Optical System for High-Resolution UV-C Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical inspection devices for semiconductor manufacturing face challenges in achieving high-resolution defect inspection without disrupting production speed, due to limitations in UV-C wavelength band absorption, chromatic aberration, and increased complexity with multiple lenses, which slows down inspection speed and increases manufacturing costs.
Innovation Solution
An optical system that focuses inspection and monitoring light on different locations using a dioptric group and reflection dioptric group, with specific lens configurations and materials to correct chromatic aberration, allowing both lights to converge to the same point without requiring extensive lens assemblies, thus maintaining high resolution and rapid inspection capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If UV-C wavelength band light is used for optical inspection, then inspection resolution is improved, but the number of usable optical elements is reduced due to light absorption
Solution Approach 1:
The patent changes the wavelength parameter of the inspection light from visible/UV-A to UV-C band, which provides better resolution but is strongly absorbed by most optical materials. This parameter change fundamentally alters which optical elements can be used, requiring a redesign of the optical path to use only UV-C transparent materials.
2Manufacturing precision
If multiple lenses are used to correct chromatic aberration in UV-C optical systems, then imaging quality is improved, but assembly difficulty and manufacturing cost increase exponentially
Solution Approach 1:
The patent extracts the chromatic aberration correction function from a complex multi-lens system and implements it through a simplified design using only two lenses (first and second lenses) with specific optical characteristics. This reduces the system from potentially many lenses to just two, dramatically reducing assembly difficulty while maintaining imaging quality.
Solution Approach 2:
The patent employs composite optical design where the first and second lenses have different optical characteristics (different refractive indices, aberration coefficients) that work together to correct chromatic aberration. This composite approach allows two lenses to achieve what would require many more lenses in a traditional system.
3Measurement precision
If autofocus is implemented to maintain high resolution inspection, then inspection accuracy is improved, but production speed is reduced due to additional focusing time
Solution Approach 1:
The patent performs preliminary focus adjustment by pre-positioning the optical system at the optimal focal plane before inspection begins. The optical system is designed with a fixed focal length that is pre-optimized for the inspection target, eliminating the need for real-time autofocus adjustments during high-speed inspection and maintaining both accuracy and speed.
4Device complexity
If monitoring light and inspection light follow the same optical path, then system simplicity is improved, but chromatic aberration causes different focal locations
Solution Approach 1:
The patent applies different optical characteristics to different parts of the optical system: the first lens is optimized for monitoring light (longer wavelength) while the second lens is optimized for inspection light (UV-C wavelength). This local optimization allows each lens to be designed for its specific wavelength, enabling both light types to focus at the same location despite chromatic aberration.
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 rapid and accurate high-resolution defect inspection of electronic parts by focusing inspection light and monitoring light on the same point, reducing chromatic aberration and maintaining production speed, while minimizing the complexity and cost of the optical system.
Implementation Method 1
a dioptric group configured to receive inspection light and monitoring light and to primarily focus the inspection light and the monitoring light on different locations
Implementation Method 2
a reflection dioptric group configured to reflect and refract the inspection light and the monitoring light that have passed through the dioptric group and to bring the inspection light and the monitoring light into one focus
Implementation Method 3
a reflection dioptric group configured to reflect and refract the inspection light and the monitoring light
Data Source
AI summary
Disclosed is an optical system for imaging, which enables high resolution. An optical system for imaging, which focuses inspection light and monitoring light on an inspection target, includes a dioptric group configured to receive inspection light and monitoring light and to primarily focus the inspection light and the monitoring light on different locations, and a reflection dioptric group configured to reflect and refract the inspection light and the monitoring light that have passed through the dioptric group and to bring the inspection light and the monitoring light into one focus.