cell. 2 . The solar module of claim 1 , wherein the bus bar of the first solar cell and the bus bar of the second solar cell are composed of a first metal, and the plurality of wires are composed of a second metal that is different from the first metal.

3. The solar module of claim 1, wherein the plurality of wires are made of copper metal or an alloy thereof.

4. The solar module according to claim 1, wherein the bus bar is made of silver metal or an alloy thereof.

5. The solar module of claim 1 wherein the extension portion of each top side load pad extends away from the main portion of the top side load pad.

6. The solar module of claim 5, wherein the bus bar includes a first portion extending between the main portions of the top load pads, and each main portion of the top load pads has a width greater than a width of the first portion of the bus bar.

7. The solar module of claim 1, wherein each solar cell further comprises: a plurality of fingers extending in a direction perpendicular to the plurality of lines, and The resistance of the plurality of lines is less than the resistance of the fingers.

8. The solar module of claim 1 , wherein each solar cell further comprises a plurality of fingers extending in a direction perpendicular to the plurality of lines; and The plurality of fingers are comprised of a first metal and the plurality of lines are comprised of a second metal that is different from the first metal.

9. The solar module of claim 1 , wherein each solar cell further comprises a plurality of fingers extending in a direction perpendicular to the plurality of lines; and The spacing between the plurality of fingers is smaller than the spacing between adjacent lines in the plurality of lines.

10. The solar module of claim 1, wherein a conductive adhesive connects the first solar cell to the second solar cell in the region.

11. The solar module of claim 1 , wherein each of the plurality of wires has a circular cross-sectional shape.

12. The solar module of claim 9, wherein each of the plurality of wires has a triangular cross-sectional shape.

13. The solar module of claim 12, wherein each of the plurality of lines is oriented such that the plurality of fingers are in contact with a base of the triangular cross-sectional shape.

14. The solar module of claim 1, wherein in each solar cell, the plurality of wires extend generally perpendicular to the bus bar.

15. A method of manufacturing a solar module, the method comprising: At least one first solar cell and at least one second solar cell are provided, each comprising: Top and bottom sides, a bus bar including a plurality of top side load pads, and a plurality of wires disposed on the top side, the plurality of wires extending from and electrically connected to the bus bar, and each of the plurality of wires connected at an end of the plurality of wires to a top side load pad of the plurality of top side load pads; and arranging the first solar cell to overlap a region of the second solar cell to be electrically connected to the second solar cell and to form a shingled arrangement, The first solar cell comprises overlapping edges, wherein in the second solar cell, the plurality of lines are connected to the bus bar outside the area; wherein each top side load pad comprises a main portion and an extension portion, the main portion is hidden under the overlapped area, and the extension portion is at least partially disposed outside the overlapped area; wherein each bottom side includes a bottom side load pad; and There are gaps between ends of the plurality of lines of the second solar cell and the overlapping edges of the first solar cell.

16. The method of manufacturing a solar module of claim 15, further comprising attaching each of the plurality of wires to a corresponding solar cell using infrared radiation welding. 17 . The method of manufacturing a solar module of claim 15 , further comprising printing a conductive adhesive onto the plurality of wires to attach each of the plurality of wires to a corresponding solar cell.

18. The method of manufacturing a solar module according to claim 15, further comprising: coating each of the plurality of wires with a coating material; as well as The coating material is heated to attach the plurality of wires to the solar cell.

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