[ Technical Papers ]

Journal of the Korean Society of Manufacturing Technology Engineers - Vol. 28, No. 5, pp.306-312

ISSN: 2508-5107 (Online)

Print publication date 15 Oct 2019

Received 24 Sep 2019 Revised 09 Oct 2019 Accepted 14 Oct 2019

DOI: https://doi.org/10.7735/ksmte.2019.28.5.306

반도체 제조 공정용 초음파 유량계의 파형 A/D 변환을 이용한 약액 온도 변화 오차 개선

배일진^a^{, *}

Improvement of Measurement Error by Chemical Solution Temperature Change Using Waveform A/D Conversion of Ultrasonic Flow-Meter for Semiconductor Manufacturing Process

Il Jin Bae^a^{, *}

aDepartment of Semiconductor Equipment Engineering, Far East University, 76-32, Daehak-gil, Gamgok-myeon, Eumseong-gun, Chungbuk-do, 27601, Korea

Correspondence to: ^*Tel.: +82-43-880-3233 Fax: +82-43-879-3727 E-mail address: baeiljin@gmail.com (IlJin Bae).

Abstract

In this research, we studied a method of improving measurement errors due to the temperature change of ultrasonic flow-meter chemicals of the time difference method for semiconductor manufacturing processes. The temperature change of these chemicals causes changes in the ultrasonic sound speed and time difference measurement cycle of ultrasonic waves: these changes affect the flow rate value offset and, generate measurement errors. We analyzed the A / D converted waveform of the ultrasonic sound velocity change, identified its waveform, and improved it through automatic compensation. The A / D converted waveform datum gradually increase and decrease in the resonance and free vibration section. By Using the amplitude ratios of these vibrations, we improved the measurement cycle of sound waves to always measure the same period despite changes in sound velocity. Utilizing this improved compensation function we confirmed the improvement of the measuring performance up to 5% compared to the conventional method.

Keywords:

Chemical, Semiconductor, Transit-type ultrasonic flowmeter, Measurement error, Waveform, A/D conversion

References

KAIST, 1988, Report for Developing of a Ultrasonic Flow Meter, KAIST Report, Daejeon, Korea, 13:19 42-54.
Central Institute of DaeSung, 1995, Technical Development for Application of Ultrasonic Flow Meter, Report, Seoul, Korea.
Nykolai B., George S.,1993, Speed of sound in pure water as a function of temperature, Acoustical Society of America, 93:3 1609-1612. [https://doi.org/10.1121/1.406819]
Vatansever, D., Siores, E., Shah, T., 2012, Shah Alternative Resources for Renewable Energy: Piezoelectric and Photovoltaic Smart Structures, Global Warming-Impacts and Future Perspective, 263:1 266. [https://doi.org/10.5772/50570]
Xiaotang, G., Frederic, C., 2019, The Effect of Internal Pipe Wall Roughness on the Accuracy of Clamp-on Ultrasonic Flowmeters, IEEE Transactions on Instrumentation and Measurement, 68:1 65-72. [https://doi.org/10.1109/TIM.2018.2834118]
Calzolai, M., Capineri, L., Fort, A., Masotti, L., Rocchi, S., et al., 1999, A 3-D PW Ultrasonic Doppler Flowmeter: Theory and Experimental Characterization, IEEE Transaction on Ultrasonics, Ferroelelectrics, and Frequency Control, 46:1 108-113. [https://doi.org/10.1109/58.741518]
Ahn, Y. K., 2009, Technical Trends of Ultrasonic Flowmeters, Korean Society for Noise and Vibration Engineering, 19:5 11-18.
Lee, C. H., Lee, K. J., Hong, Y. S., 2015, A Design and Implementation of an Ultrasonic Water Meter Using Differential Time-of-Flight Flow Measurement Method, Journal of Korean Institute of Information Technology, 13:4 17-26. [https://doi.org/10.14801/jkiit.2015.13.4.17]