Fine Metal Mask Frame Flatness via Opposite Force Pre-deformation

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Solution Overview

Problem

In the preparation of OLED displays, the stringent requirements for fine metal masks (FMMs) in high-resolution products are not adequately met due to issues with flatness and accuracy, leading to defects and reduced evaporation effectiveness.

Innovation Solution

A method involving the application of equal and directed opposite forces during the molding and welding processes of the mask frame to ensure precise alignment and flatness, using a mechanical force applying device to maintain the mask pattern's accuracy and prevent relaxation, resulting in a flat contact area within ±10 to 30 μm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional molding and welding processes are used for the mask frame, then the manufacturing process is simple, but the flatness and accuracy of the mask pattern are insufficient

Engineering Contradiction:

Improveflatness and accuracy of mask patternVSAvoidcomplexity of molding and welding process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary anti-action by pre-deforming the mask frame in the opposite direction of the expected deformation during welding. Specifically, the frame is pre-bent concavely during molding, which compensates for the convex deformation that occurs during welding, thereby maintaining flatness and accuracy of the mask pattern throughout the manufacturing process.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements preliminary action by performing deformation compensation during the molding process before welding occurs. The mask frame is pre-formed with a specific curvature that anticipates and counteracts the deformation that will occur during subsequent welding, ensuring the final product meets flatness requirements without requiring additional correction steps.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If opposite forces are applied to the frame during molding and welding, then the flatness and accuracy are improved, but the process complexity increases

Engineering Contradiction:

Improveflatness of mask patternVSAvoidease of molding and welding process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges the force application into the standard molding and welding equipment capabilities. The opposite forces are integrated into the existing molding press and welding fixture designs, allowing the same equipment to apply controlled forces during both molding and welding without requiring entirely new specialized devices, thus maintaining ease of manufacture while improving precision.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the mask frame is deformed during welding, then the welding process is simpler, but the alignment accuracy of the mask pattern deteriorates

Engineering Contradiction:

Improvewelding process simplicityVSAvoidalignment accuracy of mask pattern

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #9Preliminary anti-action

Data Source

PatentUS10739672B2Method for preparing mask, mask and evaporation system

Publication Date: 2020.08.11 BOE TECHNOLOGY GROUP CO LTD

AI summary

A method of preparing a mask, a mask and an evaporation system are provided. The mask includes a frame having an opening in a middle region thereof and a mask pattern disposed above the frame. The method of preparing the mask includes: applying first opposite forces to the frame during a molding process of the frame; applying second opposite forces to the frame, during a welding process when the mask pattern is welded to at least part of the frame to cover an inner opening region of the frame; wherein the first opposite forces and the second opposite forces are equal in magnitude and the same in direction.