Method for producing a solar module, and solar module

Abstract

The invention relates to a method for producing a solar module which comprises a front-side element (14) having an outer side (12) and a cell side (11), a plurality of solar cells (15) which are electrically interconnected to form a solar cell string and are arranged on the cell side (11) of the front-side element (14), a glass rear-side element (1) having an outer side (12) and a cell side (11) on which the plurality of solar cells (15) are arranged, an opening (2) which extends through the glass rear-side element (1) from the cell side (11) to the outer side (12) and has an opening edge surrounding the opening (2), and a cross-connector (10) which runs beneath the opening (2) and is electrically interconnected to the solar cell string, wherein the method includes a step for sealing the opening (2) in the glass rear-side element (1), the step comprising the following sub-steps: a) applying an active solder coating (3) to one side of the rear-side element (1) circumferentially around the opening edge by means of active ultrasonic soldering of an active solder (5) with connection of the active solder (5) to the glass of the glass rear-side element (1), and b) filling the opening (2) with a solder sealing material (7) by means of soldering a solder (8) so as to form an integrally bonded connection between the solder (8) and the active solder coating (5) and the cross-connector (10). The invention also relates to a corresponding solar module.

Description

[0001] Method for producing a solar module and solar module

[0002] The invention relates to a method for producing a solar module and to a solar module. The solar module has a plurality of solar cells that are electrically connected to form a solar cell string. The solar module is constructed from a front element with an outer side and a cell side, and a rear element with an outer side and a cell side. The plurality of electrically connected solar cells are arranged between the cell side of the front element and the cell side of the rear element. The solar module further has an opening extending through the rear element from the cell side to the outer side, with an opening edge enclosing the opening, and a cross connector that is electrically connected to a solar cell string. The cross connector typically extends from the cell side through the opening to the outer side of the rear element.This allows the cross connector to be electrically contacted outside the solar module, e.g., via a junction box.

[0003] Typically, a butyl seal is used to seal the opening. However, over time, moisture and / or dirt can penetrate such an opening through which the cross connector passes, reducing the lifespan of the solar module. Therefore, there is a need for better, permanently weatherproof sealing of such openings.

[0004] The present invention is therefore based on the object of providing a method for producing a solar module and a solar module with improved service life.

[0005] This object is achieved by a method having the features of claim 1 and by a solar module having the features of claim 8. Preferred embodiments emerge from the subclaims explained below. According to the invention, the method comprises a step for sealing the opening of the glass back element, with the following substeps: a) applying an active solder coating to one side of the back element circumferentially around the opening edge by means of active ultrasonic soldering of an active solder, thereby bonding the active solder to the glass of the glass back element, and b) filling the opening with a solder sealing material by means of soldering a solder, thereby forming a material-to-material connection between the solder and the active solder coating and to the cross connector.

[0006] The active solder is used to bond the active solder metals to the glass, creating an active solder coating that forms a metallic ring along the edge of the opening. This creates a very strong and permanently weather-resistant bond between the solder metals and the glass backing element. The opening is then sealed with the solder, which bonds with the active solder coating and the cross connector, acting as a solder sealing material. This seals the opening and permanently makes it weather-resistant, particularly moisture- and oxygen-tight. The active solder coating is sealed with the solder and is long-term stable. The seal is corrosion-resistant and mechanically robust. Furthermore, this seal increases the efficiency of the solar module.

[0007] In a preferred embodiment, the active solder contains a plurality of metals selected from the group consisting of Sn, Ag, Cu, Ti, Ce, Ga, Zn, Al, Be, Sb, In, Bi, Pb, and rare earth metals. The active solder is preferably an active ultrasonic solder designed to bond glass to the active solder metals during an ultrasonic soldering process. The active solder is preferably a soft solder, preferably having a liquidus temperature of max. 450°C. The active solder preferably has a relatively high Sn content, for example 93.0 wt.%. During the ultrasonic soldering process, an ultrasonic soldering technique is carried out in an atmosphere up to 450°C. The solder preferably comprises a plurality of metals selected from the group consisting of Sn, Ag, and Cu. The solder is a "classic" solder that forms the bonded connection by soldering to the metals of the active solder coating and the cross connector.The solder preferably contains or consists of Sn, Ag, Cu.

[0008] In a preferred embodiment, the ultrasonic soldering in sub-step a) is carried out with the active solder, wherein the active solder has a melting point in the range of 137 to 308°C as the liquidus range.

[0009] Preferably, the soldering in sub-step b) is carried out with the solder, wherein the solder has a melting point of 137 to 308 °C as its liquidus range. Further preferably, the soldering in sub-step b) is carried out such that the opening is completely filled with the solder sealing material.

