CH683730A5 - Curved solar module - has semiconductor cells bonded in place by a transparent adhesive mass - Google Patents

Abstract

To form a solar module, for photovoltage generation, a viscous paste mass (3) is placed between the semiconductor cell (2.1) and the front plate (1.1) and between the cells and the shrouding to fix at least one cell in place. Before the adhesive mass (3) is set, measured pressure is applied at the first cross linking point and successively, without air entry, on the cell to force the mass into place. Also claimed is a solar module with a curved front plate (1.1). It has at least one cylindrical photovoltage semiconductor cell (2.1) held by a voltage transparent adhesive mass (3) for the whole of its surface to be bonded to the front plate (1.1). The semiconductor cells (2.1) have no inherent mechanical tension, with a shape which does not match the front plate (1.1) curvature. Also claimed is an assembly appts. with a spray beam with a given number of at least two jets for the simultaneous delivery of a number of spaced droplets of adhesive mass on the front plate (1.1) and shrouding. A holding beam has a number of holders for the semiconductor cells (2.1) so that each droplet is applied to a cell at the same time and pressed into place. USE/ADVANTAGE - For prodn. of solar modules. The system allows curved solar modules to be produced, simply and cost-effectively.

Description

1

CH 683 730 A5

2nd

description

Technical field

The invention relates to a method for producing a photovoltaic solar module, in which at least one disk-shaped, flat, crystalline photovoltaic semiconductor cell is arranged between a translucent windshield and a rear cover.

The invention also relates to a device for carrying out this method and a solar module, preferably produced by this method.

State of the art

A method of the type mentioned at the outset is known from EP-0 421 248-A2. Solar cells are cast between two glass plates using a hardenable, optically fully transparent resin. Before potting, the solar cells on the back are attached to the rear glass pane with a spacer. This known method is apparently intended to eliminate the problems that exist with laminating, which occur when producing large-area solar modules. In the known lamination, the crystalline semiconductor cells are brought between two foils and thus pressed onto the front glass pane at elevated temperature and under suitable pressure. The problem with this process is that air pockets can occur if the pressure is too low and the semiconductor cells can break if the pressure is too high.

The technology of solar cell production is now so well developed that such crystalline cells with diameters up to about 10 cm and disc thicknesses of 0.8 mm and less can be produced in large series. This makes it possible to manufacture solar modules at relatively low cost. Increasingly, solar modules are now to be manufactured that satisfy not only in terms of energy and cost, but also in terms of aesthetics. For example, there is a desire to produce modules with a curved surface. However, such modules cannot be easily implemented with crystalline semiconductor wafers. The semiconductor wafers are flat and inflexible and brittle.

To the problem of inflexibility resp. To avoid the risk of breakage, amorphous, thin semiconductor layers have therefore been deposited on curved panes. However, the advantage of mechanical flexibility has to be bought through the lower efficiency of such layers.

Presentation of the invention

The object of the invention is now to provide a method for producing a photovoltaic solar module of the type mentioned at the outset, with which curved modules can also be produced. The process itself should be simple and inexpensive and lead to modules with high efficiency and a long lifespan.

According to the invention the solution to this problem is that to fix the at least one semiconductor cell, a paste-like, viscous adhesive between the semiconductor cell and the front window, respectively. is introduced between the semiconductor cell and the cover, and that, before the adhesive is solidified, it is gradually displaced without air inclusion, starting at a first wetting point, by appropriate pressure on the semiconductor cell.

According to the invention, the viscosity of the adhesive and the manner in which the semiconductor cell is inserted play a central role. It is e.g. It is possible to apply the adhesive relatively evenly and to lay the semiconductor cell on the edge at an angle and then to fold it successively into the mass (scissors-like insertion).

Preferably, the adhesive is introduced with an irregular thickness, between the semiconductor cell and the front window, respectively. Covering an increased thickness is provided. Little or no adhesive is applied between the individual semiconductor cells.

