Liquid Crystal Writing Screen Passivation Layer Design

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Solution Overview

Problem

Current liquid crystal writing screens have complex structures and complicated preparation processes due to the need for additional insulation protective layers to prevent short circuits, which increases power consumption and reduces reliability.

Innovation Solution

A simplified liquid crystal writing screen design where the pixel electrode is placed between the base substrate and the passivation layer, eliminating the need for a separate insulation protective layer, and using a spacer with a specific density to support the second substrate and prevent short circuits, while maintaining effective insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an additional insulation protective layer is added to prevent short circuits, then reliability is improved, but device complexity and preparation process complexity increase

Engineering Contradiction:

Improveshort circuit preventionVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The passivation layer is designed to serve dual functions: it passivates the thin film transistor and simultaneously acts as an insulation protective layer preventing short circuits between the pixel electrode and common electrode. This merging of functions eliminates the need for a separate insulation protective layer, reducing structural complexity while maintaining reliability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The passivation layer is configured to perform multiple roles within the liquid crystal writing screen structure. By making the passivation layer extend over the pixel electrode and common electrode, it provides both transistor passivation and inter-electrode insulation, reducing the total number of layers needed

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If an additional insulation protective layer is added to prevent short circuits, then reliability is improved, but the preparation process becomes more complicated

Engineering Contradiction:

Improveshort circuit preventionVSAvoidpreparation process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The passivation layer is formed to extend in advance over the pixel electrode and common electrode regions during the manufacturing process. This preliminary extension of the passivation layer ensures insulation protection is already in place before subsequent electrode formation steps, preventing short circuits without requiring additional process steps

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If the pixel electrode is placed between the base substrate and passivation layer, then structure is simplified, but insulation effectiveness may be compromised

Engineering Contradiction:

Improvestructure simplicityVSAvoidinsulation effectiveness

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The passivation layer is configured to extend not only horizontally but also vertically in the layered structure, covering the pixel electrode and common electrode from the transistor side. This three-dimensional extension of the passivation layer provides insulation protection while maintaining the simplified electrode stacking sequence

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The design simplifies the structure and preparation process, reduces the risk of short circuits, and maintains reliable operation with lower power consumption and improved handwriting thickness control.

Implementation Method 1

Current liquid crystal writing screens mostly achieve a visual effect by reflecting ambient light by means of bistable liquid crystals

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS20240427183A1Liquid crystal writing screen and preparation method thereof

Publication Date: 2024.12.26 HEFEI XINSHENG OPTOELECTRONICS TECH CO LTD

AI summary

A liquid crystal writing screen, including: first substrate and second substrates, and a bistable liquid crystal layer between the first and second substrates, where the first substrate includes: a first base substrate; a plurality of pixel units on a side of the first base substrate proximate to the second substrate, each pixel unit including a thin film transistor, and a pixel electrode electrically connected to a first electrode of the thin film transistor; a passivation layer on a side of the thin film transistor distal from the first base substrate and in contact with the thin film transistor; where the pixel electrode is between the first base substrate and the passivation layer; and a spacer on a side of the passivation layer distal from the first base substrate and in contact with the passivation layer. A method for preparing the liquid crystal writing screen is further provided.