Using a Flow Sensor in a Semiconductor Manufacturing Application

This document is part of a comprehensive tutorial on industrial Digital I/O and Counter/Timer hardware. Learn about National Instruments product offerings for digital and timing I/O, the Industrial Feature Set including watchdog timers and isolation, complementary devices like relays, solenoids and encoders, concepts like sinking and sourcing, and see how these devices can be used in your industrial application.

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Using a Flow Sensor in a Semiconductor Manufacturing Application

Chemical delivery is the process of measuring and controlling the distribution of a given number of chemicals. This process is essential to the mixing of acids and bases in semiconductor manufacturing facilities. These systems must be able to accurately verify the amount of chemicals being delivered in order to successfully manufacture the delicate wafers and maintain a high yield.

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In most semiconductor systems, both acids and bases are required for proper fabrication of the silicon chip. Because of this, the systems are composed of a number of flow sensors, each of which takes independent measurements with their own ground reference. These systems are equipped with industrial strength sensors, such as the GF SIGNET 7002 Vortex Flow Sensors. The measurement from this flow sensor is provided by a frequency output with a peak-to-peak voltage of up to 24 VDC.

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The NI 6624 provides an ideal solution to measure and test such as system. With the +-48 V voltage input range, the NI 6624 module can easily acquire the 24V output of the GF SIGNET flow sensor while providing up to 400V transient overvoltage protection. Along with high voltage protection, channel-to-channel isolation allows each sensor to operate with their own ground reference and eliminate problems and incorrect readings that can result from ground loops. Manufacturing facilities tend to be very noisy environments, so the extra isolation protects the NI 6624 and the rest of the system from unexpected voltage spikes.

Using automatic code generation with NI-DAQmx, a system can quickly be configured to acquire the flow sensors’ outputs and engineers can easily develop an application to properly monitor the chemical delivery of the system. The following image shows an easy-to-use configuration window in NI-DAQmx that helps to quickly configure and develop code for the proper measurement.


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NI 6624

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