Metal OLED Deposition Mask with Uniform Zigzag Through-Holes

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Solution Overview

Problem

Existing deposition masks with elliptical-shaped through-holes in a zigzag form suffer from non-uniformity in through-hole sizes and island sizes, leading to variations in deposition patterns.

Innovation Solution

A deposition mask design with controlled size deviations in large and small surface holes, featuring elliptical through-holes in a zigzag form, includes half-etched portions and island portions to maintain uniformity across different directions, ensuring consistent deposition patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If elliptical-shaped through-holes are disposed in a zigzag form to achieve high-resolution deposition patterns, then deposition resolution is improved, but uniformity of through-hole sizes and island sizes deteriorates

Engineering Contradiction:
Improvedeposition pattern uniformityVSAvoidthrough-hole size consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies asymmetry by intentionally designing the zigzag arrangement of elliptical through-holes with specific geometric parameters. The elliptical shape itself is asymmetric, and the zigzag pattern creates intentional asymmetry in the arrangement. By carefully controlling the asymmetry ratio and zigzag geometry, the patent achieves uniform deposition patterns while maintaining reliable through-hole sizes across different orientations.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If circular through-holes are used to achieve uniform deposition patterns, then through-hole uniformity is improved, but deposition resolution and pattern diversity deteriorate

Engineering Contradiction:
Improvethrough-hole size consistencyVSAvoiddeposition pattern quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the geometric parameters of the through-holes from circular to elliptical shape, and modifies the arrangement pattern from regular to zigzag. By adjusting parameters such as the aspect ratio of the ellipses, the zigzag angle, and the spacing between through-holes, the patent achieves both uniformity and high-resolution deposition patterns that cannot be obtained with simple circular holes.

Inventive Principle:
Principle #35Parameter changes

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 design improves the uniformity of through-hole diameters and island sizes, enhancing the quality and consistency of deposition patterns regardless of direction, thereby improving the overall deposition process.

Implementation Method 1

the organic material included in an emission layer of the OLED may be deposited on a substrate by a deposition mask called a fine metal mask (FMM)

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Data Source

PatentEP4141977B1Deposition mask made of metal for OLED pixel deposition
Publication Date: 2025.09.24 LG INNOTEK CO LTD
  • EP4141977B1 patent drawingFigure 1
  • EP4141977B1 patent drawingFigure 2~3
  • EP4141977B1 patent drawingFigure 4

AI summary

A deposition mask according to an embodiment comprises a metal plate comprising a deposition area and a non-deposition area. The through-hole comprises a communicating portion connected to a first facing hole configured such that the first diameter slopes at an acute angle with regard to one surface in the transverse-axis direction of the metal plate, and a communicating portion connected to a second facing hole configured such that the first diameter slopes at an obtuse angle with regard to one surface in the transverse-axis direction of the deposition mask. In the longitudinal-axis direction of the metal plate, the first facing hole and the second facing hole are arranged alternately in a row. In the transverse-axis direction of the metal plate, the first facing hole and the second facing hole are arranged alternately in a row. A first island portion is arranged between two adjacent first facing holes in a first diagonal direction joining the first diameters of the communicating portions connected to the first facing holes. A second island portion is arranged between two adjacent second facing holes in a second diagonal direction joining the first diameters of the communicating portions connected to the second facing holes. A rib is arranged between the first island portion and the second island portion. The deviation in size between the first island portion and the second island portion, which are adjacent to each other, is 30% or less.