It is particularly advantageous if the adhesive is at least partially introduced in the form of individual drops of a particular volume and then the drop between the semiconductor cell and the front pane, respectively. Cover is crushed air-free.

A well-dosed drop is used for each cell. Before this drop can flow, the semiconductor cell is pressed into it. The adhesive, which was initially introduced relatively centrally with respect to the cell, begins to flow outwards on all sides under this gentle pressure. The air is gradually pushed outwards, so that air pockets cannot occur. If the drop has been crushed in the desired manner and the pressure is removed from the semiconductor cell, then the cell is free of mechanical residual stresses in the desired manner. If such residual stresses existed, they could be balanced by the viscous adhesive.

The method according to the invention thus leads to a sandwich-like structure. The semiconductor cells are enclosed airtight between the front screen and the rear cover. The adhesive mass forms at least part of the embedding mass. The adhesive thus takes both a fixation and an embedding or. Sealing function true.

In terms of production technology, the invention can in principle be implemented in at least two different ways. In one case it is a pure adhesive technique and in the other it is a combined adhesive-casting technique.

With the pure adhesive technology, the drop is inserted between the front pane and the semiconductor cell. A fully transparent material in the solidified state is used as the adhesive.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

2nd

3rd

CH 683 730 A5

4th

The amount is preferably just such that when the semiconductor cell is pressed into a predetermined position, the adhesive mass oozes out from under the cell on all sides. In particular, it can be advantageous to measure the drop volume so precisely that the amount is just sufficient to glue the entire front of the semiconductor cell to the windshield. In this way, adhesive can be saved without loss of quality in the module. In principle, no high-quality adhesive is required between the individual semiconductor cells. Likewise, no transparent layer is required on the back of the semiconductor cells, but only an adhesive for attaching the cover.

A viscous, polymerizing silicone is preferably used as the adhesive. This is characterized by a high UV resistance, good adhesion with regard to glass and semiconductor material. Otherwise it does not yellow, so to speak.

In order to seal the back of the solar module, a vapor-blocking layer or film can be applied as a cover. If a glass pane is not also used on the back, the solar module will of course be lighter, which is particularly advantageous when used in vehicle construction. In the case of buildings (structural glazing), on the other hand, weight is less important. In particular for the production of partially transparent solar modules, the cover is designed as a glass or plastic pane.

In the combined adhesive-casting technique, a film serving as a cover is held on a molded part by means of vacuum, then exactly one drop is inserted between the film and each semiconductor cell and each drop is crushed by gentle pressure on the semiconductor cell. Next, the front pane is glued to the film in a vapor-tight manner. The free space between the film and the windscreen is filled with a fully transparent material. After the material has hardened, the molded part is removed.

In this way it is possible to use the casting technique to produce a solar module that is only limited on one side by a dimensionally stable pane. As with the pure adhesive process, the back cover is only a thin, preferably vapor-blocking film.

A highly liquid silicone is advantageously used for pouring. However, well-known cast resins or polyurethane can also be used.

A hot melt (butylidene rubber) can also advantageously be used to fix the semiconductor cells. It is known that this is a permanently plastic material, the viscosity of which can be determined almost arbitrarily by choosing the processing temperature.

The features listed below can be applied to both embodiments with corresponding advantages.

In terms of production, it is particularly efficient if on the windscreen resp. several drops are simultaneously applied to the cover at a certain distance from one another and then a corresponding number of semiconductor cells are gently pressed into these drops at the same time. In this way, in the case of a large solar module, the semiconductor cells, which are preferably arranged in a matrix, can be applied in rows.

A metal foil, in particular an aluminum foil, is preferably suitable as the vapor barrier cover. The heat generated in the solar module can also be dissipated well via the metal foil.

If a preformed, suitably curved glass pane is used as the front pane, the particularly preferred curved solar modules result. With the combined adhesive-casting technique, the molded part is then suitably adapted to the curvature of the windscreen.

A photovoltaic solar module produced according to the method is characterized in that the front pane is curved and in that the at least one crystalline photovoltaic semiconductor cell with a fully transparent adhesive is glued to the entire face of the front pane, the semiconductor cell being free of mechanical residual stresses in the solar module included and not adapted to the curvature of the windscreen.

