Method for segregating resources in composite parts.

Abstract

The invention relates to a method for separating resources of a composite part (00) comprising several material layers. The composite part (00) comprises a material layer (04) absorbing the energy of a radiation source and at least one plastic sheet. In an exposure area, the composite part (00) is heated by means of a radiation source for less than one second, whereby the heating of the absorbing material layer (04) results in the decomposition of the chemical bonds of the plastic in the boundary layer (09) of the at least one plastic sheet (03, 05) facing the absorbing material layer (04) with the generation of gas. Prior to the heating, at least one targeted break point (08) is formed in the plastic film in such a way that it breaks in a controlled manner under the pressure of the gas generated by the plastic sheets (03, 05) at the targeted break point.

Description

[Technical field]

[0001] The invention generally relates to a method for separating resources in a composite part having at least one material layer absorbing the energy of an electromagnetic radiation source and at least one plastic sheet. Alternatively, the plastic sheet may adjoin the absorbing material layer directly or indirectly, via a heat-transfer layer, thus forming a layer sequence absorbing the energy of an electromagnetic radiation source, hereinafter also called radiation source. In the separation method mentioned at the beginning, the absorbing material layer or layer sequence is heated by means of a radiation source in the exposure area for less than one second. The invention particularly relates to a method for separating resources in a solar energy module, such as a component of a photovoltaic module or a concentrated solar power module, or from the area of ​​a display. [Background technology]

[0002] After their normal use, photovoltaic modules and displays fall into the category of "electronic waste" and contain valuable and reusable raw materials. In the European Union, electronic waste must be recycled according to European Union standards. Depending on the structure, the modules contain, for example, silicon wafers and silver, or rare substances such as indium, gallium or tellurium, and other materials in the composite.

[0003] A composite part is made up of a number of components that interact to achieve a function in use and for which purpose must remain attached to one another for the duration of the use of the composite part. Temporary attachment of individual components to one another or with auxiliary means during the fabrication of a composite part prior to completion of the composite part is not included in the term composite part as used herein.

[0004] Typically, the exposure area of ​​the radiation source includes at least a part of the surface of the composite part, so that the absorbing material layer and possibly the absorbing layer sequence together with the absorbing material layer are partially or optionally completely warmed.

[0005] A special case for separating composite parts is described in patent application WO 2018 / 137735. There, the radiation source suitable for separation is one or more gas discharge lamps for heating the resource in the photovoltaic module. Currently, the preferred reusable material is silicon. Moreover, the method can also be applied to other materials and other composite parts. The method of WO 2018 / 137735 is incorporated in its entirety by reference.

[0006] About 85% of all photovoltaic modules produced consist mainly of a composite of successive materials above and below, in the form of a glass panel or an upper plastic sheet, several silicon wafers lying side by side in one plane and parallel to the glass panel, and a stack of composite sheets, the latter consisting of several plastic sheets, with this example the method according to the invention being described below.

[0007] In WO 2018 / 137735, intense visible light 01 passes through a glass panel 02 in front of a photovoltaic module 00 in a time span of less than one second, passes through an upper plastic sheet 03, transparent to visible light, adjacent to the glass panel 02, as shown for example in FIG. 1, and is absorbed by a material layer (for example a silicon wafer 04, which is in a first approximation square and located side by side in a plane) located below, which absorbs the light from the radiation source. As a result of the light absorption, the material layer is heated, so that the plastic sheets 03, 05 bonded to it are peeled off. In the process, pyrolysis gases are generated in a few millimeters thick layer of plastic directly adjacent to the absorbing material layer.

[0008] The plastic sheet 05 of the sheet stack, which is directly bonded to the silicon wafer, is typically made of the same material as the upper plastic sheet 03. Sheet stacks that include an additional sheet are referred to in the literature as backsheets. Hereinafter, for simplicity, the sheet stack 05 below the wafer will be referred to as the lower plastic sheet 05 and the sheet above the wafer will be referred to as the upper plastic sheet 03.

