Display Encapsulation Inspection Using Dam-Region Light Reflection
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Solution Overview
Problem
The formation of an organic encapsulation layer in display devices can result in defects due to overflow of organic material beyond the display region, affecting the reliability of the device.
Innovation Solution
An inspection method is employed to radiate a light of specific wavelength ranges to dam regions outside the display area, analyzing the reflected light to detect any remaining organic encapsulation layer after etching, ensuring accurate placement and minimizing interference from underlying layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic encapsulation layer is formed using organic material, then protection of light emitting element is improved, but overflow of organic material to edge of display region causes defects
Solution Approach 1:
A dam structure is formed in advance at the periphery of the display region to define the boundary where organic material should be contained. This preliminary structural preparation prevents organic material overflow during the subsequent encapsulation layer formation process, resolving the contradiction between providing adequate protection and maintaining precise material placement.
2Measurement precision
If inspection is performed after formation of organic encapsulation layer, then defect detection is improved, but underlying inorganic encapsulation layers may interfere with inspection accuracy
Solution Approach 1:
The inspection method selectively targets and inspects only the organic encapsulation layer by using wavelength ranges that are transmitted through the inorganic encapsulation layers but absorbed by the organic material. This extraction of the specific inspection target from the multi-layer structure enables accurate detection without interference from underlying inorganic layers.
Solution Approach 2:
The inspection utilizes specific wavelength ranges (e.g., 290-410 nm) that differentiate the optical properties of organic versus inorganic materials. By changing the wavelength parameter of the inspection light, the method achieves selective detection of the organic encapsulation layer while the inorganic layers remain transparent or non-interfering at these wavelengths.
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 method enhances the reliability of the display device by accurately inspecting and correcting the organic encapsulation layer, preventing defects and improving overall performance.
Implementation Method 1
receiving a second light reflected from the first dam region
Implementation Method 2
analyzing the radiation wavelength range of the second light to inspect an organic encapsulation layer
Data Source
AI summary
An inspection method for a display device includes radiating a first light including a light of a radiation wavelength range to a first dam region located in a non-display region of the display device located outside a display region of the display device, receiving a second light reflected from the first dam region, and analyzing the radiation wavelength range of the second light to inspect an organic encapsulation layer remaining in the first dam region after etching the organic encapsulation layer.