DE102022124476B4 - Solar cell module and method for producing a solar cell module - Google Patents

Abstract

solar cell module,
with a plurality of photovoltaic solar cells with electrically contactable backs,
wherein the solar cells are arranged in a matrix shingle arrangement comprising a plurality of spatially parallel solar cell rows each having a plurality of solar cells, wherein the solar cell rows are arranged overlapping in overlapping regions so that the rear sides of the solar cells of one solar cell row partially cover the front sides of the solar cells of an adjacent solar cell row, and
the solar cells are arranged such that at least one rear side of a solar cell (1) of a solar cell row partially covers the front sides of at least two solar cells of an adjacent solar cell row,
wherein at least one solar cell row has an electrically conductive cross-connector (5) which covers the rear sides of at least the non-edge solar cells (1) of the solar cell row at least by 50% and makes electrical contact therewith, and
that the solar cells of at least the solar cell row on which the cross-connector (5) is arranged each have a metallic rear-side contacting structure (9) which extends beyond an overlapping region on the rear side of the solar cell (1), so that a series connection partial region (10) of the metallic rear-side contacting structure (9) in the overlapping region (4) lies against the front side of an adjacent solar cell and a cross-connection partial region (11) of the metallic rear-side contacting structure (9) is covered by the cross-connector (5) and is directly electrically connected to it.

Description

The invention relates to a solar cell module according to claim 1 and a method for producing a solar cell module according to claim 12.

Photovoltaic solar cells typically have metallic contact structures on their front surfaces. Such contact structures are impermeable to incident electromagnetic radiation, thus reducing the area available for absorption on the front surface.

It is therefore known to design solar cell modules with a shingle arrangement. In a shingle arrangement, neighboring solar cells overlap, so that the back of one solar cell covers the front of an adjacent solar cell in an overlapping area. As a result, the metallic contact structure on the front of a solar cell is located in the overlapping area and thus beneath the adjacent solar cell, whereby the upper solar cell in the overlapping area does not need to have a large-area metallic contact structure on its front. Relative to the area of the solar cell module, a larger proportion of the solar cell area available for light absorption can thus be achieved.

A particularly advantageous arrangement of solar cells is a matrix shingle arrangement. In this arrangement, several solar cell rows, each containing several solar cells, are arranged spatially parallel, and in the overlapping area, one solar cell covers the front sides of at least two adjacent solar cells. In a direction of extension transverse to the solar cell rows, the solar cells in the matrix shingle arrangement are thus staggered.

In the overlapping area, the solar cell rows are electrically connected to form an electrical series connection of the solar cell rows.

Basically, solar cell modules require connection elements to electrically connect the solar cell module to external electrical elements and/or other solar cell modules.

In addition, for typical solar cell module sizes, the provision of bypass diodes is necessary to avoid local overheating (hotspot) and resulting damage to the solar cell module in the event of partial shading.

Out of DE3708548A1 A solar cell module is known in which the solar cells of the solar cell module are arranged in solar cell rows. These solar cell rows are positioned and electrically connected to one another in such a way that the resulting butt joints between the solar cells in one row are offset from those in neighboring rows.

DE102010016975A1 discloses an arrangement and interconnection of solar cells. The solar cells in the contact area are arranged so as to overlap with neighboring solar cells. These solar cells are interconnected using a contact material in the overlap area, with the contact material bridging the insulating substrate. The solar cells are interconnected on a front side, on a back side, or between the end faces of the solar cells, or between one or more end faces and a front or back side of the solar cells.

Out of US20150349167A1 A solar cell module is known in which the solar cells are connected in series. A bypass element is connected in parallel to the solar cells. The solar cells are arranged such that the long sides of adjacent solar cells overlap and are connected to each other with a conductive adhesive.

Out of WO2013020590A1 A solar cell arrangement is disclosed, wherein at least one current collection bus extends across the front sides of the solar cells to collect the generated current. Furthermore, at least one further current collection bus extends across the rear side of the solar cell, which also serves to collect the current generated by the solar cell.

The present invention is therefore based on the object of providing a solar cell module and a method for producing a solar cell module with solar cells in a matrix shingle arrangement, which enables robust and cost-effective interconnection with external circuits and/or internal electrical elements, in particular bypass diodes.

This object is achieved by a solar cell module according to claim 1 and a method for producing a solar cell module according to claim 12. Advantageous embodiments can be found in the dependent subclaims.

The solar cell module according to the invention is preferably produced by means of the method according to the invention, in particular by means of a preferred embodiment thereof. The method according to the invention is preferably designed for producing a solar cell module according to the invention, in particular a preferred embodiment thereof.

The solar cell module according to the invention has a plurality of photovoltaic solar cells with electrically contactable rear sides. The solar cells are arranged in a matrix shingle arrangement which has a plurality of spatially parallel solar cell rows, each having a plurality of solar cells, wherein the solar cells are arranged to overlap in overlapping regions such that the rear sides of the solar cells in one solar cell row partially cover the front sides of the solar cells in an adjacent solar cell row, and the solar cells are arranged such that at least one rear side of a solar cell in one solar cell row partially covers the front sides of at least two solar cells in an adjacent solar cell row. An electrically conductive connection between the overlapping solar cells is preferably formed in the overlapping region. An electrical series connection of the solar cell rows is preferably formed by means of the electrically conductive connection in the overlapping region.

This arrangement corresponds to the matrix shingle arrangement described above.