From the rear, a solar module with semiconductor cells arranged in the form of a matrix looks like a section of a polyhedral surface. The individual flat partial areas of the polyhedral cutout are formed by the (covered) rear sides of the semiconductor cells.

With the method according to the invention, in particular solar modules can be produced whose front pane has a curvature that is greater than the maximum permissible deflection of the semiconductor cell. In particular, the front screen has a radius of curvature that is less than 20 m. With the invention, radii of curvature of a few meters (e.g. 1-5 m) can be easily realized. The curvature can be one or two dimensional. In the one-dimensional case it is a developable (e.g. cylindrical) surface and in the two-dimensional one it is a non-developable (e.g. spherical) surface.

According to a preferred embodiment, the fully transparent adhesive is only present between the semiconductor cell and the front pane. The back of the semiconductor cells is preferably sealed over the entire surface with another material in an airtight manner. Since the transparent adhesive has to meet high requirements with regard to the longevity of the module, it is advantageous if it does not have to perform an additional sealing function.

The cover can be a sprayed layer or Layer sequence or a film. If a fully elastic adhesive, preferably a silicone, is used as the fully transparent adhesive, then slight deformations of the front pane can be absorbed by the elasticity of the adhesive. In this way, the risk of breakage of the semiconductor cells can be considerably reduced. Depending on the application, it can also be advantageous to use a

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

3rd

5

CH 683 730 A5

6

use very hard material as an adhesive. The adhesive then has a stiffening effect on the windscreen. The deformations resulting in response to predetermined forces are then much smaller than in the unstiffened state of the washer. The solar module thus becomes more robust overall against the effects of force.

The semiconductor cells are typically silicon wafers with a diameter of at least 5 cm and a thickness of at most 0.8 mm, in particular at most 0.4 mm (e.g. 0.2 mm or more). The larger the cells are, of course, the less effort is required to manufacture a solar module with a specific area. The thinner the cells, the more efficient they are. However, the risk of breakage is correspondingly greater. However, since essentially no residual stresses are induced in the individual cell either in the method according to the invention or in the manufactured solar module itself, the desired trend towards thinner semiconductor wafers can be followed with the invention.

The method according to the invention can in principle be used to produce solar modules of any size. In contrast to laminar technology, no extensive pressure and temperature distributions are required.

Typically, several, essentially rectangular semiconductor cells are provided in a regular, matrix-like arrangement between the front pane and the cover.

If the energy yield is to be as large as possible, the semiconductor cells are arranged as close as possible to one another. In terms of partial transparency of the solar module, of course, very specific distances can also be realized (structural glazing).

A device in order to be able to produce large-area solar modules in an efficient manner has a spray bar with a certain number of at least two nozzles for simultaneously applying a corresponding number of spaced drops of adhesive to the windshield or. the cover on and a support bar with a corresponding number of semiconductor cell holders. The latter is designed such that a corresponding number of semiconductor cells can be pressed onto the applied drops at the same time. In this way, semiconductor cells arranged in a matrix-like manner can be stuck on quickly and precisely. The device is suitable for both the pure adhesive process and for the combined adhesive-casting process.

Further preferred embodiments of the invention result from the following description and the entirety of the claims.

Brief description of the drawings

The invention will be explained in more detail below on the basis of exemplary embodiments and in connection with the drawings. Show it:

Fig. 1: A perspective view of a solar module with a curved windscreen;

2: A schematic representation of a section through a solar module according to the invention;

3a-e: A schematic representation of the individual steps for producing the solar module according to FIG. 2;

Fig. 4: a solar module, manufactured according to the adhesive casting technique; and

5a-d: A schematic representation of the essential steps in the adhesive casting process.

In the figures, the same parts are basically provided with the same reference numerals.

Ways of Carrying Out the Invention

1 shows a solar module with a two-dimensionally curved windscreen 1.1. Such a module could, for example, be used as a car roof with solar cells. The curvature of the front window 1.1 would then correspond to the intended shape of the car roof.

