|dc.description.abstract||Similar to the front-end development of semiconductors, the (back-end) manufacturing process of Wafer Level Chip Scale Packaging (WLCSP) uses a tremendous amount of volatile organic compounds (VOCs), which may potentially cause a higher health risk to the employees in clean rooms when VOC spreading-out incidents occur due to that the local exhaust ventilation capacity is insufficient or the person in charge of preventive maintenance is incompetent during the process. Surprisingly, while considerable work on the safety or hazard assessment of the semiconductor and liquid crystal panel production has been conducted, litte work has been undertaken analyzing these issues for the WLCSP industry, even though the gross of this industry is 220 billions a year. As such, the purpose of this research was to investigate the level and distribution of VOCs in the operating clean room of a WLCSP factory through sampling and analysis, and to ensure that the standards established by both of the Labor Safety and Health Law as well as SEMI S2 would be met. For this purpose, Photo-Ionization Detection (PID) and GC/MS were used to quantify the level of the total volatile organic compound (TVOC) and identify the VOC species.
Investigation results indicate that for the material safety data sheet (MSDS) of the raw materials, only 49.2% of the factories revealed more than 80% of the product composition in the MSDS, in accord with other investigations that 38% of the factories were reported to perform hazard analysis. Resuls also point out that IPA and acetone were identified as the major VOCs in the operating area, and of the 60 measurement locations in the regular area, only a few exceeded 7 ppm during the initial stage of the improvement, while the rest were well within the target of improvements. As for the areas having the TVOC odor issue, the yellow zone and the etching area on the 5th floor showed significant improvement, while the wet bench area on the 3rd floor only improved slightly. Further, the 3rd floor web bench area was dected the highest long temr monitoring values of TVOC, followed by the 3rd floor yellow zone, the 3rd floor etching area, and finally the bond zone of the 4th floor. In addition, according to the obtained GC/MS environmental measurement results, even though the levels of ethanol, acetone and IPA were all well below the legally allowed limits, they did not meet the standards established by the SEMI S2 Safety Guideline (i.e., 4 ppm for ethanol, 7.5 ppm for acetone, and 4 ppm for IPA): the ethanol level was 18.51 ppm for the Bonding Area on the 4th floor; the acetone level was 7.70 ppm for the Wet Bench Area on the 3rd floor and 67.06 ppm for Etching Area on the 5th floor; the IPA level was 4.29 ppm for the Wet Bench Area on the 3rd floor. Lastly, while verifying the effectiveness of the environmental measurement in the operating areas, 7 out of 9 areas across different floors showed significant improvements, and the other areas were kept stable.