Preferably, at least each non-edge solar cell of a solar cell row, in particular each non-terminal solar cell row, partially covers the front sides of at least two solar cells of an adjacent solar cell row with its rear side. Depending on the configuration of the matrix arrangement, edge solar cells of some solar cell rows may have a smaller width, so that these edge solar cells do not cover two solar cells, but only one solar cell of an adjacent solar cell row.

It is essential that at least one solar cell row has an electrically conductive cross-connector which covers at least 50% of the back sides of at least the non-edge solar cells of the solar cell row and makes electrical contact therewith.

• Mehrere Solarzellen werden in einer Matrix-Schindelanordnung angeordnet, sodass mehrere räumlich parallel angeordnete Solarzellenreihen mit jeweils mehreren Solarzellen ausgebildet werden. Die Solarzellenreihen werden in Überlappungsbereichen überlappend angeordnet, sodass die Rückseiten der Solarzellen einer Solarzellenreihe die Vorderseite der Solarzellen einer benachbarten Solarzellenreihe teilweise überdecken und die Solarzellen derart angeordnet werden, dass zumindest eine Rückseite einer Solarzelle einer Solarzellenreihe die Vorderseiten von zumindest zwei Solarzellen einer benachbarten Solarzellenreihe teilweise überdeckt. Im Überlappungsbereich wird bevorzugt eine elektrisch leitende Verbindung der sich überlappenden Solarzellen ausgebildet.

Accordingly, the object mentioned at the outset is achieved by a method for producing a solar cell module, which comprises the following method steps:

• A plurality of solar cells are arranged in a matrix shingle arrangement, forming a plurality of spatially parallel solar cell rows, each comprising a plurality of solar cells. The solar cell rows are arranged to overlap in overlapping regions, such that the rear sides of the solar cells in one solar cell row partially overlap the front sides of the solar cells in an adjacent solar cell row, and the solar cells are arranged such that at least one rear side of a solar cell in one solar cell row partially overlaps the front sides of at least two solar cells in an adjacent solar cell row. Preferably, an electrically conductive connection between the overlapping solar cells is formed in the overlapping region.

It is essential that an electrically conductive cross-connector is arranged on at least one solar cell row, which covers at least 50% of the back sides of at least the non-edge solar cells of the solar cell row and makes electrical contact.

According to the invention, a cross connector is thus provided which covers at least the rear sides of a solar cell row over a large area and makes electrically conductive contact.

This creates a wide range of possibilities for attaching connecting elements to solar cells arranged in a matrix shingle arrangement.

Due to its large-area arrangement and extensive contact with the backs of the solar cells, the cross-connector provides a mechanically stable connection and thus a robust structure. Furthermore, due to the large area covered by the cross-connector on the back of the solar cell in the solar cell array, a low absolute electrical contact resistance between the cross-connector and the backs of the solar cells can be achieved. This cost-effective and robust design enables the attachment of connecting elements such as terminals for external wiring, junction boxes, or electrical or electronic elements of the solar cell module, in particular bypass diodes.

To improve mechanical stability and reduce electrical contact resistance between the solar cells and the cross-connector, it is advantageous for the cross-connector to cover and electrically contact the rear sides of at least the non-edge solar cells of the solar cell row by at least 60%, preferably at least 70%, in particular at least 80%. Accordingly, in the method according to the invention, it is advantageous for the cross-connector to cover and electrically contact the rear sides of at least the non-edge solar cells of the solar cell row by at least 60%, preferably at least 70%, in particular at least 80%.

The two edge solar cells of the solar cell row, on which the electrically conductive cross-connector is arranged, can be used to reduce the requirements for process accuracy and/or to save material, they can also be covered to a lower degree by the electrically conductive cross-connector. Advantageously, the two edge-positioned solar cells of the solar cell row are each covered by the electrically conductive cross-connector to at least 20%, preferably at least 30%, in particular at least 40%, and are electrically conductively connected to the latter. To reduce the contact resistance, it is advantageous for the two edge-positioned solar cells of the solar cell row to be each covered by the electrically conductive cross-connector to at least 50%, in particular at least 60%, preferably at least 70%, in particular at least 80%. In particular, it is advantageous for the two edge-positioned solar cells of the solar cell row to have the same degree of coverage by the electrically conductive cross-connector as the inner (non-edge-positioned, arranged between the two edge-positioned solar cells) solar cells of the solar cell row.

The percentage coverages described above refer to the area percentage of the back of the respective solar cell.

A particularly simple and cost-effective design results in an advantageous embodiment in which the cross-connector is designed as an electrically conductive adhesive tape. Accordingly, an electrically conductive adhesive tape is advantageously used as the cross-connector in the method according to the invention.

Such electrically conductive tapes (or charge collection tapes) are commercially available. They also have the advantage that no heat treatment, which could compromise solar cell components, is required to form the mechanical and electrically conductive connection.

In a further advantageous embodiment, the cross-connector is mechanically and electrically connected to the solar cells by means of a conductive adhesive. In particular, the cross-connector is preferably formed as a metal foil. In the method according to the invention, the cross-connector is accordingly preferably arranged in a solar cell row by means of a conductive adhesive, with a metal foil preferably being used as the cross-connector.

The use of a metal foil, in particular a flexible metal foil, has the advantage that commercially available metal foils can be used, which have very good conductivity.

Conductive adhesives (ECA - electrically conductive adhesive) are also commercially available.

For typical conductive adhesives, heat treatment is necessary or at least advantageous to cure the conductive adhesive.