Under the windscreen 1.1, which e.g. consists of high-quality glass, semiconductor cells 2.1 to 2.4 are arranged in a matrix. The light incident under the direction of incidence 14 (from above in FIG. 1) is converted into electricity by the aforementioned semiconductor cells 2.1 to 2.4 on a photovoltaic basis. The semiconductor cells 2.1 to 2.4 are wired to one another in a suitable and known manner and e.g. connected to a battery or an electric motor.

The individual semiconductor cells 2.1 to 2.4 are essentially square. Monolytic (single-crystalline) semiconductor cells preferably have a diameter of approximately 12.5 cm. The corners of such semiconductor cells are rounded, so that there is a side length of approximately 10 cm. Polycrystalline semiconductor cells are typically completely square and have a side length of e.g. 11.5 cm. In principle, the goal is to use semiconductor cells that are as large as possible. Of course, the invention can also be used successfully with smaller diameters of a few cm (e.g. 5 cm). The larger the cells are, of course, the less work is required to produce a solar module of a given area.

If good utilization of the incident radiation is desired, then the individual cells are joined together as close as possible (e.g. a few mm apart). In the case of partially transparent solar modules, the cells are spaced e.g. several cm.

FIG. 2 now schematically shows a section through the curved solar module according to FIG. 1. At the top is the curved windscreen 1.1. It has a concave inside surface 1.1a and a convex outside surface 1.1b. The radius of curvature can vary as required. The pane can of course also have flat parts or be flat overall. A pane can be described as flat if the solar module instead of with

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

4th

7

CH 683 730 A5

8th

the method according to the invention could also be produced in an autoclave in accordance with the known lamination technique. In any case, this is no longer the case with radii of curvature of 20 m and less. The front screen 1.1 should now have such a pronounced curvature.

The semiconductor cells 2.1 to 2.4 are arranged on the concave side of the completely transparent glass pane. Its light-sensitive side faces the concave surface 1.1a. They are airtight between the windscreen and a cover that e.g. is formed by a metal foil 5.1, embedded. An important aspect of this airtight seal is protection against corrosion (e.g. through penetrating water vapor).

Between the front window 1.1 and the semiconductor cells 2.1 to 2.4 there is a (solidified) adhesive 3, which is optically fully transparent. So that the efficiency of the solar module does not collapse over a long period of time, the optical properties (light transmission) must also be resistant to the UV light that usually occurs. If this is not the case, yellowing may occur to a greater or lesser extent over time.

It goes without saying that the semiconductor material (e.g. silicon) must not react chemically with the adhesive. Otherwise the cell can be destroyed. According to a particularly preferred embodiment, the adhesive is a highly transparent, at least slightly elastic silicone. This not only has the properties required above, but also good adhesion both to glass and to the surface of the semiconductor cell (silicon dioxide). Furthermore, the refractive index of silicone is well adapted to the pane, so that reflection losses are low. Finally, such an adhesive can withstand the internal temperatures of the solar module that are up to 60 ° C above the ambient temperature. Silicon even survives so-called hot spots, which arise when a semiconductor element fails and can easily lead to overheating of 160 ° C.

The adhesive 3 fills at least the area between the light-sensitive surface of the semiconductor cells 2.1 to 2.4 and the front window 1.1. The rear side of the semiconductor cells 2.1 to 2.4 is covered with an insulation layer 4. In principle, this can be very thin and simply forms the electrical insulation with respect to the metal foil 5.1 which is preferably used as a cover. The insulation layer 4 can consist of an inexpensive material. Since it is provided on the back of the semiconductor cells 2.1 to 2.4, it need not be transparent. Of course, it can also consist of the same silicone as the adhesive 3.

The metal foil 5.1, which is preferably an aluminum foil, is glued to the front pane 1.1 in the edge area 8.1 of the module. A vapor-tight adhesive made of synthetic resin is best suited for this.

