Apparatus for manufacturing an electrode assembly

Abstract

1. An apparatus for manufacturing an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell, the electrode assembly comprising a plurality of conductive elements arranged substantially parallel to one another in a longitudinal direction and substantially spaced apart in a laterally direction, the apparatus comprising first and second rolls spaced apart to define a gap therebetween for receiving the plurality of conductive elements, and an actuator configured to rotate at least one of the first roll and the second roll, the apparatus being configured to periodically reduce a gap between the first roll and the second roll as at least one of the first roll and the second roll rotates to periodically apply a compressive force to the plurality of conductive elements disposed in the gap.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to an apparatus for and method of manufacturing an electrode assembly for a solar cell assembly The present disclosure further relates to a method of manufacturing a solar cell assembly, an electrode assembly and a solar cell assembly. [Background technology]

[0002] A solar module for providing electrical energy from sunlight comprises an array of cells, each of which comprises a photovoltaic element or substrate. The solar cells are typically connected to transmit electrical current from one solar cell to another via electrical connectors. Each of the electrical connectors comprises a number of conductive elements (e.g., wires) that form electrical connections with electrodes (e.g., finger electrodes) disposed on the front and back surfaces of each of the solar cells.

[0003] A general objective for solar cell development is to achieve high conversion efficiency balanced with the need for reduced production costs. Efforts to achieve this have focused on the electrical connections between the solar cells. Despite these efforts, there remains a need to improve the electrical connections between solar cells. Summary of the Invention

[0004] According to a first aspect of the present invention, an apparatus is provided for manufacturing an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell. The electrode assembly may comprise a plurality of conductive elements arranged substantially parallel to each other in a longitudinal direction and substantially spaced apart in a transverse direction. The apparatus comprises a first roll (e.g., a roller) and a second roll (e.g., a roller) spaced apart to define a gap for receiving the plurality of conductive elements, and an actuator configured to rotate at least one of the first roll and the second roll, and the apparatus is configured to periodically reduce the gap between the first roll and the second roll as at least one of the first roll and the second roll rotates to periodically apply a compressive force to the plurality of conductive elements disposed in the gap.

[0005] Generally, the apparatus provides a convenient means for periodically forming compressed sections in a plurality of conductive elements of an electrode assembly, the resulting compressed sections being advantageously configured to be disposed within overlap regions of the first and second solar cells to provide a more stable mechanical connection therebetween.

[0006] According to a particular type of solar module, the solar cells may be arranged in a "gapless" configuration, where the front surface of a first solar cell is partially overlapped by the back surface of a second solar cell. In this situation, a conductive element (e.g., an electrical connector, or wire) extends from the first solar cell to the second solar cell across the overlap area, and is typically soldered to the respective front surfaces of the solar cells.

[0007] When the solar cell is in use, stresses caused by mechanical loads and temperature changes can accumulate in the overlap area. In the case of rounded conductive elements (e.g., wires with circular cross sections), these stresses tend to concentrate at the interface between the solar cell and the conductive element, which can lead to the formation of cracks in the solder.

[0008] One approach to solving this problem has been to provide a conductive element configured with a rectangular profile (e.g., a conductive ribbon) that increases the contact area between the ribbon and the solar cell surface in the overlap region. The larger contact area results in a reduction in the concentration of stress in the overlap region. However, such ribbons are less effective at scattering the incident light, at least compared to rounded wires, which can result in reduced absorption conditions at the front surface of the solar cell.

[0009] As described above, the apparatus according to the first aspect of the present invention is configured to fabricate a plurality of conductive elements including compressed sections that can be positioned within the overlapping regions of the solar cells. The compressed sections provide a more stable mechanical bond between the solar cells within the overlapping regions. The improved mechanical stability of the overlapping regions thereby increases the strength and reliability of the solar cell assembly, thereby extending the operational life of the solar module and reducing associated maintenance costs. Furthermore, non-compressed sections of the conductive elements can be positioned on the front and back surfaces of the first and second solar cells to increase light scattering, thereby increasing the operational efficiency of the solar cells.

[0010] Furthermore, the rotation of the first and second rolls allows the compression of the periodic sections of the conductive element to proceed continuously. In this manner, the rolls are configured to reduce the height of the sections without stopping (e.g., pausing or pausing) the fabrication of the electrode, thereby improving the efficiency of the manufacturing process.

[0011] The following are optional features, which may be applied alone or in any combination with any aspect.

[0012] The first roll and the second roll may be substantially axially parallel to one another and radially spaced apart to define a gap therebetween, such that the axis of rotation of the first roll may be aligned parallel to the axis of rotation of the second roll.

[0013] The apparatus may be configured to not periodically apply a compressive force to the plurality of conductive elements. The apparatus may be configured to alternate between applying a compressive force and not applying a compressive force. Thus, the apparatus may be configured to not periodically apply a compressive force (i.e., a force that may substantially reduce the thickness of the conductive element) along the entire length of the conductive element. Successive periodic sections having reduced thickness may define compressed (e.g., deformed or flattened) sections of the conductive element that are interleaved (e.g., alternating) with uncompressed sections of the conductive element (e.g., in a sequence of compressed, uncompressed, compressed, uncompressed, etc.).

[0014] In an embodiment, the resulting conductive element may be comprised of a compressed section disposed between two uncompressed sections, the compressed section may be disposed in the overlap region between two solar cells, and the uncompressed sections may be disposed on the front and back surfaces of each of the overlapping solar cells.

[0015] The front surface of the solar cell may define a surface of the solar cell on which light is incident when the solar cell assembly is in use (e.g., the front-most surface of the solar cell). The back surface of the solar cell defines a surface of the solar cell opposite the front surface (e.g., the back-most surface of the solar cell). The back surface of the solar cell may not be directly exposed to incident light during use. The solar cell assembly may be configured such that light that is transmitted through the solar cell from the front to the back (e.g., not absorbed) is then reflected towards the back surface of the solar cell, providing further opportunity for light to be absorbed.

[0016] The reduction in height of the compressed section causes a "spreading" of the material forming the conductive element. The material may spread laterally (e.g., in a direction perpendicular to the movement of the element through the gap). This deformation increases the width of the compressed section (e.g., can be located on either side (i.e., front and back) of the compressed section) compared to the uncompressed section. The deformation of the conductive element between the rolls also creates a force that pushes the rolls apart (i.e., opposing the compressive force applied by the rolls to the conductive element). As will be appreciated by those skilled in the art, this separation force, or rolling load, may increase as the conductive element is compressed between the rolls.

[0017] The first roll may be configured to rotate in the opposite direction to the second roll, or vice versa, to ensure that the rolls do not interact with each other while pulling the conductive element through the gap.

[0018] The first and second rolls may each be configured to rotate at substantially the same speed (e.g., the rolls rotate at substantially the same number of revolutions per minute), thereby preventing friction between the rolls and the conductive element.

[0019] The second roll may be disposed substantially above the first roll. Thus, the gap between the rolls may be defined by two substantially vertical openings disposed on either side of the gap. The conductive element may be fed horizontally through one of the vertical openings (e.g., the first opening). During operation of the apparatus, the conductive element may be pulled (e.g., by rotation of at least one of the rolls) through the gap and then pushed out of the other of the vertical openings (e.g., the second opening).

[0020] The contact angle can be defined as the enclosed angle between a first line from the point where the conductive element first contacts one of the rolls to the center of that roll and a second line connecting the axes of the first and second rolls. The contact angle of the first roll may be larger and / or smaller than the contact angle of the second roll when the conductive element is compressed between the rolls. For example, when the rolls are aligned vertically, the conductive element may be fed into the gap between the rolls in a non-horizontal plane. Alternatively, the contact angle of the first roll may be substantially the same as the contact angle of the second roll when the element is simply pulled through the rolls. For example, when the rolls are aligned vertically, the conductive element may be fed into the gap in a substantially horizontal plane.

[0021] The placement of the second roll above the first roll allows the conductive element to be placed on the upwardly facing surface of the bottom roll (i.e., the first roll). The bottom roll may be configured to grip the conductive element by gravity, which helps guide the conductive element through the gap.

[0022] During operation of the apparatus, the gap between the first roll and the second roll may vary (i.e., may increase and decrease periodically) with the continuous rotation of the rolls. The maximum gap between the first roll and the second roll (e.g., at the maximum separation point between the rolls) may be at least 0.3 mm and / or at most 5 mm. Thus, the distance between the rolls at the maximum separation point is such that both rolls do not touch the conductive element because the thickness of the uncompressed conductive element (e.g., 0.2 mm) is smaller than the maximum gap between the rolls (e.g., at least 0.3 mm). In an exemplary arrangement, the conductive element may be placed on the lower roll without touching the upper roll.

[0023] The minimum gap between the first and second rolls (e.g., at the narrowest point between the rolls) can be at least 0.05 mm and / or at most 4.75 mm. Thus, the gap between the rolls at their narrowest points (e.g., about 0.08 mm) is periodically smaller than the thickness of the uncompressed conductive element (e.g., about 0.2 mm). This causes the rolls to periodically compress the height of the conductive element (e.g., to 0.08 mm) as they rotate. For example, during periods when the narrowest point is smaller than the thickness, the portion of the conductive element between the rolls is compressed, but during periods when the narrowest point is larger than the thickness, the portion of the conductive element between the rolls is not compressed.

[0024] In an exemplary embodiment, the maximum distance between the rolls is about 0.5 mm and the minimum distance between the rolls is about 0.08 mm.

[0025] Only one of the first roll and the second roll may be configured to reduce the gap between the first roll and the second roll. For example, at least one of the first roll and the second roll may be configured to not periodically apply a compressive force to the plurality of conductive elements. In other words, at least one of the first roll and the second roll may be configured to alternate between periodically applying a compressive force and not applying a compressive force.

[0026] One of the rolls may be shaped (i.e., dimensioned) to generate an eccentric rotation about its axis, which results in a periodic reduction in the gap between the first roll and the second roll (e.g., the roll may have an elliptical cross-section). In this situation, the other of the rolls may be configured to provide a substantially non-eccentric rotation about its axis (e.g., the other roll may have a circular cross-section). Thus, the other of the rolls (i.e., the non-eccentric roll) will not contribute to the reduction in the size of the gap between the first roll and the second roll. In use, both rolls are configured to exert a force on the conductive element, which will contribute to the reduction in the thickness (e.g., thickness / depth) of the conductive element.

[0027] In an embodiment, the first roll may have a substantially circular cross-section, and the second roll may be configured to periodically reduce the gap between the first and second rolls. Configuring one of the rolls to have a circular cross-section reduces the complexity and cost of manufacturing the device. In an alternative arrangement, both the first and second rolls may be configured to reduce the gap between the rolls. For example, each of the rolls may be configured (e.g., shaped) to generate an eccentric rotation about its respective axis of rotation to contribute to the reduction in the size of the gap between the rolls.