During the production of a solar cell module, the solar cells are typically arranged between a carrier substrate and at least one flexible covering element, in particular an encapsulation film. Subsequently, a material-to-material thermal bonding takes place by means of lamination to bond the carrier substrate and film.

Connecting the cross-connector to the solar cell row using conductive adhesive has the advantage that the conductive adhesive can cure during lamination, thus eliminating the need for an additional heat treatment step. Advantageously, in the method according to the invention for producing a solar cell module, the conductive adhesive cures during lamination of the solar cell module. In particular, the solar cells are preferably arranged between a carrier substrate and a flexible cover film, with a material-to-material bond between the carrier substrate and the cover film occurring during lamination, and preferably a material-to-material bond between the cross-connector and the solar cells.

It is within the scope of the invention that the cross connector is designed as a metal foil, particularly preferably as a metal foil made of one of the following metals: copper, tinned copper, aluminum.

The metal foil preferably has a thickness in the range 5 µm to 100 µm, more preferably 10 µm to 50 µm, particularly preferably 25 µm to 35 µm.

It is also within the scope of the invention that the cross-connector has several layers, in particular a flexible carrier layer which is coated with a conductive metal layer.

The total thickness of the cross-connector when designed as an adhesive tape and/or multi-layer cross-connector is preferably in the range 5 µm to 100 µm, more preferably in the range 10 µm to 50 µm.

With the present invention, individual rows of the solar cell module can thus be electrically contacted separately or connected to further electrical or electronic elements such as bypass diodes in a simple manner, even when the solar cells are arranged in a matrix shingle arrangement.

For this purpose, it is advantageous for the solar cell module to have at least one electrically conductive longitudinal connector, which is electrically connected to the cross connector of a solar cell row. The longitudinal connector extends over additional solar cell rows. It is within the scope of the invention for the longitudinal connector to extend over additional cross connectors of the solar cell module.

The longitudinal connector thus enables the simple interconnection of a solar cell row having a cross connector, in particular the electrically conductive connection of a solar cell row to a junction box of the solar cell module.

The longitudinal connector is preferably designed as a metallic longitudinal connector, particularly preferably made of copper, and preferably has a thickness in the range of 300 µm to 500 µm.

Advantageously, the longitudinal connector is electrically insulated from the other solar cell rows and/or other cross connectors of the solar cell module by means of an electrically insulating layer. It is within the scope of the invention for the longitudinal connector to be coated with an electrically insulating layer. It is also within the scope of the invention for an electrically insulating layer to be arranged only between the longitudinal connector and the elements to be insulated, in particular the other solar cells of the solar cell module and/or other cross connectors.

In an alternative advantageous embodiment, the longitudinal connector is electrically connected to at least one electrical cross-connector. Advantageously, the cross-connector has greater flexibility than the longitudinal connector. It is therefore advantageous for the longitudinal connector to be arranged between the solar cells and the cross-connector.

Advantageously, the longitudinal connector is electrically connected to the solar cells in the area where the cross connector overlaps the longitudinal connector. This also creates an electrically conductive connection, in this case an indirect electrically conductive connection via the longitudinal connector, between the cross connector and the solar cells of the solar cell row in the area where the longitudinal connector is arranged between the solar cells and the cross connector.

It is known that solar cell modules have one or more junction boxes, particularly on the rear side of the solar cell module. Junction boxes serve to protect connection elements and/or electrical or electronic components from external influences.

It is therefore advantageous that the solar cell module has a junction box on at least two solar cell rows and that the longitudinal connector extends between the junction boxes, in particular electrically connecting electrical connections of the two junction boxes.

It is advantageous to arrange one or more bypass diodes in one or more junction boxes of the solar cell module.

As previously described, the cross connector provides a simple way to electrically connect a bypass diode in a matrix shingle arrangement.

In an advantageous embodiment, the solar cell module therefore has at least one bypass diode, and the cross-connector is electrically connected to the bypass diode of the solar cell module. In particular, it is advantageous for the solar cell module to have at least two solar cell rows, each with a cross-connector, and for the bypass diode to be electrically connected to the two solar cell rows in the usual manner by means of the cross-connectors, in particular to be connected in parallel to the solar cell rows in the usual manner.

To create a visually homogeneous image of the front side of the solar cell module, it is advantageous for the cross-connector, on the side facing the solar cells of the solar cell row, to have a color that matches the color of the front sides of the solar cells, preferably over the entire surface, at least in the spaces between the solar cells. Typical solar cells have a blue or black color impression on the front side. Therefore, the cross-connector is preferably blue or black, preferably black, on the side facing the solar cells of the solar cell row, at least in the spaces between the solar cells, preferably over the entire surface.

In an advantageous embodiment, the solar cell module therefore has a plurality of cover strips arranged between the solar cells and the cross-connector in the regions where the cross-connector extends across the space between two adjacent solar cells of a solar cell row. As a result, only the cover strip, but not the cross-connector, is visible from the front of the solar cell module. The cover strips preferably have a color that corresponds to the color of the front sides of the solar cells, particularly preferably a blue or black color.

The cover strips are preferably designed to be electrically insulating.

The present invention has the advantage that a further development of known solar cell modules with a matrix shingle arrangement is possible by additionally providing one or more cross-connectors. In particular, it is within the scope of the invention to use previously known photovoltaic solar cells, in particular typically used subcells, to form the solar cell module.

