Reflectivity Measurement Correction for Membrane Thickness
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Solution Overview
Problem
Existing membrane thickness measurement methods face challenges in accurately measuring membrane thickness due to fluctuations in light source intensity and environmental changes, which affect the calculation of reflectivity and membrane thickness.
Innovation Solution
A reflectivity measuring device and method that includes a measurement light source, spectroscopic detection unit, and coefficient recording unit to detect and correct for fluctuations in light intensity, allowing for accurate calculation of reflectivity and membrane thickness by using a conversion coefficient based on reference measurement object data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the each wavelength's intensity of reflected light from a reference measurement object is acquired at factory shipment and recorded, then the device complexity is reduced, but the measurement precision deteriorates due to light source fluctuations
Solution Approach 1:
The patent applies preliminary action by acquiring the spectrum waveform of the reference measurement object at factory shipment and storing it as reference data before actual measurements. This preliminary reference data is then used to correct measurements taken at different times, eliminating the need for repeated reference measurements while maintaining precision despite light source fluctuations.
Solution Approach 2:
The patent implements feedback by using the stored reference spectrum waveform to correct measurements of measurement objects. The system continuously compares measurement data against the reference data and applies correction factors, creating a feedback loop that compensates for light source intensity changes and environmental variations without requiring manual recalibration.
2Measurement precision
If the each wavelength's intensity of reflected light from a reference measurement object is re-acquired frequently, then the measurement precision is improved, but the productivity deteriorates
Solution Approach 1:
The patent performs the reference measurement action in advance at factory shipment, storing the results for future use. This eliminates the need for repeated reference measurements during production, maintaining measurement precision through the stored reference data while significantly improving productivity by removing time-consuming recalibration steps.
Solution Approach 2:
The system uses the pre-acquired reference data to self-correct measurements automatically. The stored reference spectrum waveform serves as a permanent correction standard that the system applies autonomously to all subsequent measurements, eliminating the need for external recalibration operations and maintaining both precision and productivity.
3Productivity
If the recorded each wavelength's intensity of reflected light from a reference measurement object is used, then the productivity is improved, but the measurement precision deteriorates due to light source fluctuations
Solution Approach 1:
The patent implements a feedback mechanism where the stored reference spectrum waveform is continuously used to correct measurements. By comparing measurement object data against the reference data and applying correction factors, the system maintains measurement precision despite using the same recorded reference data for multiple measurements, while preserving the productivity benefits of not needing frequent recalibration.
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
Enables accurate measurement of membrane thickness despite fluctuations in light source intensity, reducing variability and improving measurement efficiency by canceling out light source fluctuations without requiring frequent recalibration with a reference object.
Implementation Method 1
detects reflected light from the measurement object
Implementation Method 2
This utilizes interference due to light reflected on a front surface and a back surface of a thin membrane
Implementation Method 3
When the interference light is dispersed into multi-wavelength, there is a change in each wavelength's intensity
Data Source
AI summary
A reflectivity measuring device 1 includes a measurement light source 30 that supplies irradiation light L1 to a measurement object, a spectroscopic detection unit 80 that detects, at multi-wavelength, intensity of the irradiation light L1 and intensity of reflected light L2 from the measurement object, a coefficient recording unit 92 that records a conversion coefficient K(λ) for converting a detected value of each wavelength's intensity of the irradiation light L1 into a value corresponding to a detected value of each wavelength's intensity of reflected light L2 from a reference measurement object, and a reflectivity calculation unit 93 that calculates each wavelength's reflectivity based on the value corresponding to the each wavelength's intensity of the reflected light L2 from the reference measurement object obtained from the detected value of the each wavelength's intensity of the irradiation light L1 and the conversion coefficient K(λ).