[0009] Between the silicon wafers there are areas 06 of plastic, hereafter referred to as "webs", which arise on the upper or lower side of the wafer during the lamination of the upper and lower plastic sheets 03, 05 during the production of a photovoltaic module. The webs 06 prevent complete separation of sheets 05 and 03 upon exposure in the aforementioned method of WO 2018 / 137735. Thus, after exposure, the silicon typically remains in the sheet pockets which are bonded together by the webs. The lower plastic sheet remains attached to the upper plastic sheet via the webs after exposure.

[0010] Since multiple variables of the composite part, such as the type of plastic, the dimensions of the wafers, the light absorption of the wafers and the spacing between the wafers, i.e. the web width and many other variables, vary widely not only between different productions of modules but also between the production of one production module, in practical applications it is hardly possible to adjust a single light amount for separating the material layers optimally and simultaneously for all module types. Therefore, in every possible case, a minimum temperature and thus a corrected minimum light amount must be selected to ensure a complete and reliable separation of the material to be separated, for example semiconductor, as an absorbent material layer, for example silicon, from the plastic of the composite part.

[0011] The minimum light intensity causes more extensive pyrolysis of the plastic in most photovoltaic modules than desired, resulting in excessive gassing and blackening of the silicon and precipitates on the plastic surfaces adjacent to the silicon. In practice, the separation of the material layers is not uniform, repeatable, and does not occur at the same location, even for the same type of module and the same process variables. In extreme cases, individual silicon fragments penetrate or remain stuck in the sheet stack 05 due to temperatures significantly above the minimum temperature and the resulting excessive gassing.

[0012] If the generally reinforced upper cover glass is already broken before exposure, then the glass panels (whose splitters are still connected to each other by the upper plastic sheet 03) can bend towards the light source. In this case, pyrolysis gases can escape. The splitters can peel off and ultimately the light source can be adversely affected or even destroyed. Since many of the plastics of the sheet stack 05 have only poor mechanical resistance due to aging exposed to the ultraviolet light of the sun, the sheet stack 05 breaks down into many small pieces, which become mixed with the silicon and thus require a laborious subsequent sorting, for example by means of an air classifier. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. 2018 / 137735 Summary of the Invention [Problem to be solved by the invention]

[0014] The challenge is therefore to separate reusable composite part materials, such as semiconductors, in particular silicon, of wafers or other materials as electronic components, from existing composites that include one of a glass panel and / or a plastic sheet, so that these materials can be subsequently removed.

[0015] Furthermore, the minimum light amount is optimized and in particular reduced compared to known methods. This makes it possible, inter alia, to avoid the aforementioned adverse effects and damage to the composite parts or devices.

[0016] Furthermore, the separation of the materials of the composite parts and the resulting extraction of the resources of the composite parts must be feasible on an industrial scale and must be applicable for composite parts of different generations and manufacturers with constant or automatically controlled light intensity. [Means for solving the problem]

[0017] According to the invention, the separation of the resources is carried out in the absence of oxygen in the boundary layer by means of thermochemical decomposition of the boundary layer of the plastic sheet, the energy required for this being provided on the basis of the absorption of radiation incident for less than a second by the absorbent material layer of the composite part, as described above in the prior art.

[0018] The duration of the exposure depends in particular on the materials involved and on the layer sequence of the materials in the composite part. The exposure time can be set so that the introduced radiant energy is sufficient to ensure the generation of such an amount of gas that it causes pyrolysis and the plastic sheet is peeled off from the adjacent layers as a result of gas evolution in the exposed areas.

[0019] The exposure time for the light exposure to separate the layers can be significantly shorter than 1 second. The exposure time depends on many variables related to absorption and heat transfer in the composite part. For various types of photovoltaic modules, the separation of the absorbing material layers can take place for example in the range of 5 μs to 500 ms, alternatively 100 μs to 100 ms, and further alternatively 500 μs to 50 ms. The method can also be carried out and the resources separated with exposure times of less than 1 millisecond. All intermediate values ​​can be used depending on the various variables.

