Deposition Mask Surface Composition for Resist Adhesion
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Solution Overview
Problem
The challenge in manufacturing deposition masks for high-pixel-density organic EL display devices is the difficulty in forming narrow resist patterns on metal plates with high adhesion force, as conventional methods face issues with resist film adhesion to iron-nickel alloys, leading to pattern peeling during etching.
Innovation Solution
A method involving an iron alloy metal plate with a specific surface composition analyzed by X-ray photoelectron spectroscopy to ensure a ratio of nickel oxide and hydroxide to iron oxide and hydroxide is 0.4 or less, enhancing the adhesion force of the resist pattern, and using a dry film with high resolution to form stable narrow resist patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pixel density of organic EL display device is increased, then the fineness and resolution of display improve, but the size and arrangement pitch of through-holes in deposition mask decrease, making it difficult to form stable narrow resist patterns
Solution Approach 1:
The patent changes the chemical composition parameters of the metal plate surface by controlling the ratio of nickel compounds to iron compounds (A1/A2 ≤ 0.4) through surface treatment. This parameter change enhances the adhesion between resist film and substrate, enabling stable formation of narrow resist patterns required for high pixel density displays
Solution Approach 2:
The patent creates a composite surface structure on the metal plate by forming a specific composition of nickel oxide, nickel hydroxide, iron oxide, and iron hydroxide. This composite surface layer provides both the adhesion properties needed for narrow resist patterns and the etch resistance required for precise through-hole formation
2Measurement precision
If the width of resist pattern is narrowed to achieve higher pixel density, then the resolution improves, but the contact area between resist pattern and metal plate is reduced, leading to poor adhesion and pattern peeling during etching
Solution Approach 1:
The patent modifies the surface chemistry parameters of the metal plate by controlling the oxidation state and composition ratio of surface compounds. By maintaining A1/A2 ≤ 0.4, the surface provides optimal adhesion properties that compensate for the reduced contact area in narrow resist patterns
Solution Approach 2:
The patent introduces a chemically active surface layer composed of specific ratios of nickel and iron compounds as an intermediary between the resist film and the bulk metal plate. This intermediate layer enhances interfacial adhesion, preventing pattern peeling during the etching process
3Ease of manufacture
If conventional photolithographic etching is used on iron-nickel alloy metal plates, then the manufacturing process is simple, but the resist film adhesion is insufficient, causing pattern peeling during etching
Solution Approach 1:
The patent performs preliminary surface treatment on the metal plate before applying the resist film. By pre-controlling the surface composition (A1/A2 ≤ 0.4), the substrate is prepared in advance to ensure strong adhesion, eliminating the need for complex adhesion promotion steps during the etching process
Solution Approach 2:
The patent changes the surface composition parameters of the metal plate to optimize adhesion. By controlling the ratio of nickel compounds to iron compounds on the surface, the material maintains both ease of manufacture through conventional photolithography and high reliability in pattern adhesion
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
This approach allows for the stable formation of narrow resist patterns on metal plates, ensuring high-pixel-density deposition masks with improved adhesion, preventing pattern peeling and enhancing the manufacturing efficiency of organic EL display devices.
Implementation Method 1
an inspection step of analyzing a composition of a first surface of the metal plate by using an X-ray photoelectron spectroscopy
Data Source
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AI summary
There is provided a method of inspecting a metal plate used for manufacturing a deposition mask having a plurality of through-holes formed therein. The method comprises a composition analysis step of analyzing a composition of a first surface of the metal plate by using an X-ray photoelectron spectroscopy. The method further comprises a selection step of selecting the metal plate based on the result of the composition analysis step. In the composition analysis of the first surface of the metal plate by means of the X-ray photoelectron spectroscopy, an incident angle of an X-ray emitted to the metal plate on the first surface is 45 degrees, and an acceptance angle of photoelectrons discharged from the metal plate is 90 degrees. The selection step selects the metal plate which satisfies the condition (1) defined herein.