Mask Sheet Non-Uniform Thickness for Display Deposition Stress

Solution Overview

Problem

The challenge in manufacturing display apparatuses lies in maintaining the consistency of patterns on mask sheets during the deposition process, as existing technologies face issues with stress concentration and deformation, leading to inconsistent gaps and defects in the pattern, especially when the mask sheets are stretched.

Innovation Solution

A mask assembly comprising a mask frame and a mask sheet with a pattern of openings, where the thickness of the pattern is different from the rest of the sheet, reducing stress concentration and allowing for consistent gap maintenance during stretching, and a reinforcement member to prevent deformation, ensuring accurate deposition of materials onto a substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the mask sheet is stretched to fit the substrate, then the mask sheet can be applied to large-area substrates, but stress concentration and deformation occur leading to inconsistent gaps and pattern defects

Engineering Contradiction:

Improvemask sheet areaVSAvoidpattern consistency

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The mask sheet is designed with non-uniform thickness: the pattern region has a first thickness while the non-pattern region has a second thickness greater than the first. This local quality differentiation allows the thinner pattern region to be more flexible and accommodate stretching without deformation, while the thicker non-pattern region provides structural support and maintains gap consistency during the stretching process.

Inventive Principle:

Principle #3Local quality

2Strength

If the mask sheet thickness is increased to prevent deformation, then structural stability improves, but stress concentration occurs during stretching causing pattern inconsistency

Engineering Contradiction:

Improvemask sheet strengthVSAvoidpattern gap consistency

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The mask sheet is designed with non-uniform thickness: the pattern region has a first thickness while the non-pattern region has a second thickness greater than the first. This local quality differentiation allows the thinner pattern region to be more flexible and accommodate stretching without deformation, while the thicker non-pattern region provides structural support and maintains gap consistency during the stretching process.

Inventive Principle:

Principle #3Local quality

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 solution enables consistent deposition of materials onto the substrate, reducing defects and maintaining the pattern integrity, resulting in improved performance and accuracy of the display apparatus.

Implementation Method 1

the mask sheet is stretched by applying tensile force and affixed onto the mask frame

Methodology Applied

Scientific EffectTensile force: Tension

Implementation Method 2

a deposition source disposed facing the mask assembly, wherein the mask assembly includes: a mask frame; and a mask sheet disposed on the mask frame

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentUS9837608B2Mask assembly and apparatus and method of manufacturing display apparatus using the same

Publication Date: 2017.12.05 SAMSUNG DISPLAY CO LTD

AI summary

A mask assembly includes: a mask frame; and a mask sheet disposed on the mask frame, wherein the mask sheet is stretched by applying tensile force and affixed onto the mask frame, wherein the mask sheet includes a pattern including a plurality of openings, and wherein a thickness of the pattern is different from thicknesses of other portions of the mask sheet.