[0010] In a preferred embodiment, sub-step a) is performed on the outside of the back element. Preferably, the opening in sub-step b) is filled from the outside. This seals the opening of the solar module from the outside of the glass back element. Sub-steps a) and b) can be performed before and / or after lamination of the solar module. Before sub-step a), a laminated solar module can be provided that comprises the plurality of solar cells electrically interconnected to form a solar cell string, the front element, the back element, the opening, and the cross connector. However, sub-steps a) and b) can also be performed before lamination of the solar module, so that lamination of the solar module is performed after sub-step b). Finally, sub-step a) can also be performed before lamination and sub-step b) after lamination of the solar module.In a preferred embodiment, the cross-connector extends from the interior of the solar module through the opening, and a cross-connector connection element is soldered in, projecting from the exterior. The cross-connector connection element can be electrically connected, for example, to a junction box. Alternatively, the cross-connector preferably runs exclusively below the opening. Because the solder sealing material is electrically conductive, no cross-connector leading out of the interior of the solar module is necessary; rather, the junction box can also be electrically connected to the cross-connector via the solder sealing material.

[0011] Preferably, the solar module has a plurality of cross connectors and the rear side element is formed with a plurality of openings, each of which is assigned to one or two of the cross connectors.

[0012] The invention further relates to a solar module, comprising a front-side element with an outer side and a cell side, a plurality of solar cells which are electrically connected to form a solar cell string and are arranged on the cell side of the front-side element, a glass back-side element with an outer side and a cell side on which the plurality of solar cells are arranged, an opening extending through the glass back-side element from the cell side to the outer side and having an opening edge enclosing the opening, a cross-connector which is electrically connected to the solar cell string, an active solder coating which is applied circumferentially around the opening edge on the outer side and is materially bonded to the glass of the glass back-side element, and a solder sealing material which fills the opening and is materially bonded to the active solder coating and the cross-connector.Further developments, modifications and advantages described for the process apply accordingly to the solar module.

[0013] In a preferred embodiment, the cross-connector extends from the interior of the solar module through the opening and protrudes from the exterior. This allows the cross-connector to be easily electrically connected to a junction box. Alternatively, the cross-connector can also be electrically connected to the junction box via the solder sealing material. Therefore, no cross-connector extending through and out of the opening is necessary.

[0014] Preferably, the active solder coating contains several metals selected from the group consisting of Sn, Ag, Cu, Ti, Ce, Ga, Zn, Al, Be, Sb, In, Bi, Pb and rare earth metals.

[0015] Preferably, the solder sealing material comprises a plurality of metals selected from the group consisting of Sn, Ag, Cu.

[0016] Further properties and advantages of the method according to the invention are explained in more detail in the preferred embodiment described below. It shows schematically and not to scale:

[0017] Fig. 1 is an exploded perspective view of a solar module;

[0018] Figs. 2 and 3 show a perspective view of a method for producing a solar module according to a first embodiment;

[0019] Fig. 4 is a perspective view of the solar module according to the first embodiment; and

[0020] Fig. 5 is a perspective view of a solar module according to a second embodiment.

[0021] Fig. 1 shows a perspective exploded view of a solar module. The solar module has a front-side element 14 with an outer side 12 and a cell side 11, a plurality of solar cells 15 which are interconnected to form a solar cell string using interconnection elements 16 and arranged on the cell side 11 of the front-side element 14, and a glass back-side element 1 with an outer side 12 and a cell side 11 on which the plurality of interconnected solar cells 15 are arranged. An encapsulation material such as EVA, which is not shown for the sake of clarity, is arranged between the solar cells 15 and the front-side element 14 and the glass back-side element 1. The solar module preferably has an opening 2 extending through the glass back-side element 1 from the cell side 11 to the outer side 12 and having an opening edge enclosing the opening 2.Furthermore, the solar module has a cross connector, which is also not shown for the sake of clarity.

[0022] 2 and 3 show, in perspective view, method steps for producing a solar module according to a first embodiment. The solar module shown in FIGS. 2 and 3 corresponds to the solar module shown in FIG. 1. For the sake of clarity, the front-side element, the solar cells, and the interconnection elements are no longer shown, but the cross-connector 10 is illustrated, which extends from the interior of the solar module through the opening 2, with a cross-connector connection element 6 projecting relative to the outer side 12. The solar module shown in FIG. 1 is subjected to the method. The method comprises a method step for sealing the opening 2 of the glass back-side element 1.

[0023] Fig. 2 shows a sub-step of the method step which comprises applying an active solder coating 3 to one side of the back element 1 circumferentially around the opening edge by means of active ultrasonic soldering of an active solder 5 using a soldering iron 4, thereby bonding the active solder 5 to the glass of the glass back element 1. This sub-step is carried out on the outer side 12 of the back element 1. Fig. 3 shows a further sub-step of the method step which comprises filling the opening 2 with a solder sealing material 7 by soldering a solder 8 using a further soldering iron 9, thereby forming a material-to-material connection between the solder 8 and the active solder coating 5 and with the cross-connector 10. The cross-connector terminal 6 is soldered into the opening 2. In this sub-step, the opening 2 is filled from the outer side 12.

