• 반도체디스플레이기술학회지
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• 제7권3호
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• pp.29-34
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• 2008

This paper describes the fabrication and characterization of a differential pressure type integrated mass-flow controller made of stainless steel for reactive and corrosive gases. The fabricated mass-flow controller is composed of a normally closed valve and differential pressure sensor. A stacked solenoid actuator mounted on a base-block is utilized for precise and rapid control of gas flow. The differential pressure flow sensor consisting of four diaphragms can detect a flow rate by deflection of diaphragm. By a feedback control from the flow sensor to the valve actuator, it is possible to keep the flow rate constant. This device shows a fast response less than 0.3 sec. Also, this device shows accuracy less than 0.1% of full scale. It is confirmed that this device is not attacked by toxic gas, so the integrated mass-flow controller can be applied to advanced semiconductor processes which need fine mass-flow control corrosive gases with fast response.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.531-537
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• 2004

In this paper, the static and dynamic characteristics in the sensor tube of a mass flow controller(MFC) were studied by experiments. In the sensor tube of MFC. the difference of temperature between inlet and outlet was necessary for calculating the mass flow rate. Therefore, the relations among flow rate, heat generated by heating wire. and sensor location were investigated to find optimized condition. Finally, the relation between sensor voltage through analog digital conversion(ADC) and flow rate in the sensor tube can be represented. Based on this study, static and dynamic characteristics of sensor tube can be used for design of mass flow controller.

• 동력기계공학회지
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• 제7권3호
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• pp.35-39
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• 2003

In this paper, the heat transfer phenomena in the sensor tube of a mass flow controller(MFC) were studied by experiments. In the sensor tube of MFC, the difference of temperature between inlet and outlet was necessary for calculating the mass flow rate. Therefore, the relations of flow rate, generated heat by heating wire, sensor location and tube thickness were investigated to find the optimized condition. Based on this study, static and dynamic characteristics of sensor can be used for mass flow controller.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.55-58
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• 2008

The objective of the research is to design, manufacture and test a Mass Flow Controller(MFC) capable of measuring compressible fluid flows based on a "bucket and stop-watch"method. The basic principle is the measurement of time, where the time taken to fill and empty a bucket of known volume is measured. This method of flow measurement is a new concept when compared to a commercilized current mass flow controller. For the flow meter to be able to compete with established designs it not only must be comparable in cost and robustness, it must be very accurate and reliable as well. This device should be able to handle fluid flows in the range of 0.1ml/min to 10ml/min within an accuracy of ${\pm}$1%. A possible application for a device such as this is in electronics industry where arsenic gas is used in the production of silicon chips.

• 한국산학기술학회논문지
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• 제4권2호
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• pp.63-70
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• 2003

본 논문에서는 반도체 제조장비의 핵심 부품 중에 하나인 질량유량제어기(MFC, Mass Flow Controller)클 설계하고 구현하였다 Microchip社의 마이크로콘트롤러(Microcontroller) PIC 16F876을 사용하여 개발된 MFC는 여러가지 문제점을 가진 아날로그(Analog) 방식의 MFC와 고가의 DSP(Digital Signal Processor) 및 고분해능의 AD변환기(Analog to Digital Convertor)를 사용하는 디지털 MFC의 장점을 혼합한 하이브리드형(Hybrid-Type)이다. 본 논문에서 개발된 MFC는 크게 센서부(Sensor Unit), 제어부(Control Unit), 구동기부(Actuator Unit)로 구성되었으며, 성능향상을 위한 자동보정(Automatic Calibration) 알고리즘과 표준테이블(Reference Table) 방식을 사용하였다.

• 대한의용생체공학회:의공학회지
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• 제42권4호
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• pp.193-200
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• 2021

Flowmeter and oxygen sensors are listed in COVID-19 essential medical devices. This article reports a Teensy microcontroller-based Oxygen mass flow controller (MFC), core part of the oxygen respirator or extracorporeal membrane oxygenation (ECMO). The developed MFC consisting of the microcontroller, MEMS flow sensor, and solenoid valve was able to accurately control 0 to 100 sccm of oxygen flow rate. The pressure of vacuum chamber increased proportionally to the flow rate (0.998 of Pearson correlation coefficient). The experimental results proved that the developed MFC exhibits comparable performance to a commercial MFC in accuracy, settling time, linearity with pressure, and repeatability of oxygen mass flow control. It is expected that this simple and cheap MFC is utilized for oxygen therapy against the severe acute respiratory syndrome coronavirus 2.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.80-87
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• 2003

Air partial pressure ratio and inlet air mass flow are influenced by water vapor and gaseous fuel in mixture on Compressed Natural Gas (CNG) engines. In this paper, the effects of the water vapor and the gaseous fuel that change the air mass flow and the air-fuel ratio are studied. Effective air mass ratio is defined as the air mass flow divided by mixture mass flow, and also it is applied to the estimation of the inlet air mass flow and the air-fuel ratio. The presence of the gaseous fuel and the water vapor in the mixture reduces the air partial pressure and the effective air mass ratio of the CNG engines. The experimental results for the CNG engine show that estimation of the air-fuel ratio based upon the effective air mass ratio is more accurate than that of a normal mode.

• 동력기계공학회지
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• 제7권3호
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• pp.69-73
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• 2003

In this paper, the relation between displacement of piezoelectric disk and electric field was proposed. From Navier-Stokes equation and Reynold's equation, the relation between flow and gap of plate was determined. This models were further verified by experiments. Based on theoretical study and experimental verification, the proposed model between flow rate and voltage can be used in the design of mass flow controller in gas supplying system.

• 반도체디스플레이기술학회지
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• 제7권3호
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• pp.55-58
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• 2008

The objective of this research is to design, manufacture and test a mass flow controller capable of measuring compressible as well as incompressible fluid flows based on a 'bucket and stop-watch' method. The basic principle behind such a system is the measurement of time, where the time taken to fill and empty a bucket of known volume is measured. This device should be able to handle fluid flows in the range of 0.1 ml/min to 10 ml/min within an accuracy of ${\pm}$1%. For the flow meter to be able to compete with established designs, it must be not only comparable in cost and robustness, but also very accurate and reliable as well.

• 연구논문집
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• 통권22호
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• pp.85-96
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• 1992

A mass flow controller(MFC) is commonly used in the semiconductor industries to control the flow rate of various process gases. The measurement and precise control of the of flow rate the gas are the key for a succesful IC fabrication. To eventually design a reliable MFC, a pre-proto type MFC was built and its flow characteristics were investigated. Most of the functional components of the pre-proto type were built for the present study, but the remainder were adopted from a commercial unit. The flow control characteristics were compared with that of a standard MFC. Major dimensions of an MFC for 0-10 SLM capacity were suggested.