OLED Pixel Defect Compensation via Evaporation Mask Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in manufacturing OLED display devices is achieving uniform thickness of the organic film layer in pixel regions using inkjet printing, as it often results in non-uniform surface shapes, affecting the optical properties and display quality.
Innovation Solution
A method involving the formation of a pixel-defining layer on a substrate, determining areas to be compensated based on the surface shape of the organic film layer, aligning an evaporation source and mask openings to correspond with these areas, and forming an electron function layer through evaporation to compensate for the surface shape, ensuring uniformity and improving optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing method is used to form organic film layer, then equipment cost is reduced and mass production is enabled, but the organic film layer cannot achieve uniform thickness in pixel region
Solution Approach 1:
The patent applies local quality by creating different thickness regions within the electron function layer. The compensation area receives additional electron function layer material to specifically address the non-uniform thickness problem in certain regions, while other areas maintain their original structure. This localized modification enables uniform overall thickness without requiring complete redesign of the entire film formation process.
Solution Approach 2:
The patent implements preliminary action by pre-defining compensation areas based on the expected non-uniform thickness distribution before actual deposition. The mask is designed with opening patterns that anticipate where thickness compensation is needed, allowing the electron function layer to be deposited with predetermined compensation regions, thus preventing the uniformity problem rather than correcting it afterward.
2Manufacturing precision
If vacuum vapor deposition is used, then uniform film quality is achieved, but equipment investment is high and material utilization rate is low
Solution Approach 1:
The patent merges inkjet printing and vacuum vapor deposition techniques by using inkjet to form the organic film layer and then using vacuum vapor deposition to form the electron function layer with compensation capabilities. This combination allows the system to achieve the uniformity benefits of vacuum deposition while maintaining the cost-effectiveness and mass production capabilities of inkjet printing for the primary organic layer.
Solution Approach 2:
The patent applies local quality by using vacuum vapor deposition selectively only in the compensation area rather than the entire substrate. The mask restricts the electron function layer deposition to specific regions where thickness compensation is needed, reducing material consumption and equipment complexity compared to applying vacuum deposition uniformly across the entire device.
3Measurement precision
If mask opening size is reduced to improve alignment accuracy, then positioning precision increases, but the area to be compensated may not be fully covered
Solution Approach 1:
The patent applies segmentation by dividing the compensation area into multiple discrete opening regions within the mask. Instead of using a single large opening that would compromise alignment accuracy, the compensation area is segmented into multiple smaller openings that maintain positioning precision while collectively covering the entire compensation region. This segmented approach allows each opening to be precisely positioned while the aggregate coverage meets the compensation requirements.
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 effectively compensates for non-uniformities in the organic film layer, enhancing the uniformity and optical properties of the OLED display device, thereby improving the display effect without affecting the electrical properties.
Implementation Method 1
forming an electron function layer in the area to be compensated by means of evaporation of the evaporation source
Data Source
AI summary
The present disclosure discloses a method for manufacturing an OLED display device, including: forming a pixel-defining layer on a substrate to define a plurality of pixel regions, forming an organic film layer in each pixel region, determining at least one area to be compensated in the pixel region according to a surface shape of the organic film layer; aligning an evaporation source, an opening of a mask and the pixel region, making each opening of the mask respectively correspond to the position of each area to be compensated; forming an electron function layer in the area to be compensated by means of evaporation of the evaporation source, wherein the electron function layer is configured to compensate a surface shape of the organic film layer in the pixel region.