Abstract: In a method for producing a front-side emitter electrode as front contact for a silicon solar cell on a silicon wafer, a depression is produced in the front side of said silicon wafer. A front-side n-doped silicon layer and an antireflection layer are then produced. A paste is then introduced into the depression, said paste containing electrically conductive metal particles and etching glass frit. Said paste, as a result of momentary heating, etches through the antireflection layer to the n-doped silicon layer making electrical contact with the latter. Afterwards, electrically conductive front contact metal is galvanically attached as front contact onto the heat-treated paste in the depression.

Abstract: When holes are being drilled in an electric circuit substrate, a laser beam is moved on concentric circular tracks in the region of the hole to be drilled. The transition from one circular track to the next takes place in each case on an arc that departs approximately tangentially from the circular track last traversed and nestles approximately tangentially against the circular track newly to be described in such a way that in each case the starting point of a new circular track is offset by a prescribed angle from the starting point of the preceding circular track.

Abstract: When holes are being drilled in an electric circuit substrate, a laser beam is moved on concentric circular tracks in the region of the hole to be drilled. The transition from one circular track to the next takes place in each case on an arc that departs approximately tangentially from the circular track last traversed and nestles approximately tangentially against the circular track newly to be described in such a way that in each case the starting point of a new circular track is offset by a prescribed angle from the starting point of the preceding circular track.