• Wesentlich ist, dass die Solarzellen zumindest der Solarzellenreihe, an welcher der Querverbinder angeordnet ist, jeweils eine metallische Rückseitenkontaktierungsstruktur auf, welche sich über einen Überlappungsbereich hinaus an der Rückseite der Solarzelle erstreckt, sodass ein Reihenverschaltungs-Teilbereich der metallischen Rückseitenkontaktierungsstruktur im Überlappungsbereich an der Vorderseite einer benachbarten Solarzelle anliegt und ein Querverbindungs-Teilbereich der metallischen Rückseitenkontaktierungsstruktur von den Querverbinder überdeckt und unmittelbar mit diesem elektrisch leitend verbunden ist.

In an advantageous development of the solar cell module, solar cells with a modified metallic back-side contact structure are used at least for the solar cell rows which are electrically connected by means of a cross-connector:

• It is essential that the solar cells, at least of the solar cell row on which the cross-connector is arranged, each have a metallic back-side contact structure which extends beyond an overlapping region on the back of the solar cell, so that a series connection portion of the metallic back-side contact structure in the overlapping region lies against the front of an adjacent solar cell and a cross-connection portion of the metallic back-side contact structure is covered by the cross-connector and is directly electrically connected to it.

It is known to form a strip-like metallic back-side contact structure in the manner of a busbar on at least one side of solar cells for shingle arrangements. The solar cell overlaps this metallic back-side contact structure, so that the metallic back-side contact structure abuts a metallic front-side contact structure of the adjacent solar cell in the overlapping region to form an electrical series circuit.

In the present development, the metallic back-side contact structure has a cross-connection subregion in addition to the series connection subregion, which overlaps with the adjacent solar cell. In the cross-connection subregion, the solar cell does not overlap with the adjacent solar cell, so that the metallic back-side contact structure is accessible in the cross-connection subregion on the rear side, so that the cross-connector can be arranged on the cross-connection subregion of the metallic back-side contact structure and electrically connected thereto.

This has the advantage that an electrically conductive connection with a very low contact resistance can be formed.

The metallic back-side contact structure is preferably formed of at least 50% of a metal from the group silver, copper.

Typical prior art solar cells have a large, particularly full-surface aluminum layer on the back, which serves to combine and conduct charge carriers. Aluminum is more cost-effective than other metals, particularly silver, but has the disadvantage that the typically used connection methods, particularly soldering, result in contacts with lower mechanical stability and comparatively high contact resistance. It is therefore known to provide so-called "solder pads" made of a different metal to create a stable electrically conductive connection with low contact resistance.

The present invention has the advantage that, due to the large-area coverage of the backs of the solar cells in the solar cell array by the cross-connector, a mechanically stable contact with low contact resistance is also formed directly on the aluminum back of a solar cell. This is due to the large area that achieves the advantageous mechanical stability and electrical quality of the contact. The electrical quality is further enhanced by the advantageous design of the previously described cross-connection subregions of the metallic back-side contact structure.

In an advantageous development of the solar cell module according to the invention, the solar cells of at least the solar cell row on which the cross-connector is arranged are each formed on the rear side with a rear-side contact surface made of aluminum, wherein the rear-side contact surface preferably covers at least 60%, particularly preferably 80%, of the rear side of the solar cell, and the rear-side contact surface is preferably formed of aluminum over its entire surface. The cross-connector is arranged on the rear-side contact surfaces and is directly electrically conductively connected to the rear-side contact surfaces made of aluminum.

In order to form an efficient matrix shingle arrangement, it is advantageous that in each solar cell row of the solar cell module, apart from an end solar cell row, at least the non-edge solar cells in the overlapping area cover at least two solar cells of the adjacent solar cell row.

Advantageously, the cross connector is on at least 80% of the surface, more preferably at least At least 90% of the area, particularly preferably 100% of the area, with which the cross connector covers the backs of the solar cells of the solar cell array is mechanically connected to the solar cells. This ensures high mechanical stability.

In order to form a low contact resistance, the cross connector is advantageously electrically connected to the solar cells on at least 80% of the area, more preferably at least 90% of the area, particularly preferably on 100% of the area with which the cross connector covers the back sides of the solar cells of the solar cell row.

In an advantageous embodiment, the solar cell module has an electrically conductive cross-connector on each of at least the two end solar cell rows, which covers at least 50% of the backs of at least the non-edge solar cells of the solar cell row and makes electrical contact. These two cross-connectors serve to connect the solar cell module to external circuits or other solar cell modules. In this embodiment, the end solar cell row whose backside overlaps an adjacent solar cell row is inactive, i.e., it does not contribute to the conversion of electromagnetic radiation into electrical energy. This embodiment is characterized by a visually uniform front side and yet simple interconnection thanks to the two cross-connectors on the end solar cell rows.

The percentages for the formation of the metallic contact structures refer to mass percent.

