Influence of Elevator Moving Pattern on the Contaminant Exclusion for an LCD Panel Delivery Facility

Abstract

Because of the increasing panel size, the difficulty on delivering the glass substrate has been enhanced dramatically and become a critical problem in the LCD manufacturing industry. Nowadays, most of panel fabrication factory utilize the fully-automated delivering technology instead of the traditional labor delivery for diminishing the possibility of polluted particles on the LCD board. Thus, this study investigates the flow patterns on maintaining the air quality inside the delivering facility with a moving elevator. Also, influence on the moving pattern of the elevator via numerical technique is the focus of this investigation. Firstly, CFD code Fluent is used to execute the CFD simulation and evaluate the flow patterns inside this delivery equipment. It is found that the inferior air is generated mainly by the increasing vortex inside the delivery equipment for an upward-moving elevator. On the contrary, the flow field becomes very smooth without obvious vortex phenomenon, and thus induces a better air quality when the elevator moves downward. However, a better uniform flow field occurred when the elevator is moving upward. In addition, the airflow uniformity is not effectively improved by reducing the elevator velocity and increasing the FFU airflow velocity. It is not evident for improving the pollute exclusion by reducing elevator moving velocity which slows down the transporting efficiency, so it is suggested that the moving speed of elevator should maintain at 0.16m/s. On another way, it is useful to enhance the capability of pollute exclusion by increasing the FFU’s air velocity, thus it is proposed to raise FFU velocity to 0.71m/s. Consequently, it is concluded that the moving pattern of elevator has an essential impact and can be utilized to improve the air quality inside the LCD delivery facility.

Numerical Study on an Airflow Field of a Reticle Stocker with a Moving Crane in a Mini-Environment

“…In this studied case, we chose a crane that moved vertically from bottom side to top side (Y = 0.84 to 2.1 m). This is mainly based on the results appearing in the literature [11], which reported that the inferior air is generated by the increasing vortex (where particles are easily trapped [10]) in the stocker for an upward-moving crane; by contrast, the flow field becomes smoothly without obvious vortex generation for a downward-moving crane, indicating a better air quality. Therefore, a crane that moves vertically from bottom side to top side should be the most critical condition for the movement of contaminant particles.…”