[0020] The exposure time depends, for example, on the material and layer thickness (micrometers) of the absorbing material layer, as well as on the material and layer thickness of the adjacent material layers, since these determine the heat losses by heat transfer and further on the type and operation of the radiation source. Another variable is the temperature to be reached for the pyrolysis of the plastic. The main criteria for the exposure time are the material and layer thickness of the absorbing material layer, so that for example for thin-film solar modules with light-absorbing layers that are about two orders of magnitude thinner, the required times can vary greatly.

[0021] Some of the above variables for various absorbent materials are listed in the table below, which are exemplary but not limiting.

[0022] All values ​​are only approximate. Heat capacity does not play a significant role and is therefore not taken into account here. At higher temperatures, heat radiation plays an important role, since it is proportional to the fourth power of temperature. Light absorption is also an important factor, since for example silver and aluminum absorb mainly in the UV range, therefore in this case a relatively short pulse width is necessary for a relatively high current density of the flash lamp or a relatively strong UV radiation. The window glass example is entered just for comparison, but does not include a polymer.

[0023] The glass frit often consists of glass and lead oxide after tempering. Due to the poor thermal conductivity of the glass frit, the exposure time must be quite long at a relatively low intensity.

[0024] [Table 1]

[0025] The above table shows only a few variables for setting the exposure time. For each present case, the variables are determined by experiments and / or simulations based on the situation.

[0026] By exposed area is meant in the sense of the present invention each surface area of ​​the composite part on which the light of an external radiation source is incident, including exposure areas of the size of the composite part or larger.

[0027] The term external radiation source is used herein to mean a source that is not a component part of a composite piece, but is part of the apparatus performing the method.

[0028] Amount of light is generally understood to be the radiant energy introduced into the composite part in the exposure area during the exposure process for a given time relative to the mass being treated, the latter being determined by the size of the composite part in the exposure area.

[0029] Based on the materials of the involved layers of the composite part to be treated in the method cycle, a suitable minimum light amount for the cycle can be determined using appropriate simulations and / or experiments.

[0030] Based on the described pyrolysis of a thin boundary layer of the plastic sheet against an adjacent layer of hot material, gas-filled pockets form throughout the radiation-absorbing material. The bonds between two plastic sheets that remain after exposure, as described above for the prior art, result from the lack of absorption and therefore the lack of warming of another non-absorbing or low-absorbing component of the web or of the composite part, defining the pockets.

[0031] The gas-filled pocket openings are formed in the underlying plastic sheet by one or more targeted break locations, and are optimally realized for all of the targeted break locations. As a result, the adjacent hot material layer is at least partially exposed. At least one targeted break location, and preferably multiple break locations, are formed in the plastic sheet prior to exposure of the composite sheet to light.

[0032] The targeted break points allow for precise and reproducible opening of the plastic sheet for various module types. Based on the minimum light requirement for processing various configurations of certain composite parts, excess generated gas can escape without causing adverse consequences to the composite part or the device, because excess generated gas does not build up high pressure between the absorbent material layer and the plastic sheet, resulting in no bending of the cover glass or damage to the light source when the glass breaks. Pieces of the hot material layer are ejected from the opening, instead of penetrating or becoming lodged in the plastic sheet, as would occur without the targeted break points.

[0033] A targeted breaking point is to be understood here as a point in the lower plastic sheet, which is locally specified by a special structure and / or shape, which is formed in the plastic sheet from the underside and breaks in a defined manner under a defined load due to the structure with gas-filled pockets. The targeted breaking point can penetrate the plastic sheet partially or completely.

