Polysilazane Barrier Film Nitrogen Gradient Moisture Resistance

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Solution Overview

Problem

Existing barrier films fail to maintain excellent barrier properties against oxygen and moisture, especially under moist-heat conditions, and do not adequately balance light transmittance and water vapor transmission rates.

Innovation Solution

A barrier film comprising a base layer and an inorganic layer with distinct regions of varying elemental contents (Si, N, O) formed through plasma modification of polysilazane, where the first region is thicker and closer to the base layer, and the second region has a higher nitrogen concentration, achieving a dense structure with improved moisture barrier properties and light transmittance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional barrier film structure is used, then manufacturing is simple, but barrier properties against oxygen and moisture deteriorate under moist-heat conditions

Engineering Contradiction:
Improvebarrier propertiesVSAvoidfilm structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inorganic layer is divided into two distinct regions: a first region adjacent to the base layer with lower nitrogen content, and a second region farther from the base layer with higher nitrogen content. This segmentation allows each region to perform different functions - the first region provides strong adhesion to the base layer while the second region delivers superior barrier properties against moisture and oxygen, especially under moist-heat conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the inorganic layer are assigned different elemental compositions tailored to their specific functions. The first region has lower nitrogen content optimized for adhesion, while the second region has higher nitrogen content optimized for barrier performance. This local quality differentiation resolves the contradiction by ensuring each part of the film structure contributes optimally to overall reliability without requiring complete structural redesign.

Inventive Principle:
Principle #3Local quality

2Reliability

If the inorganic layer is made thicker to improve barrier properties, then water vapor transmission rate decreases, but light transmittance deteriorates

Engineering Contradiction:
Improvewater vapor transmission rateVSAvoidlight transmittance
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The invention optimizes the thickness of the inorganic layer and the nitrogen content distribution within it to achieve the desired balance. By controlling the total thickness to be in the range of 50-200 nm and creating a nitrogen gradient across the layer, the film achieves a water vapor transmission rate of 10 × 10^-4 g/m²·day or less while maintaining high light transmittance. The parameter optimization allows thin film formation that satisfies both barrier and optical requirements.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If polysilazane is converted to silica through heating or hydrolysis, then barrier properties are improved, but manufacturing complexity increases

Engineering Contradiction:
Improvebarrier propertiesVSAvoidconversion process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the conversion parameters by controlling the heating temperature range (200-400°C) and atmosphere to achieve the desired nitrogen gradient and elemental composition. By optimizing these parameters, the conversion process produces the two-region structure with appropriate Si, N, and O content distribution, achieving excellent barrier properties while maintaining manufacturing feasibility through a single-step controlled conversion process.

Inventive Principle:
Principle #35Parameter changes

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 film achieves a water vapor transmission rate of 10 × 10^-4 g/m²·day or less and maintains high light transmittance, ensuring effective protection against moisture while allowing sufficient light transmission, even under moist-heat conditions.

Implementation Method 1

Barrier films for blocking external components such as oxygen and moisture

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

the inorganic layer is formed through plasma modification of polysilazane

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP3872224B1Barrier film
Publication Date: 2024.11.27 LG CHEM LTD
  • EP3872224B1 patent drawingFigure 1~2
  • EP3872224B1 patent drawingFigure 3
  • EP3872224B1 patent drawing

AI summary

The present application relates to a barrier film. The present application can provide a barrier filmexhibiting excellent barrier properties and optical properties. A barrier film produced prepared by means of the present application can be used for an electronic product sensitive to moisture or the like.