OLED Deposition Mask Patterns for Stress Relief and Flatness

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Solution Overview

Problem

The existing deposition masks for OLED pixel deposition, particularly fine metal masks, suffer from reduced deposition reliability due to stress-induced waviness and variations in through-hole intervals, leading to positional changes and decreased accuracy.

Innovation Solution

A deposition mask with a metal plate featuring a deposition region and non-deposition region, including effective and non-effective areas, where through-holes are disposed, and patterns are strategically placed between effective regions to disperse residual stress and minimize waviness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a fine metal mask is used to deposit multi-color organic materials, then light efficiency is improved and separate color filters are eliminated, but manufacturing complexity increases and alignment accuracy deteriorates due to stress-induced waviness

Engineering Contradiction:

Improvelight efficiencyVSAvoidmanufacturing complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The metal mask is divided into multiple effective regions separated by non-effective regions. The non-effective regions act as stress relief zones that prevent waviness propagation between pixel deposition areas, allowing the mask to maintain structural integrity during multi-color deposition processes

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the mask are designed with different functional properties - effective regions contain through-holes for precise pixel pattern deposition while non-effective regions provide stress dispersion. This local differentiation allows the mask to simultaneously achieve high deposition precision and stress relief

Inventive Principle:

Principle #3Local quality

2Productivity

If the metal mask is stretched to fix multiple fine metal masks, then productivity is improved, but surface flatness deteriorates due to generated stress and waviness

Engineering Contradiction:

ImproveproductivityVSAvoidsurface flatness

Core Design Contradiction:

ProductivityVSShape

Solution Approach 1:

The continuous metal mask structure is segmented into effective and non-effective regions. The non-effective regions serve as stress absorption zones that prevent tension-induced waviness from affecting the effective deposition regions, maintaining surface flatness while allowing the mask to be stretched for productivity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stress generated by stretching the mask is converted into a beneficial effect where non-effective regions absorb and distribute the tension forces. This transforms the harmful stress that would cause waviness into a useful stress dispersion mechanism that maintains overall mask flatness

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Manufacturing precision

If through-holes are formed at precise positions for pixel patterns, then manufacturing precision is improved, but reliability deteriorates due to positional changes caused by stress-induced waviness

Engineering Contradiction:

Improvethrough-hole position accuracyVSAvoiddeposition reliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The mask is segmented into effective regions with through-holes and non-effective stress relief regions. This segmentation isolates the through-hole positions from stress propagation sources, ensuring that precise pixel pattern positions remain stable and reliable during the deposition process

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The non-effective regions act as intermediary elements between the stretched mask edges and the through-hole regions. These intermediary zones absorb and distribute stress, preventing direct transmission of tension forces that would cause through-hole positional shifts

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The mask design improves deposition reliability by reducing waviness and maintaining consistent through-hole intervals, ensuring precise and reliable deposition of RGB pixel patterns on the substrate.

Implementation Method 1

patterns are strategically placed between effective regions to disperse residual stress and minimize waviness

Methodology Applied

Scientific EffectStress dispersion:

Implementation Method 2

The organic material is deposited on the deposition substrate using the large surface hole as an inlet and the small surface hole as an outlet

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentUS20260071318A1Deposition mask for OLED pixel deposition

Publication Date: 2026.03.12 LG INNOTEK CO LTD

AI summary

A deposition mask comprising; a metal plate including a deposition region and a non-deposition region, wherein the metal plate has a first direction, which is a longitudinal direction, and a second direction, which is a width direction, defined, wherein the deposition region includes a plurality of effective regions; and a non-effective region, wherein the non-effective region includes a first non-effective region between effective regions, wherein a plurality of through-holes is disposed in the effective region, wherein at least one pattern is disposed in the first non-effective region, wherein the pattern and the through-hole are formed in different shapes.