Method and apparatus for forming the separating lines of a photovoltaic module with series-connected cells

Abstract

For forming the separating lines, ( 5, 6, 7 ) which are produced in the functional layers ( 2, 3, 4 ) deposited on a transparent substrate ( 1 ) during manufacture of a photovoltaic module with series-connected cells (C 1 , C 2 , . . . ), there are used laser scanners ( 8 ) whose laser beam ( 14 ) produces in the field ( 17 ) scanned thereby a plurality of adjacent separating line sections ( 18 ) in the functional layer ( 2, 3, 4 ). The laser scanners ( 8 ) are then moved relative to the coated substrate ( 1 ) in the direction (Y) of the separating lines ( 5, 6, 7 ) by a distance corresponding at the most to the length (L) of the scanned field ( 17 ) to thereby form continuous separating lines ( 5, 6, 7 ) through mutually flush separating line sections ( 18 ).

1 . A method for forming separating lines during manufacture of a photovoltaic module with series-connected cells, whereby the separating lines are produced in the transparent front electrode layer, the semiconductor layer and/or the back electrode layer, which are deposited on a substrate as functional layers, with laser scanners, each with a rotatable mirror and laser beam during manufacture of a photovoltaic module with series-connected cells, the laser scanners producing adjacent separating line sections in adjacent fields in the functional layer or layers by deflection of the laser beam with the rotatable mirror, and the laser scanners and the coated substrate are moved relative to each other along the separating lines to be formed in order to produce further adjacent separating line sections in the functional layer or layers, so that continuous separating lines are formed from the separating line sections, characterized in that the laser beam, after producing a separating line section in the particular field, is so aligned with the mirror that it produces the next parallel separating line in the field, and a plurality of the laser scanners adjacent in the transverse direction (X) to the separating lines are used, whereby the width (B) of the field scanned by each laser scanner is dimensioned in the transverse direction (X) to the separating lines such that it is at the most one separating line spacing away from the field scanned by the adjacent laser scanner. 
     
     
         2 . The method according to  claim 1 , characterized in that the laser scanner, after scanning the particular field, is moved relative to the coated substrate in the direction (Y) of the separating lines by a distance corresponding at the most to the length (L) of the scanned field in the direction of the separating lines. 
     
     
         3 . The method according to  claim 1  characterized in that the at least one laser scanner is moved relative to the coated substrate in the transverse direction (X) transverse to the direction (Y) of the separating lines by a distance corresponding at the most to the width (B) of the scanned field until the coated substrate is provided with the adjacent separating line sections across its total width. 
     
     
         4 . The method according to  claim 2 , characterized in that the length (L) or width (B) of the field scanned by each laser scanner in the direction (Y) of the separating lines or transverse direction (X) is at least 100 mm. 
     
     
         5 . The method according to  claim 1 , characterized in that the laser beam scans the coated substrate at a speed of at least 1 m/s. 
     
     
         6 . An apparatus for carrying out the method according to  claim 1 , characterized in that the laser scanners each have at least one rotatable mirror for deflecting the laser beam, and there are provided a holder for the laser scanners disposed in the transverse direction (X) to the separating lines, a receiving means for the coated substrate, and a device for moving the holder and the receiving means relative to each other in the direction (Y) of the separating lines to be formed, further a drive for activating the at least one mirror of the laser scanners such that the laser beam produces in the field scanned thereby a plurality of adjacent separating line sections in the functional layer or layers, whereby the device for relative motion of the holder and the receiving means is drivable such that the laser scanners and the coated substrate are moved relative to each other by a distance corresponding at the most to the length (L) of the field in the direction (Y) of the separating lines in order to form continuous separating lines with the mutually flush separating line sections, and the fields scanned by two adjacent laser scanners are at the most one separating line spacing away from each other in the transverse direction (X). 
     
     
         7 . The apparatus according to  claim 6 , characterized in that the adjacent laser scanners are disposed on the holder so as to be offset in the direction (Y) of the separating lines such that a laser scanner offset in one direction is aligned in staggered relationship with two laser scanners offset in the opposite direction. 
     
     
         8 . The apparatus according to  claim 6 , characterized in that the holder is formed by a gantry movable in the direction (Y) of the separating lines. 
     
     
         9 . The apparatus according to  claim 6 , characterized in that the receiving means for the coated substrate is configured to be movable in the direction (Y) of the separating lines and optionally in the transverse direction (X). 
     
     
         10 . The apparatus according to  claim 6 , characterized in that a device is provided for splitting the laser beam of the laser source into partial beams, there being disposed in each partial beam at least one mirror of the laser scanner. 
     
     
         11 . The apparatus according to  claim 6 , characterized in that the drive of the at least one mirror is formed by a galvanometer drive. 
     
     
         12 . The apparatus according to  claim 6 , characterized in that the laser scanner has two rotatable mirrors disposed at an angle to each other via which the laser beam is reflected onto the coated substrate. 
     
     
         13 . The apparatus according to  claim 6 , characterized by a device for transporting the coated substrate received by the receiving means from a loading station on one side of the laser patterning apparatus, which constitutes the processing station of the machine, to an unloading station on the other side of the processing station. 
     
     
         14 . The apparatus according to  claim 13 , characterized in that a multi-axis robot is provided for loading the loading station with the coated substrate. 
     
     
         15 . The apparatus according to  claim 6 , characterized in that the receiving means has a fixing device for the coated substrate. 
     
     
         16 . The apparatus according to  claim 6 , characterized by a device for position detection and adjustment of the substrate received by the receiving means. 
     
     
         17 . The apparatus according to  claim 6 , characterized in that the laser of the laser scanner is formed by a neodymium-doped yttrium aluminum garnet laser or yttrium vanadate solid-state laser.