[0028] At least one of the first roll and the second roll may have a cross-sectional shape configured such that as it rotates, the gap between the first roll and the second roll decreases periodically in the radial direction. In one embodiment, both rolls may have such a profile. In another embodiment, one roll may have such a profile and the other roll may have, for example, a circular cross-section. In one embodiment, during use (e.g., while one or more rolls are rotating), the apparatus holds the first roll (e.g., the axis of rotation of the first roll) in a fixed relationship with the second roll (e.g., the axis of rotation of the second roll). Thus, the aforementioned cross-sectional shape alternates between decreasing and increasing the gap as it rotates, and alternates between applying and not applying a compressive force to successive portions of the conductive element in the gap.

[0029] At least one of the first roll and the second roll may have an elliptical cross-section. For example, the second roll may be configured to have an elliptical cross-section and the first roll may be configured to have a circular cross-section.

[0030] The elliptical cross-section may have one axis of symmetry. The elliptical cross-section may have two axes of symmetry. For example, the elliptical cross-section may be in the form of a regular ellipse. In an alternative arrangement, the elliptical cross-section may have only one axis of symmetry. For example, the cross-section may have an oval shape (e.g., an irregular circle) that resembles the outline of an egg (e.g., a 2D projection of the egg shape).

[0031] At least one of the first roll and the second roll may have a cross-section shaped as an elliptical segment (e.g., an oval or short circle), such as a circular segment (e.g., an oval or short circle). In an embodiment, at least one of the first roll and the second roll may have a semi-elliptical cross-section, such as a semi-circular cross-section.

[0032] At least one of the first roll and the second roll may have a first surface and a second surface. The first and second surfaces may be configured to be outwardly curved, with the first surface having a variable radius of curvature (e.g., like an ellipse) and the second surface having a substantially constant radius of curvature (e.g., like a circle). Such a shape may correspond to an egg shape, with a clearly defined boundary between its wider and narrower ends.

[0033] At least one of the first roll and the second roll may have a cross-section with a geometric center (e.g., the arithmetic mean location of all points in the shape). At least one of the first roll and the second roll may be configured to have an axis of rotation offset from the geometric center. The resulting roll may be configured to have an axis of rotation offset from the center. A roll configured in this manner may be configured for eccentric rotation about its axis of rotation even if the cross-section of the roll has a non-eccentric shape (e.g., a circle). Thus, the roll may be configured such that the roll (i.e., its center of mass) physically moves back and forth relative to the other roll to alternately decrease and increase the gap between the two rolls. Such an arrangement may be configured to periodically decrease the gap between the first roll and the second roll to deform successive periodic sections of the conductive element as the rolls rotate.

[0034] At least one or each of the plurality of conductive elements may include a section that is compressed by the device. The compressed section may be disposed between two sections that are not compressed by the device (i.e., uncompressed sections). For example, the electrode assembly may be formed by cutting the plurality of conductive elements to form a plurality of conductive element portions, each of which includes a compressed section disposed between two uncompressed sections. In this situation, the cross-sectional circumference of at least one of the first roll and the second roll may define a length that corresponds to the combined length of the two compressed sections and the two uncompressed sections.

[0035] In a preferred arrangement of the electrode assembly, the plurality of conductive element portions may include only one compressed section disposed between two uncompressed sections. The apparatus may be configured such that each revolution of the roll deforms the conductive element to produce a sequence of two alternating compressed and uncompressed sections (e.g., compressed section, uncompressed section, compressed section, uncompressed section). This may be the case, for example, when one of the rolls has an elliptical cross section.

[0036] To produce a preferred electrode assembly, all other compressed sections may be removed (e.g., cut) from the conductive element during cutting of the conductive element. For example, cutting may be performed on either side of all other compressed sections to form multiple conductive element portions having a single compressed section disposed between two uncompressed sections. Cutting the conductive element in this manner not only separates the conductive element into respective portions, but also removes additional compressed sections. According to the above arrangement, the circumference of the cross section of at least one of the first roll and the second roll may be greater than the length of the conductive element portion of the final electrode assembly.

[0037] In an alternative arrangement, the apparatus may be configured such that each revolution of the rolls deforms the conductive element to produce one compressed section and one uncompressed section. This would be the case, for example, if one of the rolls has an oval cross-section. In this situation, the uncompressed section may be substantially longer than the compressed section, since the uncompressed section substantially corresponds to the combined length of both the front surface of the first solar cell and the back surface of the second solar cell.

[0038] According to the above arrangement, the preferred electrode assembly can be obtained by making a single cut substantially at the center (e.g., longitudinally) of each of the uncompressed sections. No other cuts are necessary because there are no additional compressed sections to remove (unlike the previous arrangement). According to this arrangement, the circumference of the cross section of at least one of the first roll and the second roll can be substantially equal to the length of the conductive element portion of the final electrode assembly.

[0039] It will be appreciated that the conductive element may be fed into the nip between the rolls at a speed that substantially matches the rotational speed of the rolls to ensure that the correct section of the conductive element is deformed.

[0040] In an embodiment, at least one or each of the plurality of conductive elements may each comprise a first section for contacting only the front surface of the first solar cell (e.g., positioned so as not to contact the second solar cell), a second section for contacting only the back surface of the second solar cell (e.g., positioned so as not to contact the first solar cell), and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell. Each of the third sections of the at least one conductive element may be configured to connect (e.g., mechanically and electrically) between the respective first and second sections. In this situation, the perimeter of the cross section of at least one of the first roll and the second roll may define a length corresponding to the combined length of the first, second, and third sections of the plurality of conductive elements. The third section may thus define a compression section in the previous example.

[0041] Prior to being deformed by the device, at least one, or each, of the conductive elements may have a substantially constant cross-section along its length. Each conductive element may be configured to be free of any axial twists or kinks along its length.

[0042] When the conductive elements are deformed by the apparatus, at least one or a portion of each of the conductive elements may have two substantially planar surfaces disposed on opposite sides of the conductive element. The first surface may define a substantially flat surface facing the front surface of the first solar cell, and the second surface may define a substantially flat surface facing the back surface of the second solar cell. In an embodiment, the first and / or second surface may be configured to be substantially parallel to the front and back surfaces of the first and second solar cells, respectively.

[0043] In an exemplary arrangement, the compressed section of the conductive element may have an oval profile (i.e., an oval-shaped cross-section). The uncompressed section of the conductive element may have a substantially elliptical profile (i.e., an elliptical-shaped cross-section). For example, the uncompressed section may have a circular cross-section.

[0044] According to a second aspect of the present invention, there is provided a method of manufacturing an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell. The method includes providing a plurality of conductive elements and arranging the plurality of conductive elements in a common plane such that they are longitudinally disposed substantially parallel to one another and laterally substantially spaced apart. The method further includes periodically decreasing heights of sections of the plurality of conductive elements.

[0045] A method of reducing a height of a section of a plurality of conductive elements includes providing a first roll (e.g., a roller) and a second roll (e.g., a roller) spaced apart to define a gap therebetween for receiving the plurality of conductive elements, feeding the plurality of conductive elements at least partially into the gap between the first roll and the second roll, and periodically reducing the gap between the first roll and the second roll as at least one of the first roll and the second roll rotates to periodically apply a compressive force to the plurality of conductive elements disposed in the gap.

[0046] The method may include periodically increasing a gap between the first roll and the second roll as at least one of the first roll and the second roll rotates to avoid periodically applying a compressive force to the plurality of conductive elements, such that periodic sections of the conductive elements located on either side of the compressed section remain undeformed (i.e., uncompressed).

[0047] The method may include disposing an electrically insulating, optically transparent film over uncompressed sections of the plurality of conductive elements, the film ensuring that each of the conductive elements remains in the same position relative to the other conductive elements (e.g., laterally and / or longitudinally) during the deformation process.

[0048] The method may include disposing an electrically insulating, optically transparent film over the conductive elements prior to feeding the conductive elements at least partially into the gap between the first roll and the second roll. By applying the film to the conductive elements prior to feeding them into the gap, the film further enhances the stability of the conductive elements during the deformation process.

[0049] The electrically insulating, optically transparent film may be positioned so as not to cover the compressed sections of the plurality of conductive elements. Not placing the film on the compressed sections ensures that the foil does not interfere with the deformation process, thereby allowing the conductive elements to be positioned flush between the respective surfaces of the first and second solar cells when the electrode assembly is placed on the solar cell assembly.

[0050] The method may include cutting a plurality of conductive elements to define a plurality of conductive element portions. Each of the conductive element portions may comprise a compressed section disposed between two uncompressed sections. In an embodiment, each of the conductive element portions may comprise a first section, a second section, and a third interconnect section, as described above.

[0051] The method step of cutting the conductive elements may be performed after the method step of reducing the height of the compressed section. Deforming the conductive elements before they are cut ensures the stability of the conductive elements during the deformation process.

[0052] According to a third aspect of the present invention, there is provided a method of manufacturing a solar cell assembly, the method comprising manufacturing an electrode assembly according to any one of the preceding statements, the method further comprising providing a first solar cell and a second solar cell.

[0053] Each solar cell may have a back surface (e.g., a back-most surface) and a front surface (e.g., a front-most surface) opposite the back surface. Thus, the method may include disposing a section of the electrode assembly on the back surface of the second solar cell to define a back connector. The method may further include disposing another section of the electrode assembly on the front surface of the first solar cell to define a front connector.

[0054] Each of the plurality of conductive elements may comprise a first section for contacting only a front surface of the first solar cell, a second section for contacting only a back surface of the second solar cell, and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell. Each of the third sections of the at least one conductive element may be configured to connect (e.g., mechanically and electrically) between a respective first and second section.

[0055] The method may include positioning the second solar cell such that a back surface of the second solar cell faces substantially upward, and / or positioning the second solar cell such that a front surface of the second solar cell faces substantially downward.

[0056] The method may include overlaying a second section of the plurality of conductive elements of the electrode assembly on a back surface of a second solar cell.

[0057] The method may include overlapping a front surface of the first solar cell over a first section of the plurality of conductive elements such that the front surface of the first solar cell partially overlaps a back surface of the second solar cell. The method steps may also include overlapping the front surface of the first solar cell such that a third section of the plurality of conductive elements is disposed between an overlapping portion of the front surface of the first solar cell and the back surface of the second solar cell.

[0058] The method may further include connecting first and second sections of the plurality of conductive elements to a front and back surface of the first and second solar cells, respectively.

[0059] At least one, or each, of the plurality of conductive elements may have a first surface and a second surface, the second surface being disposed substantially opposite to the first surface of the conductive element, In use, the first surface may define a front surface (i.e., a front-facing surface) of the conductive element and the second surface may define a back surface (i.e., a back-facing surface) of the conductive element.

[0060] The method may further include connecting (e.g., electrically and / or mechanically) a first surface (i.e., front surface) of the at least one conductive element onto a back surface of the second solar cell. The method may further include connecting (e.g., electrically and / or mechanically) a second surface (i.e., back surface) of the at least one conductive element onto a front surface of the first solar cell.