• - Vorderseitenglas (PV front glass)
• - Vordere Verkapselungsfolie (PV encapsulant foil), bevorzugt aus EthylenVinylacetat (EVA), Polyolefin Elastomere (POE)
• - Solarzellen des Solarzellenmoduls, bevorzugt aus Silizium
• - im Bereich des Querverbinders: Querverbinder bevorzugt aus Kupfer
• - hintere Verkapselungsfolie (PV encapsulant foil), bevorzugt aus EthylenVinylacetat (EVA), Polyolefin Elastomere (POE)
• - Rückseitenabdeckung (PV backsheet), bevorzugt aus Polyethylen (PE), Polyethylenterephthalat (PET)

The solar cell module may comprise encapsulation elements known per se. In particular, it is within the scope of the invention that the solar cell module, starting from a side facing the radiation during use, comprises at least one or more, preferably all, of the following layers:

• - Front glass (PV front glass)
• - Front encapsulant foil (PV encapsulant foil), preferably made of ethylene vinyl acetate (EVA), polyolefin elastomers (POE)
• - Solar cells of the solar cell module, preferably made of silicon
• - in the area of the cross connector: cross connectors preferably made of copper
• - rear encapsulant foil (PV encapsulant foil), preferably made of ethylene vinyl acetate (EVA), polyolefin elastomers (POE)
• - Back cover (PV backsheet), preferably made of polyethylene (PE), polyethylene terephthalate (PET)

• 1 eine photovoltaische Solarzelle für ein erstes Beispiel eines Solarzellenmoduls;
• 2 eine Seitenansicht und
• 3 eine Draufsicht von hinten auf das erste Beispiel eines Solarzellenmoduls;
• 4 eine Draufsicht von hinten auf ein zweites Beispiel und
• 5 eine Draufsicht von hinten auf ein drittes Beispiel eines erfindungsgemäßen Solarzellenmoduls;
• 6 eine photovoltaische Solarzelle für ein Solarzellenmodul gemäß 7;
• 7 ein in Draufsicht von hinten dargestelltes Ausführungsbeispiel eines erfindungsgemäßen Solarzellenmoduls;
• 8 ein in Draufsicht von hinten dargestelltes viertes Beispiel eines Solarzellenmoduls und
• 9 bis 11 Schnittbilder zu 8, wobei die Schnittebene jeweils senkrecht zur Zeichenebene in 8 steht.

Further advantageous features and embodiments are explained below using exemplary embodiments and the figures. Herein:

• 1 a photovoltaic solar cell for a first example of a solar cell module;
• 2 a side view and
• 3 a rear plan view of the first example of a solar cell module;
• 4 a rear view of a second example and
• 5 a rear plan view of a third example of a solar cell module according to the invention;
• 6 a photovoltaic solar cell for a solar cell module according to 7 ;
• 7 an embodiment of a solar cell module according to the invention shown in a plan view from the rear;
• 8 a fourth example of a solar cell module shown in plan view from the rear and
• 9 to 11 Cut images of 8 , where the cutting plane is perpendicular to the drawing plane in 8 stands.

All figures are schematic representations, not to scale. Identical reference symbols in the figures indicate identical or equivalent elements.

In 1 A front plan view of a schematic representation of a photovoltaic solar cell 1 for a first example of a solar cell module is shown. The solar cell 1 has a metallic contact structure on the front side, which is comb-shaped in a known manner, with several parallel contact fingers 2 that are electrically connected by a busbar 3 running perpendicular to the contact fingers 2.

The solar cell 1 is designed in a manner known per se as a photovoltaic solar cell based on a silicon wafer as a semiconductor substrate and has an emitter on the front side, which is contacted by means of the contact fingers 2 and the busbar 3. An aluminum layer is arranged over the entire surface of the rear side of the solar cell in order to electrically contact the base of the solar cell. It is within the scope of the invention to develop further developments of this solar cell structure or other solar cell structures as solar cells for a device according to the invention. to use a suitable solar cell module. In particular, it is within the scope of the invention to arrange additional layers on the front side to improve the electrical quality, in particular to reduce the recombination rate at the surface or the optical properties.

The 1 The solar cell shown represents a partial solar cell produced by dividing a larger silicon substrate on which several partial solar cells were formed. It is also within the scope of the invention to use solar cells produced entirely on an undivided silicon wafer.

In 1 An overlapping area 4 is indicated by dashed lines, where, due to the shingle arrangement, the back of a neighboring solar cell is in contact with the front of the 1 overlaps the solar cell shown.

• Das Solarzellenmodul gemäß erstem Beispiel weist eine Mehrzahl photovoltaischer Solarzellen 1 gemäß 1 mit elektrisch kontaktierbaren Rückseiten auf, wobei die Rückseiten vollflächig mit einer Aluminiumschicht bedeckt sind.

A schematic representation of the first example of a solar cell module is shown in 2 in side view and 3 shown in top view from behind:

• The solar cell module according to the first example comprises a plurality of photovoltaic solar cells 1 according to 1 with electrically contactable backs, whereby the backs are completely covered with an aluminum layer.

The solar cells 1 are arranged in a matrix shingle arrangement, which in the present case has three spatially parallel solar cell rows, each with several solar cells.

In 3 It is evident that the figures shown in the illustration 3 The bottom and top rows of the spatially parallel solar cell rows each have five solar cells, with the middle solar cell row having four solar cells 1.

As in 2 As can be seen, the solar cell rows are arranged overlapping in overlapping areas 4, so that the rear sides of the solar cells 1 of a solar cell row partially cover the front sides of the solar cells 1 of an adjacent solar cell row.

Furthermore, the solar cells are arranged such that at least one rear side of a solar cell of a solar cell row partially covers the front sides of at least two solar cells of an adjacent solar cell row. In the embodiment according to 3 For example, solar cell 1a partially covers solar cells 1d and 1e, solar cell 1b partially covers solar cells 1e and 1f, and solar cell 1c partially covers solar cells 1f and 1g.

In order to form this partial overlap, the edge solar cells 1 of the lowest and the top solar cell row are arranged according to 3 each only half the width of the remaining solar cells 1 of the solar cell module.

