Method and device for separating different material layers of a composite component

Abstract

A method for separating different types of material layers of a composite component that has at least one material layer that is transparent for visible light and at least one further material layer, is provided, wherein the light from an external source falls through the at least one transparent material layer into the at least one further material layer and there is at least partially absorbed. With the help of at least one gas discharge lamp, the light-absorbing material layer is heated in less than one second to separate material layers of the composite component. A device that can be used for this method comprises at least one separation chamber and therein at least one gas discharge lamp suitable for irradiation.

Claims

1. A method for separating heterogeneous material layers of a composite component which comprises at least one material layer transparent to visible light, having a transparency of more than 40%, and at least one further material layer, wherein light from an external source falls through the at least one transparent material layer into the at least one further material layer and is at least partially absorbed, wherein the light from the external source is provided by at least one gas discharge lamp and is used to irradiate and heat the light-absorbing further material layer in an exposure field which encompasses at least a proportion of a surface of the composite component, in less than one second; wherein the radiation in the exposure field has a constant intensity at one moment of the exposure period; wherein heating of the light-absorbing further material layer causes separation of at least two material layers of the composite component from one another; and wherein the composite component is a photovoltaic module, a display or a concentrated solar power component.

2. The method as claimed in claim 1, wherein the at least one gas discharge lamp is constructed and operated in such a way that UV light emitted by the lamp falls through the transparent material layer and leads, in at least one stratum of the light-absorbing further material layer, to destruction of bonds and, thereby, to the separation of material layers in the composite system that border one another.

3. The method as claimed in claim 1, wherein the at least one gas discharge lamp is constructed and operated in such a way that visible light emitted by the lamp falls through the transparent material layer and leads to the heating of the light-absorbing further material layer and hence to the separation of material layers in the composite system that border one another.

4. The method as claimed in claim 1, wherein a further material layer is heated which borders the transparent material layer directly or with interposition of another further material layer.

5. The method as claimed in claim 1, wherein the light-absorbing material comprises silicon.

6. The method as claimed in claim 1, wherein the proportion of the irradiated surface of the composite component is at least 5% of the surface.

7. The method as claimed in claim 6, wherein the proportion of the irradiated surface of the composite component is at least 10% of the surface.

8. The method as claimed in claim 1, wherein for composite components of more than two material layers, two material layers of the composite component are separated from one another by a first exposure period at a first intensity, so that the composite component is broken down by the separation into two elements, and at least one element of the composite component is broken down further by at least one further exposure period and at least one further intensity into further elements.

9. The method as claimed in claim 8, wherein for a further breakdown of the composite component at least one of the parameters of exposure period and intensity is greater in comparison to preceding breakdowns.

10. The method as claimed in claim 9, where a first exposure is carried out without shadow mask and a further exposure with a shadow mask.

11. The method as claimed in claim 8, wherein in a first exposure, at least a part of the composite component is masked by a shadow mask and in a further exposure, without shadow mask, at least one of the parameters of exposure period and intensity is different in comparison to the first exposure with shadow mask.

12. The method as claimed in claim 11, wherein, in the first exposure, an edge encapsulation of a photovoltaic module or of a display is exposed.

13. The method as claimed in claim 1, wherein by at least one gas discharge lamp of a portable separating device, at least one material layer of a composite component is separated from the other material layers of the composite component at the location requiring the composite components, wherein the device for separating the material layers is at least partially disposed in at least one standardized freight container.

14. The method as claimed in claim 13, wherein the at least one material layer comprises a glass layer.

15. The method as claimed in claim 1 wherein a layer of a few micrometers in thickness along the interface between the transparent material layer and further material layer is heated from an initial temperature by at least hundreds of degrees Kelvin to a required temperature.

16. A method for separating heterogeneous material layers of a composite component which comprises at least one material layer transparent to visible light, having a transparency of more than 40%, and at least one further material layer; wherein light from an external source falls through the at least one transparent material layer into the at least one further material layer and is at least partially absorbed; wherein the light from the external source is provided by at least one gas discharge lamp and is used to irradiate and heat the light-absorbing further material layer in an exposure field which encompasses at least a proportion of a surface of the composite component, in less than one second; wherein the radiation in the exposure field has a constant intensity at one moment of the exposure period; wherein heating of the light-absorbing further material layer causes separation of at least two material layers of the composite component from one another; and wherein the at least one material layer and at least one further material layer include at least 3 layers being stacked as a laminate comprising a top layer, an intermediate layer, and a bottom layer wherein either the top or bottom layer is separated from the remaining 2 layers in a first exposure and the intermediate layer and remaining layer are separated from each other in a second exposure.

17. A method for separating heterogeneous material layers of a composite component which comprises at least one material layer transparent to visible light, having a transparency of more than 40%, and at least one further material layer; wherein light from an external source falls through the at least one transparent material layer into the at least one further material layer and is at least partially absorbed; wherein the light from the external source is provided by at least one gas discharge lamp and is used to irradiate and heat the light-absorbing further material layer in an exposure field which encompasses at least a proportion of a surface of the composite component, in less than one second; wherein the radiation in the exposure field has a constant intensity at one moment of the exposure period; wherein heating of the light-absorbing further material layer causes separation of at least two material layers of the composite component from one another; and wherein for a further breakdown of the composite component at least one of the parameters of exposure period and intensity is greater in comparison to preceding breakdowns.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURE

(1) FIG. 1 shows a portable device for carrying out the method of the invention, in plan view, and

(2) FIG. 2 shows a schematic representation of the implementation of the method of the invention within an electrode chamber.

