Metal Mask Through-Hole Layout for Reduced Deposition Shadowing
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Solution Overview
Problem
Existing metal masks used in organic EL display devices suffer from shadowing issues during vapor deposition due to vapor deposition material adhering to the wall surfaces of through-holes, leading to uneven deposition and reduced strength from thinning the metal plate to prevent shadowing.
Innovation Solution
A metal mask design with specific through-hole configurations and top parts, including parallel axes and controlled area ratios, combined with an etching process to form the mask, which reduces shadowing while maintaining strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the thickness of the metal plate is reduced to prevent shadow, then shadowing is reduced, but the strength of the metal mask degrades
Solution Approach 1:
The patent applies local quality by creating non-uniform thickness distribution in the metal mask. Specifically, the mask has a first thickness in the effective region and a second thickness in the peripheral region, with the second thickness being greater than the first. This allows the effective region to be thin enough to reduce shadowing while the peripheral region maintains greater thickness for structural strength and rigidity.
2Object-affected harmful factors
If the thickness of the metal plate is reduced to prevent shadow, then shadowing is reduced, but deformation resistance decreases
Solution Approach 1:
The patent implements local quality through differentiated thickness regions. The peripheral region has a greater thickness than the effective region, providing enhanced rigidity and deformation resistance where structural support is needed, while the effective region maintains minimal thickness to reduce shadowing effects during vapor deposition.
3Manufacturing precision
If the metal mask is designed with complex top parts and through-hole configurations, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by forming the complex thickness pattern and top part structures during the manufacturing process itself. The etching process is designed to create the differentiated thickness regions and top part configurations in advance, so that the final mask product inherently possesses the required precision without requiring additional complex assembly steps or post-processing operations.
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 proposed metal mask design effectively minimizes shadowing and maintains structural integrity, ensuring uniform vapor deposition and improved image quality in organic EL display devices.
Implementation Method 1
an etching step of etching the metal plate to form the metal mask
Implementation Method 2
a vapor deposition material from a vapor deposition source to the metal mask moves in a thickness direction of a metal plate constituting the metal mask
Data Source
AI summary
A metal mask in which shadow is less likely to occur while the strength is kept, and a method for manufacturing the metal mask are provided. The metal mask includes a first surface, and a second surface positioned opposite to the first surface. The first surface has through-holes, a first top part, and a second top part. The through-holes have a first through-hole, a second through-hole, a third through-hole, a fourth through-hole, a fifth through-hole, and a sixth through-hole. The first through-hole has a first short axis and a first long axis. The second through-hole has a second short axis and a second long axis. The third through-hole has a third short axis and a third long axis. The fourth through-hole has a fourth short axis and a fourth long axis. The fifth through-hole has a fifth short axis and a fifth long axis.