May 2020
As the semiconductor industry is characterized by a number of liquid flow processes in which different abrasive, adherent, corrosive and ultra-pure liquids are applied, it is of utmost importance to keep these processes safe, stable, and of high quality. SEMIFLOW flow meters are specifically designed to meet the sector-specific demand of the semiconductor industry. The sensors are available globally throughout the SONOTEC distribution network.
SEMIFLOW flow sensors are industry-proven cutting-edge meters combining the need for a robust design with an innovative clamp-on design to eliminate any risks of contamination and leakages without the hassle of system downtimes. Due to their compact housing with onboard electronics and analysis unit, the flow meters are as small as a single transducer and can thus easily integrate into existing process chains and architectures. SEMIFLOW sensors are available in different sensor and channel sizes for a wide range of tube sizes. They are perfectly suited for PFA, PTFE and other hard plastic tubes and pipes.
Field-proven technology for use in complex semiconductor applications
Liquid flow measurement plays an important role in wafer manufacturing where several abrasive, adherent, and corrosive liquids are used in different wet processes. During a single wafer or batch cleaning process, for example, it is crucial to monitor the flow of the cleaning solution. In case it is under- or overdosed, the cleaning process must be repeated and additional resources are required. At worst, the wafers become defective and a huge loss in value is incurred. A precise flow measurement is therefore decisive for the efficient use of production resources. Beside their integration into wafer cleaning equipment, SEMIFLOW flow meters have also been successfully implemented into lithography and mixing equipment, chemical supply systems, and slurry lines.
SONOTEC has been conducting business activities in non-contact ultrasonic flow measurement devices for decades
The development of SEMIFLOW sensors benefits from decades of experience in designing non-contact ultrasonic flow sensors for highly sensitive applications in biopharma as well as for medical devices with strict safety regulations. Thus, certain sensor performance features such as high accuracy real-time instantaneous flow measurements of up to 400 L/min, the implementation of a volume-totalizer, a broad range of standard industrial interfaces, and the expertise in handling a wide range of tubing properties and geometries were successfully be adopted to the SEMIFLOW sensor series.
Physical principle utilized by ultrasonic SEMIFLOW flow meters
SEMIFLOW sensors are equipped with four ultrasonic transducers arranged in an X-pattern. Emitting pulsating ultrasonic waves in a given frequency from one side to the other, the transducers measure the time of flight of the ultrasonic wave with and against the flow direction of the liquid. The resulting time difference is directly proportional to the mean flow velocity. The flow volume results from the product of this mean flow velocity and the cross-sectional area of the tubing.
The transit-time method causes neither a pressure drop in the tube nor a risk of leakages. When appropriately calibrated, transit time can work on almost all liquids viscosity, density, color, and electromagnetic properties of fluids. Ions and particulate matter are not required to calculate the measurement.