Fingerprint Array Substrate Layout With Fewer Masking Steps
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Solution Overview
Problem
Current optical fingerprint recognition technologies for display screens require complex processes and high costs due to multiple masking processes, which complicates the manufacturing and increases expenses.
Innovation Solution
An array substrate with a fingerprint recognition area is designed, featuring a substrate with a metal electrode layer, passivation layers, and a photosensitive semiconductor layer, where the first electrode layer and photosensitive semiconductor layer are disposed on the surface of the first passivation layer, omitting a passivation layer between them, and the second electrode layer extends into openings to connect with the semiconductor layer, simplifying the structure and processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple passivation layers and masking processes are used in optical fingerprint recognition technology, then the structural integrity and electrical insulation are improved, but the manufacturing complexity and costs increase
Solution Approach 1:
The patent extracts and removes the first passivation layer that would normally be disposed between the first electrode layer and the photosensitive semiconductor layer. This extraction eliminates unnecessary structural complexity while maintaining the essential functions of electrical insulation and structural support through the remaining passivation layers and substrate architecture.
Solution Approach 2:
The remaining passivation layers (second passivation layer and third passivation layer) are designed to perform multiple functions: providing electrical insulation, maintaining structural integrity, and facilitating electrical connections through openings. This multi-functionality compensates for the removed passivation layer without increasing overall device complexity.
2Reliability
If multiple passivation layers and masking processes are used, then electrical insulation and structural support are maintained, but manufacturing costs and processing time increase
Solution Approach 1:
The first passivation layer is extracted from the structure, eliminating the need for its corresponding masking and formation processes. This reduces the total number of manufacturing steps, thereby improving productivity and reducing costs while the remaining passivation layers maintain necessary electrical insulation functions.
Solution Approach 2:
The functions of electrical insulation and structural support are merged into the remaining passivation layers and substrate architecture. The second and third passivation layers, along with the substrate, work together to provide the insulation and support that would otherwise require multiple separate layers, thus simplifying the manufacturing process.
3Ease of manufacture
If the first electrode layer and photosensitive semiconductor layer are disposed on the surface of the first passivation layer, then the manufacturing process is simplified, but the electrical connection reliability may be affected
Solution Approach 1:
The first passivation layer is extracted (removed) from between the first electrode layer and the photosensitive semiconductor layer, simplifying the manufacturing process by reducing the number of layers and masking steps. The electrical connection reliability is maintained through direct contact or proximity of the electrode layer and semiconductor layer, and through the remaining passivation layers that provide necessary insulation and support.
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 design simplifies the manufacturing process by omitting a passivation layer and reducing the number of mask processes, thereby lowering costs and improving processing stability and product yields.
Implementation Method 1
The optical fingerprint recognition technology uses principles of light refraction and reflection. When light irradiates a finger, it is reflected by the finger to a photosensitive sensor. Since valleys and ridges of a fingerprint reflect light differently, intensities of reflected light received by the photosensitive sensor from the valleys and ridges are different, and then optical signals are converted into electrical signals for fingerprint recognition.
Data Source
AI summary
An array substrate, a manufacturing method thereof, and a display device are provided. The array substrate includes a substrate, a metal electrode layer, a first passivation layer, a first electrode layer, a photosensitive semiconductor layer, a second passivation layer, and a second electrode layer. The first electrode layer and the photosensitive semiconductor layer are both disposed on a surface of the first passivation layer away from the metal electrode layer.