[0061] The method may include overlaying a front surface of a first solar cell over a first section of the electrode assembly such that a first surface of the at least one conductive element is disposed in contact with the front surface.

[0062] At least one, or each, of the plurality of conductive elements may be provided with a coating configured, in use, to solder them to a respective surface of the solar cell over which they are overlaid.

[0063] The method may include applying heat and / or pressure (e.g., soldering) to a first section of the conductive element (i.e., of the front connector) to melt at least a portion of the coating. For example, the molten coating disposed on a first surface of the conductive element (i.e., the surface facing the back side of the second solar cell) may be configured to form an ohmic contact with a conductive surface (e.g., a finger electrode) of the second solar cell over which the conductive element is overlaid.

[0064] The coating of the conductive element may be composed of a material having a lower melting point than the material from which the conductive element is formed. The method may include applying heat and / or pressure (e.g., soldering) to a second section of the conductive element (i.e., of the back connector) to melt at least a portion of the coating. The molten coating disposed on the second surface of the conductive element (i.e., the surface facing the back of the second solar cell) may be configured to form an ohmic contact with a conductive surface (e.g., a finger electrode) of the second solar cell over which the conductive element is overlaid.

[0065] The method may include first attaching one of the front and back connectors to each of the first and second solar cells, and then attaching the other of the front and back connectors to the other of the first and second solar cells, respectively. The conductive element coatings of the front and back connectors may be connected to the surfaces of each of the first and second solar cells separately or during the same process.

[0066] If the electrode assembly comprises a film (e.g., an insulating and / or optically transparent film), the method may further include attaching the film to the conductive element (e.g., forming an electrode assembly according to an exemplary arrangement). The method may include attaching the film to the conductive element before overlaying and / or attaching the conductive element to the solar cell. The method may include applying heat and / or pressure to the film (e.g., laminating) to adhere the film to the conductive element.

[0067] When a first section of the plurality of conductive elements is disposed on a first film portion and / or a second section of the plurality of conductive elements is disposed on a second film portion, the first and / or second film portions may be attached to the respective first and / or second sections of the conductive elements.

[0068] The method may further include disposing (e.g., depositing) a plurality of finger electrodes on at least one or each of the front and back surfaces of the first and second solar cells. It is understood that the method of disposing the finger electrodes can be performed before connecting the electrode assembly to the solar cells. The finger electrodes may be formed using a printing material that allows it to be conveniently deposited on the surface of the solar cells. The printing material may be formed using a printable precursor such as a conductive paste that may include a metal powder (e.g., Ag, Al, Au powder) suspended in a solvent. The printable precursor / conductive paste may be dried (e.g., solidified or cured) to form the printed finger electrodes. Alternatively, the finger electrodes may be deposited by a variety of other methods, including evaporation, plating, printing, and the like. The front finger electrodes and the back finger electrodes may be deposited simultaneously (i.e., using a single deposition process) or they may be deposited separately.

[0069] According to a fourth aspect of the present invention, there is provided an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell. The electrode assembly may be manufactured according to a method according to any one of the preceding statements. As described above, each of the plurality of conductive elements may comprise a first section for contacting a front surface of the first solar cell, a second section for contacting a back surface of the second solar cell, and a third section configured to connect (e.g., directly or indirectly) the first section to the second section. The thickness (e.g., height) of the plurality of conductive elements may gradually decrease longitudinally along the plurality of conductive elements from the first section to the third section and / or from the second section to the third section. The conductive elements (e.g., the first, second, and / or third sections) may be configured to have a curved surface when viewed in an axial cross section of the conductive elements. The conductive elements (e.g., the first, second, and / or third sections) may be configured to have curved upper and lower surfaces. For example, the conductive element (e.g., the first, second, and / or third sections) comprise opposing concave surfaces. In one embodiment, the first and second sections each have a gradually decreasing thickness while the third section has a constant thickness, the constant thickness of the third section corresponding to the minimum thickness of the first and second sections. The gradually decreasing thickness defines a transition between the uncompressed sections (e.g., the first and second sections) and the compressed sections (e.g., the third section) of the conductive element. This transition region can thus be configured to combine the beneficial scattering properties of the uncompressed conductive element with the packaging advantages of the compressed conductive element.

[0070] The first section of each of the conductive elements may collectively define a front connector of the electrode assembly. Similarly, the second section may define a back connector of the electrode assembly. The third section may define an interconnect configured to electrically couple the first and second sections of each of the conductive elements (i.e., the front and back connectors of the electrode assembly). At least one or each of the third sections of the plurality of conductive elements may extend between the first and second sections of each of the plurality of conductive elements.

[0071] Each of the conductive elements may have an elongated shape, such as a wire or a portion of a wire. At least one or each of the conductive elements may comprise a single integrally formed element (e.g., a wire). Configuring the conductive elements in this manner eliminates the need to provide separate connections (such as copper ribbons) between overlapping solar cells, thereby reducing the number and complexity of manufacturing steps required to fabricate a solar cell assembly.

[0072] Each of the conductive elements may have a width, an axial length, and a depth. Each of the conductive elements may be configured such that its axial length is substantially greater than its width and / or depth. The width and axial length of the conductive elements may be measured in a perpendicular direction aligned with the plane of the surface of the solar cell in which the conductive element is disposed (e.g., the front or back surface of the solar cell). The depth (e.g., thickness) may be measured in a direction perpendicular to the same plane of the solar cell.

[0073] In an embodiment, the first and / or second section (i.e., the uncompressed section) of at least one or each conductive element may be configured to have a width of at least 0.2 mm and / or at most 0.4 mm at its widest point. The length of the first and / or second section of at least one or each conductive element may be at least 5 mm and / or at most a length corresponding to the length of the solar cell. The depth of the first and / or second section of at least one or each conductive element may be at least 0.2 mm and / or at most 0.4 mm at its deepest point. For example, at least one or each of the first and / or second sections of the conductive element may have a thickness of about 0.2 mm.

[0074] In an embodiment, the third section (i.e., the compressed section) of at least one or each conductive element may be configured to have a width, at its widest point, of 120% to 150% of the width of at least one of the uncompressed regions. For example, a conductive element having first and / or second sections having a width of 0.2 mm, the third section may have a width of 0.24 mm at its widest point. The length of the third section of at least one or each conductive element may be at least 5 mm, and / or a length that corresponds up to the length of the solar cell. The depth of the third section of at least one or each conductive element may be 25% to 60%, optionally at least 40%, of the depth of at least one of the uncompressed regions at its deepest point. For example, a conductive element having first and / or second sections having a depth of 0.2 mm at its deepest point may comprise a third section having a depth of 0.05 mm at its deepest point. Alternatively, the rolls may be configured to provide a 40% reduction in height when the compressed third section has a thickness of 0.08 mm.

[0075] It is understood that the terms "conductive" and "insulating" as used herein are expressly intended to mean electrically conductive and electrically insulating, respectively. The meaning of these terms is particularly clear when considering the technical context of the present disclosure, i.e., the context of a photovoltaic solar cell device. It is also understood that the term "ohmic contact" is intended to mean a non-rectifying electrical junction (i.e., a junction between two conductors that exhibits a substantially linear current-voltage (IV) characteristic).

[0076] The conductive elements may be formed from a conductive material, such as a metal or metal alloy material, which may include at least one of Ag, Al, Au, and Cu.

[0077] According to an exemplary arrangement, each of the plurality of conductive elements may include a coating (not shown) configured, in use, to solder the conductive elements to the respective surfaces of the solar cells on which they are covered.

[0078] The coating (i.e., the solderable coating) may include a conductive material having a melting point lower than the melting point of the conductive element. The coating may include a metal alloy formed from at least two or more components. The coating alloy may be at least one of a lead-based, tin-based, and bismuth-based alloy. The coating may include a two-phase, three-phase, or more complex metal alloy. The coating may be formed of a metal alloy including at least one of Ag, Bi, Cd, Ga, In, Pb, Sn, Ti, and the like. The coating may also include a conductive material formed from metal or alloy particles embedded within an organic matrix.

[0079] The coating may be configured to substantially cover at least one or each of the first and second surfaces of at least one conductive element. The coating may be configured to substantially cover the first and second surfaces of each conductive element. For example, in embodiments where the conductive element comprises a third surface and / or a fourth surface separating the first and second surfaces, at least one or each of the third and / or fourth surfaces may be at least partially coated with the coating. Each conductive element may be completely coated with the coating. In embodiments, the coating may be absent from a portion of the first surface and / or the second surface. In embodiments, the coating may be absent from at least a portion of the third surface and / or the fourth surface.

[0080] At least one or each of the plurality of conductive elements may be disposed within and / or on the film. The film may be configured to be insulating and / or optically transparent. The film may be configured to provide adhesion between the solar cell and the conductive elements such that the conductive elements are properly spaced on the solar cell. In this manner, the film allows the conductive elements to be properly aligned with the solar cell. The film may provide a mechanical connection between the conductive elements and the solar cell. In an exemplary arrangement, the film may not cover all of the front and / or back surface of each of the solar cells. For example, the film may not extend completely across at least one dimension (e.g., length and / or width) of the solar cell. Alternatively, the film may cover the entire surface of the solar cell, for example, the film may extend completely across the width and / or length of the solar cell.

[0081] The film may be configured such that at least a portion of at least one of the first and second surfaces of at least one conductive element is exposed from the film to form an ohmic contact with the front and back surfaces of the first and second solar cells, respectively. For example, at least a portion of the first surface of the conductive element may be exposed from the film, and / or at least a portion of the second surface of the conductive element may be exposed from the film. The film may have a thickness of at least 50 μm and / or at most 100 μm, which may be less than the thickness of the conductive element over which it is overlaid, such that the conductive element can be exposed from the film.

[0082] As discussed above, the conductive elements of the front and back connectors may define first and second sections of the plurality of conductive elements, respectively. The first section of the plurality of conductive elements may be disposed in or on a first film (e.g., an insulating and / or optically transparent film). The second section of the plurality of conductive elements may be disposed in or on a second film (e.g., an insulating and / or optically transparent film).

[0083] In use, the first film of the front connector may define the front film (i.e., the front film portion) of the electrode assembly. Similarly, the second film of the back connector may define the back film (i.e., the back film portion) of the electrode assembly. The front film may be configured to expose at least a portion of the back surface of the conductive elements of the front connector. The back film may be configured to expose at least a portion of the front surface of the conductive elements of the back connector.

[0084] As described above, a third section of the plurality of conductive elements may be configured to connect the first and second portions of the plurality of conductive elements. Thus, the third section may be configured to be disposed between overlapping surfaces of the first and second solar cells. The third section may be configured such that the conductive elements of this section are not disposed within (or on) the film (i.e., in contrast to the first and second sections).

[0085] At least one, or each, of the conductive elements may be disposed on a surface of each of the first and second films. Alternatively, or in addition, at least one of the conductive elements may be at least partially disposed within the film. In this manner, at least one conductive element may be embedded within the film such that a surface of the conductive element protrudes beyond a surface of the film.