[0034] The geometry of the target break point can be any, for example a groove or a cut can be formed in the plastic sheet, in which case according to the invention in a first step the target break point is cut into the composite part, and in a second step the resource embedded in the composite material is heated from the outside by a radiation source. The heating causes the separation of the composite material, during which gas is generated. The gas supports the separation process and can flow out of the composite part precisely by the target break point. Only a small amount of light is needed to separate the silicon from the plastic, since the gas contributes to the release of the resource during exposure.

[0035] Alternatively, the target break points can be formed in an area, such as holes or the like. The area cuts can be distributed uniformly or can be concentrated, for example at one or more points per wafer surface. There is also the option of cutting the plastic sheet not only in a rectangular or U-shaped manner at the edge of the wafer, but also in a number of relatively small serpentine strips, which remain bonded to the web on one side. This makes it possible to further reduce the gas pressure during pyrolysis. The local distribution of the target break points in the composite part is performed in such a way that each envisaged pocket has at least one target break point. The suitable geometry of the cuts, their depth and distribution can be determined, for example by experiments, depending on the properties of the composite part to be recycled.

[0036] The target break points can be formed, for example, by mechanical means, for example by a cutter, preferably by a rotary cutter, or by laser radiation. Other methods are also conceivable which lead to precise and variable cuts in terms of the shape and depth of the incision. For example, at the edge of each wafer, the plastic sheet can be completely or partially cut open from the side facing away from the glass.

[0037] In one embodiment of the method, the exposure of the absorbing material layer is performed with a light source arranged from the side where the target break point is facing away from the light source, for example on the upper side of the composite part, whereby gravity can be used to separate the absorbing layer material from the absorbing layer support material, furthermore in this way the radiation source is protected from damage due to high gas pressures during pyrolysis or from contamination by gas-based soot.

[0038] In another embodiment, composite parts are processed that have at least one material layer that is transparent to visible and / or UV light. In order to reuse the material, which should be recycled, various composite parts are known that have a support layer or a cover layer. If these are transparent to the light of the radiation source of the method, exposure through this layer and separation from this layer are possible.

[0039] The distinction between the material layers as transparent layers and other light-absorbing layers is made according to the main optical properties used for the separation process of the layers. The transparent material layers thus form an entrance window for the visible light of the external radiation source into the composite part and are therefore transparent for at least the spectral range used for the separation process used. Material layers with a visible light transparency of more than 40% have proven suitable for the applicable process, the percentage expression of the transparency being related to the radiation spectrum of a typical broad-emitting gas discharge lamp. The at least one gas discharge lamp can optimally be operated as a flash lamp, so that the energy supplied to the composite material leads to only a negligible increase in the temperature of the entire composite part.

[0040] Depending on the gas discharge lamp used, the operating variables of the gas discharge lamp, the separation process used and the layer materials, the spectral transmittance may include other regions besides the visible range of the radiation spectrum, such as light in the UV and / or IR range.

[0041] The method can also be applied to composite parts in which the transmissive material layer has a relatively high transmission value or a transmission profile tailored to the relevant spectral region. The transmission can be determined by the transmissive material layer or by several of the transmissive material layers located above and below.

[0042] In another embodiment of the method, a targeted break point may be formed in the plastic sheet such that, complementary to the exposure of the material layer to be obtained, it can also be used for the removal and separation of further components of the composite part.

[0043] The plastic is not cut open, for example along the closed course of the wafer, for example along the complete edge of the wafer, but rather in a centimeter-long section, so that a partially continuous sheet remains in the composite part, which makes it easier to separate the various materials and reduces or completely avoids another problem that exists in the prior art as a result of overexposure of the composite part.

[0044] Such a plastic sheet, broken at a targeted break point but still continuous, can aid in the separation of semiconductor material from metal materials, particularly bus bars, for example, for electrical contacts of semiconductor devices.

[0045] The busbars are generally tinned copper conductors which electrically connect the wafers to one another and are guided through the web. In this case, the connections almost always extend from the front side of one wafer to the back side of the adjacent wafer, so that the semiconductor diodes are connected in series, wafer by wafer. If the aforementioned uncut portions are then selected exactly in the area of ​​the wafer edge where the busbars extend through the web, the busbars will remain attached to the wafer after exposure or will not be mixed with the extracted semiconductor material, e.g. silicon. As a result, the semiconductor material can be extracted pure with the method according to the invention.

