Partition Wall Reverse Taper Shape for Display Fingerprint Sensing
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Solution Overview
Problem
Current display devices with integrated fingerprint sensors face challenges in minimizing noise and improving accuracy when sensing fingerprints due to the design of the light emitting and receiving elements, particularly in the placement and separation of electrodes and the partition wall structure.
Innovation Solution
The display device incorporates a substrate with a pixel element layer including light emitting and receiving elements, where the partition wall has a reverse taper shape, allowing for the separation of electrodes and minimizing noise by reducing current leakage, and includes a thin film encapsulation layer and a touch sensor for enhanced functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the partition wall has a conventional shape, then the manufacturing process is simple, but the electrodes cannot be adequately separated leading to current leakage and noise
Solution Approach 1:
The partition wall is designed with an asymmetric reverse taper shape where the upper width is greater than the lower width, creating an obtuse angle (>90°) between the side surface and lower surface. This asymmetric geometry effectively separates the light emitting electrode and light receiving electrode, preventing current leakage and reducing noise in fingerprint sensing operations.
2Measurement precision
If additional patterning processes are used to separate electrodes, then electrode separation and noise reduction are improved, but manufacturing time and cost increase
Solution Approach 1:
The partition wall is segmented into distinct regions including a lower surface, side surface, and upper surface, with the reverse taper shape creating natural separation zones. This segmentation allows the light emitting electrode and light receiving electrode to be deposited separately without requiring additional patterning steps, as the partition wall geometry itself provides the necessary isolation.
Solution Approach 2:
The partition wall structure is prepared in advance with the reverse taper shape before electrode deposition. This preliminary structuring creates pre-defined separation zones that guide subsequent electrode formation, eliminating the need for complex real-time patterning processes during electrode fabrication.
3Object-generated harmful factors
If the partition wall has a reverse taper shape, then electrode separation and noise minimization are improved, but the manufacturing precision requirements increase
Solution Approach 1:
The partition wall geometry is defined by specific parameter ranges: the angle between the side surface and lower surface exceeds 90°, and the upper width is greater than the lower width. These parameter specifications provide clear manufacturing targets while the reverse taper shape itself inherently provides tolerance to dimensional variations, maintaining effectiveness across a range of manufacturing precision levels.
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 configuration enhances the accuracy of fingerprint sensing by minimizing noise and allowing for separate deposition of electrodes without additional patterning processes, reducing manufacturing time and cost while maintaining optical path integrity for accurate fingerprint recognition.
Implementation Method 1
a light emitting element electrically connected to the pixel circuit
Implementation Method 2
a light sensor. The light sensor may obtain fingerprint information by receiving reflected light or the like generated by the user's fingerprint
Data Source
AI summary
A display device of the disclosure includes a substrate, a circuit layer disposed on the substrate and including a pixel circuit and a sensor circuit, a pixel element layer disposed on the circuit layer and including a light emitting element electrically connected to the pixel circuit, a light receiving element electrically connected to the sensor circuit, and a pixel defining layer disposed on the circuit layer, and a partition wall disposed on the pixel defining layer. The partition wall has a reverse taper shape.