[0086] The films (e.g., front and / or backing films) can be formed from polymeric materials having high ductility, good insulating properties, optical transparency and thermal stability, resistance to shrinkage. Exemplary polymeric materials may include acetate, epoxy, fluoroplastics, polyamide, polysulfone, rayon, polyolefin, plastyrene, rayonext, polyethylene terephthalate (PET), polyvinyl fluoride film, modified ethylene tetrafluoroethylene, and the like. In one embodiment, at least one of the first and second films is comprised of a single layer of material, while in some other embodiments, at least one of the first and second films includes two or more layers, and two or more of these layers may include different materials and / or material properties.

[0087] The surface of the film facing the conductive elements may be coated with a transparent adhesive. During fabrication of the solar cell assembly, heat and / or pressure may be applied to the film to soften the adhesive, allowing for adhesion of the film to the conductive elements by application of force. In this manner, the wire may be at least partially embedded in the adhesive. In an embodiment, the conductive elements may be partially embedded in the adhesive but do not actually contact the film. The first and / or second films may be configured to provide structural support to the conductive elements prior to placement on the solar cell when multiple conductive elements are being handled.

[0088] When the front and back connectors are assembled with their respective first and second solar cells, the associated film may deform to conform to the shape of the conductive elements sandwiched between the film and the solar cell. In other words, the surface of the film may be substantially planar in the non-element contact areas and may form ridges / protuberances above the conductive elements in the element contact areas. In this manner, each (e.g., longitudinal) conductive element contact area of ​​the film may have a non-planar (e.g., transverse) profile.

[0089] The film of the front connector may have a back surface (i.e., facing toward the solar cells) and a front surface (i.e., facing away from the solar cells) opposite the back surface. At least one conductive element of a first portion of the plurality of conductive elements may be disposed on the back surface of the front film.

[0090] The back connector film may have a front surface (i.e., facing toward the solar cells) and a back surface opposite the front surface (i.e., facing away from the solar cells). At least one conductive element of the second portion of the plurality of conductive elements may be disposed on the front surface of the back film.

[0091] According to a fifth aspect of the present invention, there is provided a solar cell assembly comprising a first solar cell, a second solar cell, and an electrode assembly according to any one of the preceding statements. The plurality of conductive elements may be configured to electrically couple a front surface of the first solar cell with a back surface of the second solar cell.

[0092] The solar cell assembly may be manufactured according to the method of any one of the preceding statements. The plurality of conductive elements may be configured to electrically couple the front surface of the first solar cell with the back surface of the second solar cell. The back surface of the second solar cell may be configured to at least partially overlap the front surface of the first solar cell. A third section of the plurality of conductive elements may be disposed between the partially overlapping surfaces of the first and second solar cells. The deformed third section of the conductive elements is thereby configured to distribute loads between the partially overlapping first and second solar cells. The resulting electrode assembly may provide a stronger mechanical connection between the solar cells in the overlapping region.

[0093] The conductive elements may be configured to form ohmic contacts with the conductive surfaces (e.g., conductive portions of the surfaces) of the solar cells. Each of the solar cells may have a layered structure that includes a photovoltaic element, as will be understood by those skilled in the art. The conductive surfaces may be disposed (e.g., printed) on the front and back surfaces of the solar cells and may include one or more finger electrodes that conduct charge carriers generated by the layered structure.

[0094] Each of the first and second solar cells may have a length, a width, and a depth. The length of the solar cell may be less than its width, and the depth may be less than both its width and length. The longitudinal and lateral directions across the front and back surfaces of the solar cell may be parallel to the length and width directions of the solar cell, respectively. Thus, the multiple conductive elements may be configured to extend across the length of the solar cell and be spaced apart along its width.

[0095] Each conductive element may be configured to extend longitudinally, vertically, relative to a surface of the solar cell on which it is overlaid. The conductive elements may be spaced laterally, relative to the solar cell surface, to define longitudinally extending spaces between the conductive elements. The conductive elements may be parallel to one another, or substantially parallel. The conductive elements may be laterally equally or substantially equally spaced. Thus, the plurality of conductive elements may form an array of parallel laterally spaced (e.g., equally spaced) conductive elements.

[0096] The electrode assembly may be configured to form an electrical connection with the conductive surfaces (or conductive portions of the surfaces) of the first and second solar cells. As described above, the conductive elements of the electrode assembly are configured to optimize the optoelectronic properties of the front and / or back connectors, such as their current collection and solar cell shading properties.

[0097] Each of the conductive surfaces of the solar cell may include a plurality of finger electrodes extending across the respective solar cell surface. The finger electrodes may be formed using a printed material that allows them to be conveniently deposited on the surface of the solar cell.

[0098] Each finger electrode of the plurality of front finger electrodes and / or back finger electrodes may be configured to have an axial length that is substantially greater than its width. Both the width and the axial length of the finger electrodes may be measured vertically in the plane of the respective surface of the solar cell. The finger electrodes may extend in a lateral direction parallel to the width direction of the solar cell.

[0099] The finger electrodes within each of the plurality of front and / or back finger electrodes may be spaced apart across a respective surface to define laterally extending spaces between the finger electrodes. The finger electrodes may be spaced apart in a longitudinal direction that is substantially parallel to a length of the solar cell. The finger electrodes of each of the plurality of finger electrodes may be substantially parallel to one another.

[0100] The axial length of at least one of the plurality of back finger electrodes may be substantially offset (e.g., substantially non-parallel or substantially perpendicular) from the axial length of at least one of the conductive elements of the electrode assembly overlaid thereon. Thus, the conductive element of the electrode assembly may be configured to extend across a surface of the solar cell and form an ohmic contact with each of the plurality of finger electrodes. In this manner, the conductive element may be conveniently positioned to optimize charge collection from the surface of the solar cell.

[0101] The solar cell of the solar cell assembly may comprise a plurality of layers, or elements, including a photovoltaic element, at least one of the plurality of layers being formed from a semiconductor material. The photovoltaic element (or layer) may be formed from a crystalline silicon wafer. It is understood that the solar cell may be configured to define any type of solar cell structure. For example, the solar cell may define a heterojunction solar cell. Alternatively, the solar cell may define a tandem junction solar cell.

[0102] The surface of a solar cell may be textured to create a textured surface that corresponds to a non-uniform surface or has non-uniform characteristics, thereby improving the efficiency of the solar cell by increasing the amount of light incident on the solar cell.

[0103] The solar module may include a frame for housing the plurality of solar cell assemblies. The frame may include a front plate and a back plate disposed on the front and back sides of the plurality of solar cell assemblies, respectively. At least one or each of the front plate and the back plate may be formed of glass (e.g., a glass sheet). The solar module may include an encapsulant that provides adhesion between the front plate and the back plate and the plurality of solar cell assemblies. In this manner, the encapsulant may be disposed between the glass sheet of the solar module and an insulating optically transparent film of one of the plurality of solar cell assemblies. The encapsulant may also be disposed between the back sheet of the solar module and an insulating optically transparent film of one of the plurality of solar cell assemblies. The encapsulant may be configured to prevent ingress of moisture into the solar module. Thus, the encapsulant may be formed of ethylene vinyl acetate (EVA), or any other suitably moisture resistant material.

[0104] Those skilled in the art will appreciate that, unless mutually exclusive, a feature or parameter described in connection with any one of the above aspects may be applied to any other aspect. Further, unless mutually exclusive, any feature or parameter described herein may be applied to any aspect and / or may be combined with any other feature or parameter described herein. [Brief description of the drawings]

[0105] Embodiments will now be described, by way of example only, with reference to the drawings in which:

[0106] [Figure 1] 1 is an enlarged cross-sectional side view of a solar module including a solar cell assembly, the solar cell assembly comprising a first solar cell and a second solar cell arranged in an overlapping configuration. [Diagram 2] 2 is a plan view of the top surface of a first and second solar cell, the first and second solar cells being joined by an electrode assembly as shown in FIG. 1; [Diagram 3]3 is an enlarged transverse cross-sectional view of the first solar cell taken along line AA shown in FIG. 2. [Figure 4] 3 is an enlarged transverse cross-sectional view of the first and second solar cells taken along line BB shown in FIG. 2. [Diagram 5] 5 is an enlarged longitudinal cross-sectional view of the first and second solar cells taken along line CC shown in FIGS. 2 and 4. FIG. [Figure 6] FIG. 6 is a perspective view of an apparatus for flattening a section of the electrode assembly shown in FIGS. 2-5. [Figure 7] FIG. 7 is a side view of the device shown in FIG. [Figure 8] 8A and 8B are cross-sectional views of the first and second rolls of the apparatus shown in FIGS. 6 and 7, illustrating different stages in a method of planarizing a section of an electrode assembly. [Figure 9] 8A and 8B are cross-sectional views of the first and second rolls of the apparatus shown in FIGS. 6 and 7, illustrating different stages in a method of planarizing a section of an electrode assembly. [Figure 10] 8A and 8B are cross-sectional views of the first and second rolls of the apparatus shown in FIGS. 6 and 7, illustrating different stages in a method of planarizing a section of an electrode assembly. [Figure 11] 8A and 8B are cross-sectional views of the first and second rolls of the apparatus shown in FIGS. 6 and 7, illustrating different stages in a method of planarizing a section of an electrode assembly. [Figure 12] 8A and 8B are cross-sectional views of the first and second rolls of the apparatus shown in FIGS. 6 and 7, illustrating different stages in a method of planarizing a section of an electrode assembly. [Figure 13] 8 is a cross-sectional view of an alternative roll suitable for use in the planarizing apparatus shown in FIGS. 6 and 7. FIG. [Figure 14] 8 is a cross-sectional view of an alternative roll suitable for use in the planarizing apparatus shown in FIGS. 6 and 7. FIG. [Figure 15] 8 is a cross-sectional view of an alternative roll suitable for use in the planarizing apparatus shown in FIGS. 6 and 7. FIG. [Figure 16] 8 is a cross-sectional view of an alternative roll suitable for use in the planarizing apparatus shown in FIGS. 6 and 7. FIG. [Figure 17] 8 is a cross-sectional view of an alternative roll suitable for use in the planarizing apparatus shown in FIGS. 6 and 7. FIG. [Figure 18] 1 is a flow chart illustrating a method of manufacturing an electrode assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0107] Aspects and embodiments of the present disclosure will now be described with reference to the accompanying drawings, in which: Further aspects and embodiments will be apparent to those skilled in the art.

[0108] In the drawings, the thicknesses of layers, films, elements, etc. have been exaggerated for clarity. Furthermore, when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it is understood that it may be directly on the other element or that intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

[0109] 1 shows a solar cell assembly 10 according to the present invention disposed within a support assembly 102 of a solar module 100 (e.g., a solar panel). The solar cell assembly 10 includes a first solar cell 20, a second solar cell 30, and an electrode assembly 12 disposed to electrically connect a front surface 22 of the first solar cell 20 to a back surface 34 of the second solar cell 30.