[0046] For example, if the wafer edge is only cut on three sides, i.e. in a U-shape, the result is that the busbars guided on the underside of the wafer are not separated, with this part of the busbar remaining connected to the plastic of the web when the silicon is removed, whereas the busbars leading from the upper side of the wafer to the opposite web remain attached to the plastic sheet.

[0047] In many cases where the absorbent material layer is embedded between two plastic sheets and the exposure of the absorbent material layer is carried out through the transparent material layer with a minimum amount of light, it may be advantageous to carry out a separation method with two exposure steps: in a first exposure step, the aforementioned pocket is formed by a first exposure with a light amount lower than the minimum amount of light, filled with gas and opened at the target break point.

[0048] In this positional relationship, the pockets are formed in the plastic sheet, which is located on the side of the absorbent material layer facing away from the incidence of light, also referred to here as the lower plastic sheet. However, gas generation and the associated separation also take place in the upper plastic sheet, which is located on the side facing the incidence of light, but to a lesser extent. In this case, the detachment of the absorbent material layer from the upper plastic sheet may not be complete or may only be incomplete. By a second exposure that follows in time, it is possible to completely open the pockets in the lower plastic sheet and to peel off the absorbent material layer, which is still at least partially attached, from the upper plastic sheet.

[0049] In the first exposure, a longer exposure time is preferably used than in the subsequent exposures, since in order to open the pockets, the surface of the silicon adjacent to the lower plastic sheet must be heated, and the light absorption takes place in the opposite surface of the silicon adjacent to the upper plastic sheet. A certain material-dependent time is therefore required for the heat transfer from the front to the back of the absorbent material layer. In contrast, in the second exposure, an exposure length, for example 10 to 100 times shorter than the first exposure time, is sufficient, since here it is desired to heat the upper surface of the absorbent material layer in order to completely peel it off from the upper plastic sheet and thus from the transparent material layer.

[0050] Ideally, in this method variant, the maximum pressure generated by the pyrolysis gases is reduced by two successive exposures compared to one exposure, and adverse effects such as pressure waves or pyrolysis blackening on the light source or on the transparent material layer, which is often made of glass, can be minimized by the two exposures.

[0051] Furthermore, the two-step exposure and the associated consequences can reduce the maximum temperature of the transparent material layer. For example, fragments of the absorbent material layer, which have been strongly heated in one exposure, can come into contact with the underside of the lower plastic sheet and be melted thereto. While this effect or other adverse effects due to the high energy density of the one-step exposure can also occur in other forms of composite parts, the two-step exposure can also be applied in this case.

[0052] For the duration of the two exposures, the aforementioned variations are applicable depending on the variables of the composite part in question. If the time interval between the exposures is selected to be short enough so that the absorbing material layer has a higher temperature at the beginning of the second exposure than at the beginning of the first exposure, the amount of the second exposure can be reduced to save energy. In another variation of this embodiment of the method, the first exposure step may also consist of several steps.

[0053] The above-mentioned method is also applicable to composite parts in which the absorbent material layer is formed by several wafers, in which several wafers, or alternatively all the wafers, are placed in the exposure area and exposed, which are separated from one another by a web, in which case the pockets formed are defined by the web and an effective and reproducible method form with a high throughput is conceivable.

[0054] The invention will now be described in more detail, in an illustrative and non-limiting manner, on the basis of an embodiment, in which the features realized in the various forms of the invention described above and below can be combined by the skilled artisan in further embodiments, if deemed expedient and meaningful for the purpose. [Brief description of the drawings]

[0055] [Figure 1] 1 shows a schematic structure of a photovoltaic module as a composite component according to the prior art; [Diagram 2] 2 shows diagrammatically the composite part according to FIG. 1 after carrying out the method according to the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] The drawings only show the subject matter of the invention in a schematic manner and to the extent necessary for understanding the invention. The drawings do not require completeness or scale.

