Colorless Polyimide Display Panel Laser Separation

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Solution Overview

Problem

Existing display device manufacturing methods face challenges in effectively separating the display panel from the substrate without damaging the layers, particularly in achieving high transmittance and processability while ensuring proper adhesion and thermal stability.

Innovation Solution

A display device manufacturing method involving the formation of a base layer with a colorless polyimide layer and a functional silicon oxide layer, cured at specific temperatures and cooled with outside air, followed by laser separation with controlled intensity and wavelength to ensure efficient detachment from the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a colorless polyimide layer is formed to improve transmittance, then light transmittance is improved, but adhesion to the substrate deteriorates

Engineering Contradiction:

Improvelight transmittanceVSAvoidadhesion

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The base layer is divided into multiple colorless polyimide layers (first colorless polyimide layer and second colorless polyimide layer) with a barrier layer positioned between them. This segmentation allows each layer to serve specific functions: the first layer provides transmittance, the barrier layer provides adhesion and prevents defects, and the second layer provides additional structural support.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A barrier layer is introduced as an intermediary between the first and second colorless polyimide layers. This barrier layer acts as a mediator that prevents adhesion defects and ensures proper bonding between layers, thereby maintaining both high transmittance and strong adhesion throughout the base layer structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If laser intensity is increased to improve separation efficiency, then separation speed is improved, but damage to the display panel layers increases

Engineering Contradiction:

Improveseparation speedVSAvoiddamage to layers

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The laser separation process uses precisely controlled parameters including intensity (6.0-6.8 MW/cm² at 90% maximum), wavelength (300-400 nm), and beam profile (minor axis width of 370-400 μm with steepness of 30-60 μm). These optimized parameters enable effective separation while minimizing damage to the display panel layers.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The base layer structure is prepared in advance with specific polyimide layers and barrier layers positioned to optimize laser separation. The curing process (heating to 430-470°C for 10-30 minutes) is performed beforehand to ensure the layers are properly formed and positioned, enabling clean separation when laser is applied.

Inventive Principle:

Principle #10Preliminary action

3Stability of the object's composition

If curing temperature is increased to improve thermal stability, then thermal stability is improved, but process complexity increases

Engineering Contradiction:

Improvethermal stabilityVSAvoidcuring process complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The curing process uses periodic heating with a controlled temperature profile: raising temperature from 180°C to the curing temperature (430-470°C) over 4-6 minutes, holding at the curing temperature for 10-30 minutes, then cooling with outside air. This periodic action ensures thorough curing and thermal stability while maintaining process control.

Inventive Principle:

Principle #19Periodic action

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 method achieves improved transmittance, adhesion, and processability of the display panel, allowing for normal separation from the substrate with reduced damage and stress, enhancing the manufacturing process.

Implementation Method 1

separating the display panel from the processing substrate by emitting laser having an intensity such that about 90% of a maximum intensity is about 6.0 MW/cm2 to about 6.8 MW/cm2

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 2

separating the display panel from the processing substrate by emitting laser

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

curing the colorless polyimide material at a curing temperature that is higher than about 430° C. and that is lower than or equal to about 470° C. for about 10 minutes to about 30 minutes

Methodology Applied

Scientific EffectCuring:

Implementation Method 4

curing the colorless polyimide material at a curing temperature

Methodology Applied

Scientific EffectThermal energy: Heating

Implementation Method 5

The colorless polyimide layer may have a yellow index of about 7 or less, and a light transmittance of about 83% or greater in a visible wavelength region

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS20240081137A1Display device manufacturing method and display device

Publication Date: 2024.03.07 SAMSUNG DISPLAY CO LTD

AI summary

Provided is a display device manufacturing method including forming a display panel on a processing substrate by forming a base layer including a colorless polyimide layer, and a functional layer, and separating the display panel from the processing substrate by emitting laser having an intensity such that about 90% of a maximum intensity is about 6.0 MW/cm2 to about 6.8 MW/cm2.