The metal foil 5.1 is not only a good vapor barrier, but also dissipates the heat generated in the module to the outside. The thinner the insulation layer 4, of course, the better the possibility of cooling the semiconductor cells 2.1 to 2.4.

The section shown in FIG. 2 clearly shows that the semiconductor cells 2.1 to 2.4 are not molded onto the curved front pane 1.1. Rather, they bridge the curved surface 1.1a in a sinew shape. The distance between the light-sensitive surface of the semiconductor cell (e.g. 2.1) and the surface 1.1a of the front pane 1.1 is therefore smaller at the edge of the semiconductor cell 2.1 than at its center. Due to the planar semiconductor cells, the cover on the back looks in principle polygonal on average.

3a to 3e will now be used to explain how this aesthetically satisfactory solar module can be manufactured. It is assumed that the windscreen is suitably pre-shaped 1.1. (The shaping of, for example, glass panes is known in the prior art and is not the subject of the invention.) Individual drops 9.1 to 9.4 of the adhesive composition are now applied to the concavely curved surface 1.1a. This can e.g. with the help of a spray bar provided with nozzles, the individual drops being well metered in volume and having a defined mutual distance. The distance is chosen according to the intended arrangement of the semiconductor cells. They are preferably located where the center of the respective cell should be located (Fig. 3a).

The adhesive is paste-like, respectively. viscous. The drops 9.1 to 9.4 flow very slowly. For the same reason, the drops placed on slightly inclined areas (e.g. 9.1 and 9.4) do not immediately flow into flatter areas (e.g. towards the center).

The semiconductor cells 2.1 to 2.4 are now positioned above the drops 9.1 to 9.4 (FIG. 3b). This happens e.g. with a support bar that has as many semiconductor cell holders as drops have been placed before. The individual semiconductor cells are e.g. held by vacuum. So that the cells cannot break when they are subsequently pressed in, the entire surface of the semiconductor cell should rest on a suitable support surface of the cell holder.

Now the individual semiconductor cells 2.1 to 2.4 are pressed simultaneously on the corresponding drops 9.1 to 9.4 (see arrows). Under this pressure, the viscous drop (e.g. 9.1) is crushed between the semiconductor cell 2.1 and the front pane 1.1. The adhesive therefore flows from the center (the semiconductor cell 2.1 was placed as centrally as possible on the drop 9.1) on all sides. Due to the viscosity and the surface tension of the adhesive, the air is gradually forced outwards, so that no air pockets (voids) can occur.

The semiconductor cells 2.1 to 2.4 are pressed into a precisely defined position. This position can e.g. be specified by a minimal distance between the edge of the cell and the windscreen (e.g. just touching).

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

5

G

CH 683 730 A5

10th

When crushing the drops g.1 to 9.4, the pressure exerted on the semiconductor cells 2.1 to 2.4 is to be measured in accordance with the configuration of the semiconductor cell holder and the load capacity of the semiconductor cells. In view of a high working speed, a pulse-like pressure curve with a high pulse peak is of course desirable. So that the semiconductor wafer is not damaged, the pressure curve is. to limit the pressure maximum. A semiconductor cell holder, which ensures extensive support of the semiconductor cell, allows a higher injection pressure than a wide-meshed, grid-like support. Since the semiconductor cell should not be mechanically stressed (by arcing), the insertion pressure can be described as gentle.

The volume of the droplet is preferably dimensioned such that the adhesive 3 just springs out laterally under the semiconductor cell 2.1 after it has been pressed into the predetermined position. If the semiconductor cells 2.1 to 2.4 are arranged sufficiently close to one another, a coherent adhesive layer 3 is formed in this way (FIG. 3c). In the case of larger distances, either larger drops can be placed, in which case the adhesive mass which swells excessively to the side under the semiconductor cells must be distributed, or the area of the surface 1.1a which is exposed between the cells is covered with another layer.

The application of the semiconductor cells 2.1 to 2.4 must be done relatively quickly so that the drops cannot flow away on their own. As soon as the semiconductor cells 2.1 to 2.4 are in the desired position, the polymerisation of the adhesive can begin. In this way, row by row of a matrix-shaped cell arrangement is applied.

