Display Inspection Patterns for Large Panel Alignment

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Solution Overview

Problem

The division exposure method in display device manufacturing faces challenges in accurately measuring misalignment and stitch defects at shot boundaries, particularly as the size of display panels increases, limiting the effectiveness of existing inspection techniques.

Innovation Solution

A display device with an inspection pattern comprising color filters and reference patterns disposed at different heights and intervals, allowing for the measurement of overlay deviations and line width deviations at shot boundaries, facilitating the correction of misalignment and prevention of stitch defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a division exposure method is used to manufacture large-sized display panels, then the manufacturing capability for large panels is improved, but the measurement precision of misalignment and stitch defects at shot boundaries deteriorates

Engineering Contradiction:

Improvedisplay panel sizeVSAvoidmisalignment measurement precision

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The display panel is divided into multiple shot regions, and inspection patterns are specifically placed at the boundary parts between shots. This segmentation allows for targeted measurement of misalignment at critical interfaces while maintaining overall large panel manufacturing capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Reference patterns are introduced as intermediary elements between adjacent color filters at shot boundaries. These reference patterns serve as mediators for precise measurement of overlay deviations and line width deviations, enabling accurate misalignment detection without compromising the division exposure manufacturing process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If inspection patterns are added to measure misalignment at shot boundaries, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:

Improvemisalignment measurement precisionVSAvoidinspection pattern structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The inspection pattern structure is optimized by placing reference patterns only at critical shot boundary regions rather than uniformly across the entire panel. The reference patterns are positioned specifically between adjacent color filters where misalignment measurement is most needed, reducing overall device complexity while maintaining measurement precision.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The inspection patterns including reference patterns are pre-formed during the manufacturing process before final inspection. This preliminary action integrates the measurement functionality into the manufacturing flow, avoiding the need for complex post-manufacturing inspection equipment.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If reference patterns are disposed between adjacent color filters, then the measurement capability for overlay deviations is improved, but the manufacturing precision may deteriorate due to additional process steps

Engineering Contradiction:

Improveoverlay deviation measurementVSAvoidpattern formation precision

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The reference patterns and color filters are formed in an integrated manner during the same photolithography process. The inspection pattern is configured to include both reference patterns and color filters that can be manufactured simultaneously, merging the measurement function with the display structure fabrication to avoid additional process steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The reference patterns serve multiple functions: they act as measurement references for overlay deviation detection, serve as structural elements in the inspection pattern, and can be integrated with the display panel manufacturing flow. This multi-functionality reduces the impact on manufacturing precision by eliminating the need for separate dedicated measurement structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11222560B2Display device

Publication Date: 2022.01.11 SAMSUNG DISPLAY CO LTD

AI summary

An exemplary embodiment provides a display device including: a display part configured to include a display part color filter; and a peripheral part disposed at the upper side of the display part and including an inspection pattern for checking an alignment of the display part color filter. The inspection pattern may include a plurality of color filters having colors and reference patterns disposed at at least one side of the plurality of color filters. A number of the plurality of color filters of each color corresponds to a number of shots of a division exposure process. Adjacent color filters among the plurality of color filters may be disposed at different heights.