It is essential that the solar cell module has an electrically conductive cross-connector 5, which covers at least 50% of the rear sides of each solar cell 1 of the middle solar cell row and electrically contacts them. In this exemplary embodiment, the solar cell row contacted by the cross-connector has four solar cells 1. The two non-edge solar cells 1e and 1f are presently covered by the cross-connector to approximately 80% (drawing not to scale), as are the 3 right-edge solar cell 1g, on which the cross connector 5 for contacting extends beyond the right edge of the solar cell 1. In the left-edge solar cell 1d, the cross connector is spaced apart from the left edge of the solar cell, so that the degree of coverage is somewhat lower.

The cross connector 5 is designed as an electrically conductive adhesive tape and extends according to 3 on the right edge of the solar cell module beyond the surface of the solar cells, so that a simple connection to other electronic elements, in particular a bypass diode of the solar cell module, is possible.

Schematically, in 3 a wiring diagram with two bypass diodes 6 is shown, wherein one bypass diode 6 is connected between a lower terminal of the solar cell module and the cross connector 5 and a second bypass diode 6 is connected between the cross connector 5 and an upper terminal of the solar cell module.

In a modification of the first example of a solar cell module, the cross-connector 5 is formed as a copper foil with a thickness of 30 µm. Conductive adhesive is arranged between the cross-connector 5 and the solar cells 1 of the middle solar cell row. In a later process step in the production of the solar cell module, lamination takes place in a manner known per se. For this purpose, a transparent carrier substrate (glass) of the solar cell module is arranged on the front side and a protective cover (backsheet) on the back. A front encapsulation film (EVA) is arranged between the carrier substrate and solar cells, and a rear encapsulation film (EVA) is arranged between the solar cells and the backsheet. The films are joined by lamination, so that the solar cells 1 and the cross-connector 5, in particular, are embedded between the films. In this modification of the first exemplary embodiment, During lamination, the conductive adhesive applied between cross connector 5 and solar cells 1 of the middle solar cell row hardens.

In the 4 and 5 Two further examples of a solar cell module are shown. To avoid repetition, only the essential changes are discussed.

In the 4 and 5 The examples shown also include the 1 The photovoltaic solar cell 1 shown in the figure is used, which is arranged in a matrix shingle arrangement. 4 and 5 The examples shown each have 7 spatially parallel arranged rows of solar cells, whereby, as in the first example, the solar cell rows alternately have five and four solar cells, whereby in the solar cell rows with five solar cells, the edge solar cells are only half the width.

In the 4 In the second example shown, a cross-connector 5, designed as an electrically conductive adhesive tape, is arranged in each of the second and sixth rows. In this embodiment, the cross-connectors do not protrude beyond the solar cell surface. A junction box 7, which contains a bypass diode, is arranged centrally on the rear side of the solar cell module.

By means of two longitudinal connectors 8, which are designed as copper strips, an electrical supply line is established from the two cross connectors 5 to the junction box 7. The bypass diode arranged in the junction box 7 is electrically connected to the longitudinal connectors 8, so that a bypass diode is interposed between the two cross connectors 5.

The 5 The third example of a solar cell module, shown in rear view, has three cross-connectors 5. The cross-connectors 5 are arranged on the first, fourth and seventh solar cell row. The solar cell module also has a junction box 7 and two longitudinal connectors 8 in the middle. Two bypass diodes 6 are arranged in the junction box 7, with a first bypass diode 6 being electrically connected to the lower longitudinal connector 8 and the middle cross-connector 5, and a second bypass diode 6 being electrically connected to the middle cross-connector 5 and the upper longitudinal connector 8. A schematic representation of the resulting electrical circuit diagram is shown for illustration on the left edge of the 5 shown.

In 6 a plan view of the back of a photovoltaic solar cell 1 for an embodiment of a solar cell module according to the invention is shown.

The design of the front of the 6 The photovoltaic solar cell shown corresponds to the one in 1 shown solar cell 1.

In contrast to the 1 The solar cell shown in 6 The solar cell shown has a metallic back-side contact structure 9 with cross-connection arches arranged on the aluminum layer on the back side, which is predominantly made of silver. The back-side contact structure 9 has a busbar 9a and the cross-connection arches 9b, which extend from the busbar 9a across the back surface of the solar cell.

In 6 is indicated by dashed lines that in the matrix shingle connection of the solar cell 1 according to 6 in a series connection sub-region 10, in particular the busbar 9a rests on the front side of an adjacent solar cell 1 and a cross-connection sub-region 11, which essentially comprises the cross-connection arches 9b, is covered by a cross-connector 5 and is directly electrically connected to this cross-connector 5.

In 7 A rear view of an embodiment is shown. This embodiment represents a further development of the 1 to 3 The further development consists in the 6 described rear contact structure 9 with busbar 9a and cross-connection arcs 9b. As in 7 As shown, only the solar cells 1 of the middle solar cell row have the backside contact structure 9. In the backside view, only the cross-connection arches 9b are visible. For clarity, only two cross-connection arches are shown per full-width solar cell 1, and only one cross-connection arch 9b is shown per half-width solar cell 1 (the edge solar cells).

The cross connector 5 essentially covers the cross connecting arches 9b. In the illustration according to 7 In order to more clearly illustrate the arrangement of the cross-connecting arches 9b, the cross-connecting arches 9b are also shown completely in the area covered by the cross connector 5.