[0110] The front surface 22 of the first solar cell 20 is partially overlapped by the back surface 34 of the second solar cell 30 to define an overlap region 15 of the solar cell assembly 10. The electrode assembly 12 extends along the front surface 22 of the first solar cell 20 through the overlap region 15 and then further extends along the back surface 34 of the second solar cell 30.

[0111] The electrode assembly 12 is configured to reduce stress build-up in the overlap region 15 between the solar cells 20, 30, as described in more detail below. The electrode assembly 12 is also positioned to provide an improved electrical path between the first solar cell 20 and the second solar cell 30, while simultaneously enhancing light scattering and absorption conditions at the front surface 22 of the first solar cell 20.

[0112] The solar cell assembly 10 is one of a plurality of solar cell assemblies arranged within a support assembly 102. For example, the front surface 32 of the second solar cell 30 is electrically coupled to the back surface of a third solar cell by a second electrode assembly 14. Also, a third electrode assembly 16 is provided to couple the back surface 24 of the first solar cell 20 to the front surface of a fourth solar cell.

[0113] For example, it will be understood that the second and third solar cells in this arrangement are electrically connected by the second electrode assembly 14 to define a second solar cell assembly, whereby the multiple solar cells 20, 30 are joined by the electrode assemblies 12, 14, 16 to define a single string.

[0114] The front plate 104 of the support assembly 102 comprises a transparent (e.g., glass) sheet configured to allow light to pass through to a central chamber 106 in which the solar cell assembly 10 rests. The arrows at the top of Figure 1 indicate the direction of solar radiation incident on the solar cell assembly 10.

[0115] A back plate 108 of the support assembly 102 is positioned to enclose the solar cell assembly 10 within a central chamber 106. The back plate 108 includes a reflective sheet configured to reflect any light incident on its front surface (i.e., the front-facing surface) toward the solar cell assembly 10. The central chamber 106 is filled with an encapsulant material (shaded area shown in FIG. 1 ) that prevents outside liquids from entering or gases from entering.

[0116] Further aspects of the solar cell assembly 10 will now be described with reference to Figures 2 to 5. In particular, Figure 2 shows a top (front) view of the first and second solar cells 20, 30. Figure 3 shows an enlarged transverse cross-sectional view of the first solar cell 20 along line AA shown in Figure 2. Figure 4 shows an alternative enlarged transverse cross-sectional view of the first and second solar cells 20, 30 along line BB shown in Figure 2. Furthermore, Figure 5 shows an enlarged longitudinal cross-sectional view of the first and second solar cells 20, 30 along a portion of line CC shown in Figures 2 and 4.

[0117] Each of the solar cells 20, 30 has a length, which is the vertical dimension in Figure 2, and a width, which is the horizontal dimension in Figure 2. The first and second solar cells 20, 30 are arranged in separate parallel cross-sections (as shown in Figure 1) such that their width and length dimensions are parallel to one another. Each of the front surfaces 22, 32 of each solar cell defines a surface onto which light is incident when the solar cell assembly 10 is in use. Each of the back surfaces 24, 34 defines a surface opposite the respective front surface 22, 32, as most clearly shown in Figure 1.

[0118] Each solar cell 20, 30 includes a layered structure (not shown) disposed between its respective front and back surfaces. The layered structure is a multi-layer semiconductor assembly that includes photovoltaic elements (or layers) configured to generate charge carriers from the absorption of incident radiation.

[0119] The first solar cell 20 includes a first plurality of finger electrodes 26 (i.e., front finger electrodes) disposed on its front surface 22 and a second plurality of finger electrodes 28 (i.e., back finger electrodes) disposed on its back surface 24. Similarly, the second solar cell 30 includes a first plurality of finger electrodes 36 disposed on its front surface 32 and a second plurality of finger electrodes 38 disposed on its back surface 34. Each of the finger electrodes 26, 36, 28, 38 is configured to conduct charge carriers generated by the respective solar cell 20, 30.

[0120] A plurality of front and back finger electrodes 26, 28, 36, 38 are arranged to extend laterally (horizontally in FIG. 2) across the solar cell 20, 30 and are equally spaced apart longitudinally (vertically in FIG. 2). The dimensions of each finger electrode 26, 28, 36, 38 are substantially the same as the dimensions of every other finger electrode 26, 28, 36, 38.

[0121] Each of the finger electrodes 26, 28, 36, 38 is aligned parallel to the other finger electrodes disposed on the same solar cell surface, and each finger electrode is aligned parallel to a corresponding finger electrode on the opposite side of the solar cell.

[0122] 2, each of the plurality of front and back finger electrodes 26, 28, 36, 38 includes 14 finger electrodes, although it should be understood that in some other embodiments the number of front and back finger electrodes 26, 28, 36, 38 may vary without departing from the scope of the present invention.

[0123] The finger electrodes 26, 28, 36, 38 are formed from a conductive material, which is formed from a metal alloy including Ag, which is a printable material that allows the finger electrodes to be easily deposited on the respective surfaces of the solar cell.

[0124] The electrode assembly 12 comprises a plurality of conductive elements 18 (or conductive element portions) that extend across the length of the solar cells 20,30 (the vertical dimension in FIG. 2).

[0125] 2, the portion of the electrode assembly 12 disposed on the bottom surface 34 of the second solar cell 30 is shown in dashed lines to indicate that the portion of the conductive element 18 is hidden from view by the second solar cell 30. In use, this portion of the electrode assembly 14 is not visible (i.e., as is the case with the corresponding portion of the third electrode assembly 16, which is hidden by the first solar cell 20).

[0126] Each of the conductive elements 18 includes a first section 18a disposed to contact the front surface 22 of the first solar cell 20, a second section 18b configured to contact the back surface 34 of the second solar cell 30, and a third section 18c electrically connecting the first and second sections. Thus, as shown most clearly in Figure 5, the third section 18c is at least partially disposed between the overlapping front and back surfaces 22, 34 of the respective first and second solar cells 20, 30 (i.e., within the overlap region 15).

[0127] As shown most clearly in Figure 3, the conductive elements 18 of the first and second sections 18a, 18b are disposed within an electrically insulating, optically transparent film 40. In contrast, the third section 18c does not include any film or foil, as shown in Figure 5.

[0128] The first section 18a collectively defines a front connection portion 12a (i.e., a front connector) of the electrode assembly 12. Similarly, the second section 18b defines a back connection portion 12b (i.e., a back connector) of the electrode assembly 12, and the third section 18c defines a third portion 12c configured to electrically connect the respective first and second portions 12a, 12b (i.e., interconnect portions).

[0129] Each of the conductive elements 18 has an integral elongated form, such as a wire, formed from a conductive material. For example, the conductive elements 18 include a metal alloy material including at least one of Ag, Al, Au, and Cu.

[0130] The first and second sections 18a, 18b of the conductive element 18 are configured to form ohmic contacts with finger electrodes 26, 38 disposed on the front and back surfaces 22, 34 of the first and second solar cells 20, 30, respectively. The conductive element 18 is formed from a conductive material such that it is configured to allow charge carriers to flow between the conductive element 18 and the finger electrodes 26, 38 on the front and back surfaces 22, 34 of the first and second solar cells 20, 30.

[0131] During operation of the solar module 100, the conductive elements 18 collect charge carriers from the front finger electrodes 26 of the first solar cell 20 and transfer them to the back finger electrodes 38 of the second solar cell 30. Each of the conductive elements 18 thus defines a current collector of the electrode assembly 12.

[0132] According to an exemplary arrangement, each of the plurality of conductive elements 18 includes a coating (not shown) configured to, in use, solder the first section 18a and the second section 18b to a surface of the respective solar cell 20, 30 on which they are overlaid. The coating is formed of a conductive material having a melting point lower than that of the conductive elements 18. The coating includes a metal alloy formed of at least two or more components, such as lead-based, tin-based, and bismuth-based alloys. Alternatively, the coating may include a two-phase, three-phase, or more complex metal alloy, as will be appreciated by those skilled in the art.

[0133] The number of conductive elements 18 in the electrode assembly 12 is between 4 and 20. According to embodiments described herein, the first electrode assembly 12 has 16 conductive elements 18, as shown in Figure 2. However, it is understood that in some other embodiments, a different number of conductive elements may be present without departing from the scope of the present invention.

[0134] First, second, and third sections 18a, 18b, 18c of the plurality of conductive elements 18 extend lengthwise (vertically in FIG. 2) parallel to the front and back surfaces 22, 34 of the solar cell. The conductive elements 18 are also equally spaced laterally relative to the front and back surfaces 22, 34 (horizontally in FIG. 2) so as to define longitudinally extending spaces between the conductive elements 18.

[0135] Each of the first sections 18a is parallel to a corresponding second section 18b of the same electrode assembly 12. Thus, each of the first and second sections 18a, 18b defines an array of parallel, laterally spaced apart conductive elements 18. Also, as shown in FIG. 5, the first section 18a of the first electrode assembly 12 is parallel to the second section 18b of the third electrode assembly 16, with a first solar cell 20 interposed therebetween. Similarly, the second section 18b of the first electrode assembly 12 is parallel to the first section 18a of the second electrode assembly 14, with a second solar cell 30 interposed therebetween.

[0136] According to the above-described arrangement, it will be understood that the first and second sections 18a, 18b of the plurality of conductive elements 18 are arranged perpendicular to the plurality of front finger electrodes and back finger electrodes 26, 38, as shown in FIG.

[0137] Each of the conductive elements 18 has substantially the same width, length, and depth as every other conductive element 18. The length of each conductive element 18 defines an axial length that is substantially greater than its width and depth. The first and second sections 18a, 18b are configured to have a substantially circular cross-section, as shown most clearly in Figures 3 and 4. In contrast, each of the third sections 18c is configured to have a substantially oval or rectangular cross-section, as shown most clearly in Figure 4.

[0138] The cross-sectional shape of the third section 18c is configured to have a height (vertical direction as shown in FIG. 4) that is substantially less than its width (horizontal direction as shown in FIG. 4). The flattened or compressed shape of the third section 18c defines substantially flat portions of the front surface 48 and back surface 46 of the conductive element 18. The planar front and back surfaces provide a larger contact area with the respective surfaces 22, 34 of the first and second solar cells 20, 30 (i.e., compared to the curved surfaces of the first and second sections 18a, 18b). For example, when the electrode assembly 12 is disposed between the first solar cell 20 and the second solar cell 30, the back surface 46 of the third section 18c is configured to face the front surface 22 of the first solar cell 20 and be disposed parallel to the front surface 22 of the first solar cell 20, as shown in FIG. 4. Similarly, the front surface 48 is configured to face the back surface 34 of the second solar cell 30 and be parallel to the back surface 34 of the second solar cell 30.

