Flow Analysis and Relative Humidity (RH) Measurement in the Horizontal Plane of a Front Opening Unified Pod (FOUP)

Moisture removal techniques such as purge have been developed for the front opening unified pod (FOUP) in the semiconductor industry. The FOUP purge can significantly increase the quality of integrated circuit (IC) products. An experimental model of a simulated clean room, was designed at Taipei Tech. A mini environment (ME) and a FOUP were installed inside the model. Smoke flow visualization technique was performed with the assistance of an innovative laser light sheet generation system. A homemade smoke generator simulates the moist air flow pattern into the FOUP. The FOUP top view flow pattern was recorded by a Hamamatsu digital camera. The particle image velocimetry (PIV) in the FOUP horizontal plane was analyzed. Moreover, the relative humidity (RH) was monitored inside the FOUP. The results show that a purge flow rate of 200 LPM is the optimum purge flow rate for moisture removal performance inside the FOUP. The findings of the present study could significantly increase the quality of chip products in semiconductor manufacturing, decreasing product defect rates and significantly reducing energy consumption.