OLED Substrate Auxiliary Cathode Deformation for Brightness Uniformity
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Solution Overview
Problem
Top emission type OLED display panels face significant voltage drops due to large impedance in cathode materials, leading to uneven display brightness, especially as panel size increases.
Innovation Solution
A method is introduced to fabricate an OLED substrate by forming an auxiliary cathode with a stacked bottom and top electrode, applying voltage to deform the auxiliary cathode to rupture an organic material functional layer and create a connection channel, and then forming a cathode electrically connected to the auxiliary cathode, reducing voltage drop and improving brightness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If transparent conductive materials are used for cathodes in top emission type OLED display panels, then the aperture ratio is improved, but the impedance increases causing significant voltage drop and uneven display brightness
Solution Approach 1:
The cathode structure is segmented into multiple components: a transparent cathode layer, an auxiliary cathode, and a connection channel. This segmentation allows the transparent cathode to maintain high aperture ratio while the auxiliary cathode provides additional conduction paths through the connection channel, reducing overall impedance and voltage drop to improve brightness uniformity.
Solution Approach 2:
A connection channel is introduced as an intermediary structure that electrically connects the auxiliary cathode to the transparent cathode. This connection channel, formed by rupturing the organic material functional layer, serves as a conductive pathway that reduces impedance without affecting the aperture ratio of the display region.
2Area of stationary object
If the size of the display panel is increased, then the display area is improved, but the voltage drop of the cathode increases significantly resulting in uneven display brightness
Solution Approach 1:
The cathode system is divided into distributed auxiliary cathodes positioned at different locations, each connected to the transparent cathode through separate connection channels. This segmentation creates multiple parallel conduction paths that reduce overall impedance, allowing larger display panels to maintain uniform brightness by compensating for increased voltage drop across the expanded area.
3Reliability
If traditional laser boring methods are used to form connection channels, then the cathode can be electrically connected, but the product yield decreases and manufacturing costs increase
Solution Approach 1:
The organic material functional layer itself is utilized to form the connection channel structure. By applying voltage to deform the auxiliary cathode, the organic material functional layer is ruptured to create the connection channel, eliminating the need for separate laser boring processes. This self-service approach improves product yield and reduces manufacturing costs while achieving reliable electrical connection.
Solution Approach 2:
The mechanical laser boring process is replaced with an electrical field-based method. Voltage is applied to the auxiliary cathode to generate electrical forces that deform the auxiliary cathode and rupture the organic material functional layer, forming the connection channel. This substitution eliminates the need for expensive laser equipment and improves manufacturing efficiency.
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 reduces voltage drop and enhances display brightness uniformity, increasing product yield and reducing costs associated with traditional laser boring methods while maintaining high aperture ratios.
Implementation Method 1
applying a voltage to the auxiliary cathode to deform the auxiliary cathode, such that the organic material functional layer is ruptured by the deformed auxiliary cathode to form a connection channel
Data Source
AI summary
Embodiments of the present disclosure provide an OLED substrate and a fabrication method thereof, and a display panel. The method for fabricating an OLED substrate includes: forming an auxiliary cathode in a display region on a base substrate; forming an organic material functional layer in the display region on the base substrate where the auxiliary cathode is formed; applying a voltage to the auxiliary cathode to deform the auxiliary cathode, such that the organic material functional layer is ruptured by the deformed auxiliary cathode to form a connection channel; and forming a cathode in the display region on the base substrate where the organic material functional layer is formed. The cathode is electrically connected to the auxiliary cathode at the connection channel.