[0057] 1, reference is made to the above description in the prior art of the structure of a photovoltaic module 00 as an example of a composite part which can be treated with the method. The currently preferred composite part is a photovoltaic module having a front glass and a rear sheet. Moreover, the method is in principle also applicable to other composite parts having a comparable layer structure.

[0058] FIG. 2 shows the composite part after carrying out the method of the present invention, where the lower plastic sheet 05 has been partially cut open at the edge region 07 of the wafer 04 (shown in dashed lines) and the wafer 04 has been removed.

[0059] To separate the wafer 04 from the upper plastic sheet 03 and the lower plastic sheet 05, a target break point 08 is first made in the lower plastic sheet 05 using a laser (not shown) or alternatively using a mechanical cutter. The target break point 08 extends around the wafer 04 in its edge region 07, but not around the entire circumference.

[0060] The photovoltaic cell module 00 is then exposed for 10 milliseconds with cylindrical flash lamps (not shown) arranged in a plane parallel to each other in an exposure field that includes all the wafers shown, parallel to the lamp plane (indicated by arrows extending parallel to each other in FIG. 1). The light of the flash lamps strongly heats the wafer 04, which now serves as a light-absorbing material layer. In the boundary layer 09 of the upper plastic sheet 03 and the lower plastic sheet 05, a pyrolysis process is triggered, so that pyrolysis gases are generated in both boundary layers to the wafer 04.

[0061] By the latter, the sheet pockets 10 in which the wafers are embedded are expanded in the lower plastic sheet 05 and the upper plastic sheet 03 , respectively, and the lower plastic sheet 05 is broken along the target breaking point 08 .

[0062] Pyrolysis gases of the upper plastic sheet 03 collect as a gas layer 11 (represented by the thick black line) at the boundary layer 09, which also separates the wafer 04 from the upper plastic sheet 03. Such a gas layer 11 is shown above the wafer 04, and also forms below it. After the target break point 08 breaks, the gas escapes from the lower gas layer.

[0063] As a result of the rupture of the lower plastic sheet 05 for each wafer 04, the pocket 10 opens and the wafer 04, separated from both plastic sheets 03, 05 under the action of the pressure of the pyrolysis gases, can then fall out of the open pocket 10. Due to the pressure, the wafer 04 breaks into pieces, often up to several square centimeters in size. The pieces are ejected from the pocket 10 upon opening of the flap. The silicon can then be easily separated from the other materials.

[0064] Once the edge region 07 of the wafer 04 has been cut all around, the area of ​​the lower plastic sheet 05 covering the wafer 04 can be completely separated from the rest of the module, exposing the wafer 04 for removal.

[0065] In summary, the method according to the invention offers, inter alia, the following advantages:

[0066] The method is suitable for extracting resources from various composite parts: due to the targeted break points the resources can be precisely removed from the composite parts, since the gases generated during the pyrolysis of the plastics aid the separation process.

[0067] A suitable radiation source is one or more gas discharge lamps, for example flash lamps, on the basis of the steep heating gradients that can be obtained and on the basis of the possibility to treat surfaces of a size of several square meters in less than one second.

[0068] The target break point can be selected such that after separation of the material composite, the individual material layers are not mixed as fragments with the removed resource.

[0069] The method can be carried out in one or multiple steps and is thus adaptable to a variety of composite parts.

[0070] Resource extraction is made more efficient in terms of energy consumption and resource yield and can in principle also be used in a continuous manner.