Next, the insulation layer 4 is applied (Fig. 3d). It can be a spread, poured, knife or sprayed on plastic layer. While there are rather thin layers when spraying on, thick layers of e.g. Apply 1 mm or more. The insulation layer 4 can optionally be applied after the application of a single row of semiconductor lines, or only after the entire front pane has been fitted.

Finally, a metal foil 5.1 is preferably applied as a cover. It is glued airtight on the surface of the front pane 1.1 equipped with semiconductor cells 2.1 to 2.4 to the pane itself in an airtight manner. Of course, make sure that there are no air bubbles underneath the cover.

The photovoltaic solar module is now finished.

For the sake of simplicity, the wiring of the semiconductor cells has not been discussed. This can be done in a manner known per se, since the invention does not require any inventive changes in this technology. In connection with wiring, the invention has the advantage that the semiconductor cells are fixed by the adhesive and do not have to be held by separate gauges.

An exemplary embodiment of the adhesive casting technique will now be given.

4 shows a photovoltaic solar module produced using this method. Again, a curved front window 1.2 is used, on the concave curved surface 1.2a of which the semiconductor cells 2.5 to 2.8 are arranged. The individual cells are embedded in a fully transparent casting material (casting resin 7). The module is sealed on the back with a metal foil 5.2. The adhesive 6.1 to 6.4 is located between the semiconductor cells 2.5 to 2.8 and the metal foil 5.2 (cover). According to a preferred embodiment, the cover is adapted to the shape of the windshield. The solar module is therefore essentially the same thickness everywhere. In the edge area 8.2, the metal foil 5.2 is glued directly to the front window analogously to the first embodiment according to FIG. 2.

5a-d show the individual method steps in the manufacture of the module shown in FIG. 4. In contrast to pure adhesive technology, this starts on the back. A film is therefore first laid out on a molded part 11. This has a suitably designed air duct system 12 with which the air is sucked out from under the film and the film can thereby be held over the entire surface (FIG. 5a). The curvature of the molded part 11 is adapted to the windshield 1.2 to be fitted later. A peripheral rib 15 is provided on the edge, on which the windshield 1.2 can later rest. The film is also drawn over this rib 15.

Individual drops 10.1 to 10.4 of the adhesive are now placed on the stretched film. With regard to flowability and consistency, what has been said above about the adhesive also applies. In contrast to the above, it is not necessary to use a fully transparent, optically high-quality material. The individual drops are arranged according to the geometric arrangement of the semiconductor cells to be attached. The volume of the individual drop does not have to be very large, since the drop only has to perform a fixing function.

Next, the semiconductor cells 2.5 to 2.8 are positioned, with the blind back on the corresponding drops 10.1 to 10.4.

Now the drops 10.1 to 10.4 are crushed using gentle pressure on the semiconductor cells 2.5 to 2.8 (see arrows). Since the volume of the individual drops was relatively small, the adhesive 6.1 to 6.4 does not protrude laterally under the semiconductor cell 2.5 to 2.8. As mentioned, this is not necessary. It is only important that the semiconductor cell 2.5 is fixed on the film by the adhesive 6.1 and that no air pockets occur. However, the latter is not the case due to the suitably chosen viscosity and adhesion.

Now an adhesive (e.g. synthetic resin) is applied to the edge of the film and the windscreen over

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

6

11

CH 683 730 A5

12th

the prepared semiconductor cell arrangement is placed and connected to the film in an airtight manner by the adhesive (FIG. 5d). There is now a pourable cavity 13. A casting resin 7 (FIG. 4) is now filled in via a suitably designed feed, not shown. Only as much casting resin is filled in as is required by the finished module.

The front window 1.2 bulges slightly due to the pressure of the liquid. Accordingly, the volume of the cavity 13 has become somewhat larger. The module held vertically when filling is now slowly moved horizontally, the pressure on the windscreen easing and the cavity again taking on the desired size. The filled amount of casting resin then completely fills the cavity.

