Ultrasonic Probe Sensor Crosstalk Reduction
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Solution Overview
Problem
Conventional ultrasonic probes for measuring chemical reagent levels in semiconductor manufacturing face challenges in making reliable electrical connections for a higher number of sensors, leading to reduced accuracy and increased complexity due to space constraints and crosstalk issues.
Innovation Solution
The design incorporates a flexible connector, multi-conductor shielded cable, and sequential signal transmission to reduce interference, allowing for a greater number of ultrasonic sensors to be used within existing standardized container fittings, with a controller that transmits signals one sensor at a time to minimize crosstalk and enable closer sensor placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electrical connection methods are used for multiple ultrasonic sensors, then the number of sensors can be increased to improve measurement accuracy, but the probe size exceeds the capacity of standardized container fittings and crosstalk issues arise
Solution Approach 1:
Multiple electrical connections are merged into a single integrated circuit board that consolidates all sensor connections, power supply, and signal processing into one compact unit. This allows multiple ultrasonic sensors to be electrically connected without increasing the external dimensions of the probe, resolving the contradiction between measurement accuracy (requiring multiple sensors) and probe size (constrained by standardized fittings).
Solution Approach 2:
The electrical connections are transitioned from a three-dimensional spatial arrangement (multiple separate cables and connectors occupying volume) to a two-dimensional planar arrangement (integrated circuit board layout). This dimensional transformation allows multiple sensor connections to be made within a compact footprint that fits through standardized container fittings while maintaining all necessary electrical connections for multiple sensors.
2Measurement precision
If multiple ultrasonic sensors are operated simultaneously, then measurement coverage is improved, but crosstalk between sensors increases and reliability decreases
Solution Approach 1:
The controller operates ultrasonic sensors in a periodic, sequential manner rather than simultaneously. Each sensor is activated in turn at predetermined time intervals, allowing the system to collect measurements from multiple sensors over time while preventing crosstalk interference. This periodic operation maintains measurement accuracy through multiple data points while ensuring reliable operation by eliminating simultaneous interference.
Solution Approach 2:
The integrated circuit board is configured to pre-establish proper electrical isolation and shielding between sensor channels before sensors are activated. This preliminary arrangement of electrical connections, including ground planes and signal routing design, prevents crosstalk from occurring in the first place, allowing sensors to be operated with higher reliability even when activated in sequence.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the accuracy and reliability of chemical reagent level measurements by allowing more sensors to be used without increasing the probe's size, while maintaining a reliable and efficient electrical connection system.
Implementation Method 1
generate bursts of sound waves that pass through the conduit and echo back to the sensors
Implementation Method 2
sound waves that pass through the conduit and echo back to the sensors
Implementation Method 3
the speed with which the ultrasonic waves travel through the conduit and the intensity of the echoed ultrasonic wave will differ depending on whether that portion of the conduit contains chemical reagent or gas or vapor
Data Source
Figure 1A~1B
Figure 2A
Figure 2B
AI summary
An ultrasonic sensor probe (100) and controller (109). The controller (109) is operationally configured to determine and display wet and dry status of each of a plurality of ultrasonic sensors (156) positioned in the barrel (123) of the probe (100). The controller (109) may change the status of a sensor (156) from wet to dry or dry to wet if certain conditions are met, such as the sensor (156) consistently indicates the new status over multiple readings or over a predetermined period of time. The controller (109) preferably includes a two-wire output capable of producing a stepped analog or digital signal that indicates the fluid level in a container in which the probe (100) is positioned.