• Das Solarzellenmodul weist 27 Solarzellenreihen mit jeweils sieben nebeneinander angeordneten Solarzellen auf. An der Rückseite der Solarzellen sind vier Querverbinder 5 angeordnet. Die Querverbinder 5 sind elektrisch leitend durch Längsverbinder 8 verbunden, wobei jeweils mittig zwischen zwei Querverbindern 5 eine Anschlussdose 7 angeordnet ist, zu welcher Längsverbinder 8 führen. In der Anschlussdose 7 ist jeweils eine Bypassdiode angeordnet, welche die in die Anschlussdose 7 mündenden Längsverbinder 8 verbindet. Am rechten Rand ist zur Verdeutlichung schematisch die Verschaltung mit den Bypassdioden 6 als Ersatzschaltbild dargestellt.

In 8 A rear view of a fourth example of a solar cell module is shown. The structure corresponds in essential parts to the structure of the 4 solar cell module shown. To avoid repetition, only the main differences are discussed below:

• The solar cell module has 27 solar cell rows, each with seven arranged next to each other. solar cells. Four cross-connectors 5 are arranged on the back of the solar cells. The cross-connectors 5 are electrically connected by longitudinal connectors 8, with a junction box 7 being arranged centrally between each two cross-connectors 5, to which longitudinal connectors 8 lead. A bypass diode is arranged in each junction box 7, which connects the longitudinal connectors 8 leading into the junction box 7. For clarity, the wiring with the bypass diodes 6 is shown schematically as an equivalent circuit diagram on the right-hand edge.

The solar cell module according to 8 thus has a total of four longitudinal connectors 8: The edge cross connectors 5 are each connected to the nearest junction box 7 by a longitudinal connector 8. The middle junction box 7 is connected to the upper and lower junction boxes 7 by a longitudinal connector 8 as shown in 8 .

In this illustration, too, only one solar cell is marked with reference number 1 at the top left for better clarity.

The 8 The solar cell module shown has a plurality of cover strips 12, which are arranged between the solar cells 1 and the cross connectors 5 in the regions in which the cross connectors 5 extend over the space between two adjacent solar cells 1 of a solar cell row. From the front side of the solar cell module, the cross connectors 5 are therefore concealed by the cover strips 12 in the spaces between the solar cells. The cover strips are black in this case. Furthermore, the cover strips are electrically insulating in order to prevent unwanted current flows. For clarity, only the cover strips 12 at the top and bottom edges of the solar cell module are provided with reference numerals.

The 9 to 11 show sectional views of the 8 The section planes are perpendicular to the drawing plane in 8 . 9 shows a section along the section line A in 8 , 10 along the section line B and 11 along the section line C in 8 . The cutting plane in 11 is thus perpendicular to the cutting planes of the 9 and 10 .

In 9 a section is shown along section line A, in an area in which the cross connector 5 crosses the longitudinal connector 8. The 8 The second cross connector 5, starting from below, is therefore not shown diagonally striped for better clarity.

As in 8 As can be seen, the cross connectors 5 cover the longitudinal connectors 8, so that in this overlap area the longitudinal connectors 8 are arranged between the solar cells 1 and the cross connectors 5.

• - Eine Rückseitenabdeckung 13, ca. 400 µm, (z.B. aus PE, PET);
• - Eine hintere Verkapselungsfolie 14, ca. 400 µm (z.B. aus EVA, POE);
• - Die Solarzellen 1 des Solarzellenmoduls ca. 180 µm (z.B. aus Silizium);
• - Eine vordere Verkapselungsfolie 15, ca. 400 µm (z.B. aus EVA, POE) und ein Vorderseitenglas 16 ca. 3,2 mm.

In 9 As can be seen, the solar cell module has the following layers starting from the back:

• - A back cover 13, approx. 400 µm, (e.g. made of PE, PET);
• - A rear encapsulation film 14, approx. 400 µm (e.g. made of EVA, POE);
• - The solar cells 1 of the solar cell module approx. 180 µm (e.g. made of silicon);
• - A front encapsulation film 15, approx. 400 µm (e.g. made of EVA, POE) and a front glass 16 approx. 3.2 mm.

At the position of section A there is also a transverse connector 5 and a longitudinal connector 8, which cross each other at the position of section A.

Additionally, a longitudinal connector insulation film 17 is arranged as an insulating element between the longitudinal connector 8 and the solar cells 1, wherein the longitudinal connector insulation film 17 leaves out at least the area in which the cross connector 5 covers the longitudinal connector 8. Thus, an electrically conductive connection exists between the cross connector 5, the longitudinal connector 8, and the solar cells 1.

Cross connector 5, longitudinal connector 8 and longitudinal connector insulation film 17 are thus arranged in this order between rear encapsulation film 14 and solar cells 1.

In 8 the full-surface rear cover 13 and rear encapsulation film 14 are not shown.

The cut according to section line B in 10 shows an area in which the cross connector 5 is directly adjacent to the solar cells 1.

A cover strip 12 is arranged at the position of the cutting line C. The cover strip is arranged between the cross connector 5 and the solar cells 1, so that when viewed from the front, in the illustration according to 11 from below, in the space between the solar cells 1, the cross connector 5 is covered by the cover strip 12, so that a visually uniform image is created.

