Ultra thin die pickup: peel stage and pickup tool design comparison

Latest developments in thin die pickup from wafer tape are analyzed experimentally and theoretically: the layout of the rubber pickup tool and the design of the die ejector peel stage. A pickup tool layout with vacuum holes is compared to one with grooves. A peel stage design with straight edges is benchmarked against a design with structures. The experimental comparison is done by peeling analysis from the wafer tape backside, and by mass flow measurements during peeling. On theoretical side, peel and vacuum forces, die bending stress and peel front propagation are simulated in 2D and 3D. The analysis gives new insights into the impact of design details on the peel performance. As an outcome, it is recommended to apply pickup tools with grooves rather than holes, and structured stages rather than straight edge stages.