[0071] By means of the method, the pyrolysis gases that are generated are precisely guided away from the side of the composite material that faces away from the exposure source, thus avoiding any adverse effects or damage to the light source, which makes it possible, for example, to treat photovoltaic modules whose front glass panel has been broken, according to the method of patent application WO 2018 / 137735. [Explanation of symbols]

[0072] 00 Composite parts 01 Exposure 02 Permeable material layer 03 Upper plastic sheet 04 Absorbent material layer, wafer 05 Lower plastic sheet 06 Web 07 Edge Area 08 Target break point 09 Boundary layer 10 Seat Pocket 11 Gas Reservoir

Claims

1. A method for separating the resources of a composite part (00) having multiple layers of material by heating the layers using at least one external source of electromagnetic radiation, comprising the steps of: The composite part comprises a material layer (04) absorbing the energy of the radiation source and at least one plastic sheet, the plastic sheet being adjacent to the absorbing material layer (04) directly or indirectly via a thermally conductive layer, the layer sequence of the second option being also referred to herein as the absorbing layer sequence, the absorbing material layer (04) or the absorbing layer sequence being heated by a radiation source in an exposure area comprising at least a part of the surface of the composite part for less than 1 second, A method for separating, characterized in that at least one of the radiation sources is operated to heat the absorbent material layer (04) at least in the exposure area at the interface (09) of the at least one plastic sheet (03, 05) facing the absorbent material sheet (04) while generating gas and causing decomposition of chemical bonds of plastic, and prior to said heating, at least one targeted break point (08) is formed in the at least one plastic sheet (03, 05) such that the plastic sheet (03, 05) breaks at the targeted break point (08) under the pressure of the gas generated by the plastic sheet (03, 05).

2. 2. The method of claim 1, wherein the exposure of the absorbent material layer (04) is performed from the side of the composite part (00) facing away from the target breaking point (08).

3. 3. The method according to claim 1 or 2, characterized in that the composite part (00) comprises at least one layer (02) of material transparent to visible light having a transmittance of more than 40%, and the heating of the absorbent layer (04) of material is carried out through the at least one layer (02) of material transparent to visible light.

4. 4. The method according to claim 1, characterized in that the geometric shape of the target break point (08) and the distribution of the target break point (08) in the plastic sheet (03, 05) are performed in such a way that the plastic sheet (03, 05) remains as a continuous and open layer in the exposed area after the breakage of the target break point (08).

5. 5. The method of claim 4, wherein the photovoltaic module is processed and, as a result of the heating and the breaking of the targeted breaking points (08), the area across the busbars of the photovoltaic module remains as a continuous area.

6. 6. The method according to claim 1, wherein the composite part (00) comprises one plastic sheet (03, 05) on each side of the absorbent material layer (04), and the absorbent material layer (04) or the absorbent layer sequence is irradiated with a minimum amount of light such that each plastic sheet (03, 05) having the target breaking point (08) breaks at the target breaking point (08) and the absorbent material layer (04) or the absorbent layer sequence is at least partially peeled off from the second plastic sheet (03, 05).

7. The method of claim 3 in combination with claim 6, characterized in that in a first step, the absorbent material layer (04) is irradiated and heated for less than 1 second with a light dose that is less than the minimum light dose but causes breakage of the target break point (8), followed by a second heating of the absorbent material layer (04) for less than 1 second, whereby the absorbent material layer (04) is at least partially peeled off from the second plastic sheet.

8. 8. A method according to claim 7, characterized in that the second warming step is carried out for a time interval relative to the first warming step such that the temperature of the layer of absorbent material (04) is higher at the start of said warming step than at the start of the preceding warming step.

9. 9. A method according to claim 7 or 8, characterized in that the first warming step lasts longer than the second warming step and / or consists of one part or of several parts.

10. 10. Method according to any one of the preceding claims, characterized in that the targeted breaking point (8) is produced by mechanical means and / or by means of a laser.

11. 11. The method according to claim 1, wherein the absorbent material layer (04) is formed by a plurality of wafers and the exposure is performed in an exposure area having n wafers, n being a natural number greater than or equal to 1, or completely including the composite part.

12. 12. The method according to claim 1, wherein the radiation source is at least one gas discharge lamp or at least one laser.

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