List of reference symbols

1

solar cell

2

Contact fingers

3, 9a

Busbar

4

Overlap area

5

Cross connectors

6

Bypass diode

7

Junction box

8

Longitudinal connector

9

Backside contact structure

9b

Cross-connecting arches

10

Series connection sub-area

11

Cross-connection sub-area

12

Cover strips

13

Back cover

14

rear encapsulation film

15

front encapsulation film

16

Front glass

17

Longitudinal connector insulation foil

Claims (15)

A solar cell module, with a plurality of photovoltaic solar cells with electrically contactable rear sides, wherein the solar cells are arranged in a matrix shingle arrangement comprising a plurality of spatially parallel solar cell rows, each comprising a plurality of solar cells, wherein the solar cell rows are arranged overlapping in overlapping regions, so that the rear sides of the solar cells of one solar cell row partially cover the front sides of the solar cells of an adjacent solar cell row, and the solar cells are arranged such that at least one rear side of a solar cell (1) of a solar cell row partially covers the front sides of at least two solar cells of an adjacent solar cell row, wherein at least one solar cell row has an electrically conductive cross-connector (5) which covers and electrically contacts the rear sides of at least the non-edge solar cells (1) of the solar cell row by at least 50%, and wherein the solar cells of at least the solar cell row on which the cross-connector (5) is arranged each have a metallic rear-side contact structure (9) extending over a Overlap region extends beyond the rear side of the solar cell (1), so that a series connection sub-region (10) of the metallic rear-side contact structure (9) in the overlap region (4) lies against the front side of an adjacent solar cell and a cross-connection sub-region (11) of the metallic rear-side contact structure (9) is covered by the cross-connector (5) and is directly electrically connected thereto. Solar cell module according to Claim 1 , characterized in that the cross connector (5) covers and electrically contacts the rear sides of at least the non-edge solar cells of the solar cell row by at least 60%, preferably by at least 70%, in particular by at least 80%. Solar cell module according to one of the preceding claims, characterized in that the cross connector (5) is designed as an electrically conductive adhesive tape. Solar cell module according to one of the Claims 1 until 2 , characterized in that the cross connector (5) is arranged mechanically and electrically conductively on the solar cells by means of a conductive adhesive, in particular that the cross connector (5) is designed as a metal foil. Solar cell module according to one of the preceding claims, characterized in that the solar cell module has at least one electrically conductive longitudinal connector (8) which is electrically conductively connected to the cross connector (5) of a solar cell row, wherein the longitudinal connector (8) extends over further solar cell rows and/or further cross connectors (5) of the solar cell module and preferably the longitudinal connector (8) is electrically insulated from the further solar cell rows and/or cross connectors of the solar cell module by means of an electrically insulating layer of the solar cell module. Solar cell module according to Claim 5 , characterized in that the solar cell module has a junction box (7) on at least two solar cell rows and the longitudinal connector (8) extends between the junction boxes, in particular electrically conductively connects electrical connections of the two junction boxes. Solar cell module according to one of the preceding claims, characterized in that the cross connector (5) is electrically conductively connected to a bypass diode (6) of the solar cell module, in particular that the solar cell module has at least two solar cell rows, each with a cross connector (5), and the bypass diode (6) is electrically connected to the cross connectors. Solar cell module according to one of the preceding claims, characterized in that that the cross connector (5) is arranged on a terminal solar cell row of the solar cell module and is electrically conductively connected to a connection element for connecting the solar cell module to an external electrical element, in particular an external current discharge connection and/or a further solar cell module. Solar cell module according to one of the preceding claims, characterized in that the cross connector (5) on the side facing the solar cells of the solar cell row is formed at least in spaces between the solar cells, preferably blue or black over its entire surface, preferably black. Solar cell module according to one of the preceding claims, characterized in that the rear contact structure (9) is formed of at least 50% of a metal from the group silver, copper. Solar cell module according to one of the preceding claims, characterized in that on the rear side of at least the solar cell row on which the cross connector (5) is arranged, the solar cells each have a rear contact surface made of aluminum and the cross connector (5) is arranged on the rear contact surfaces and is directly electrically conductively connected to the rear contact surfaces. Method for producing a solar cell module, comprising the method steps of arranging a plurality of solar cells in a matrix shingle arrangement, so that a plurality of spatially parallel solar cell rows, each having a plurality of solar cells, are formed, wherein the solar cell rows are arranged overlapping in overlapping regions, so that the rear sides of the solar cells of one solar cell row partially cover the front sides of the solar cells of an adjacent solar cell row, and the solar cells are arranged such that at least one rear side of a solar cell (1) of a solar cell row partially covers the front sides of at least two solar cells of an adjacent solar cell row, characterized in that an electrically conductive cross-connector (5) is arranged at least on one solar cell row, which cross-connector covers and electrically contacts the rear sides of at least the non-edge solar cells (1) of the solar cell row by at least 60%, and in that the solar cells of at least the solar cell row on which the cross-connector (5) is arranged each form a metallic rear-side contacting structure (9), which extends beyond an overlapping region on the rear side of the solar cell (1) extends so that a series connection partial region (10) of the metallic back-side contacting structure is formed in the overlapping region (4) on the front side of an adjacent solar cell and a cross-connection partial region (11) of the metallic back-side contacting structure (8) is covered by the cross-connector (5) and is directly electrically connected thereto. Procedure according to Claim 12 , characterized in that the cross connector (5) is designed to cover and electrically contact the rear sides of at least the non-edge solar cells of the solar cell row by at least 60%, preferably by at least 70%, in particular by at least 80%. Method according to one of the Claims 12 until 13 characterized in that an electrically conductive adhesive tape is used as the cross connector (5). Method according to one of the Claims 12 until 13 , characterized in that the cross connector (5) is arranged on the solar cell row by means of a conductive adhesive and is electrically conductively connected to it and that the conductive adhesive hardens during lamination of the solar cell module.