[0139] The large contact area between the third section 18c and the solar cell surface means that any force or pressure in the overlap region 15 is distributed across the width of the first and second solar cells 20, 30 (i.e., horizontally in FIG. 4). This then reduces the risk of damage to the solar cells due to external and / or thermal loading of the solar module 100. As shown most clearly in FIG. 5, the reduced height of the third section 18c also reduces the height of the overlap region 15, thereby increasing the structural stability of the solar cells. This can also result in an overall reduction in the height (i.e., thickness) of the overlapping solar cells, thereby improving the packaging efficiency of the solar cell assembly 10.

[0140] The curved surface of the conductive element 18 in the first section 18a increases the scattering of light incident on the front surface 22, thereby improving light absorption and device performance of the first solar cell 20. Similarly, the conductive element 18 in the second section 18b is configured to either transmit through the solar cell or scatter light that is reflected from the back plate 108 to the back surface of the solar cell.

[0141] The first and second sections 18a, 18b of the conductive element 18 have a width and height (e.g., thickness) of about 0.2 mm. Each of the first and second sections 18a, 18b is configured to extend substantially across the surface of the respective solar cell on which they are overlaid. Each of the third sections 18c has a width of about 0.24 mm and a height (e.g., thickness) of about 0.08 mm. Thus, the third sections 18c are about 120% wider and about 40% taller than the first and second sections 18a, 18b.

[0142] As described above, the electrode assembly 12 comprises an insulating, optically transparent film 40 in which at least a portion of the conductive elements 18 are embedded. The first and second sections 18a, 18b of the plurality of conductive elements 18 are each disposed in a separate film portion. For example, the front connector 12a includes a first film portion defining a front film portion 42, and the back connector 12b includes a second film portion defining a back film portion 44. It should be noted, however, that the conductive elements 18 of the third section 18c are not covered by any film or foil.

[0143] According to an exemplary arrangement of the solar cell assembly 10, each of the first and second sections 18a, 18b of the conductive element 18 is attached to a surface of its respective film 42, 44 that faces the solar cell. This "solar cell facing surface" of the films 42, 44 is coated with an adhesive that adheres the conductive element to the respective film 42, 44.

[0144] 3, the film portions 42, 44 are positioned to contact the surface of the solar cell in the area between the conductive element 18 and the front finger electrodes 26, 28. In an exemplary arrangement of the solar cell assembly 10, each of the film portions 42, 44 is configured to at least partially (e.g., completely) surround or encircle a respective conductive element 18 and a respective finger electrode 26, 38.

[0145] The film portions 42, 44 are positioned to provide adhesion between the solar cell and the conductive element 18 such that the conductive element is properly positioned on the solar cell (i.e., aligned with the finger electrodes). In an exemplary embodiment, the front film portion 42 and the back film portion 44 do not completely cover the respective surfaces of the solar cell. For example, the film portions are not positioned in the overlap region 15 between the solar cells 20, 30, as shown in FIG.

[0146] Furthermore, front film portion 42 does not extend to the edge of front surface 32 of second solar cell 30 that overlaps first solar cell 20, as is clearly shown in FIG.

[0147] On the other hand, the front film portion 42 and the back film portion 44 shown in the drawings have substantially flat bottom and top surfaces, respectively. It is understood that the film 40 (i.e., film portions 42, 44) may be configured to conform to the structural components of the solar cells and / or the conductive elements. Thus, the film 40 may consist of elongated channels recessed towards the solar cells in areas of the solar cell surface between the conductive elements, or may form ridges / protrusions on the structural electrodes (e.g., finger electrodes and conductive elements), if present.

[0148] The front and back film portions 42, 44 may be thinner than the conductive element 18 (e.g., the first and second uncompressed sections 18a, 18b of the conductive element). For example, the first and second uncompressed sections 18a, 18b of the conductive element 18 may have a thickness of 200 μm to 350 μm (e.g., about 200 μm, or 0.2 mm), while the film may have a thickness of 50 μm to 100 μm (e.g., about 75 μm, or 0.075 mm).

[0149] The front and back film portions 42, 44 are each formed from a polymeric material having high ductility, good insulating properties, optical transparency, and thermal stability and resistance to shrinkage. An exemplary polymeric material comprises modified ethylene tetrafluoroethylene. The front and back film portions 42, 44 are applied with heat and pressure onto the respective surfaces of the solar cell such that the films conform to the finger electrodes and conductive elements disposed thereon.

[0150] An apparatus 50 used to manufacture the electrode assembly 12 will now be described with reference to Figures 6 and 7. In particular, the apparatus 50 is configured to form the third sections 18c of the plurality of elongated conductive elements 18.

[0151] The apparatus 50 has a first roll 52 and a second roll 54 rotatably mounted on a pair of supports 56 disposed at axial ends of the rolls 52, 54. The first and second rolls 52, 54 are axially parallel to one another and radially spaced apart to define a gap 60 therebetween. During operation of the apparatus 50, a plurality of conductive elements 18 are fed into the gap 60 between the first roll 52 and the second roll 54. The apparatus 50 is configured to cyclically deform successive sections of the conductive elements 18, as described in more detail below.

[0152] 7, the first roll 52 is disposed vertically above the second roll 54. Specifically, the axis of rotation of the first roll 52 is disposed vertically above the axis of rotation of the second roll 54. Thus, the first roll 52 and the second roll 54 define upper and lower rolls, respectively, of the apparatus 50.

[0153] Each of the rolls 52, 54 includes an axle surrounded by an outer body. The outer body is formed of a resilient material, such as hardened steel, and is configured to resist deformation due to interaction of the roll with the plurality of conductive elements. However, it is understood that the rolls may be formed from different materials without departing from the scope of the present invention.

[0154] As shown most clearly in Figure 7, the first roll 52 has a first axle 62 and the second roll 54 has a second axle 64. The first and second axles 62, 64 are received in respective apertures in the support 56. A pair of bearings are provided between each of the axles 62, 64 and the receiving apertures (not shown). The bearings are configured to allow the rolls 52, 54 to rotate freely relative to the support 56 during operation of the apparatus 50.

[0155] An actuator 58 is coupled to the first and second rolls 52, 54 and configured to control their rotation. The actuator 58 includes an electric motor coupled to the first and second axles 62, 64 by a drive belt (not shown). The drive belt is configured to transfer power from the electric motor to the roll axles 62, 64, as would be understood by one of ordinary skill in the art. The actuator 58 is configured to rotate the rolls 52, 54 at substantially the same speed (i.e., the same number of revolutions per minute).

[0156] The actuator 58 is configured to rotate the first roll 52 in a direction opposite to that of the second roll 54, such that the rolls cooperate to push and pull the conductive element 18 through the gap 60. For example, as shown in FIG. 7, when viewed from the right side of the apparatus 50, the first roll 52 is rotated in a counterclockwise direction and the second roll 54 is rotated in a clockwise direction.

[0157] Each of the supports 56 comprises an elongated pillar or column disposed vertically with its longitudinal axis as shown in Figure 6. Each of the supports 56 includes an upper end that is attached to the first and second rolls 52, 54. A lower end of each of the supports 56 is configured to be placed on the ground, thereby supporting the weight of the apparatus 50.

[0158] As mentioned above, the apparatus 50 is configured to receive a plurality of conductive elements 18 passing through a gap 50 between a first roll 52 and a second roll 54. The conductive elements 18 are arranged substantially parallel to one another in the longitudinal direction and substantially spaced apart in the transverse direction, as shown most clearly in FIG.

[0159] The first roll 52 has a circular cross-section and the first axle 62 (i.e., defining the axis of rotation of the first roll 52) is substantially aligned with the geometric center of the circular cross-section (i.e., defining the geometric axis of the first roll 52). This means that the first roll 52 is aligned concentrically with the first axle 62, as shown most clearly in FIG.

[0160] The second roll 54 has an elliptical cross-section that includes two-fold symmetry, as indicated by the dashed lines in Figure 8. The elliptical cross-section of the second roll 54 has a major axis and a minor axis that define the diameters (i.e., lines passing through the geometric center) of the elliptical cross-section. The major axis is the longest diameter and the minor axis is the shortest diameter. Thus, the major axis connects between the two eccentric ends of the elliptical cross-section and the minor axis connects between the two non-eccentric ends.

[0161] The second axle 64 (i.e., defining the axis of rotation of the second roll 54) is substantially aligned with the geometric center of the roll's elliptical cross-section (i.e., defining the geometric axis of the second roll 54). Furthermore, the rotational and geometric axes of the first roll 52 and second roll 54 all lie in a common vertical plane. As shown in Figures 8-12, the axes remain in the same vertical plane as the rolls 52, 54 are rotated.

[0162] Thus, the second roll 54 is configured such that as it rotates, the gap 60 between the first roll 52 and the second roll 54 decreases in a radial direction of the second roll 54. This decrease in the height of the gap 60 (in the vertical direction shown in FIG. 7 ) results in a compressive force being applied to successive periodic sections of the plurality of conductive elements 18.

[0163] The first and second rolls 52, 54 enable the continuous production of the electrode assemblies 12 by cyclically decreasing the height (vertical direction as shown in FIG. 7 ) of successive periodic sections as the conductive element 18 is fed into the gap 60 between the rolls 52, 54. This cyclic application of compressive force occurs without pausing or stopping the electrode assembly manufacturing process.

[0164] The resulting periodic sections define third sections 18c of the plurality of conductive elements 18. Thus, the apparatus 50 provides a means for fabricating an electrode assembly 12 having modified interconnect sections 12c that can be positioned within the overlapping regions of the first and second solar cells 20, 30 of the solar cell assembly 10.

[0165] As mentioned above, the second roll 54 is configured to cyclically reduce the gap 60 between the first roll 52 and the second roll 54 as the rolls rotate. This change in size of the gap 60 will now be described with reference to Figures 8-12.

[0166] 8, the second roll 54 is positioned so that its long axis is parallel to the longitudinal axis of the conductive element 18. The conductive element 18 extends through the gap 60 between the rolls. When the rolls are positioned as shown in FIG. 8, the gap 60 between the first roll 52 and the second roll 54 is at a maximum.

[0167] The portion of the conductive element 18 disposed directly within the gap 60 is configured such that its front surface 48 faces the bottom surface of the second roll 54 and the back surface 46 of the conductive element 18 faces the top surface of the first roll 52. The first roll 52 is positioned below the second roll 54 such that gravity causes the conductive element 18 to rest on the top surface of the first roll 52. The second roll 54 is configured such that its bottom surface is spaced apart from the conductive element 18, as shown in FIG.

[0168] As the rolls rotate, the first roll 52 rotates in a counterclockwise direction, which pulls the conductive element 18 substantially horizontally through the gap 60. The second roll 54 rotates in a clockwise direction such that one of its eccentric ends contacts the front surface 48 of the conductive element 18, as shown in FIG. 9. The clockwise rotation of the second roll 54 reduces the gap 60 between the first roll 52 and the second roll 54. Upon contacting the conductive element 18, any further rotation of the second roll 54 results in a compressive force being applied to the element as it is compressed between the first roll 52 and the second roll 54.

