Display Substrate Pinhole Shielding Against Plasma Light Leakage
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Solution Overview
Problem
Existing display technologies using the pinhole imaging principle for in-screen fingerprint identification suffer from light leakage due to the accumulation of plasmas and electric arcs during high-temperature film-forming processes, which break down the light-shielding layer, affecting fingerprint identification accuracy.
Innovation Solution
A display substrate design that includes a light-shielding layer with imaging pinholes and a first protection layer between the light-shielding and TFT array layers, preventing plasma accumulation and electric arc breakdown by using a low-temperature process for the protection layer deposition, thereby maintaining the integrity of the light-shielding layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light-shielding layer is deposited at the active display area to enable pinhole imaging for fingerprint identification, then fingerprint identification capability is achieved, but light leakage occurs due to plasma accumulation and electric arc breakdown during high-temperature film-forming processes
Solution Approach 1:
A first protection layer is introduced as an intermediary between the light-shielding layer and the TFT array layer. This protection layer acts as a mediator that prevents direct interaction between the plasma/electric arcs during high-temperature film-forming processes and the light-shielding layer, thereby preventing light leakage while maintaining fingerprint identification capability.
Solution Approach 2:
The first protection layer is deposited beforehand on the light-shielding layer before subsequent high-temperature film-forming processes. This preliminary protective measure ensures that the light-shielding layer is already protected when plasma accumulation and electric arc breakdown occur during manufacturing, preventing light leakage defects.
2Adaptability or versatility
If imaging pinholes are formed in the light-shielding layer for fingerprint imaging, then fingerprint identification is enabled, but metal film and anode layer interference affects imaging quality
Solution Approach 1:
The first protection layer serves as an intermediary that shields the imaging pinholes from interference by the metal film and anode layer. This protective barrier prevents stray light penetration and other interference effects, thereby improving imaging quality while maintaining the fingerprint imaging function.
3Ease of manufacture
If high-temperature film-forming processes are used to deposit metal layers and anode layers, then device functionality is achieved, but plasma accumulation breaks down the light-shielding layer causing light leakage
Solution Approach 1:
The first protection layer is deposited beforehand on the light-shielding layer to provide a protective cushion against plasma accumulation and electric arc breakdown during high-temperature film-forming processes. This prior protection prevents light leakage without requiring changes to the standard manufacturing process temperature and conditions.
Solution Approach 2:
The first protection layer acts as an intermediary barrier between the high-temperature film-forming processes and the light-shielding layer. It absorbs and dissipates the harmful effects of plasma and electric arcs, protecting the light-shielding layer from breakdown while allowing the manufacturing process to proceed at high temperatures.
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
Prevents light leakage and enhances fingerprint identification accuracy by shielding the pinholes from metal film and anode layer interference, ensuring effective fingerprint imaging without stray light penetration.
Implementation Method 1
a first protection layer between the light-shielding layer and the TFT array layer, preventing plasma accumulation and electric arc breakdown by using a low-temperature process for the protection layer deposition
Data Source
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AI summary
A display substrate, a method for manufacturing the display substrate, a display panel and a display device are provided. The display substrate includes a base substrate, and a light-shielding layer and a TFT array layer arranged sequentially in that order on the base substrate. Imaging pinholes are formed in the light-shielding layer. A first protection layer is arranged between the light-shielding layer and the TFT array layer. The base substrate is provided with a first region, an orthogonal projection of a metal film layer of the TFT array layer onto the base substrate is located outside the first region, and at least a part of an orthogonal projection of the imaging pinhole onto the base substrate is located within the first region. An orthogonal projection of the first protection layer onto the base substrate at least covers a part of the first region. The first region includes a pinhole region. The orthogonal projection of the first protection layer onto the base substrate at least covers the pinhole region. The display substrate further includes a buffer layer. The display substrate, the method for manufacturing the display substrate, the display panel and the display device in the present disclosure are able to improve a fingerprint identification effect.