[0024] Fig. 4 shows a perspective view of the solar module according to the first embodiment. The solar module shown in Fig. 4 corresponds to the solar module shown in Fig. 1, with the difference that it has an active solder coating 3 applied circumferentially around the opening edge on the outer side 12 and is integrally bonded to the glass of the glass back element 1, and a solder sealing material 7 that fills the opening 2 and is integrally bonded to the active solder coating 3 and the cross-connector 10. The cross-connector connection element 6 is soldered into the opening 2. For the sake of clarity, the front-side element, the solar cells, and the interconnection elements are not shown in Fig. 4; instead, the cross-connector 10 is shown, which extends from the interior of the solar module through the opening 2, with a cross-connector connection element 6 being arranged protruding with respect to the outer side 12.

[0025] Fig. 5 shows a perspective view of a solar module according to a second embodiment. The solar module shown in Fig. 5 corresponds to the solar module shown in Fig. 2, with the difference that the cross-connector 10 runs exclusively below the opening 2. This means that it does not have a cross-connector connection element 6 that extends from the interior of the solar module through the opening 2, projecting to the outside 12 of the glass backing element 1. The electrical contact from the cross-connector 10 to the outside of the solar module is established exclusively through the metallic solder sealing material in the opening 2, which is in a materially bonded connection with the cross-connector 10. List of reference symbols:

[0026] 1 rear element

[0027] 2 Opening

[0028] 3 Active solder coating

[0029] 4 soldering irons

[0030] 5 Active Lot

[0031] 6 Cross connector connection element

[0032] 7 Solder sealing material

[0033] 8 Lot

[0034] 9 additional soldering irons

[0035] 10 cross connectors

[0036] 11 cell page

[0037] 12 Outside

[0038] 14 Front element

[0039] 15 solar cells

[0040] 16 interconnection element

Claims

Patent claims:

1. A method for producing a solar module comprising a front-side element (14) with an outer side (12) and a cell side (11), a plurality of solar cells (15) electrically connected to form a solar cell string and arranged on the cell side (11) of the front-side element (14), a glass back-side element (1) with an outer side (12) and a cell side (11) on which the plurality of solar cells (15) are arranged, an opening (2) extending through the glass back-side element (1) from the cell side (11) to the outer side (12) with an opening edge enclosing the opening (2), and a cross-connector (10) extending below the opening (2) and electrically connected to the solar cell string,wherein the method comprises a step for sealing the opening (2) of the glass back element (1) with the following sub-steps: a) applying an active solder coating (3) on one side of the back element (1) circumferentially around the opening edge by means of active ultrasonic soldering of an active solder (5) to bond the active solder (5) to the glass of the glass back element (1), and b) filling the opening (2) with a solder sealing material (7) by means of soldering a solder (8) to form a material-to-material connection between the solder (8) and the active solder coating (3) and the cross connector (10).

2. Method according to claim 1, characterized in that the active solder (5) contains several metals selected from the group consisting of Sn, Ag, Cu, Ti, Ce, Ga, Zn, Al, Be, Sb, In, Bi, Pb and rare earth metals.

3. Method according to claim 1 or 2, characterized in that the solder (8) comprises several metals selected from the group consisting of Sn, Ag, Cu.

4. Method according to one of the preceding claims, characterized in that the ultrasonic soldering in sub-step a) with the active solder (5) is carried out, wherein the active solder (5) has a melting point in the range from 137 to 308°C, and / or that the soldering in sub-step b) is carried out with the solder (8), wherein the solder (8) has a melting point in the range from 137 to 308°C.

5. Method according to one of the preceding claims, characterized in that the sub-step a) is carried out on the outer side (12) of the rear side element (1) and / or the filling of the opening (2) in the sub-step b) takes place from the outer side (12).

6. Method according to one of the preceding claims, characterized in that the cross-connector (10) extends from a solar module interior through the opening (2) and a cross-connector connection element (6) is soldered in a projecting manner with respect to the outer side (12).

7. Method according to one of the preceding claims, characterized in that the solar module has a plurality of cross connectors (10) and the rear element (1) has a plurality of openings (2), each of which is assigned to one or two of the cross connectors (10).

8. Solar module, comprising a front element (14) with an outer side (12) and a cell side (11), a plurality of solar cells (15) electrically connected to form a solar cell string and arranged on the cell side (11) of the front element (14), a glass rear element (1) with an outer side (12) and a cell side (11) on which the plurality of solar cells (15) are arranged, an opening (2) extending through the glass rear element (1) from the cell side (11) to the outer side (12) with an opening edge enclosing the opening (2), a cross connector (10) electrically connected to the solar cell string, an active solder coating (3) which is applied circumferentially around the opening edge on the outer side (12) and is materially bonded to the glass of the glass rear element (1), and a solder sealing material (7) which fills the opening (2) and is materially bonded to the active solder coating (3) and the cross connector (10).

9. Solar module according to claim 8, characterized in that the cross connector (10) extends from the interior of the solar module through the opening (2) and is projecting with respect to the outer side (12).

10. Solar module according to claim 8 or 9, characterized in that the active solder coating (3) contains a plurality of metals selected from the group consisting of Sn, Ag, Cu, Ti, Ce, Ga, Zn, Al, Be, Sb, In, Bi, Pb and rare earth metals and / or the solder sealing material (7) comprises a plurality of metals selected from the group consisting of Sn, Ag, Cu.

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