LCD Panel Alignment Marks Asymmetric Positioning
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Solution Overview
Problem
The existing photolithography process for LCD panels often results in rework and abandonment due to incorrect alignment of masks, leading to pattern shifts, as the previous design of linear symmetric alignment marks fails to differentiate between masks, causing the lithography system to align with the wrong mask.
Innovation Solution
The introduction of a photolithography process and mask design where alignment marks on the glass substrate have distinct position coordinates for each mask, arranged in a non-linear symmetric pattern, allowing the system to differentiate and prevent incorrect alignments by varying the distances and positions of alignment marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If linear symmetric alignment marks with same distances are used for all masks, then the alignment procedure can be completed, but the lithography system cannot differentiate between masks and may align with the wrong mask
Solution Approach 1:
The patent applies asymmetry by designing alignment marks with different distances from the LCD panel area for different masks. Specifically, the first alignment mark is positioned at a first distance from the LCD panel area, while the second alignment mark is positioned at a second distance that is different from the first distance. This asymmetric positioning enables the lithography system to differentiate between masks and prevent alignment with the wrong mask, while still allowing the alignment procedure to be completed.
2Device complexity
If the same alignment mark design is used for all masks, then the mask structure is simple, but the lithography system aligns with wrong masks causing pattern shifts
Solution Approach 1:
The patent applies local quality by making each alignment mark have a unique local characteristic - specifically, different distances from the LCD panel area. The first alignment mark has a first distance and the second alignment mark has a second distance, creating local differentiation. This allows the overall alignment mark structure to remain relatively simple while providing the necessary precision for accurate mask alignment and preventing pattern shifts.
3Ease of operation
If alignment marks are positioned symmetrically at equal distances, then the alignment process is straightforward, but incorrect mask alignment occurs leading to rework and abandonment of glass substrates
Solution Approach 1:
The patent resolves this contradiction by introducing asymmetric positioning of alignment marks. The first alignment mark is positioned at a first distance from the LCD panel area and the second alignment mark at a second distance, breaking the symmetric pattern. This maintains alignment process simplicity while enabling the lithography system to correctly identify and align with the appropriate mask, thereby preventing rework and abandonment of glass substrates and improving manufacture yield rate.
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 solution effectively prevents the rework and abandonment of glass substrates by ensuring accurate mask alignment, thereby improving the yield rate of LCD panel manufacturing.
Implementation Method 1
The light generated by the light source passes through the main optical system and reaches the mask and the glass substrate respectively. After reflection, the image of the alignment marks A, C on the mask and the image of the alignment mark B on the glass substrate passes through the objective lens and the alignment scope.
Implementation Method 2
performing photolithography to a glass substrate for manufacturing the plurality of LCD panels
Data Source
AI summary
Disclosed is an LCD panel photolithography process, employed in a lithography system for manufacturing a plurality of LCD panel, comprising steps of: performing photolithography to a glass substrate with a first mask, and the first mask comprises a plurality of sets of alignment marks corresponding to a plurality of following masks thereafter, and a plurality of sets of alignment marks corresponding to the plurality of following masks thereafter are formed on the glass substrate; and employing the plurality of sets of alignment marks on the glass substrate respectively, to perform alignment procedure and photolithography for the plurality of following masks with the plurality of sets of alignment marks on the glass substrate to form patterns; wherein corresponding to the same LCD panel area, the plurality of sets of alignment marks on the glass substrate have different position coordinates respectively.