Optical Sensor Barrier Layer for Low-Leakage Fingerprint Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fingerprint sensors integrated with display devices face challenges in minimizing leakage current, which affects the accuracy of fingerprint sensing due to noise in the sensing current.
Innovation Solution
The implementation of a barrier layer on the photoelectric element, specifically formed of an inorganic film, spaced apart from the first electrode and covered by an insulating layer, helps minimize leakage current by preventing side surface damage and reducing noise in the sensing current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a barrier layer is added on the photoelectric element to prevent side surface damage, then reliability is improved, but device complexity increases
Solution Approach 1:
The barrier layer is formed on the photoelectric element before subsequent processing steps to prevent side surface damage and leakage current in advance. This preliminary protective action ensures reliability from the outset, preventing the need for complex corrective measures later in the manufacturing process.
Solution Approach 2:
The barrier layer acts as an intermediary protective layer between the photoelectric element and the external environment. It mediates the interaction by providing a protective interface that prevents direct exposure to damaging factors, thereby reducing leakage current while maintaining a relatively simple overall structure.
2Measurement precision
If the barrier layer is spaced apart from the first electrode to reduce noise, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The barrier layer is selectively positioned at specific locations on the photoelectric element, particularly spaced from the first electrode in regions where noise reduction is most critical. This localized quality enhancement improves measurement precision without requiring uniform spacing throughout the entire device structure.
Solution Approach 2:
The spacing between the barrier layer and first electrode creates a vertical dimensional separation that reduces noise interference. By utilizing the vertical dimension for noise reduction rather than horizontal displacement, the design maintains compactness while improving sensing current accuracy.
3Reliability
If an insulating layer is added to cover the photoelectric element and barrier layer, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The insulating layer is merged with the barrier layer to form an integrated protective structure. This combination approach provides both electrical insulation and mechanical protection in a single unified layer, improving reliability while avoiding the need for separate manufacturing processes for distinct protective layers.
Solution Approach 2:
The insulating layer serves multiple functions simultaneously: it provides electrical insulation, mechanical protection, and structural support. This multi-functionality reduces the need for additional specialized layers, simplifying the overall manufacturing process while maintaining high reliability.
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 solution effectively reduces leakage current, enhancing the accuracy of fingerprint sensing by minimizing noise in the sensing current, thereby improving the overall performance of fingerprint recognition systems.
Implementation Method 1
A fingerprint sensor integrated display device uses a sensor that can sense light. A fingerprint sensor integrated display device that uses a light sensing method uses a light emitting element provided in a pixel as a light source, and includes an optical sensor array.
Data Source
AI summary
An optical sensor includes a substrate, a photoelectric element disposed on the substrate and that includes a first electrode, an intermediate layer disposed on the first electrode, and a second electrode disposed on the intermediate layer, a barrier layer disposed on the second electrode, an insulating layer that covers the photoelectric element and the barrier layer, and a bias electrode disposed on the insulating layer and electrically connected to the second electrode. The barrier layer is spaced apart from the first electrode.