DETAILED DESCRIPTION

(3) FIG. 1 shows in plan view an example of a portable device (100) which is sited in an ISO container (110), having a length of 40 feet. The device consists of different segments (121) to (126) with a footprint of around 2.0 m1.5 m for, respectively, at least one process step, and locks between the segments in order to prevent light, noise, gas or dust emerging from one segment during an exposure process.

(4) If the segments, as shown in the drawing, are arranged on the central longitudinal axis of the container, then each segment is readily accessible for maintenance or repair work even without being uninstalled from the container. In the description of the processes in the individual segments, the text below focuses on the breakdown of above-described CIGS thin-layer solar modules; there might be slight differences in some segments for other designs of composite components, referred to as module in the exemplary embodiment.

(5) In the first segment (121) there is a cassette 1 with modules stacked horizontally and therefore parallel to the floor area, this cassette being filled outside the container before the first process step, with the front glass side of the module on the top side in relation to the ceiling of the container. From this cassette 1, a module is conveyed via a transport system, as for example a conveyor belt, into the second segment (122), of the mask chamber, and, before a first exposure, in each case a lock between the first and second segment and also a lock between the second and third segment (123) are closed in order to prevent emergence of light, noise, gas or dust from the segment (122).

(6) A shadow mask is subsequently lowered onto the module in the segment (122), onto the front glass side, from above the module, and this mask shades off all of the regions of the module apart from the edge encapsulation during the first exposure, and the module is then exposed through the shadow mask by gas discharge lamps above the shadow mask. Following this first exposure, the lock between segment (122) and (123) is first opened, the module is thereafter transferred into the segment (123), of the separation chamber, the lock between segment (122) and (123) is closed again, and finally the module is exposed a second time, albeit now the entire top face of the front glass.

(7) Following the second exposure, the two glass sheets of the thin-layer module are no longer joined to one another. Using suction cups, for example, the front glass is now taken off from the underlying back glass and placed subsequently into the absorber chamber of the segment (124), the front glass still bearing the EVA foil and also the current-generating layer. The back glass, including the molybdenum layer which has remained thereon, in contrast, is transported on into the turning chamber of the segment (124). The absorber chamber and the turning chamber are arranged one above the other, for example, allowing the respective glass sheets to undergo further operations in mutually separate regions of the plants.

(8) Prior to a third exposure (exposure 3a) of the front glass in the absorber chamber, the lock between the absorber chamber of the segment (123) and the segment (124) is closed. In the turning chamber, conversely, the back glass is turned over, so that the molybdenum layer points downward. In the course of the exposure 3a, then, the current-generating layer is detached. After opening of the lock between segment (124) and segment (125), the front glass is first transported into the foil chamber, the locks are closed in a further step, and thereafter, by means of a fourth exposure (exposure 4a), the EVA layer is separated from the front glass. In the electrode chamber beneath, conversely, the molybdenum layer is now removed from the back glass by means of a third exposure (exposure 3b).

(9) The front glass and the back glass, finally, are sorted into different cassettes 2a and 2b in the segment (126), since these glasses typically have different thicknesses and material compositions. The front glass is generally a safety glass and has a higher transparency, owing to the smaller proportion of iron, in contrast to the back glass.

(10) FIG. 2 shows by way of example components of the chamber and the process carried out in the electrode chamber (200) of the segment (125) by means of the exposure 3a. The transport direction of the substrate or the longitudinal direction of the ISO container is perpendicular to the plane of the paper. This drawing shows a simplified cross section of the plant segment, with the gravitational force being directed downward in the plane of the paper.

(11) A field of cylindrical flash lamps (220) in the transport direction generates light (210) which falls through the back glass (230) and is absorbed by the molybdenum layer (240). An air flow 250a and also a further air flow 250b blow the detached molybdenum particles (not shown) along in a channel which is formed by a spacing between the back glass and the section of the plant wall (260). The particles subsequently fall through an opening (260a) into a collecting container (260b), in which a major part of the particles remains. The remaining fraction of the molybdenum particles is intercepted by a dust filter (260c)in particular, particles of very low weightbefore the air flow is passed into the open. For the design of the above-described channel, spacers (270) are used which are permeable to the air flow 250a and 250b, respectively, and which ensure uniform distribution of the air flow over the entire area (240).

LIST OF REFERENCE SYMBOLS

(12) 100: Portable device 110: Outline of ISO container 121: Cassette 1 122: Mask chamber 123: Separation chamber 124: Absorber chamber and turning chamber 125: Foil chamber and electrode chamber 126: Cassette 2a and cassette 2b 200: Cross section of electrode chamber in segment (125) 210: Light beams from gas discharge lamps 220: Field of cylindrical gas discharge lamps 230: Back glass 240: Molybdenum layer on back glass (230) 250a: Air flow 250b: Air flow 260: Section of plant wall 260a: Opening in plant wall 260b: Collecting container 260c: Dust filter 270: Spacer