[0169] As the rotation of the first roll 52 and the second roll 54 continues, the minimum gap 60 between the rolls is achieved when the position is reached where the major axis of the second roll 54 is perpendicular to the longitudinal axis of the elongated element 18, as shown in Figure 10. This position corresponds to the maximum compressive force being applied to the conductive element 18.

[0170] As the first and second rolls 52, 54 rotate further, the gap 60 between the rolls begins to increase, as shown in Figure 11. The second roll 54 separates from the front surface 48 of the conductive element 18, leaving a deformed section of the conductive element 18.

[0171] The front and back surfaces of the conductive element 18 are both deformed by the respective first and second rolls 52, 54. Thus, the conductive element 18 is provided with opposing concave surfaces that correspond to the curved surfaces of the first and second rolls 52, 54.

[0172] 12 shows the first and second rolls 52, 54 having completed a 180 degree rotation. Again, the second roll 54 is positioned so that its long axis is parallel to the longitudinal axis of the conductive element 18. The gap 60 between the first roll 52 and the second roll 54 is again at a maximum (i.e., the second roll 54 is spaced away from the conductive element 18) so that the conductive element 18 is in contact only with the first roll 52. However, the eccentric end of the second roll now faces in the opposite direction from the direction it faced at the start of the rotation.

[0173] The maximum distance between the first roll 52 and the second roll 54 (e.g., at the maximum separation point between the rolls) is at least 0.3 mm and / or at most 5 mm. Thus, the thickness of the uncompressed conductive element 18 (e.g., about 0.2 mm) is not as thick as the maximum gap between the rolls (e.g., at least 0.3 mm), and the distance between the rolls at the maximum separation point is configured such that both rolls do not contact the conductive element 18 at the same time.

[0174] The minimum distance between the first roll 52 and the second roll 54 (e.g., at the narrowest point between the rolls) is at least 0.05 mm and / or at most 4.75 mm. Thus, the gap between the rolls at their narrowest points is periodically smaller than the thickness of the uncompressed conductive element (e.g., about 0.2 mm), such that as the rolls rotate, the rolls periodically compress the height of the conductive element (e.g., to 0.08 mm). For example, the maximum distance between the rolls is about 0.5 mm and the minimum distance between the rolls is about 0.08 mm.

[0175] In accordance with the above, it will be appreciated that the rolls 52, 54 are configured such that as the rolls rotate, the distance between the surfaces of the first roll 52 and the second roll 54 periodically decreases and increases. In this manner, the apparatus 50 defines a conductive element deformation apparatus.

[0176] The apparatus 50 can be operated sequentially to deform the periodic sections of the conductive element 18 for each 180 degree rotation of the second roll 54 during the rotation of the roll. As described above, the second roll 54 is separated from the conductive element 18 during a portion of its rotation. The second roll 54 does not apply a compressive force to the intervening sections of the conductive element 18. Thus, the apparatus 50 is configured to apply only a compressive force to successive periodic sections that are intended to be deformed.

[0177] The deformed section corresponds to the third section 18c of the plurality of elongated conductive elements 18, as described above with respect to FIG. 4. Additionally, the non-deformed sections disposed on either side of the deformed section correspond to the first and second sections 18a, 18b of the conductive elements 18. The cross-sectional perimeter of the second roll 54 defines a length corresponding to the combined length of the first, second and third sections 18a, 18b, 18c of the plurality of conductive elements 18. This allows the deformed sections to be spaced apart the correct distance such that the non-deformed first and second sections 18a, 18b are sized to fit the front and back surfaces 22, 34 of the first and second solar cells 20, 30, respectively.

[0178] In the exemplary arrangement, all of the alternating deformed sections are disconnected from the conductive element 18, leaving a single deformed section (i.e., the third section 18c) bonded between two non-deformed sections (i.e., the first and second sections 18a, 18b). In this arrangement, the permitter of the second roll 54 is larger than the combined length of the first, second and third sections 18a, 18b, 18c to account for the length of the alternating deformed sections that have been removed.

[0179] The curvature of the first and second rolls 52, 54 causes the conductive element 18 to gradually decrease in thickness in the longitudinal direction, extending from the undeformed to the deformed sections, thereby providing smooth transitions between the first section 18a and the third section 18c, and between the third section 18c and the second section 18b, as shown most clearly in Figure 4. These transition regions combine the enhanced light scattering properties of a rounded element (i.e., the undeformed portions of the first and second sections 18a, 18b) with the enhanced charge extraction properties associated with a flattened element (i.e., the third section 18c).

[0180] Each deformation region of conductive element 18 (e.g., including first, second, and third sections 18a-c) is configured such that the upper and lower surfaces of the deformation region are substantially curved when viewed in axial cross-section of conductive element 18 (as shown in Figures 5, 7, 11, and 12). The tapered profile of conductive element 18 contrasts with deformation regions produced by other manufacturing methods. For example, stamping methods produce deformation regions that exhibit a step profile that defines a step change in thickness of the conductive element between uncompressed and compressed regions.

[0181] The second roll 54 may be configured with different cross-sectional shapes, as shown in Figures 13, 14, 15, 16, and 17, without departing from the scope of the present invention. The roll 54 shown in Figure 13 has the same elliptical cross-section as described above in connection with the apparatus 50 shown in Figures 6 and 7.

[0182] An alternative arrangement of the second roll 54a is shown in Figure 14, where the outer body 66a has a cross-section shaped as an elliptical segment. In this manner, the outer body 66a has a first surface that is substantially flat and a second surface that is configured to curve outwardly (i.e., the second surface is convex).

[0183] 15 shows a further alternative arrangement of a second roll 54b having a first surface and a second surface. The first and second surfaces are outwardly curved (i.e., the surfaces are convex) and the first surface has a larger radius of curvature than the second surface. In this arrangement, the curved first surface replaces the substantially flat first surface of the roll 54a shown in FIG.

[0184] Yet another alternative arrangement for the second roll 54c is shown in Figure 16, where the outer body 66c has an elliptical cross-section having only one axis of symmetry. According to this arrangement, the roll 54c is configured to have an egg-shaped cross-section.

[0185] 13-16, the rolls 54, 54a, 54b, 54c are all configured with their geometric axes substantially aligned with their respective axes of rotation, and the periodic reduction in the gap 60 between the first and second rolls is therefore determined by the shape of the second rolls 54, 54a-c, and in particular the cross-sectional shapes of their outer bodies 66, 66a-c.

[0186] In an alternative arrangement shown in FIG. 17, the roll 54d is configured such that its geometric axis is not substantially aligned with its rotation axis. In particular, the roll 54d comprises an outer body 66d configured to have a circular cross section with a geometric center (i.e., one that defines the geometric axis of the roll 54d). The axle 64 of the second roll 54d is radially offset from the geometric center of its outer body 66d. The resulting misalignment between the geometric axis and the rotation axis means that when the axle 64 of the second roll is rotated, it rotates the outer body 66d eccentrically about the rotation axis. This eccentric rotation of the roll 54d results in a periodic reduction of the gap between the first and second rolls of the device. In this arrangement, the compressive force being applied to the conductive element is achieved due to the offset between the geometric axis and the rotation axis of the second roll 54d.

[0187] An exemplary method for manufacturing the electrode assembly 12 will now be described with reference to Figures 6-12, which show an apparatus 50 used to manufacture the electrode assembly 12. Reference is also made to Figure 18, which shows a flow chart of the corresponding method steps.

[0188] The method begins in a first step 202 where a plurality of conductive elements 18 are provided. In a second step 204, the conductive elements 18 are arranged in a common plane such that they are arranged substantially parallel to one another in the longitudinal direction. As shown in FIG. 6, the conductive elements 18 are also laterally spaced apart.

[0189] The second step 204 also includes applying an electrically insulating, optically transparent film to the conductive elements 18, as shown in Figure 7. A front film portion 42 is applied to a back surface 46 of the first section 18a, and a back film portion 44 is applied to a front surface of the second section 18b. The application of the film portions 42, 44 to the conductive elements 18 helps to maintain the relative position of the conductive elements 18 (e.g., by maintaining a lateral orientation) as the elements are fed into the apparatus 50.

[0190] The method proceeds to method step 206, which includes reducing the height of the third sections 18c of the plurality of conductive elements 18 using the element deformation apparatus 50, as described above. In particular, this includes method step 208 of at least partially feeding the plurality of conductive elements 18 into the gap 60 between the first roll 52 and the second roll 54. It also includes method step 210 of rotating the first and second rolls 52, 54 to apply a compressive force to successive third sections 18c. It will be appreciated that method steps 208 and 210 are performed simultaneously such that the apparatus 50 is configured to apply a compressive force to successive periodic sections of the conductive elements 18 on an ongoing basis.

[0191] Once the thickness of the third section 18c is reduced (in accordance with method step 206), the method moves to method step 212 which includes cutting the plurality of conductive elements 18 at predetermined locations along their length to define a plurality of conductive element portions.

[0192] Each of the conductive element portions includes a pair of non-deformed sections (i.e., first and second sections 18a, 18b) joined by a deformed section (i.e., third section 18c), for example as shown in FIG. 4. Thus, a method of cutting the conductive element 18 includes removing all other deformed sections along the length of the conductive element 18. To accomplish this, a first cut is made at the leading end of the first section 18a of the conductive element portion. In addition, a second cut is made at the trailing end of the second section 18b of the same conductive element portion. The leading and trailing ends of each of the first and second sections 18a, 18b are characterized as boundaries where the thickness of the element begins to decrease (i.e., limits of the non-deformed sections).

[0193] Cutting the conductive elements 18 only after they have been deformed ensures that each conductive element remains in the same position (i.e., relative to any other elements) during the deformation process. This also means that the elements can be held under tension (e.g., by additional roll sets placed on either side of the apparatus 50) to ensure that the elements are deformed in the correct position along their length.

[0194] An exemplary method for manufacturing the solar cell assembly 10 will now be described with reference to Figures 1 to 5. The method begins with a first step in which a first solar cell 20, a second solar cell 30, and an electrode assembly 12 are provided, as described above.

[0195] Prior to fabricating the solar cell assembly, the solar cells 20, 30 are fabricated in a conventional manner, as will be understood by those skilled in the art. In particular, the method includes configuring each of the solar cells with a conductive surface (or conductive portion) on the front and back surfaces of each of the solar cells. For example, this can be accomplished by forming a plurality of front and back finger electrodes 26, 36, 28, 38 through deposition of conductive material on the front and back surfaces 22, 24, 32, 34 of the first and second solar cells 20, 30, respectively.

[0196] According to an exemplary method, the finger electrodes 26, 36, 28, 38 are deposited on their respective surfaces using a screen printing process, as will be understood by those skilled in the art.

[0197] Once the plurality of finger electrodes 36, 38 have been deposited on the surfaces of the first and second solar cells 20, 30, the electrode assembly 12 can be connected to the solar cells 20, 30 to define a solar assembly 10 according to the present invention.