When the casting resin has solidified, the molded part 11 can be removed. The solar module shown in Fig. 4 is ready.

The invention is not restricted to the exemplary embodiments described. On the contrary, the scope of the proposed methods is very large. Of course, flat ones can also be used instead of the curved windscreens. Modules with a concave instead of a convex light-facing surface can also be manufactured. Glass panes are preferred because of their durability. Other transparent materials can also be used for the windscreens, e.g. Polyester or polycarbonate.

The modules shown in FIGS. 2 and 4 have a film as a cover. It is of course also within the scope of the invention to use a dimensionally stable pane (e.g. made of glass) for this cover too.

Instead of silicone, a fully transparent resin with a suitable viscosity in the liquid state can also be used. As already mentioned, the fact that such a resin has a very high strength in the dried state improves the stability of the solar module.

The adhesive is typically a two-component adhesive. Instead of two-component adhesives, UV-curing adhesives can also be used. The same applies to the pouring material in the combined adhesive-casting technique.

If the cover itself is an insulator and not a metal foil as described, then in principle the separate insulation layer 4 can be dispensed with. On the other hand, additional layers can also be provided with which corrosion protection measures are specifically implemented. In this sense, e.g. layers can also be applied as mechanical protection against point loads. If the adhesive in FIG. 2 is very elastic in the solidified state and the back of the solar module is not protected, then the semiconductor cells can break when loads occur at points. On the back you can e.g. a rubber-like layer can be applied, which distributes the point-like forces to a certain area. If the solar module is used as the roof of a car, then the back of the module can be covered against the passenger compartment with a molded plastic insert.

In conclusion, it can be established that the method according to the invention can be used to produce photovoltaic solar modules which are energy-efficient and can be adapted to a wide variety of aesthetic needs (shapes). It is also an advantage of the invention that very large modules can be produced in terms of area without problems.

Claims (21)

