Abstract
Although the semiconductor industry has expanded rapidly in recent years, especially in Taiwan this industry has entered 12-inch wafer era, the risk of muscloskeletal injuries has increased as well. For 8-inch wafer, this study was designed to evaluate the MAWL for 12 hours dynamically wafer-handling task in different combinations of climbing stairs, pod (8-inch wafer container) type, carrying distance and gender, to evaluate the safety of the maximal handling weight in the fab, and to evaluate the two pods’ handle design. For 12-inch wafer, this study focused on evaluating the MAWL for 12 hours dynamically wafer-handling task in the combinations of handling frequency and handling height, and setting the cart height for carrying FOUP, 12-inch wafer container. A psychophysical approach was employed. The operator's heart rate, oxygen consumption, wrist posture, and ratings of perceived exertion were measured in each experiment session. Three experiments were designed and executed for this study. Pod type and carrying distance were investigated in the first experiment (Experiment I) and the second experiment (Experiment II) focused on climbing stairs and pod type. For evaluating the effect of handling frequency and handling height on the ability of 12-inch dynamically wafer-handling task, two factors were assigned to third experiment (Experiment III).For the first experiment, a total of six sessions (3 pod type ’ 2 carrying distance) were conducted by each of the 16 subjects. The results of the first experiment indicate that pod type had significant effect on MAWL and wrist posture, but not on heart rate, wrist RPE and whole body RPE. Applying the new pod induced the lowest ulnar deviation, the highest radial deviation and the greatest MAWL.For the second experiment, a total of six sessions (3 climbing stairs ’ 2 pod types) were conducted by each of the 12 subjects (6 males and 6 females). The results of the second experiment indicate that climbing stairs had significant influence on MAWL and VO2. The MAWL declined with the increased number of climbing stairs. Conversely, the VO2 increased with the increased number of climbing stairs. The pod type effect on wrist posture was significant. The gender differences on MAWL, VO2 and wrist posture were also significant.For third experiment, a total of six sessions (3 handling heights ’ 2 handling frequencies) were conducted by each of the 24 female subjects. The results of the third experiment indicate that handling frequency and handling height had significant influence on MAWL and HR. The smallest MAWL and HR appeared at 90/125. There is no significant difference in MAWL between 90/90 and 90/35. Handling height effect on wrist posture was significant, but no handling frequency effect on wrist posture. The findings of this study can provide useful information for the designs of handles of pod and wafer handling jobs and cart height.