| abstract |
Custom laser pulse shapes are used to machine the workpieces. For example, laser dicing of semiconductor device wafers on a die adhesive film (DAF) may scribe device layers under the semiconductor substrate, dice the semiconductor substrate, and increase the die shear strength, Different custom laser pulse shapes may be used to cut the base DAF and / or post-process the upper die edges. Different mono-type laser pulse trains can be used for respective recipe steps or passes of the laser beam over the scribe line. In yet another embodiment, scribing the semiconductor device wafer comprises only a single pass of the laser beam along the scribe line using a mixed-type laser pulse train comprising at least two laser pulses that are different from each other. Also, or in other embodiments, one or more custom pulse shapes can be selected and immediately provided to the workpiece. The selection may be based on sensor feedback. |