[0198] As described above, the electrode assembly 12 includes a plurality of conductive element portions having first, second, and third sections 18a, 18b, 18c. The first and second film portions 42, 44 are disposed on the first and second sections 18a, 18b of the conductive element, respectively, and define the front and back connectors 12a, 12b of the electrode assembly 12.

[0199] The second solar cell 30 is placed so that its back surface 34 faces upward. When the second solar cell 30 is flipped over, the back connector 12b of the electrode assembly 12 is then superimposed on the back surface 34 of the second solar cell 30. Thus, the conductive elements 18 are superimposed on the back surface 34 such that they are perpendicular to the finger electrodes 38.

[0200] A portion of the third section 18c of the conductive element is arranged to cover a portion of the back surface 34 of the second solar cell 30 at one of its longitudinal ends. This end of the back surface 34 at least partially defines the overlap area 15 between the solar cells 20, 30 when the solar cells are stacked. Thus, the front surfaces of the second and third sections 18b, 18c of the conductive element are in contact with the back finger electrode 38 of the second solar cell 30.

[0201] The method proceeds with the first solar cell 20 being inverted and stacked on the front connector 12a. In doing so, the back surface 46 of the first section 18a of the conductive element is brought into contact with the front surface 22 of the first solar cell 20. A portion of the third section 18c of the conductive element is positioned to cover a portion of the front surface 22 of the first solar cell at one of its longitudinal ends. This end of the front surface 22 at least partially defines the overlap region 15 between the solar cells 20, 30 when they are stacked, as shown in FIG.

[0202] The method also includes overlapping the front surface 22 of the first solar cell 20 onto the back surface 34 of the second solar cell 30. In this manner, the third section 18c of the conductive element 18 is disposed in the overlap region 15, whereby the overlap region 15 is defined between the overlapping surfaces of the first and second solar cells 20, 30.

[0203] The method also includes applying heat and / or pressure to the conductive elements 18 of the front connector 12a and back connector 12b to bond the elements to the surfaces of the first and second solar cells 20, 30, respectively, under compressive force. In particular, the conductive elements 18 are provided with a coating of a material having a lower melting point than the material from which the conductive elements are formed. The coating is at least partially melted by the application of heat and pressure, which causes the coating to flow toward the surface of the solar cells. When the coating cools and solidifies, it forms ohmic contact with the underlying finger electrodes 36, 38. The application of heat and pressure also laminates the front and back films 42, 44 onto the front and back surfaces 22, 34 of the solar cells 20, 30, respectively.

[0204] It is understood that at least some of the above method steps can be performed simultaneously or in any order. For example, the method steps including placing the first and second solar cells 20, 30 inverted relative to the electrode assembly 12 can be performed substantially simultaneously. Similarly, the front and back connectors 12a, 12b can also be connected simultaneously to the front and back surfaces 22, 34 of the first and second solar cells 20, 30, respectively.

[0205] As a result of the above-described method, the front and back connectors 12a, 12b of the electrode assembly 12 are both mechanically and electrically connected to the respective first and second solar cells 20, 30 to form a solar cell assembly 10 according to the present invention.

[0206] It is understood that the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the concepts described herein. Any feature can be used separately or in combination with any other feature, except where mutually exclusive, and the present disclosure extends to and includes all combinations and subcombinations of one or more features described herein.

[0207] Feature List Solar cell assembly 10 Electrode assemblies 12, 14, 16 Overlap area 15 Front connector 12a Back connector 12b Interconnection part 12c Conductive element 18 A first section of conductive element 18a A second section of conductive element 18b Third section of conductive element 18c First solar cell 20 First solar cell - front side 22 First solar cell - back side 24 Front Finger Electrode 26 Back finger electrode 28 Second solar cell 30 Second solar cell - front 32 Second solar cell - back side 34 Front Finger Electrode 36 Back finger electrode 38 Film 40 Front film part 42 Back film part 44 Third Section Conductive Element - Backside 46 Third Section Conductive Element-Front 48 equipment 50 1st Roll 52 Second Roll 54 Support 56 Actuator 58 Roll gap 60 1st roll axle 62 Second roll axle 64 outer body 66 Solar Module 100 Support Assembly 102 Front panel 104 Central Chamber 106 Back plate 108 Method steps 200-212

Claims

1. 1. An apparatus for manufacturing an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell, the electrode assembly comprising a plurality of conductive elements arranged substantially parallel to one another in a longitudinal direction and substantially spaced apart in a laterally direction; The device comprises: a first roll and a second roll spaced apart to define a gap for receiving the plurality of conductive elements; an actuator configured to rotate at least one of the first roll and the second roll; an apparatus configured to periodically reduce the gap between the first roll and the second roll as the at least one of the first roll and the second roll rotates to periodically apply a compressive force to the plurality of conductive elements disposed within the gap.

2. 10. The apparatus of claim 1, wherein the apparatus is configured to periodically not apply the compressive force to the plurality of conductive elements, and optionally to alternate between applying the compressive force and not applying the compressive force.

3. The apparatus of claim 1 , wherein the second roll is positioned substantially above the first roll.

4. 2. The apparatus of claim 1, wherein the maximum gap between the first roll and the second roll is at least 0.3 mm and / or at most 5 mm, and the minimum gap between the first roll and the second roll is at least 0.05 mm and / or at most 4.75 mm.

5. 2. The apparatus of claim 1, wherein the first roll has a substantially circular cross-section and the second roll is configured to periodically decrease the gap between the first roll and the second roll.

6. 2. The apparatus of claim 1, wherein each of the plurality of conductive elements comprises a first section for contacting only the front surface of the first solar cell, a second section for contacting only the back surface of the second solar cell, and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell, the third section configured to connect the first section to the second section, and wherein a perimeter of the cross section of the at least one of the first roll and the second roll defines a length corresponding to a combined length of the first, second, and third sections of the plurality of conductive elements.

7. 2. The apparatus of claim 1, wherein the at least one of the first roll and the second roll has a cross-sectional shape configured such that, upon rotation, the gap between the first roll and the second roll decreases periodically in a radial direction.

8. The apparatus of claim 7 , wherein the at least one of the first roll and the second roll has an oval cross section.

9. The device of claim 8 , wherein the elliptical cross section has two axes of symmetry.

10. The device of claim 8 , wherein the elliptical cross section has only one axis of symmetry.

11. The apparatus of claim 1 , wherein the at least one of the first roll and the second roll has a cross section formed as an elliptical segment.

12. 2. The apparatus of claim 1, wherein the at least one of the first roll and the second roll comprises a first surface and a second surface, the first and second surfaces configured to curve outward, the first surface having a variable radius of curvature and the second surface having a constant radius of curvature.

13. 2. The apparatus of claim 1, wherein the at least one of the first roll and the second roll has a cross-section having a geometric center, and the at least one of the first roll and the second roll is configured with an axis of rotation that is misaligned with the geometric center.

14. 1. A method of manufacturing an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell, comprising: providing a plurality of conductive elements; disposing the plurality of conductive elements in a common plane such that the conductive elements are longitudinally disposed substantially parallel to one another and laterally spaced apart substantially; periodically decreasing heights of sections of the plurality of conductive elements; providing a first roll and a second roll spaced apart to define a gap for receiving the plurality of conductive elements; feeding the plurality of conductive elements at least partially into the gap between the first roll and the second roll; and periodically reducing the gap between the first roll and the second roll as at least one of the first roll and the second roll rotates to periodically apply a compressive force to the plurality of conductive elements disposed within the gap.

15. 15. The method of claim 14, comprising periodically increasing the gap between the first roll and the second roll as the at least one of the first roll and the second roll rotates to periodically remove the compressive force from the plurality of conductive elements.

16. The method of claim 14 , comprising disposing an electrically insulating, optically transparent film over the uncompressed sections of the plurality of conductive elements.

17. 17. The method of claim 16, wherein the method includes disposing the electrically insulating, optically transparent film before feeding the plurality of conductive elements at least partially into the gap between the first roll and the second roll.

18. 17. The method of claim 16, wherein the electrically insulating, optically transparent film is positioned so as not to cover compressed sections of the plurality of conductive elements.

19. 15. The method of claim 14, comprising cutting the plurality of conductive elements to define a plurality of conductive element portions, each portion comprising a compressed section disposed between two uncompressed sections.

20. 20. The method of claim 19, wherein the method step of severing the conductive element occurs after the method step of reducing the height of the compressed section.

21. 1. A method of manufacturing a solar cell assembly, comprising:

21. Manufacturing the electrode assembly of any one of claims 14 to 20, wherein each of the plurality of conductive elements comprises a first section for contacting only the front surface of the first solar cell, a second section for contacting only the back surface of the second solar cell, and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell, the third section being configured to connect the first section to the second section; providing a first solar cell and a second solar cell; positioning the second solar cell so that its back surface faces substantially upward; overlaying the second section of the plurality of conductive elements of the electrode assembly on the back surface of the second solar cell; overlapping the front surface of the first solar cell over the first section of the plurality of conductive elements such that the front surface of the first solar cell partially overlaps the back surface of the second solar cell and the third section of the plurality of conductive elements is disposed between the overlapping portion of the front surface of the first solar cell and the back surface of the second solar cell; connecting the first and second sections of the plurality of conductive elements to the front and back surfaces of the first and second solar cells, respectively.

22. An electrode assembly produced by the method of any one of claims 14 to 20.

23. 23. The electrode assembly of claim 22, wherein the plurality of conductive elements each comprise a first section for contacting only the front surface of the first solar cell, a second section for contacting only the back surface of the second solar cell, and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell, the third section configured to connect the first section to the second section, and thicknesses of the plurality of conductive elements gradually decrease from each of the first and second sections toward the third section in a longitudinal direction along the plurality of conductive elements.

24. 22. A solar cell assembly manufactured by the method of claim 21, wherein the plurality of conductive elements are configured to electrically connect a front surface of the first solar cell to a back surface of the second solar cell, the back surface of the second solar cell is configured to partially overlap the front surface of the first solar cell, and the third section of the plurality of conductive elements is disposed between the partially overlapping surfaces of the first and second solar cells.

25. an electrode assembly for connecting a front surface of a first solar cell to a back surface of a second solar cell, the electrode assembly comprising a plurality of conductive elements arranged substantially parallel to one another in a longitudinal direction and substantially spaced apart in a laterally direction; each of the plurality of conductive elements comprises a first section for contacting only the front surface of the first solar cell, a second section for contacting only the back surface of the second solar cell, and a third section for contacting both the front surface of the first solar cell and the back surface of the second solar cell, the third section configured to connect the first section to the second section; An electrode assembly, wherein the thickness of the plurality of conductive elements gradually decreases longitudinally along the plurality of conductive elements from each of the first and second sections toward the third section.

26. 26. The electrode assembly of claim 25, wherein each of the conductive elements is configured to have a curved surface when viewed in axial cross section of the conductive element.

27. 26. The electrode assembly of claim 25, wherein each of the conductive elements is configured with opposing concave surfaces.

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