Focus-less Inspection Apparatus for Semiconductor Tilt Measurement
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Solution Overview
Problem
Conventional methods for inspecting the tilt of semiconductor dies and surface angles are limited by the need for large spaces due to significant changes in reflection angles, leading to difficulties in miniaturizing inspection equipment and generating noise from diffraction patterns formed in air.
Innovation Solution
A focus-less inspection apparatus that uses a structured-light source to radiate structured lights with a specific phase range, adjusting optical paths with lenses, and capturing reflected lights with an image sensor to derive surface angles based on light quantity values, eliminating the need to measure changed imaging positions and reducing noise by not using diffraction patterns formed in air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional reflection angle measurement methods are used to measure tilt, then measurement precision is improved, but the equipment size increases significantly
Solution Approach 1:
The patent transitions from measuring tilt through spatial position changes (conventional method requiring large space) to measuring through optical phase changes in a different dimension. By projecting structured light patterns and analyzing phase shifts in the reflected light, the system achieves precise tilt measurement without requiring the large physical space needed for conventional reflection angle measurement methods.
Solution Approach 2:
The patent replaces the mechanical/optical measurement system that relies on physical position changes and reflection angle measurements with an optical phase measurement system. This substitution allows tilt detection through phase shifts of projected light patterns rather than through mechanical movement and position tracking, thereby reducing equipment size while maintaining precision.
2Measurement precision
If diffraction pattern methods are used to measure tilt angle, then measurement precision is improved, but noise is generated from patterns formed in air
Solution Approach 1:
The patent introduces a structured light projection system as an intermediary that eliminates the need for diffraction patterns to form in air. By directly projecting controlled light patterns (such as grid or stripe patterns) onto the object surface and capturing the reflected patterns, the system avoids the noise-generating diffraction process while still enabling precise tilt angle measurement through phase shift analysis of the projected patterns.
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 efficient measurement of tilt and surface angles without increasing equipment size and is robust against noise, allowing for precise inspection of semiconductor components.
Implementation Method 1
a structured-light source configured to radiate structured lights with a specific phase range
Implementation Method 2
at least one lens configured to adjust, for each of the plurality of structured lights, optical paths of light beams corresponding to phases of the phase range
Implementation Method 3
an image sensor configured to capture a plurality of reflected lights generated by each of the plurality of structured lights being reflected from the partial region
Data Source
AI summary
An inspection apparatus may include: a structured-light source configured to sequentially radiate a plurality of structured lights having one phase range; a lens configured to adjust, for each of the plurality of structured lights, optical paths of light beams corresponding to phases of the phase range such that a light beam corresponding to one phase of the phase range arrives at each point of a partial region on an object; an image sensor configured to capture a plurality of reflected lights generated by the structured lights being reflected from the partial region; and a processor configured to acquire a light quantity value of the reflected lights; and derive an angle of the surface by deriving phase values of the reflected lights based on the light quantity value for the reflected lights.