Effects-of pickup variations on chip placement in SMT by finite element modeling

SMT (Surface Mount Technology) is a key part in the semiconductor packaging industry. It is required that the components should be picked up, transferred and placed efficiently, stably and accurately. In this work, the impacts of pickup variation on the final chip placement deviation were studied by finite element simulation. The effects of different picking positions on the chip placement were investigated by changing the nozzle/chip contact position, including chip center, 0.5mm to the right of the chip center, and 0.5mm to the left of the chip center. Different accelerations (20m/s
²
, 23m/s
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, and 25m/s
²
) were also applied to the nozzle to reveal the influences of process parameters. When the chip pickup position was at the center of the chip and the acceleration was 20m/s
²
, the final chip offset displacement was 0.04353mm. The final chip offset displacement gradually increased with acceleration. The final offset displacement was 0.47498mm, and the final chip offset displacement from the center position increased gradually with the increase of nozzle acceleration when the chip pickup position was 0.5mm to the right of the chip center and the nozzle acceleration was 20m/s. The final offset displacement was 0.34438 mm, and the final chip offset displacement from the center position decreased gradually with the increase of nozzle acceleration When the pickup position was 0.5 mm to the left of the chip center and the nozzle acceleration was 25 m/s
²
. When the picking position is closer to the chip center and the picking speed is smaller, the chip placement deviation and the chip surface stress are smaller. This can provide important insights and guidelines for optimizations on process parameters in SMT.