- Thesis topic: Study of Volatile Organic Compound Emission in Semiconductor and Optoelectronic Industries

- Doi: https://doi.org/10.6840/cycu202201214

- Abstract: 

       The semiconductor and optoelectronics industry is one of the most important industries in our country. According to the statistics of the Environmental Protection Agency, the total of VOCs emission load in the semiconductor industry and optoelectronics industry in 2019 was 33670.62 tons and 27651.71 tons, respectively. Therefore, this study analyzes the periodic inspection reports of volatile organic compounds in the semiconductor and optoelectronic industries and uses the inspection data and approval data to comprehensively integrate the emission concentration, emission volume and control equipment of volatile organic compounds to calculate their emission coefficients.
        The research results show that the emission concentration of volatile organic compounds in the semiconductor industry ranges from 1 to 147 ppm, and about 91.7% of the emission concentrations are lower than 22 ppm, and processes with a concentration of more than 22 ppm are in the diode process and the integrated circuit manufacturing process; in the optoelectronic industry, the emission concentration of volatile organic compounds ranges from 1 to 18 ppm, and the process with more than 10 ppm is the manufacturing process of other optoelectronic materials and components. The research uses the concentration and exhaust volume of the test report to calculate the emissions.
The results show that the emission range of volatile organic compounds in the semiconductor industry is 0.0010 ~ 2.7189kg/hr, and 97.7% of the emissions are in compliance with the regulations of 0.6kg/hr, and more than 0.6kg/hr processes are also in the diode process and the integrated circuit manufacturing process; the emission range of volatile organic compounds in the optoelectronics industry is 0.0005 ~ 0.9628kg/hr, 99.2% is 0.4kg/hr in compliance with the regulations; only one (other optoelectronic materials and components manufacturing process) is more than 0.4kg/hr. In the semiconductor and optoelectronic industries, common control equipment includes scrubbers, adsorption equipment, zeolite concentration wheels, incineration equipment, etc. About 30% of the semiconductor industry uses zeolite concentration wheels, 27% uses scrubbers, and 16% uses adsorption equipment.In the optoelectronics industry, 61% of the control equipment uses scrubbers, and about 3 ~ 7% separately uses adsorption equipment, zeolite concentration wheels, incineration equipment, and other control equipment.
        The emissions and concentrations of the control equipment in the semiconductor industry are highly correlated, and the correlation between the dry-based exhaust gas and the emissions is weak or there is no correlation. The following are the results: The correlation coefficient between the emission concentration and the emission amount of the scrubber is 0.9616, the correlation coefficient between the emission concentration and the emission amount of the adsorption equipment is 0.8809, the correlation coefficient between the emission concentration and the emission amount of the zeolite rotor concentrator wheel is 0.4906, and the zeolite concentration is 0.4906. The correlation coefficient between the emission concentration and the emission amount of the concentration runner + incineration equipment is 0.8457.The correlation coefficient between the emission concentration and the emission amount of the photoelectric industry scrubber is 0.6618; the correlation coefficient between the emission concentration and the emission amount of the adsorption equipment is 0.7797; the correlation coefficient between the emission concentration and the emission amount of the zeolite concentration runner is 0.4459; and the zeolite rotor concentrator wheel is 0.4459. The correlation coefficient between the emission concentration and the emission amount of the incineration equipment is 0.8175.
        In the calculation of the emission factor, the result of the emission factor of the semiconductor diode process is 23.106kg/m2, which is the average result of two data from one manufacturer, but one of the two data is 8.8988kg/m2, which is 10.2kg/m2 lower than the regulation; the other data is 37.3135kg/m2; the main reason for the larger than the standard is the exhaust volume; the result of the emission coefficient of the integrated circuit process is 2.324kg/m2, which is slightly higher than the legal value of 2.24kg/m2; the result of the industry's liquid crystal display process emission factor is 0.0003 kg/m2, which is lower than the regulatory standard of 0.18 kg/m2, the above results show that there is still a place for improvement process operation and control equipment manipulation in further.

Keywords: Volatile Organic Compounds (VOCs), Semiconductor, Optoelectronic, Emission Factor