Substrate Edge Position Correction for Warpage-Aware Alignment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing aligners face challenges in accurately adjusting the center position and angle of substrates with warpage due to variations in optical magnification caused by warpage, leading to decreased calculation accuracy.

Innovation Solution

A method involving measuring edge positions along the substrate's periphery, calculating optical magnification ratios, and correcting positional data to account for warpage, allowing for accurate center position and angle adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed-focus camera is used to image the substrate edge, then the device structure is simplified, but measurement precision decreases when the substrate has warpage

Engineering Contradiction:

Improvedevice structureVSAvoidedge position measurement precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the optical parameter (focusing state) dynamically by switching between in-focus and out-of-focus states to detect different features (edge position and warpage), thereby resolving the contradiction between device simplicity and measurement precision

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses periodic focusing actions, alternating between in-focus and out-of-focus imaging modes, to sequentially obtain different measurement data (edge position and warpage state) that are then synthesized for accurate positioning

Inventive Principle:

Principle #19Periodic action

2Measurement precision

If the stage is moved up and down to correct substrate height, then the substrate edge can be brought into focus, but the accuracy of center position and angle adjustment decreases

Engineering Contradiction:

Improvesubstrate edge focus accuracyVSAvoidcenter position and angle adjustment accuracy

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent introduces an intermediary computational process that uses out-of-focus imaging data to calculate warpage compensation amounts, which are then applied to correct the positioning data, thereby maintaining both focus accuracy and positioning precision without physical stage adjustment

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical stage height adjustment mechanism with a computational correction approach, using optical imaging data and algorithms to compensate for warpage effects, thereby eliminating the trade-off between focusing and positioning accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If curve fitting with spline curve is used to estimate warpage, then the processing is simplified, but the accuracy of grasping warpage state along the entire periphery decreases

Engineering Contradiction:

Improveprocessing simplicityVSAvoidwarpage state detection accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent segments the warpage measurement into discrete points around the substrate periphery, measuring warpage at multiple specific locations and using this distributed data to accurately represent the overall warpage state, thereby improving precision while maintaining reasonable processing complexity

Inventive Principle:

Principle #1Segmentation

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 precise center position and angle adjustments for substrates with warpage by compensating for optical magnification variations, enhancing alignment accuracy.

Implementation Method 1

a device including a camera that images a part of a periphery of a substrate is proposed

Methodology Applied

Scientific EffectOptical imaging: Photography

Implementation Method 2

detects a position where the luminance distribution in the taken image exhibits a significant change rate as a position of the edge of the substrate

Methodology Applied

Scientific EffectLuminance distribution detection: Photoelectric Effect

Data Source

PatentUS12487082B2Method for positioning substrate

Publication Date: 2025.12.02 JEL

AI summary

A method for adjusting a position of a substrate, includes: acquiring primary positional data indicating the positions of the edge portions (S31); acquiring secondary positional data indicating the positions of the edge portions after a stage has been moved (S33); calculating, using the primary positional data and the secondary positional data, difference amounts between the positions of the edge portions before the stage has been moved and the positions of the edge portions after the stage has been moved; and calculating an optical magnification ratio of each of the edge portions from each of the difference amounts and an amount of movement of the stage and correcting each of the positions of the edge portions of the primary positional data based on the calculated optical magnification ratio of each of the edge portions, thereby acquiring corrected positional data (S34).