Patent DE-102009026064-A1 (DE)
Title: Method for exposing an electric contact covered by a layer consisting of plastic by a laser beam, comprises determining a layer of an electric contact by a sensor and removing the layer of plastic in a flat area
Inventor: HEINRICI AXEL
IPC: H01L31/18
Filed: 2009-06-29
Abstract: The method for exposing an electric contact covered by a layer (18, 20) consisting of plastic by a laser beam (16) or exposing cross connector (10) of a laminated solar cell module (12) to be connected in contact of a junction box, comprises determining a layer of an electric contact by a sensor and removing the layer of plastic in a flat area under consideration of the determined layer of electric contact corresponding to a pattern discarded in a control of a laser scanner (14). The projection of the flat area lies in the direction of the contact. The method for exposing an electric contact covered by a layer (18, 20) consisting of plastic by a laser beam (16) or exposing cross connector (10) of a laminated solar cell module (12) to be connected in contact of a junction box, comprises determining a layer of an electric contact by a sensor and removing the layer of plastic in a flat area under consideration of the determined layer of electric contact corresponding to a pattern discarded in a control of a laser scanner (14). The projection of the flat area lies in the direction of the contact. A two-axial scan system with plane field optic or a three-axial scan system with fixed focal length or carbon dioxide laser system is used as laser scanner. A pulsed laser system is used, whose pulse frequency is = 10 kHz. The laser beam used for wearing out is moved with a speed of 3300-3700 mm/sec over the ablated area for wearing out the plastic layer, where the laser beam is moved over the wear out area for wearing out the plastic layer in two or three times or meander- or zigzag shaped manner. The laser beam is moved along lines running parallel to each other over the support area, where an interval between the lines is 0.1-0.2 mm. The laser system is operated in edge area of the support surface in such a way that the pulse-width is 10-400 mu s. The laser is operated in such a way that the ablation rate is 100-200 mm 2>/s in a layer thickness of 0.5-1.0 mm. The laser beam is focused in point-shaped manner on the ablation area with a diameter of 0.4-0.8 mm. The laser system is operated with a power of 200-400 Watt. An optical sensor with image processing is used as sensor. The optical sensor is positioned related to the laser scanner on opposite side of an electric contact. The layer of the electric contact is optically determined in through-beam method. The electric contact is formed in stripe-forming manner that is sealed in its edge area limiting the exposed area through materials of plastic layer melted by the laser beam. The cross connector is covered by a transparent plastic layer made of ethylene vinyl acetate or silicon rubber and/or a plastic film that consists of polyvinyl fluoride. The contact of the junction box is applied after exposing the cross connector of the solar module cell by a handling device on the exposing area of the cross connector and is connected with the exposing area in power- and/or material-fit manner. The exposing area is connected with the contacts by soldering such as laser soldering in material-fit manner. The exposing area is connected with the contacts or the junction box with the solar module by silicone or adhesive band. The position of the solar cell module is detected with the exposing area by image processing and the data of a control of the handling device is transmitted for aligning the contacts on the exposing area.