Display Panel Motherboard Test Structure for Cathode Position Sensing
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Solution Overview
Problem
Existing OLED display devices face challenges in achieving high transmittance for under-screen cameras due to low screen transmittance caused by cathode evaporation, which is difficult to measure accurately using current methods.
Innovation Solution
A display panel motherboard with a fluorescent layer and positioning reference portion that allows for accurate determination of the target test layer's position by creating a light and dark contrast, enabling precise formation of the light-emitting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a Fine Metal Mask (FMM) is used for evaporating the cathode to improve transmittance for under-screen camera function, then the transmittance of the OLED screen is improved, but the ability to measure the positional accuracy of cathode evaporation is lost because the cathode does not emit light under fluorescence
Solution Approach 1:
The patent introduces a fluorescent layer as an intermediary substance between the target test layer and the measurement system. This fluorescent layer emits fluorescence under UV irradiation, creating a visible contrast that enables measurement of the target test layer's position without interfering with the cathode evaporation process or the under-screen camera function. The fluorescent layer acts as a mediator that translates the invisible cathode pattern into a measurable fluorescent signal.
2Reliability
If the cathode is evaporated using FMM to achieve high transmittance, then the under-screen camera function is enabled, but the positional accuracy of the cathode evaporation cannot be monitored on-line
Solution Approach 1:
The patent utilizes fluorescence as an optical property change to enable measurement. The fluorescent layer exhibits different optical characteristics (fluorescence emission) under UV irradiation compared to normal light, creating a visible contrast that allows real-time monitoring of the target test layer's position during the evaporation process. This color/optical property change enables non-contact, on-line measurement without affecting the cathode's electrical or optical properties.
3Device complexity
If the target test layer is formed without a fluorescent layer, then the structure is simpler, but the actual position of the target test layer cannot be determined accurately because it does not emit light
Solution Approach 1:
The fluorescent layer serves as an intermediary that indirectlly reveals the position of the target test layer. Instead of attempting to measure the non-luminescent target test layer directly, the fluorescent layer is deposited in a pattern that corresponds to the target test layer's position, and its fluorescence emission under UV light provides a visible template for accurate position determination.
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
Enhances positional accuracy of the light-emitting layer formation, improving the transmittance required for under-screen camera functionality.
Implementation Method 1
a fluorescent layer, disposed on the surface of the array mother substrate and emitting light upon being irradiated by activation light
Data Source
AI summary
The application provides a display panel motherboard and manufacturing method thereof. The display panel motherboard includes display panel forming areas distributed in an array and a test area adjacent to the display panel forming areas. The display panel motherboard includes an array mother substrate; a light-emitting layer, disposed on a surface of a side of the array mother substrate and located in the display panel forming areas; and a test component, disposed on the surface of the array mother substrate and located in the test area, the test component including a test block including a fluorescent layer, disposed on the surface of the array mother substrate and emitting light upon being irradiated by activation light; a target test layer, disposed on the side of the fluorescent layer facing away from the surface; and a positioning reference portion, disposed at a peripheral side of the target test layer.