Low-Temperature Poly-Silicon Panels with Array-Substrate Light Shielding

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Solution Overview

Problem

Low temperature poly-silicon (LTPS) display panels experience light leakage issues when bent due to the relative shift between the color filter and array substrates, which is exacerbated by high pixel density and limited opening regions, affecting display performance.

Innovation Solution

The array substrate includes a light shielding layer positioned on the side of the source-drain layer facing away from the base substrate, with parts of the light shielding layer located on the second insulating layer or between pixel electrodes, defining the opening region and maintaining high aperture ratio without increasing coverage area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the area of the opening region is reduced to reduce metal layer exposure, then light leakage is reduced, but the pixel density and display performance are significantly affected

Engineering Contradiction:

Improvelight leakageVSAvoidpixel density

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The light shielding layer is extended from the substrate plane into the vertical dimension by forming it on the array substrate above the color filter layer. This three-dimensional configuration allows the light shielding layer to cover the metal layer in the opening region without reducing the opening area, thus blocking light leakage while maintaining high pixel density and display performance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The light shielding layer acts as an intermediary structure between the color filter layer and the metal layer. It is positioned to overlap with the metal layer in the opening region, effectively blocking light from reaching the metal layer and preventing light leakage, while not interfering with the normal light transmission through the color filter layer to the liquid crystal layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the color filter substrate and array substrate are bent for curved screen application, then display adaptability is improved, but the relative position shifts cause metal layer exposure and light leakage

Engineering Contradiction:

Improvecurved screen adaptabilityVSAvoidlight leakage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The light shielding layer is formed on the array substrate in a vertical arrangement above the color filter layer, creating a three-dimensional structure. This vertical positioning ensures that when the display panel is bent, the light shielding layer remains positioned to cover the metal layer in the opening region, preventing light leakage while maintaining curved screen adaptability.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The light shielding layer is pre-formed on the array substrate during the manufacturing process, positioned to overlap with the metal layer in the opening region. This preliminary configuration ensures that even when the panel is subsequently bent for curved screen applications, the light shielding layer is already in place to prevent metal layer exposure and light leakage.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If high-temperature processes are used in manufacturing, then material properties are improved, but the color filter and light shielding layers are affected and degraded

Engineering Contradiction:

Improvematerial propertiesVSAvoidcolor filter layer integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The manufacturing process is segmented into distinct temperature stages: high-temperature processes (such as laser annealing and source-drain layer formation) are performed first on the array substrate, followed by low-temperature processes for forming the color filter layer and light shielding layer. This temporal and thermal segmentation allows the metal layers to achieve desired properties through high-temperature treatment while protecting the organic color filter and light shielding layers from thermal degradation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

High-temperature processes are performed in advance before forming the color filter layer and light shielding layer. The metal layers (gate electrode, source-drain electrode) are fully processed and stabilized at high temperatures first, then the temperature-sensitive color filter and light shielding layers are added subsequently at lower temperatures, ensuring their integrity is not compromised.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250306415A1Low temperature poly-silicon display panels, manufacturing method thereof, and liquid crystal display devices

Publication Date: 2025.10.02 XIAMEN TIANMA MICRO ELECTRONICS

AI summary

A display panel includes an array substrate and an alignment substrate that are opposite to each other, and liquid crystals filled between the array substrate and the alignment substrate. The array substrate includes a base substrate, and an active layer, a gate layer, and a source-drain layer are arranged on the base substrate. The display panel further includes a color filter layer disposed on the array substrate and located on a side of the source-drain layer facing away from the base substrate. At least part of the light shielding layer is provided on the array substrate, and the light shielding layer provided on the array substrate is located on the side of the source-drain layer facing away from the base substrate. The array substrate further includes a planarization layer; a common electrode; a second insulating layer; and pixel electrodes.