Claims 1. A method for producing a photovoltaic solar module, in which at least one disk-shaped, flat, crystalline photovoltaic semiconductor cell (2.1 to 2.8) is arranged between a translucent front pane (1.1, 1.2) and a rear cover (5.1, 5.2), characterized in that to fix the at least one semiconductor cell (2.1 to 2.8) a paste-like, viscous adhesive (3; 9.1 to 9.4; 10.1 to 10.4) between the semiconductor cell (2.1 to 2.4) and the front window (1.1) or is inserted between the semiconductor cell (2.5 to 2.8) and cover (5.2), and that before the adhesive (3; 9.1 to 9.4; 10.1 to 10.4) solidifies, it begins successively without air inclusion, starting with a first wetting point, by applying adequate pressure to the semiconductor cell (2.1 to 2.4; 2.5 to 2.8) is displaced. 2. The method according to claim 1, characterized in that the adhesive (3; 9.1 to 9.4; 10.1 to 10.4) is introduced with an irregular thickness, wherein between the semiconductor cell (2.1 to 2.4; 2.5 to 2.8) and the front window (1.1) and. Coverage (5.2) an increased thickness is provided. 3. The method according to claim 1 or 2, characterized in that the adhesive (3; 9.1 to 9.4; 10.1 to 10.4) at least partially introduced in the form of individual drops (9.1 to 9.4; 10.1 to 10.4) of a particular volume and between semiconductor cell ( 2.1 to 2.4) and windscreen (1.1) resp. Cover (5.2) is crushed without air pockets. 4. The method according to claim 3, characterized in that the drop (9.1 to 9.4) between the front pane (1.1) and the semiconductor cell (2.1 to 2.4) is introduced and that a completely transparent adhesive (3) is used in the solidified state. 5. The method according to claim 4, characterized in that the volume of a drop (9.1 to 9.4) is dimensioned at least so large that when the semiconductor cell (2.1 to 2.4) is pressed into a predetermined position on all sides of the semiconductor cell (2.1 to 2.4) the adhesive wells up. 6. The method according to any one of claims 1 to 3, characterized in that a viscous, polymerizing silicone is used as the adhesive (3). 7. The method according to any one of claims 1 to 4, characterized in that a vapor-blocking layer or film (5.1, 5.2) is applied as a cover. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 7 13 CH 683 730 A5 14 8. The method according to claim 1, characterized in that a film (5.2) serving as a cover is held on a molded part (11) by means of vacuum, that exactly one drop (10.1 to 10.4) between the film (5.2) and each semiconductor cell (2.5 to 2.8) is introduced that each drop (10.1 to 10.4) is crushed by gentle pressure on the semiconductor cell (2.5 to 2.8), that the front pane (1.2) is glued to the edge (8.2) with the film (5.2) so that it is vapor-tight free cavity (13) between the film (5.2) and the windshield (1.2) is poured out with a fully transparent material, and that the molded part (11) is removed after the casting material has hardened. 9. The method according to claim 8, characterized in that a highly liquid silicone is used as the fully transparent casting material (7). 10. The method according to any one of claims 1 to 7, characterized in that on the front window (1.1) resp. several drops (9.1 to 9.4 or 10.1 to 10.4) are applied to the film (5.2) simultaneously at a certain distance from one another, and that a corresponding number of semiconductor cells (2.1 to 2.4 or 2.5 to 2.8) are then simultaneously introduced into the drops (9.1 to 9.4 10.1 to 10.4). 11. The method according to any one of claims 1 to 8, characterized in that a metal foil (5.1, 5.2), in particular an aluminum foil, is applied as the vapor barrier cover. 12. The method according to any one of claims 1 to 9, characterized in that a preformed, curved glass pane is used as the front pane (1.1, 1.2). 13. Photovoltaic solar module produced by the method according to claim 1, characterized in that the front window (1.1) is curved and that the at least one crystalline photovoltaic semiconductor cell (2.1 to 2.4) with a fully transparent adhesive (3) with its entire surface on the windscreen (1.1) is glued, the semiconductor cell (2.1 to 2.4) being free of mechanical residual stress and not adapted to the curvature of the windscreen (1.1). 14. Solar module according to claim 13, characterized in that the curvature of the front pane (1.1, 1.2) is greater than the maximum permissible deflection of the semiconductor cell (2.1 to 2.8), in particular that the radius of curvature is less than 20 m. 15. Solar module according to claim 13 or 14, characterized in that the fully transparent adhesive (3) is only present between the semiconductor cell (2.1 to 2.4) and the front screen (1.1) and that the back of the semiconductor cell (2.1 to 2.4) with another material airtight is sealed. 16. Solar module according to one of claims 13 to 15, characterized in that the rear cover of the solar module is formed by a coherent, all-over cover layer (5.1, 5.2). 17. Solar module according to claim 16, characterized in that the cover layer is a metal foil (5.1, 5.2). 18. Solar module according to one of claims 13 to 17, characterized in that the fully transparent adhesive (3) is a solid material in the solidified state, in particular a silicone. 19. Solar module according to one of claims 13 to 18, characterized in that the at least one semiconductor cell (2.1 to 2.4) is a silicon wafer with a diameter of at least 5 cm and a thickness of at most 0.8 mm, in particular at most 0.4 mm. 20. Solar module according to one of claims 13 to 19, characterized in that a plurality of substantially rectangular semiconductor cells (2.1 to 2.4) are provided in a regular, matrix-like arrangement between the front screen (1.1) and cover (5.1). 21. The apparatus for performing the method according to claim 1, characterized by a spray bar with a certain number of at least two nozzles for simultaneous application of a corresponding number of spaced drops (9.1 to 9.4) of the adhesive on the windshield (1.1) and. the cover (5.2) and a holding bar with a corresponding number of semiconductor cell holders, which is designed such that a corresponding number of semiconductor cells (2.1 to 2.4 or 2.5 to 2.8) are applied to the drops (9.1 to 9.4 or 10.1 to 10.4) applied can be pressed simultaneously. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 8th